AsmPrinter.cpp revision 47b7e5dae911bc98aa76fa5d2ee506c9304f941a 
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  if (!M.getModuleInlineAsm().empty()) {
130    OutStreamer.AddComment("Start of file scope inline assembly");
131    OutStreamer.AddBlankLine();
132    O << M.getModuleInlineAsm();
133
134    if (*M.getModuleInlineAsm().rbegin() != '\n')
135      OutStreamer.AddBlankLine();
136    OutStreamer.AddComment("End of file scope inline assembly");
137    OutStreamer.AddBlankLine();
138  }
139
140  DW = getAnalysisIfAvailable<DwarfWriter>();
141  if (DW)
142    DW->BeginModule(&M, MMI, O, this, MAI);
143
144  return false;
145}
146
147void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
148  switch ((GlobalValue::LinkageTypes)Linkage) {
149  case GlobalValue::CommonLinkage:
150  case GlobalValue::LinkOnceAnyLinkage:
151  case GlobalValue::LinkOnceODRLinkage:
152  case GlobalValue::WeakAnyLinkage:
153  case GlobalValue::WeakODRLinkage:
154  case GlobalValue::LinkerPrivateLinkage:
155    if (MAI->getWeakDefDirective() != 0) {
156      // .globl _foo
157      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
158      // .weak_definition _foo
159      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
160    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
161      // .globl _foo
162      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
163      // FIXME: linkonce should be a section attribute, handled by COFF Section
164      // assignment.
165      // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
166      // .linkonce discard
167      // FIXME: It would be nice to use .linkonce samesize for non-common
168      // globals.
169      O << LinkOnce;
170    } else {
171      // .weak _foo
172      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
173    }
174    break;
175  case GlobalValue::DLLExportLinkage:
176  case GlobalValue::AppendingLinkage:
177    // FIXME: appending linkage variables should go into a section of
178    // their name or something.  For now, just emit them as external.
179  case GlobalValue::ExternalLinkage:
180    // If external or appending, declare as a global symbol.
181    // .globl _foo
182    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
183    break;
184  case GlobalValue::PrivateLinkage:
185  case GlobalValue::InternalLinkage:
186    break;
187  default:
188    llvm_unreachable("Unknown linkage type!");
189  }
190}
191
192
193/// EmitGlobalVariable - Emit the specified global variable to the .s file.
194void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
195  if (!GV->hasInitializer())   // External globals require no code.
196    return;
197
198  // Check to see if this is a special global used by LLVM, if so, emit it.
199  if (EmitSpecialLLVMGlobal(GV))
200    return;
201
202  MCSymbol *GVSym = Mang->getSymbol(GV);
203  EmitVisibility(GVSym, GV->getVisibility());
204
205  if (MAI->hasDotTypeDotSizeDirective())
206    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
207
208  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
209
210  const TargetData *TD = TM.getTargetData();
211  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
212  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
213
214  // Handle common and BSS local symbols (.lcomm).
215  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
216    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
217
218    if (VerboseAsm) {
219      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
220                     /*PrintType=*/false, GV->getParent());
221      OutStreamer.GetCommentOS() << '\n';
222    }
223
224    // Handle common symbols.
225    if (GVKind.isCommon()) {
226      // .comm _foo, 42, 4
227      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
228      return;
229    }
230
231    // Handle local BSS symbols.
232    if (MAI->hasMachoZeroFillDirective()) {
233      const MCSection *TheSection =
234        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
235      // .zerofill __DATA, __bss, _foo, 400, 5
236      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
237      return;
238    }
239
240    if (MAI->hasLCOMMDirective()) {
241      // .lcomm _foo, 42
242      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
243      return;
244    }
245
246    // .local _foo
247    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
248    // .comm _foo, 42, 4
249    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
250    return;
251  }
252
253  const MCSection *TheSection =
254    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
255
256  // Handle the zerofill directive on darwin, which is a special form of BSS
257  // emission.
258  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
259    // .globl _foo
260    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
261    // .zerofill __DATA, __common, _foo, 400, 5
262    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
263    return;
264  }
265
266  OutStreamer.SwitchSection(TheSection);
267
268  EmitLinkage(GV->getLinkage(), GVSym);
269  EmitAlignment(AlignLog, GV);
270
271  if (VerboseAsm) {
272    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
273                   /*PrintType=*/false, GV->getParent());
274    OutStreamer.GetCommentOS() << '\n';
275  }
276  OutStreamer.EmitLabel(GVSym);
277
278  EmitGlobalConstant(GV->getInitializer());
279
280  if (MAI->hasDotTypeDotSizeDirective())
281    // .size foo, 42
282    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
283
284  OutStreamer.AddBlankLine();
285}
286
287/// EmitFunctionHeader - This method emits the header for the current
288/// function.
289void AsmPrinter::EmitFunctionHeader() {
290  // Print out constants referenced by the function
291  EmitConstantPool();
292
293  // Print the 'header' of function.
294  const Function *F = MF->getFunction();
295
296  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
297  EmitVisibility(CurrentFnSym, F->getVisibility());
298
299  EmitLinkage(F->getLinkage(), CurrentFnSym);
300  EmitAlignment(MF->getAlignment(), F);
301
302  if (MAI->hasDotTypeDotSizeDirective())
303    OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
304
305  if (VerboseAsm) {
306    WriteAsOperand(OutStreamer.GetCommentOS(), F,
307                   /*PrintType=*/false, F->getParent());
308    OutStreamer.GetCommentOS() << '\n';
309  }
310
311  // Emit the CurrentFnSym.  This is a virtual function to allow targets to
312  // do their wild and crazy things as required.
313  EmitFunctionEntryLabel();
314
315  // If the function had address-taken blocks that got deleted, then we have
316  // references to the dangling symbols.  Emit them at the start of the function
317  // so that we don't get references to undefined symbols.
318  std::vector<MCSymbol*> DeadBlockSyms;
319  MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
320  for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
321    OutStreamer.AddComment("Address taken block that was later removed");
322    OutStreamer.EmitLabel(DeadBlockSyms[i]);
323  }
324
325  // Add some workaround for linkonce linkage on Cygwin\MinGW.
326  if (MAI->getLinkOnceDirective() != 0 &&
327      (F->hasLinkOnceLinkage() || F->hasWeakLinkage()))
328    // FIXME: What is this?
329    O << "Lllvm$workaround$fake$stub$" << *CurrentFnSym << ":\n";
330
331  // Emit pre-function debug and/or EH information.
332  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
333    DW->BeginFunction(MF);
334}
335
336/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
337/// function.  This can be overridden by targets as required to do custom stuff.
338void AsmPrinter::EmitFunctionEntryLabel() {
339  OutStreamer.EmitLabel(CurrentFnSym);
340}
341
342
343/// EmitComments - Pretty-print comments for instructions.
344static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
345  const MachineFunction *MF = MI.getParent()->getParent();
346  const TargetMachine &TM = MF->getTarget();
347
348  DebugLoc DL = MI.getDebugLoc();
349  if (!DL.isUnknown()) {          // Print source line info.
350    DIScope Scope(DL.getScope(MF->getFunction()->getContext()));
351    // Omit the directory, because it's likely to be long and uninteresting.
352    if (Scope.Verify())
353      CommentOS << Scope.getFilename();
354    else
355      CommentOS << "<unknown>";
356    CommentOS << ':' << DL.getLine();
357    if (DL.getCol() != 0)
358      CommentOS << ':' << DL.getCol();
359    CommentOS << '\n';
360  }
361
362  // Check for spills and reloads
363  int FI;
364
365  const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
366
367  // We assume a single instruction only has a spill or reload, not
368  // both.
369  const MachineMemOperand *MMO;
370  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
371    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
372      MMO = *MI.memoperands_begin();
373      CommentOS << MMO->getSize() << "-byte Reload\n";
374    }
375  } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
376    if (FrameInfo->isSpillSlotObjectIndex(FI))
377      CommentOS << MMO->getSize() << "-byte Folded Reload\n";
378  } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
379    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
380      MMO = *MI.memoperands_begin();
381      CommentOS << MMO->getSize() << "-byte Spill\n";
382    }
383  } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
384    if (FrameInfo->isSpillSlotObjectIndex(FI))
385      CommentOS << MMO->getSize() << "-byte Folded Spill\n";
386  }
387
388  // Check for spill-induced copies
389  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
390  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
391                                     SrcSubIdx, DstSubIdx)) {
392    if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
393      CommentOS << " Reload Reuse\n";
394  }
395}
396
397
398
399/// EmitFunctionBody - This method emits the body and trailer for a
400/// function.
401void AsmPrinter::EmitFunctionBody() {
402  // Emit target-specific gunk before the function body.
403  EmitFunctionBodyStart();
404
405  // Print out code for the function.
406  bool HasAnyRealCode = false;
407  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
408       I != E; ++I) {
409    // Print a label for the basic block.
410    EmitBasicBlockStart(I);
411    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
412         II != IE; ++II) {
413      // Print the assembly for the instruction.
414      if (!II->isLabel())
415        HasAnyRealCode = true;
416
417      ++EmittedInsts;
418
419      // FIXME: Clean up processDebugLoc.
420      processDebugLoc(II, true);
421
422      if (VerboseAsm)
423        EmitComments(*II, OutStreamer.GetCommentOS());
424
425      switch (II->getOpcode()) {
426      case TargetOpcode::DBG_LABEL:
427      case TargetOpcode::EH_LABEL:
428      case TargetOpcode::GC_LABEL:
429        printLabelInst(II);
430        break;
431      case TargetOpcode::INLINEASM:
432        printInlineAsm(II);
433        break;
434      case TargetOpcode::IMPLICIT_DEF:
435        printImplicitDef(II);
436        break;
437      case TargetOpcode::KILL:
438        printKill(II);
439        break;
440      default:
441        EmitInstruction(II);
442        break;
443      }
444
445      // FIXME: Clean up processDebugLoc.
446      processDebugLoc(II, false);
447    }
448  }
449
450  // If the function is empty and the object file uses .subsections_via_symbols,
451  // then we need to emit *something* to the function body to prevent the
452  // labels from collapsing together.  Just emit a 0 byte.
453  if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
454    OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
455
456  // Emit target-specific gunk after the function body.
457  EmitFunctionBodyEnd();
458
459  if (MAI->hasDotTypeDotSizeDirective())
460    O << "\t.size\t" << *CurrentFnSym << ", .-" << *CurrentFnSym << '\n';
461
462  // Emit post-function debug information.
463  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
464    DW->EndFunction(MF);
465
466  // Print out jump tables referenced by the function.
467  EmitJumpTableInfo();
468
469  OutStreamer.AddBlankLine();
470}
471
472
473bool AsmPrinter::doFinalization(Module &M) {
474  // Emit global variables.
475  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
476       I != E; ++I)
477    EmitGlobalVariable(I);
478
479  // Emit final debug information.
480  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
481    DW->EndModule();
482
483  // If the target wants to know about weak references, print them all.
484  if (MAI->getWeakRefDirective()) {
485    // FIXME: This is not lazy, it would be nice to only print weak references
486    // to stuff that is actually used.  Note that doing so would require targets
487    // to notice uses in operands (due to constant exprs etc).  This should
488    // happen with the MC stuff eventually.
489
490    // Print out module-level global variables here.
491    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
492         I != E; ++I) {
493      if (!I->hasExternalWeakLinkage()) continue;
494      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
495    }
496
497    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
498      if (!I->hasExternalWeakLinkage()) continue;
499      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
500    }
501  }
502
503  if (MAI->hasSetDirective()) {
504    OutStreamer.AddBlankLine();
505    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
506         I != E; ++I) {
507      MCSymbol *Name = Mang->getSymbol(I);
508
509      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
510      MCSymbol *Target = Mang->getSymbol(GV);
511
512      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
513        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
514      else if (I->hasWeakLinkage())
515        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
516      else
517        assert(I->hasLocalLinkage() && "Invalid alias linkage");
518
519      EmitVisibility(Name, I->getVisibility());
520
521      // Emit the directives as assignments aka .set:
522      OutStreamer.EmitAssignment(Name,
523                                 MCSymbolRefExpr::Create(Target, OutContext));
524    }
525  }
526
527  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
528  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
529  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
530    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
531      MP->finishAssembly(O, *this, *MAI);
532
533  // If we don't have any trampolines, then we don't require stack memory
534  // to be executable. Some targets have a directive to declare this.
535  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
536  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
537    if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
538      OutStreamer.SwitchSection(S);
539
540  // Allow the target to emit any magic that it wants at the end of the file,
541  // after everything else has gone out.
542  EmitEndOfAsmFile(M);
543
544  delete Mang; Mang = 0;
545  DW = 0; MMI = 0;
546
547  OutStreamer.Finish();
548  return false;
549}
550
551void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
552  this->MF = &MF;
553  // Get the function symbol.
554  CurrentFnSym = Mang->getSymbol(MF.getFunction());
555
556  if (VerboseAsm)
557    LI = &getAnalysis<MachineLoopInfo>();
558}
559
560namespace {
561  // SectionCPs - Keep track the alignment, constpool entries per Section.
562  struct SectionCPs {
563    const MCSection *S;
564    unsigned Alignment;
565    SmallVector<unsigned, 4> CPEs;
566    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
567  };
568}
569
570/// EmitConstantPool - Print to the current output stream assembly
571/// representations of the constants in the constant pool MCP. This is
572/// used to print out constants which have been "spilled to memory" by
573/// the code generator.
574///
575void AsmPrinter::EmitConstantPool() {
576  const MachineConstantPool *MCP = MF->getConstantPool();
577  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
578  if (CP.empty()) return;
579
580  // Calculate sections for constant pool entries. We collect entries to go into
581  // the same section together to reduce amount of section switch statements.
582  SmallVector<SectionCPs, 4> CPSections;
583  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
584    const MachineConstantPoolEntry &CPE = CP[i];
585    unsigned Align = CPE.getAlignment();
586
587    SectionKind Kind;
588    switch (CPE.getRelocationInfo()) {
589    default: llvm_unreachable("Unknown section kind");
590    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
591    case 1:
592      Kind = SectionKind::getReadOnlyWithRelLocal();
593      break;
594    case 0:
595    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
596    case 4:  Kind = SectionKind::getMergeableConst4(); break;
597    case 8:  Kind = SectionKind::getMergeableConst8(); break;
598    case 16: Kind = SectionKind::getMergeableConst16();break;
599    default: Kind = SectionKind::getMergeableConst(); break;
600    }
601    }
602
603    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
604
605    // The number of sections are small, just do a linear search from the
606    // last section to the first.
607    bool Found = false;
608    unsigned SecIdx = CPSections.size();
609    while (SecIdx != 0) {
610      if (CPSections[--SecIdx].S == S) {
611        Found = true;
612        break;
613      }
614    }
615    if (!Found) {
616      SecIdx = CPSections.size();
617      CPSections.push_back(SectionCPs(S, Align));
618    }
619
620    if (Align > CPSections[SecIdx].Alignment)
621      CPSections[SecIdx].Alignment = Align;
622    CPSections[SecIdx].CPEs.push_back(i);
623  }
624
625  // Now print stuff into the calculated sections.
626  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
627    OutStreamer.SwitchSection(CPSections[i].S);
628    EmitAlignment(Log2_32(CPSections[i].Alignment));
629
630    unsigned Offset = 0;
631    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
632      unsigned CPI = CPSections[i].CPEs[j];
633      MachineConstantPoolEntry CPE = CP[CPI];
634
635      // Emit inter-object padding for alignment.
636      unsigned AlignMask = CPE.getAlignment() - 1;
637      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
638      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
639
640      const Type *Ty = CPE.getType();
641      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
642
643      // Emit the label with a comment on it.
644      if (VerboseAsm) {
645        OutStreamer.GetCommentOS() << "constant pool ";
646        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
647                          MF->getFunction()->getParent());
648        OutStreamer.GetCommentOS() << '\n';
649      }
650      OutStreamer.EmitLabel(GetCPISymbol(CPI));
651
652      if (CPE.isMachineConstantPoolEntry())
653        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
654      else
655        EmitGlobalConstant(CPE.Val.ConstVal);
656    }
657  }
658}
659
660/// EmitJumpTableInfo - Print assembly representations of the jump tables used
661/// by the current function to the current output stream.
662///
663void AsmPrinter::EmitJumpTableInfo() {
664  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
665  if (MJTI == 0) return;
666  if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
667  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
668  if (JT.empty()) return;
669
670  // Pick the directive to use to print the jump table entries, and switch to
671  // the appropriate section.
672  const Function *F = MF->getFunction();
673  bool JTInDiffSection = false;
674  if (// In PIC mode, we need to emit the jump table to the same section as the
675      // function body itself, otherwise the label differences won't make sense.
676      // FIXME: Need a better predicate for this: what about custom entries?
677      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
678      // We should also do if the section name is NULL or function is declared
679      // in discardable section
680      // FIXME: this isn't the right predicate, should be based on the MCSection
681      // for the function.
682      F->isWeakForLinker()) {
683    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
684  } else {
685    // Otherwise, drop it in the readonly section.
686    const MCSection *ReadOnlySection =
687      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
688    OutStreamer.SwitchSection(ReadOnlySection);
689    JTInDiffSection = true;
690  }
691
692  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
693
694  for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
695    const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
696
697    // If this jump table was deleted, ignore it.
698    if (JTBBs.empty()) continue;
699
700    // For the EK_LabelDifference32 entry, if the target supports .set, emit a
701    // .set directive for each unique entry.  This reduces the number of
702    // relocations the assembler will generate for the jump table.
703    if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
704        MAI->hasSetDirective()) {
705      SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
706      const TargetLowering *TLI = TM.getTargetLowering();
707      const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
708      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
709        const MachineBasicBlock *MBB = JTBBs[ii];
710        if (!EmittedSets.insert(MBB)) continue;
711
712        // .set LJTSet, LBB32-base
713        const MCExpr *LHS =
714          MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
715        OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
716                                MCBinaryExpr::CreateSub(LHS, Base, OutContext));
717      }
718    }
719
720    // On some targets (e.g. Darwin) we want to emit two consequtive labels
721    // before each jump table.  The first label is never referenced, but tells
722    // the assembler and linker the extents of the jump table object.  The
723    // second label is actually referenced by the code.
724    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
725      // FIXME: This doesn't have to have any specific name, just any randomly
726      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
727      OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
728
729    OutStreamer.EmitLabel(GetJTISymbol(JTI));
730
731    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
732      EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
733  }
734}
735
736/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
737/// current stream.
738void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
739                                    const MachineBasicBlock *MBB,
740                                    unsigned UID) const {
741  const MCExpr *Value = 0;
742  switch (MJTI->getEntryKind()) {
743  case MachineJumpTableInfo::EK_Inline:
744    llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
745  case MachineJumpTableInfo::EK_Custom32:
746    Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
747                                                              OutContext);
748    break;
749  case MachineJumpTableInfo::EK_BlockAddress:
750    // EK_BlockAddress - Each entry is a plain address of block, e.g.:
751    //     .word LBB123
752    Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
753    break;
754  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
755    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
756    // with a relocation as gp-relative, e.g.:
757    //     .gprel32 LBB123
758    MCSymbol *MBBSym = MBB->getSymbol();
759    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
760    return;
761  }
762
763  case MachineJumpTableInfo::EK_LabelDifference32: {
764    // EK_LabelDifference32 - Each entry is the address of the block minus
765    // the address of the jump table.  This is used for PIC jump tables where
766    // gprel32 is not supported.  e.g.:
767    //      .word LBB123 - LJTI1_2
768    // If the .set directive is supported, this is emitted as:
769    //      .set L4_5_set_123, LBB123 - LJTI1_2
770    //      .word L4_5_set_123
771
772    // If we have emitted set directives for the jump table entries, print
773    // them rather than the entries themselves.  If we're emitting PIC, then
774    // emit the table entries as differences between two text section labels.
775    if (MAI->hasSetDirective()) {
776      // If we used .set, reference the .set's symbol.
777      Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
778                                      OutContext);
779      break;
780    }
781    // Otherwise, use the difference as the jump table entry.
782    Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
783    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
784    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
785    break;
786  }
787  }
788
789  assert(Value && "Unknown entry kind!");
790
791  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
792  OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
793}
794
795
796/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
797/// special global used by LLVM.  If so, emit it and return true, otherwise
798/// do nothing and return false.
799bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
800  if (GV->getName() == "llvm.used") {
801    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
802      EmitLLVMUsedList(GV->getInitializer());
803    return true;
804  }
805
806  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
807  if (GV->getSection() == "llvm.metadata" ||
808      GV->hasAvailableExternallyLinkage())
809    return true;
810
811  if (!GV->hasAppendingLinkage()) return false;
812
813  assert(GV->hasInitializer() && "Not a special LLVM global!");
814
815  const TargetData *TD = TM.getTargetData();
816  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
817  if (GV->getName() == "llvm.global_ctors") {
818    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
819    EmitAlignment(Align, 0);
820    EmitXXStructorList(GV->getInitializer());
821
822    if (TM.getRelocationModel() == Reloc::Static &&
823        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
824      StringRef Sym(".constructors_used");
825      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
826                                      MCSA_Reference);
827    }
828    return true;
829  }
830
831  if (GV->getName() == "llvm.global_dtors") {
832    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
833    EmitAlignment(Align, 0);
834    EmitXXStructorList(GV->getInitializer());
835
836    if (TM.getRelocationModel() == Reloc::Static &&
837        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
838      StringRef Sym(".destructors_used");
839      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
840                                      MCSA_Reference);
841    }
842    return true;
843  }
844
845  return false;
846}
847
848/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
849/// global in the specified llvm.used list for which emitUsedDirectiveFor
850/// is true, as being used with this directive.
851void AsmPrinter::EmitLLVMUsedList(Constant *List) {
852  // Should be an array of 'i8*'.
853  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
854  if (InitList == 0) return;
855
856  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
857    const GlobalValue *GV =
858      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
859    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
860      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
861  }
862}
863
864/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
865/// function pointers, ignoring the init priority.
866void AsmPrinter::EmitXXStructorList(Constant *List) {
867  // Should be an array of '{ int, void ()* }' structs.  The first value is the
868  // init priority, which we ignore.
869  if (!isa<ConstantArray>(List)) return;
870  ConstantArray *InitList = cast<ConstantArray>(List);
871  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
872    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
873      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
874
875      if (CS->getOperand(1)->isNullValue())
876        return;  // Found a null terminator, exit printing.
877      // Emit the function pointer.
878      EmitGlobalConstant(CS->getOperand(1));
879    }
880}
881
882//===--------------------------------------------------------------------===//
883// Emission and print routines
884//
885
886/// EmitInt8 - Emit a byte directive and value.
887///
888void AsmPrinter::EmitInt8(int Value) const {
889  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
890}
891
892/// EmitInt16 - Emit a short directive and value.
893///
894void AsmPrinter::EmitInt16(int Value) const {
895  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
896}
897
898/// EmitInt32 - Emit a long directive and value.
899///
900void AsmPrinter::EmitInt32(int Value) const {
901  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
902}
903
904/// EmitInt64 - Emit a long long directive and value.
905///
906void AsmPrinter::EmitInt64(uint64_t Value) const {
907  OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/);
908}
909
910/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
911/// in bytes of the directive is specified by Size and Hi/Lo specify the
912/// labels.  This implicitly uses .set if it is available.
913void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
914                                     unsigned Size) const {
915  // Get the Hi-Lo expression.
916  const MCExpr *Diff =
917    MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
918                            MCSymbolRefExpr::Create(Lo, OutContext),
919                            OutContext);
920
921  if (!MAI->hasSetDirective()) {
922    OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
923    return;
924  }
925
926  // Otherwise, emit with .set (aka assignment).
927  MCSymbol *SetLabel =
928    OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
929                                 "set" + Twine(SetCounter++));
930  OutStreamer.EmitAssignment(SetLabel, Diff);
931  OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
932}
933
934
935//===----------------------------------------------------------------------===//
936
937// EmitAlignment - Emit an alignment directive to the specified power of
938// two boundary.  For example, if you pass in 3 here, you will get an 8
939// byte alignment.  If a global value is specified, and if that global has
940// an explicit alignment requested, it will unconditionally override the
941// alignment request.  However, if ForcedAlignBits is specified, this value
942// has final say: the ultimate alignment will be the max of ForcedAlignBits
943// and the alignment computed with NumBits and the global.
944//
945// The algorithm is:
946//     Align = NumBits;
947//     if (GV && GV->hasalignment) Align = GV->getalignment();
948//     Align = std::max(Align, ForcedAlignBits);
949//
950void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
951                               unsigned ForcedAlignBits,
952                               bool UseFillExpr) const {
953  if (GV && GV->getAlignment())
954    NumBits = Log2_32(GV->getAlignment());
955  NumBits = std::max(NumBits, ForcedAlignBits);
956
957  if (NumBits == 0) return;   // No need to emit alignment.
958
959  if (getCurrentSection()->getKind().isText())
960    OutStreamer.EmitCodeAlignment(1 << NumBits);
961  else
962    OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
963}
964
965/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
966///
967static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
968  MCContext &Ctx = AP.OutContext;
969
970  if (CV->isNullValue() || isa<UndefValue>(CV))
971    return MCConstantExpr::Create(0, Ctx);
972
973  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
974    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
975
976  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
977    return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
978  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
979    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
980
981  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
982  if (CE == 0) {
983    llvm_unreachable("Unknown constant value to lower!");
984    return MCConstantExpr::Create(0, Ctx);
985  }
986
987  switch (CE->getOpcode()) {
988  default:
989    // If the code isn't optimized, there may be outstanding folding
990    // opportunities. Attempt to fold the expression using TargetData as a
991    // last resort before giving up.
992    if (Constant *C =
993          ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
994      if (C != CE)
995        return LowerConstant(C, AP);
996#ifndef NDEBUG
997    CE->dump();
998#endif
999    llvm_unreachable("FIXME: Don't support this constant expr");
1000  case Instruction::GetElementPtr: {
1001    const TargetData &TD = *AP.TM.getTargetData();
1002    // Generate a symbolic expression for the byte address
1003    const Constant *PtrVal = CE->getOperand(0);
1004    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1005    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1006                                         IdxVec.size());
1007
1008    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1009    if (Offset == 0)
1010      return Base;
1011
1012    // Truncate/sext the offset to the pointer size.
1013    if (TD.getPointerSizeInBits() != 64) {
1014      int SExtAmount = 64-TD.getPointerSizeInBits();
1015      Offset = (Offset << SExtAmount) >> SExtAmount;
1016    }
1017
1018    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1019                                   Ctx);
1020  }
1021
1022  case Instruction::Trunc:
1023    // We emit the value and depend on the assembler to truncate the generated
1024    // expression properly.  This is important for differences between
1025    // blockaddress labels.  Since the two labels are in the same function, it
1026    // is reasonable to treat their delta as a 32-bit value.
1027    // FALL THROUGH.
1028  case Instruction::BitCast:
1029    return LowerConstant(CE->getOperand(0), AP);
1030
1031  case Instruction::IntToPtr: {
1032    const TargetData &TD = *AP.TM.getTargetData();
1033    // Handle casts to pointers by changing them into casts to the appropriate
1034    // integer type.  This promotes constant folding and simplifies this code.
1035    Constant *Op = CE->getOperand(0);
1036    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1037                                      false/*ZExt*/);
1038    return LowerConstant(Op, AP);
1039  }
1040
1041  case Instruction::PtrToInt: {
1042    const TargetData &TD = *AP.TM.getTargetData();
1043    // Support only foldable casts to/from pointers that can be eliminated by
1044    // changing the pointer to the appropriately sized integer type.
1045    Constant *Op = CE->getOperand(0);
1046    const Type *Ty = CE->getType();
1047
1048    const MCExpr *OpExpr = LowerConstant(Op, AP);
1049
1050    // We can emit the pointer value into this slot if the slot is an
1051    // integer slot equal to the size of the pointer.
1052    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1053      return OpExpr;
1054
1055    // Otherwise the pointer is smaller than the resultant integer, mask off
1056    // the high bits so we are sure to get a proper truncation if the input is
1057    // a constant expr.
1058    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1059    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1060    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1061  }
1062
1063  // The MC library also has a right-shift operator, but it isn't consistently
1064  // signed or unsigned between different targets.
1065  case Instruction::Add:
1066  case Instruction::Sub:
1067  case Instruction::Mul:
1068  case Instruction::SDiv:
1069  case Instruction::SRem:
1070  case Instruction::Shl:
1071  case Instruction::And:
1072  case Instruction::Or:
1073  case Instruction::Xor: {
1074    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1075    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1076    switch (CE->getOpcode()) {
1077    default: llvm_unreachable("Unknown binary operator constant cast expr");
1078    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1079    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1080    case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1081    case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1082    case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1083    case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1084    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1085    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1086    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1087    }
1088  }
1089  }
1090}
1091
1092static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1093                                    AsmPrinter &AP) {
1094  if (AddrSpace != 0 || !CA->isString()) {
1095    // Not a string.  Print the values in successive locations
1096    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1097      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
1098    return;
1099  }
1100
1101  // Otherwise, it can be emitted as .ascii.
1102  SmallVector<char, 128> TmpVec;
1103  TmpVec.reserve(CA->getNumOperands());
1104  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1105    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1106
1107  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1108}
1109
1110static void EmitGlobalConstantVector(const ConstantVector *CV,
1111                                     unsigned AddrSpace, AsmPrinter &AP) {
1112  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1113    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1114}
1115
1116static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1117                                     unsigned AddrSpace, AsmPrinter &AP) {
1118  // Print the fields in successive locations. Pad to align if needed!
1119  const TargetData *TD = AP.TM.getTargetData();
1120  unsigned Size = TD->getTypeAllocSize(CS->getType());
1121  const StructLayout *Layout = TD->getStructLayout(CS->getType());
1122  uint64_t SizeSoFar = 0;
1123  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1124    const Constant *Field = CS->getOperand(i);
1125
1126    // Check if padding is needed and insert one or more 0s.
1127    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1128    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1129                        - Layout->getElementOffset(i)) - FieldSize;
1130    SizeSoFar += FieldSize + PadSize;
1131
1132    // Now print the actual field value.
1133    AP.EmitGlobalConstant(Field, AddrSpace);
1134
1135    // Insert padding - this may include padding to increase the size of the
1136    // current field up to the ABI size (if the struct is not packed) as well
1137    // as padding to ensure that the next field starts at the right offset.
1138    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1139  }
1140  assert(SizeSoFar == Layout->getSizeInBytes() &&
1141         "Layout of constant struct may be incorrect!");
1142}
1143
1144static void EmitGlobalConstantUnion(const ConstantUnion *CU,
1145                                    unsigned AddrSpace, AsmPrinter &AP) {
1146  const TargetData *TD = AP.TM.getTargetData();
1147  unsigned Size = TD->getTypeAllocSize(CU->getType());
1148
1149  const Constant *Contents = CU->getOperand(0);
1150  unsigned FilledSize = TD->getTypeAllocSize(Contents->getType());
1151
1152  // Print the actually filled part
1153  AP.EmitGlobalConstant(Contents, AddrSpace);
1154
1155  // And pad with enough zeroes
1156  AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace);
1157}
1158
1159static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1160                                 AsmPrinter &AP) {
1161  // FP Constants are printed as integer constants to avoid losing
1162  // precision.
1163  if (CFP->getType()->isDoubleTy()) {
1164    if (AP.VerboseAsm) {
1165      double Val = CFP->getValueAPF().convertToDouble();
1166      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1167    }
1168
1169    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1170    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1171    return;
1172  }
1173
1174  if (CFP->getType()->isFloatTy()) {
1175    if (AP.VerboseAsm) {
1176      float Val = CFP->getValueAPF().convertToFloat();
1177      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1178    }
1179    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1180    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1181    return;
1182  }
1183
1184  if (CFP->getType()->isX86_FP80Ty()) {
1185    // all long double variants are printed as hex
1186    // api needed to prevent premature destruction
1187    APInt API = CFP->getValueAPF().bitcastToAPInt();
1188    const uint64_t *p = API.getRawData();
1189    if (AP.VerboseAsm) {
1190      // Convert to double so we can print the approximate val as a comment.
1191      APFloat DoubleVal = CFP->getValueAPF();
1192      bool ignored;
1193      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1194                        &ignored);
1195      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1196        << DoubleVal.convertToDouble() << '\n';
1197    }
1198
1199    if (AP.TM.getTargetData()->isBigEndian()) {
1200      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1201      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1202    } else {
1203      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1204      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1205    }
1206
1207    // Emit the tail padding for the long double.
1208    const TargetData &TD = *AP.TM.getTargetData();
1209    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1210                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1211    return;
1212  }
1213
1214  assert(CFP->getType()->isPPC_FP128Ty() &&
1215         "Floating point constant type not handled");
1216  // All long double variants are printed as hex api needed to prevent
1217  // premature destruction.
1218  APInt API = CFP->getValueAPF().bitcastToAPInt();
1219  const uint64_t *p = API.getRawData();
1220  if (AP.TM.getTargetData()->isBigEndian()) {
1221    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1222    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1223  } else {
1224    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1225    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1226  }
1227}
1228
1229static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1230                                       unsigned AddrSpace, AsmPrinter &AP) {
1231  const TargetData *TD = AP.TM.getTargetData();
1232  unsigned BitWidth = CI->getBitWidth();
1233  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1234
1235  // We don't expect assemblers to support integer data directives
1236  // for more than 64 bits, so we emit the data in at most 64-bit
1237  // quantities at a time.
1238  const uint64_t *RawData = CI->getValue().getRawData();
1239  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1240    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1241    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1242  }
1243}
1244
1245/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1246void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1247  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1248    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1249    if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef.
1250    return OutStreamer.EmitZeros(Size, AddrSpace);
1251  }
1252
1253  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1254    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1255    switch (Size) {
1256    case 1:
1257    case 2:
1258    case 4:
1259    case 8:
1260      if (VerboseAsm)
1261        OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1262      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1263      return;
1264    default:
1265      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1266      return;
1267    }
1268  }
1269
1270  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1271    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1272
1273  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1274    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1275
1276  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1277    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1278
1279  if (isa<ConstantPointerNull>(CV)) {
1280    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1281    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1282    return;
1283  }
1284
1285  if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV))
1286    return EmitGlobalConstantUnion(CVU, AddrSpace, *this);
1287
1288  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1289    return EmitGlobalConstantVector(V, AddrSpace, *this);
1290
1291  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1292  // thread the streamer with EmitValue.
1293  OutStreamer.EmitValue(LowerConstant(CV, *this),
1294                        TM.getTargetData()->getTypeAllocSize(CV->getType()),
1295                        AddrSpace);
1296}
1297
1298void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1299  // Target doesn't support this yet!
1300  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1301}
1302
1303/// PrintSpecial - Print information related to the specified machine instr
1304/// that is independent of the operand, and may be independent of the instr
1305/// itself.  This can be useful for portably encoding the comment character
1306/// or other bits of target-specific knowledge into the asmstrings.  The
1307/// syntax used is ${:comment}.  Targets can override this to add support
1308/// for their own strange codes.
1309void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const {
1310  if (!strcmp(Code, "private")) {
1311    O << MAI->getPrivateGlobalPrefix();
1312  } else if (!strcmp(Code, "comment")) {
1313    if (VerboseAsm)
1314      O << MAI->getCommentString();
1315  } else if (!strcmp(Code, "uid")) {
1316    // Comparing the address of MI isn't sufficient, because machineinstrs may
1317    // be allocated to the same address across functions.
1318    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1319
1320    // If this is a new LastFn instruction, bump the counter.
1321    if (LastMI != MI || LastFn != ThisF) {
1322      ++Counter;
1323      LastMI = MI;
1324      LastFn = ThisF;
1325    }
1326    O << Counter;
1327  } else {
1328    std::string msg;
1329    raw_string_ostream Msg(msg);
1330    Msg << "Unknown special formatter '" << Code
1331         << "' for machine instr: " << *MI;
1332    llvm_report_error(Msg.str());
1333  }
1334}
1335
1336/// processDebugLoc - Processes the debug information of each machine
1337/// instruction's DebugLoc.
1338void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1339                                 bool BeforePrintingInsn) {
1340  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1341      || !DW->ShouldEmitDwarfDebug())
1342    return;
1343
1344  if (!BeforePrintingInsn)
1345    // After printing instruction
1346    DW->EndScope(MI);
1347  else
1348    DW->BeginScope(MI);
1349}
1350
1351
1352/// printInlineAsm - This method formats and prints the specified machine
1353/// instruction that is an inline asm.
1354void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1355  unsigned NumOperands = MI->getNumOperands();
1356
1357  // Count the number of register definitions.
1358  unsigned NumDefs = 0;
1359  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1360       ++NumDefs)
1361    assert(NumDefs != NumOperands-1 && "No asm string?");
1362
1363  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1364
1365  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1366  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1367
1368  O << '\t';
1369
1370  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1371  // These are useful to see where empty asm's wound up.
1372  if (AsmStr[0] == 0) {
1373    O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1374    O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1375    return;
1376  }
1377
1378  O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1379
1380  // The variant of the current asmprinter.
1381  int AsmPrinterVariant = MAI->getAssemblerDialect();
1382
1383  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1384  const char *LastEmitted = AsmStr; // One past the last character emitted.
1385
1386  while (*LastEmitted) {
1387    switch (*LastEmitted) {
1388    default: {
1389      // Not a special case, emit the string section literally.
1390      const char *LiteralEnd = LastEmitted+1;
1391      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1392             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1393        ++LiteralEnd;
1394      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1395        O.write(LastEmitted, LiteralEnd-LastEmitted);
1396      LastEmitted = LiteralEnd;
1397      break;
1398    }
1399    case '\n':
1400      ++LastEmitted;   // Consume newline character.
1401      O << '\n';       // Indent code with newline.
1402      break;
1403    case '$': {
1404      ++LastEmitted;   // Consume '$' character.
1405      bool Done = true;
1406
1407      // Handle escapes.
1408      switch (*LastEmitted) {
1409      default: Done = false; break;
1410      case '$':     // $$ -> $
1411        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1412          O << '$';
1413        ++LastEmitted;  // Consume second '$' character.
1414        break;
1415      case '(':             // $( -> same as GCC's { character.
1416        ++LastEmitted;      // Consume '(' character.
1417        if (CurVariant != -1) {
1418          llvm_report_error("Nested variants found in inline asm string: '"
1419                            + std::string(AsmStr) + "'");
1420        }
1421        CurVariant = 0;     // We're in the first variant now.
1422        break;
1423      case '|':
1424        ++LastEmitted;  // consume '|' character.
1425        if (CurVariant == -1)
1426          O << '|';       // this is gcc's behavior for | outside a variant
1427        else
1428          ++CurVariant;   // We're in the next variant.
1429        break;
1430      case ')':         // $) -> same as GCC's } char.
1431        ++LastEmitted;  // consume ')' character.
1432        if (CurVariant == -1)
1433          O << '}';     // this is gcc's behavior for } outside a variant
1434        else
1435          CurVariant = -1;
1436        break;
1437      }
1438      if (Done) break;
1439
1440      bool HasCurlyBraces = false;
1441      if (*LastEmitted == '{') {     // ${variable}
1442        ++LastEmitted;               // Consume '{' character.
1443        HasCurlyBraces = true;
1444      }
1445
1446      // If we have ${:foo}, then this is not a real operand reference, it is a
1447      // "magic" string reference, just like in .td files.  Arrange to call
1448      // PrintSpecial.
1449      if (HasCurlyBraces && *LastEmitted == ':') {
1450        ++LastEmitted;
1451        const char *StrStart = LastEmitted;
1452        const char *StrEnd = strchr(StrStart, '}');
1453        if (StrEnd == 0) {
1454          llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1455                            + std::string(AsmStr) + "'");
1456        }
1457
1458        std::string Val(StrStart, StrEnd);
1459        PrintSpecial(MI, Val.c_str());
1460        LastEmitted = StrEnd+1;
1461        break;
1462      }
1463
1464      const char *IDStart = LastEmitted;
1465      char *IDEnd;
1466      errno = 0;
1467      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1468      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1469        llvm_report_error("Bad $ operand number in inline asm string: '"
1470                          + std::string(AsmStr) + "'");
1471      }
1472      LastEmitted = IDEnd;
1473
1474      char Modifier[2] = { 0, 0 };
1475
1476      if (HasCurlyBraces) {
1477        // If we have curly braces, check for a modifier character.  This
1478        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1479        if (*LastEmitted == ':') {
1480          ++LastEmitted;    // Consume ':' character.
1481          if (*LastEmitted == 0) {
1482            llvm_report_error("Bad ${:} expression in inline asm string: '"
1483                              + std::string(AsmStr) + "'");
1484          }
1485
1486          Modifier[0] = *LastEmitted;
1487          ++LastEmitted;    // Consume modifier character.
1488        }
1489
1490        if (*LastEmitted != '}') {
1491          llvm_report_error("Bad ${} expression in inline asm string: '"
1492                            + std::string(AsmStr) + "'");
1493        }
1494        ++LastEmitted;    // Consume '}' character.
1495      }
1496
1497      if ((unsigned)Val >= NumOperands-1) {
1498        llvm_report_error("Invalid $ operand number in inline asm string: '"
1499                          + std::string(AsmStr) + "'");
1500      }
1501
1502      // Okay, we finally have a value number.  Ask the target to print this
1503      // operand!
1504      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1505        unsigned OpNo = 1;
1506
1507        bool Error = false;
1508
1509        // Scan to find the machine operand number for the operand.
1510        for (; Val; --Val) {
1511          if (OpNo >= MI->getNumOperands()) break;
1512          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1513          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1514        }
1515
1516        if (OpNo >= MI->getNumOperands()) {
1517          Error = true;
1518        } else {
1519          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1520          ++OpNo;  // Skip over the ID number.
1521
1522          if (Modifier[0] == 'l')  // labels are target independent
1523            O << *MI->getOperand(OpNo).getMBB()->getSymbol();
1524          else {
1525            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1526            if ((OpFlags & 7) == 4) {
1527              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1528                                                Modifier[0] ? Modifier : 0);
1529            } else {
1530              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1531                                          Modifier[0] ? Modifier : 0);
1532            }
1533          }
1534        }
1535        if (Error) {
1536          std::string msg;
1537          raw_string_ostream Msg(msg);
1538          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1539          MI->print(Msg);
1540          llvm_report_error(Msg.str());
1541        }
1542      }
1543      break;
1544    }
1545    }
1546  }
1547  O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd();
1548  OutStreamer.AddBlankLine();
1549}
1550
1551/// printImplicitDef - This method prints the specified machine instruction
1552/// that is an implicit def.
1553void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1554  if (!VerboseAsm) return;
1555  O.PadToColumn(MAI->getCommentColumn());
1556  O << MAI->getCommentString() << " implicit-def: "
1557    << TRI->getName(MI->getOperand(0).getReg());
1558  OutStreamer.AddBlankLine();
1559}
1560
1561void AsmPrinter::printKill(const MachineInstr *MI) const {
1562  if (!VerboseAsm) return;
1563  O.PadToColumn(MAI->getCommentColumn());
1564  O << MAI->getCommentString() << " kill:";
1565  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1566    const MachineOperand &op = MI->getOperand(n);
1567    assert(op.isReg() && "KILL instruction must have only register operands");
1568    O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>");
1569  }
1570  OutStreamer.AddBlankLine();
1571}
1572
1573/// printLabel - This method prints a local label used by debug and
1574/// exception handling tables.
1575void AsmPrinter::printLabelInst(const MachineInstr *MI) const {
1576  OutStreamer.EmitLabel(MI->getOperand(0).getMCSymbol());
1577}
1578
1579/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1580/// instruction, using the specified assembler variant.  Targets should
1581/// override this to format as appropriate.
1582bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1583                                 unsigned AsmVariant, const char *ExtraCode) {
1584  // Target doesn't support this yet!
1585  return true;
1586}
1587
1588bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1589                                       unsigned AsmVariant,
1590                                       const char *ExtraCode) {
1591  // Target doesn't support this yet!
1592  return true;
1593}
1594
1595MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1596  return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1597}
1598
1599MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1600  return MMI->getAddrLabelSymbol(BB);
1601}
1602
1603/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1604MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1605  return OutContext.GetOrCreateSymbol
1606    (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1607     + "_" + Twine(CPID));
1608}
1609
1610/// GetJTISymbol - Return the symbol for the specified jump table entry.
1611MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1612  return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1613}
1614
1615/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1616/// FIXME: privatize to AsmPrinter.
1617MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1618  return OutContext.GetOrCreateSymbol
1619  (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1620   Twine(UID) + "_set_" + Twine(MBBID));
1621}
1622
1623/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1624/// global value name as its base, with the specified suffix, and where the
1625/// symbol is forced to have private linkage if ForcePrivate is true.
1626MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1627                                                   StringRef Suffix,
1628                                                   bool ForcePrivate) const {
1629  SmallString<60> NameStr;
1630  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1631  NameStr.append(Suffix.begin(), Suffix.end());
1632  return OutContext.GetOrCreateSymbol(NameStr.str());
1633}
1634
1635/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1636/// ExternalSymbol.
1637MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1638  SmallString<60> NameStr;
1639  Mang->getNameWithPrefix(NameStr, Sym);
1640  return OutContext.GetOrCreateSymbol(NameStr.str());
1641}
1642
1643
1644
1645/// PrintParentLoopComment - Print comments about parent loops of this one.
1646static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1647                                   unsigned FunctionNumber) {
1648  if (Loop == 0) return;
1649  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1650  OS.indent(Loop->getLoopDepth()*2)
1651    << "Parent Loop BB" << FunctionNumber << "_"
1652    << Loop->getHeader()->getNumber()
1653    << " Depth=" << Loop->getLoopDepth() << '\n';
1654}
1655
1656
1657/// PrintChildLoopComment - Print comments about child loops within
1658/// the loop for this basic block, with nesting.
1659static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1660                                  unsigned FunctionNumber) {
1661  // Add child loop information
1662  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1663    OS.indent((*CL)->getLoopDepth()*2)
1664      << "Child Loop BB" << FunctionNumber << "_"
1665      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1666      << '\n';
1667    PrintChildLoopComment(OS, *CL, FunctionNumber);
1668  }
1669}
1670
1671/// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks.
1672static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1673                                        const MachineLoopInfo *LI,
1674                                        const AsmPrinter &AP) {
1675  // Add loop depth information
1676  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1677  if (Loop == 0) return;
1678
1679  MachineBasicBlock *Header = Loop->getHeader();
1680  assert(Header && "No header for loop");
1681
1682  // If this block is not a loop header, just print out what is the loop header
1683  // and return.
1684  if (Header != &MBB) {
1685    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1686                              Twine(AP.getFunctionNumber())+"_" +
1687                              Twine(Loop->getHeader()->getNumber())+
1688                              " Depth="+Twine(Loop->getLoopDepth()));
1689    return;
1690  }
1691
1692  // Otherwise, it is a loop header.  Print out information about child and
1693  // parent loops.
1694  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1695
1696  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1697
1698  OS << "=>";
1699  OS.indent(Loop->getLoopDepth()*2-2);
1700
1701  OS << "This ";
1702  if (Loop->empty())
1703    OS << "Inner ";
1704  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1705
1706  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1707}
1708
1709
1710/// EmitBasicBlockStart - This method prints the label for the specified
1711/// MachineBasicBlock, an alignment (if present) and a comment describing
1712/// it if appropriate.
1713void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1714  // Emit an alignment directive for this block, if needed.
1715  if (unsigned Align = MBB->getAlignment())
1716    EmitAlignment(Log2_32(Align));
1717
1718  // If the block has its address taken, emit any labels that were used to
1719  // reference the block.  It is possible that there is more than one label
1720  // here, because multiple LLVM BB's may have been RAUW'd to this block after
1721  // the references were generated.
1722  if (MBB->hasAddressTaken()) {
1723    const BasicBlock *BB = MBB->getBasicBlock();
1724    if (VerboseAsm)
1725      OutStreamer.AddComment("Block address taken");
1726
1727    std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1728
1729    for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1730      OutStreamer.EmitLabel(Syms[i]);
1731  }
1732
1733  // Print the main label for the block.
1734  if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1735    if (VerboseAsm) {
1736      // NOTE: Want this comment at start of line.
1737      O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
1738      if (const BasicBlock *BB = MBB->getBasicBlock())
1739        if (BB->hasName())
1740          OutStreamer.AddComment("%" + BB->getName());
1741
1742      PrintBasicBlockLoopComments(*MBB, LI, *this);
1743      OutStreamer.AddBlankLine();
1744    }
1745  } else {
1746    if (VerboseAsm) {
1747      if (const BasicBlock *BB = MBB->getBasicBlock())
1748        if (BB->hasName())
1749          OutStreamer.AddComment("%" + BB->getName());
1750      PrintBasicBlockLoopComments(*MBB, LI, *this);
1751    }
1752
1753    OutStreamer.EmitLabel(MBB->getSymbol());
1754  }
1755}
1756
1757void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1758  MCSymbolAttr Attr = MCSA_Invalid;
1759
1760  switch (Visibility) {
1761  default: break;
1762  case GlobalValue::HiddenVisibility:
1763    Attr = MAI->getHiddenVisibilityAttr();
1764    break;
1765  case GlobalValue::ProtectedVisibility:
1766    Attr = MAI->getProtectedVisibilityAttr();
1767    break;
1768  }
1769
1770  if (Attr != MCSA_Invalid)
1771    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1772}
1773
1774void AsmPrinter::printOffset(int64_t Offset) const {
1775  if (Offset > 0)
1776    O << '+' << Offset;
1777  else if (Offset < 0)
1778    O << Offset;
1779}
1780
1781/// isBlockOnlyReachableByFallthough - Return true if the basic block has
1782/// exactly one predecessor and the control transfer mechanism between
1783/// the predecessor and this block is a fall-through.
1784bool AsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB)
1785    const {
1786  // If this is a landing pad, it isn't a fall through.  If it has no preds,
1787  // then nothing falls through to it.
1788  if (MBB->isLandingPad() || MBB->pred_empty())
1789    return false;
1790
1791  // If there isn't exactly one predecessor, it can't be a fall through.
1792  MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1793  ++PI2;
1794  if (PI2 != MBB->pred_end())
1795    return false;
1796
1797  // The predecessor has to be immediately before this block.
1798  const MachineBasicBlock *Pred = *PI;
1799
1800  if (!Pred->isLayoutSuccessor(MBB))
1801    return false;
1802
1803  // If the block is completely empty, then it definitely does fall through.
1804  if (Pred->empty())
1805    return true;
1806
1807  // Otherwise, check the last instruction.
1808  const MachineInstr &LastInst = Pred->back();
1809  return !LastInst.getDesc().isBarrier();
1810}
1811
1812
1813
1814GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1815  if (!S->usesMetadata())
1816    return 0;
1817
1818  gcp_iterator GCPI = GCMetadataPrinters.find(S);
1819  if (GCPI != GCMetadataPrinters.end())
1820    return GCPI->second;
1821
1822  const char *Name = S->getName().c_str();
1823
1824  for (GCMetadataPrinterRegistry::iterator
1825         I = GCMetadataPrinterRegistry::begin(),
1826         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1827    if (strcmp(Name, I->getName()) == 0) {
1828      GCMetadataPrinter *GMP = I->instantiate();
1829      GMP->S = S;
1830      GCMetadataPrinters.insert(std::make_pair(S, GMP));
1831      return GMP;
1832    }
1833
1834  llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1835  return 0;
1836}
1837
1838