AsmPrinter.cpp revision 300a4c5640fb1c717ba0d7108d15aec1bd7eb396 
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 <cerrno>
52using namespace llvm;
53
54STATISTIC(EmittedInsts, "Number of machine instrs printed");
55
56char AsmPrinter::ID = 0;
57
58typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
59static gcp_map_type &getGCMap(void *&P) {
60  if (P == 0)
61    P = new gcp_map_type();
62  return *(gcp_map_type*)P;
63}
64
65
66AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
67  : MachineFunctionPass(&ID),
68    TM(tm), MAI(tm.getMCAsmInfo()),
69    OutContext(Streamer.getContext()),
70    OutStreamer(Streamer),
71    LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
72  DW = 0; MMI = 0;
73  GCMetadataPrinters = 0;
74  VerboseAsm = Streamer.isVerboseAsm();
75}
76
77AsmPrinter::~AsmPrinter() {
78  if (GCMetadataPrinters != 0) {
79    gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
80
81    for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
82      delete I->second;
83    delete &GCMap;
84    GCMetadataPrinters = 0;
85  }
86
87  delete &OutStreamer;
88}
89
90/// getFunctionNumber - Return a unique ID for the current function.
91///
92unsigned AsmPrinter::getFunctionNumber() const {
93  return MF->getFunctionNumber();
94}
95
96TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
97  return TM.getTargetLowering()->getObjFileLowering();
98}
99
100/// getCurrentSection() - Return the current section we are emitting to.
101const MCSection *AsmPrinter::getCurrentSection() const {
102  return OutStreamer.getCurrentSection();
103}
104
105
106void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
107  AU.setPreservesAll();
108  MachineFunctionPass::getAnalysisUsage(AU);
109  AU.addRequired<MachineModuleInfo>();
110  AU.addRequired<GCModuleInfo>();
111  if (VerboseAsm)
112    AU.addRequired<MachineLoopInfo>();
113}
114
115bool AsmPrinter::doInitialization(Module &M) {
116  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
117  MMI->AnalyzeModule(M);
118
119  // Initialize TargetLoweringObjectFile.
120  const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
121    .Initialize(OutContext, TM);
122
123  Mang = new Mangler(OutContext, *TM.getTargetData());
124
125  // Allow the target to emit any magic that it wants at the start of the file.
126  EmitStartOfAsmFile(M);
127
128  // Very minimal debug info. It is ignored if we emit actual debug info. If we
129  // don't, this at least helps the user find where a global came from.
130  if (MAI->hasSingleParameterDotFile()) {
131    // .file "foo.c"
132    OutStreamer.EmitFileDirective(M.getModuleIdentifier());
133  }
134
135  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
136  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
137  for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
138    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
139      MP->beginAssembly(*this);
140
141  // Emit module-level inline asm if it exists.
142  if (!M.getModuleInlineAsm().empty()) {
143    OutStreamer.AddComment("Start of file scope inline assembly");
144    OutStreamer.AddBlankLine();
145    EmitInlineAsm(M.getModuleInlineAsm());
146    OutStreamer.AddComment("End of file scope inline assembly");
147    OutStreamer.AddBlankLine();
148  }
149
150  DW = getAnalysisIfAvailable<DwarfWriter>();
151  if (DW)
152    DW->BeginModule(&M, this);
153
154  return false;
155}
156
157void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
158  switch ((GlobalValue::LinkageTypes)Linkage) {
159  case GlobalValue::CommonLinkage:
160  case GlobalValue::LinkOnceAnyLinkage:
161  case GlobalValue::LinkOnceODRLinkage:
162  case GlobalValue::WeakAnyLinkage:
163  case GlobalValue::WeakODRLinkage:
164  case GlobalValue::LinkerPrivateLinkage:
165    if (MAI->getWeakDefDirective() != 0) {
166      // .globl _foo
167      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
168      // .weak_definition _foo
169      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
170    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
171      // .globl _foo
172      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
173      // FIXME: linkonce should be a section attribute, handled by COFF Section
174      // assignment.
175      // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
176      // .linkonce discard
177      // FIXME: It would be nice to use .linkonce samesize for non-common
178      // globals.
179      OutStreamer.EmitRawText(StringRef(LinkOnce));
180    } else {
181      // .weak _foo
182      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
183    }
184    break;
185  case GlobalValue::DLLExportLinkage:
186  case GlobalValue::AppendingLinkage:
187    // FIXME: appending linkage variables should go into a section of
188    // their name or something.  For now, just emit them as external.
189  case GlobalValue::ExternalLinkage:
190    // If external or appending, declare as a global symbol.
191    // .globl _foo
192    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
193    break;
194  case GlobalValue::PrivateLinkage:
195  case GlobalValue::InternalLinkage:
196    break;
197  default:
198    llvm_unreachable("Unknown linkage type!");
199  }
200}
201
202
203/// EmitGlobalVariable - Emit the specified global variable to the .s file.
204void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
205  if (!GV->hasInitializer())   // External globals require no code.
206    return;
207
208  // Check to see if this is a special global used by LLVM, if so, emit it.
209  if (EmitSpecialLLVMGlobal(GV))
210    return;
211
212  MCSymbol *GVSym = Mang->getSymbol(GV);
213  EmitVisibility(GVSym, GV->getVisibility());
214
215  if (MAI->hasDotTypeDotSizeDirective())
216    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
217
218  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
219
220  const TargetData *TD = TM.getTargetData();
221  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
222  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
223
224  // Handle common and BSS local symbols (.lcomm).
225  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
226    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
227
228    if (VerboseAsm) {
229      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
230                     /*PrintType=*/false, GV->getParent());
231      OutStreamer.GetCommentOS() << '\n';
232    }
233
234    // Handle common symbols.
235    if (GVKind.isCommon()) {
236      // .comm _foo, 42, 4
237      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
238      return;
239    }
240
241    // Handle local BSS symbols.
242    if (MAI->hasMachoZeroFillDirective()) {
243      const MCSection *TheSection =
244        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
245      // .zerofill __DATA, __bss, _foo, 400, 5
246      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
247      return;
248    }
249
250    if (MAI->hasLCOMMDirective()) {
251      // .lcomm _foo, 42
252      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
253      return;
254    }
255
256    // .local _foo
257    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
258    // .comm _foo, 42, 4
259    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
260    return;
261  }
262
263  const MCSection *TheSection =
264    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
265
266  // Handle the zerofill directive on darwin, which is a special form of BSS
267  // emission.
268  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
269    // .globl _foo
270    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
271    // .zerofill __DATA, __common, _foo, 400, 5
272    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
273    return;
274  }
275
276  OutStreamer.SwitchSection(TheSection);
277
278  EmitLinkage(GV->getLinkage(), GVSym);
279  EmitAlignment(AlignLog, GV);
280
281  if (VerboseAsm) {
282    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
283                   /*PrintType=*/false, GV->getParent());
284    OutStreamer.GetCommentOS() << '\n';
285  }
286  OutStreamer.EmitLabel(GVSym);
287
288  EmitGlobalConstant(GV->getInitializer());
289
290  if (MAI->hasDotTypeDotSizeDirective())
291    // .size foo, 42
292    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
293
294  OutStreamer.AddBlankLine();
295}
296
297/// EmitFunctionHeader - This method emits the header for the current
298/// function.
299void AsmPrinter::EmitFunctionHeader() {
300  // Print out constants referenced by the function
301  EmitConstantPool();
302
303  // Print the 'header' of function.
304  const Function *F = MF->getFunction();
305
306  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
307  EmitVisibility(CurrentFnSym, F->getVisibility());
308
309  EmitLinkage(F->getLinkage(), CurrentFnSym);
310  EmitAlignment(MF->getAlignment(), F);
311
312  if (MAI->hasDotTypeDotSizeDirective())
313    OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
314
315  if (VerboseAsm) {
316    WriteAsOperand(OutStreamer.GetCommentOS(), F,
317                   /*PrintType=*/false, F->getParent());
318    OutStreamer.GetCommentOS() << '\n';
319  }
320
321  // Emit the CurrentFnSym.  This is a virtual function to allow targets to
322  // do their wild and crazy things as required.
323  EmitFunctionEntryLabel();
324
325  // If the function had address-taken blocks that got deleted, then we have
326  // references to the dangling symbols.  Emit them at the start of the function
327  // so that we don't get references to undefined symbols.
328  std::vector<MCSymbol*> DeadBlockSyms;
329  MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
330  for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
331    OutStreamer.AddComment("Address taken block that was later removed");
332    OutStreamer.EmitLabel(DeadBlockSyms[i]);
333  }
334
335  // Add some workaround for linkonce linkage on Cygwin\MinGW.
336  if (MAI->getLinkOnceDirective() != 0 &&
337      (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
338    // FIXME: What is this?
339    MCSymbol *FakeStub =
340      OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
341                                   CurrentFnSym->getName());
342    OutStreamer.EmitLabel(FakeStub);
343  }
344
345  // Emit pre-function debug and/or EH information.
346  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
347    DW->BeginFunction(MF);
348}
349
350/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
351/// function.  This can be overridden by targets as required to do custom stuff.
352void AsmPrinter::EmitFunctionEntryLabel() {
353  OutStreamer.EmitLabel(CurrentFnSym);
354}
355
356
357/// EmitComments - Pretty-print comments for instructions.
358static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
359  const MachineFunction *MF = MI.getParent()->getParent();
360  const TargetMachine &TM = MF->getTarget();
361
362  DebugLoc DL = MI.getDebugLoc();
363  if (!DL.isUnknown()) {          // Print source line info.
364    DIScope Scope(DL.getScope(MF->getFunction()->getContext()));
365    // Omit the directory, because it's likely to be long and uninteresting.
366    if (Scope.Verify())
367      CommentOS << Scope.getFilename();
368    else
369      CommentOS << "<unknown>";
370    CommentOS << ':' << DL.getLine();
371    if (DL.getCol() != 0)
372      CommentOS << ':' << DL.getCol();
373    CommentOS << '\n';
374  }
375
376  // Check for spills and reloads
377  int FI;
378
379  const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
380
381  // We assume a single instruction only has a spill or reload, not
382  // both.
383  const MachineMemOperand *MMO;
384  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
385    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
386      MMO = *MI.memoperands_begin();
387      CommentOS << MMO->getSize() << "-byte Reload\n";
388    }
389  } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
390    if (FrameInfo->isSpillSlotObjectIndex(FI))
391      CommentOS << MMO->getSize() << "-byte Folded Reload\n";
392  } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
393    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
394      MMO = *MI.memoperands_begin();
395      CommentOS << MMO->getSize() << "-byte Spill\n";
396    }
397  } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
398    if (FrameInfo->isSpillSlotObjectIndex(FI))
399      CommentOS << MMO->getSize() << "-byte Folded Spill\n";
400  }
401
402  // Check for spill-induced copies
403  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
404  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
405                                     SrcSubIdx, DstSubIdx)) {
406    if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
407      CommentOS << " Reload Reuse\n";
408  }
409}
410
411
412
413/// EmitFunctionBody - This method emits the body and trailer for a
414/// function.
415void AsmPrinter::EmitFunctionBody() {
416  // Emit target-specific gunk before the function body.
417  EmitFunctionBodyStart();
418
419  // Print out code for the function.
420  bool HasAnyRealCode = false;
421  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
422       I != E; ++I) {
423    // Print a label for the basic block.
424    EmitBasicBlockStart(I);
425    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
426         II != IE; ++II) {
427      // Print the assembly for the instruction.
428      if (!II->isLabel())
429        HasAnyRealCode = true;
430
431      ++EmittedInsts;
432
433      // FIXME: Clean up processDebugLoc.
434      processDebugLoc(II, true);
435
436      if (VerboseAsm)
437        EmitComments(*II, OutStreamer.GetCommentOS());
438
439      switch (II->getOpcode()) {
440      case TargetOpcode::DBG_LABEL:
441      case TargetOpcode::EH_LABEL:
442      case TargetOpcode::GC_LABEL:
443        OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
444        break;
445      case TargetOpcode::INLINEASM:
446        EmitInlineAsm(II);
447        break;
448      case TargetOpcode::IMPLICIT_DEF:
449        EmitImplicitDef(II);
450        break;
451      case TargetOpcode::KILL:
452        EmitKill(II);
453        break;
454      default:
455        EmitInstruction(II);
456        break;
457      }
458
459      // FIXME: Clean up processDebugLoc.
460      processDebugLoc(II, false);
461    }
462  }
463
464  // If the function is empty and the object file uses .subsections_via_symbols,
465  // then we need to emit *something* to the function body to prevent the
466  // labels from collapsing together.  Just emit a 0 byte.
467  if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
468    OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
469
470  // Emit target-specific gunk after the function body.
471  EmitFunctionBodyEnd();
472
473  // If the target wants a .size directive for the size of the function, emit
474  // it.
475  if (MAI->hasDotTypeDotSizeDirective()) {
476    // Create a symbol for the end of function, so we can get the size as
477    // difference between the function label and the temp label.
478    MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
479    OutStreamer.EmitLabel(FnEndLabel);
480
481    const MCExpr *SizeExp =
482      MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
483                              MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
484                              OutContext);
485    OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
486  }
487
488  // Emit post-function debug information.
489  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
490    DW->EndFunction(MF);
491
492  // Print out jump tables referenced by the function.
493  EmitJumpTableInfo();
494
495  OutStreamer.AddBlankLine();
496}
497
498
499bool AsmPrinter::doFinalization(Module &M) {
500  // Emit global variables.
501  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
502       I != E; ++I)
503    EmitGlobalVariable(I);
504
505  // Emit final debug information.
506  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
507    DW->EndModule();
508
509  // If the target wants to know about weak references, print them all.
510  if (MAI->getWeakRefDirective()) {
511    // FIXME: This is not lazy, it would be nice to only print weak references
512    // to stuff that is actually used.  Note that doing so would require targets
513    // to notice uses in operands (due to constant exprs etc).  This should
514    // happen with the MC stuff eventually.
515
516    // Print out module-level global variables here.
517    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
518         I != E; ++I) {
519      if (!I->hasExternalWeakLinkage()) continue;
520      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
521    }
522
523    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
524      if (!I->hasExternalWeakLinkage()) continue;
525      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
526    }
527  }
528
529  if (MAI->hasSetDirective()) {
530    OutStreamer.AddBlankLine();
531    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
532         I != E; ++I) {
533      MCSymbol *Name = Mang->getSymbol(I);
534
535      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
536      MCSymbol *Target = Mang->getSymbol(GV);
537
538      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
539        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
540      else if (I->hasWeakLinkage())
541        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
542      else
543        assert(I->hasLocalLinkage() && "Invalid alias linkage");
544
545      EmitVisibility(Name, I->getVisibility());
546
547      // Emit the directives as assignments aka .set:
548      OutStreamer.EmitAssignment(Name,
549                                 MCSymbolRefExpr::Create(Target, OutContext));
550    }
551  }
552
553  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
554  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
555  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
556    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
557      MP->finishAssembly(*this);
558
559  // If we don't have any trampolines, then we don't require stack memory
560  // to be executable. Some targets have a directive to declare this.
561  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
562  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
563    if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
564      OutStreamer.SwitchSection(S);
565
566  // Allow the target to emit any magic that it wants at the end of the file,
567  // after everything else has gone out.
568  EmitEndOfAsmFile(M);
569
570  delete Mang; Mang = 0;
571  DW = 0; MMI = 0;
572
573  OutStreamer.Finish();
574  return false;
575}
576
577void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
578  this->MF = &MF;
579  // Get the function symbol.
580  CurrentFnSym = Mang->getSymbol(MF.getFunction());
581
582  if (VerboseAsm)
583    LI = &getAnalysis<MachineLoopInfo>();
584}
585
586namespace {
587  // SectionCPs - Keep track the alignment, constpool entries per Section.
588  struct SectionCPs {
589    const MCSection *S;
590    unsigned Alignment;
591    SmallVector<unsigned, 4> CPEs;
592    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
593  };
594}
595
596/// EmitConstantPool - Print to the current output stream assembly
597/// representations of the constants in the constant pool MCP. This is
598/// used to print out constants which have been "spilled to memory" by
599/// the code generator.
600///
601void AsmPrinter::EmitConstantPool() {
602  const MachineConstantPool *MCP = MF->getConstantPool();
603  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
604  if (CP.empty()) return;
605
606  // Calculate sections for constant pool entries. We collect entries to go into
607  // the same section together to reduce amount of section switch statements.
608  SmallVector<SectionCPs, 4> CPSections;
609  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
610    const MachineConstantPoolEntry &CPE = CP[i];
611    unsigned Align = CPE.getAlignment();
612
613    SectionKind Kind;
614    switch (CPE.getRelocationInfo()) {
615    default: llvm_unreachable("Unknown section kind");
616    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
617    case 1:
618      Kind = SectionKind::getReadOnlyWithRelLocal();
619      break;
620    case 0:
621    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
622    case 4:  Kind = SectionKind::getMergeableConst4(); break;
623    case 8:  Kind = SectionKind::getMergeableConst8(); break;
624    case 16: Kind = SectionKind::getMergeableConst16();break;
625    default: Kind = SectionKind::getMergeableConst(); break;
626    }
627    }
628
629    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
630
631    // The number of sections are small, just do a linear search from the
632    // last section to the first.
633    bool Found = false;
634    unsigned SecIdx = CPSections.size();
635    while (SecIdx != 0) {
636      if (CPSections[--SecIdx].S == S) {
637        Found = true;
638        break;
639      }
640    }
641    if (!Found) {
642      SecIdx = CPSections.size();
643      CPSections.push_back(SectionCPs(S, Align));
644    }
645
646    if (Align > CPSections[SecIdx].Alignment)
647      CPSections[SecIdx].Alignment = Align;
648    CPSections[SecIdx].CPEs.push_back(i);
649  }
650
651  // Now print stuff into the calculated sections.
652  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
653    OutStreamer.SwitchSection(CPSections[i].S);
654    EmitAlignment(Log2_32(CPSections[i].Alignment));
655
656    unsigned Offset = 0;
657    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
658      unsigned CPI = CPSections[i].CPEs[j];
659      MachineConstantPoolEntry CPE = CP[CPI];
660
661      // Emit inter-object padding for alignment.
662      unsigned AlignMask = CPE.getAlignment() - 1;
663      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
664      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
665
666      const Type *Ty = CPE.getType();
667      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
668
669      // Emit the label with a comment on it.
670      if (VerboseAsm) {
671        OutStreamer.GetCommentOS() << "constant pool ";
672        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
673                          MF->getFunction()->getParent());
674        OutStreamer.GetCommentOS() << '\n';
675      }
676      OutStreamer.EmitLabel(GetCPISymbol(CPI));
677
678      if (CPE.isMachineConstantPoolEntry())
679        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
680      else
681        EmitGlobalConstant(CPE.Val.ConstVal);
682    }
683  }
684}
685
686/// EmitJumpTableInfo - Print assembly representations of the jump tables used
687/// by the current function to the current output stream.
688///
689void AsmPrinter::EmitJumpTableInfo() {
690  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
691  if (MJTI == 0) return;
692  if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
693  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
694  if (JT.empty()) return;
695
696  // Pick the directive to use to print the jump table entries, and switch to
697  // the appropriate section.
698  const Function *F = MF->getFunction();
699  bool JTInDiffSection = false;
700  if (// In PIC mode, we need to emit the jump table to the same section as the
701      // function body itself, otherwise the label differences won't make sense.
702      // FIXME: Need a better predicate for this: what about custom entries?
703      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
704      // We should also do if the section name is NULL or function is declared
705      // in discardable section
706      // FIXME: this isn't the right predicate, should be based on the MCSection
707      // for the function.
708      F->isWeakForLinker()) {
709    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
710  } else {
711    // Otherwise, drop it in the readonly section.
712    const MCSection *ReadOnlySection =
713      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
714    OutStreamer.SwitchSection(ReadOnlySection);
715    JTInDiffSection = true;
716  }
717
718  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
719
720  for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
721    const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
722
723    // If this jump table was deleted, ignore it.
724    if (JTBBs.empty()) continue;
725
726    // For the EK_LabelDifference32 entry, if the target supports .set, emit a
727    // .set directive for each unique entry.  This reduces the number of
728    // relocations the assembler will generate for the jump table.
729    if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
730        MAI->hasSetDirective()) {
731      SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
732      const TargetLowering *TLI = TM.getTargetLowering();
733      const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
734      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
735        const MachineBasicBlock *MBB = JTBBs[ii];
736        if (!EmittedSets.insert(MBB)) continue;
737
738        // .set LJTSet, LBB32-base
739        const MCExpr *LHS =
740          MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
741        OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
742                                MCBinaryExpr::CreateSub(LHS, Base, OutContext));
743      }
744    }
745
746    // On some targets (e.g. Darwin) we want to emit two consequtive labels
747    // before each jump table.  The first label is never referenced, but tells
748    // the assembler and linker the extents of the jump table object.  The
749    // second label is actually referenced by the code.
750    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
751      // FIXME: This doesn't have to have any specific name, just any randomly
752      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
753      OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
754
755    OutStreamer.EmitLabel(GetJTISymbol(JTI));
756
757    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
758      EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
759  }
760}
761
762/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
763/// current stream.
764void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
765                                    const MachineBasicBlock *MBB,
766                                    unsigned UID) const {
767  const MCExpr *Value = 0;
768  switch (MJTI->getEntryKind()) {
769  case MachineJumpTableInfo::EK_Inline:
770    llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
771  case MachineJumpTableInfo::EK_Custom32:
772    Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
773                                                              OutContext);
774    break;
775  case MachineJumpTableInfo::EK_BlockAddress:
776    // EK_BlockAddress - Each entry is a plain address of block, e.g.:
777    //     .word LBB123
778    Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
779    break;
780  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
781    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
782    // with a relocation as gp-relative, e.g.:
783    //     .gprel32 LBB123
784    MCSymbol *MBBSym = MBB->getSymbol();
785    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
786    return;
787  }
788
789  case MachineJumpTableInfo::EK_LabelDifference32: {
790    // EK_LabelDifference32 - Each entry is the address of the block minus
791    // the address of the jump table.  This is used for PIC jump tables where
792    // gprel32 is not supported.  e.g.:
793    //      .word LBB123 - LJTI1_2
794    // If the .set directive is supported, this is emitted as:
795    //      .set L4_5_set_123, LBB123 - LJTI1_2
796    //      .word L4_5_set_123
797
798    // If we have emitted set directives for the jump table entries, print
799    // them rather than the entries themselves.  If we're emitting PIC, then
800    // emit the table entries as differences between two text section labels.
801    if (MAI->hasSetDirective()) {
802      // If we used .set, reference the .set's symbol.
803      Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
804                                      OutContext);
805      break;
806    }
807    // Otherwise, use the difference as the jump table entry.
808    Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
809    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
810    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
811    break;
812  }
813  }
814
815  assert(Value && "Unknown entry kind!");
816
817  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
818  OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
819}
820
821
822/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
823/// special global used by LLVM.  If so, emit it and return true, otherwise
824/// do nothing and return false.
825bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
826  if (GV->getName() == "llvm.used") {
827    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
828      EmitLLVMUsedList(GV->getInitializer());
829    return true;
830  }
831
832  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
833  if (GV->getSection() == "llvm.metadata" ||
834      GV->hasAvailableExternallyLinkage())
835    return true;
836
837  if (!GV->hasAppendingLinkage()) return false;
838
839  assert(GV->hasInitializer() && "Not a special LLVM global!");
840
841  const TargetData *TD = TM.getTargetData();
842  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
843  if (GV->getName() == "llvm.global_ctors") {
844    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
845    EmitAlignment(Align, 0);
846    EmitXXStructorList(GV->getInitializer());
847
848    if (TM.getRelocationModel() == Reloc::Static &&
849        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
850      StringRef Sym(".constructors_used");
851      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
852                                      MCSA_Reference);
853    }
854    return true;
855  }
856
857  if (GV->getName() == "llvm.global_dtors") {
858    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
859    EmitAlignment(Align, 0);
860    EmitXXStructorList(GV->getInitializer());
861
862    if (TM.getRelocationModel() == Reloc::Static &&
863        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
864      StringRef Sym(".destructors_used");
865      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
866                                      MCSA_Reference);
867    }
868    return true;
869  }
870
871  return false;
872}
873
874/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
875/// global in the specified llvm.used list for which emitUsedDirectiveFor
876/// is true, as being used with this directive.
877void AsmPrinter::EmitLLVMUsedList(Constant *List) {
878  // Should be an array of 'i8*'.
879  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
880  if (InitList == 0) return;
881
882  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
883    const GlobalValue *GV =
884      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
885    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
886      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
887  }
888}
889
890/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
891/// function pointers, ignoring the init priority.
892void AsmPrinter::EmitXXStructorList(Constant *List) {
893  // Should be an array of '{ int, void ()* }' structs.  The first value is the
894  // init priority, which we ignore.
895  if (!isa<ConstantArray>(List)) return;
896  ConstantArray *InitList = cast<ConstantArray>(List);
897  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
898    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
899      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
900
901      if (CS->getOperand(1)->isNullValue())
902        return;  // Found a null terminator, exit printing.
903      // Emit the function pointer.
904      EmitGlobalConstant(CS->getOperand(1));
905    }
906}
907
908/// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
909void AsmPrinter::EmitInlineAsm(StringRef Str) const {
910  assert(!Str.empty() && "Can't emit empty inline asm block");
911
912  // If the output streamer is actually a .s file, just emit the blob textually.
913  // This is useful in case the asm parser doesn't handle something but the
914  // system assembler does.
915  if (OutStreamer.hasRawTextSupport()) {
916    OutStreamer.EmitRawText(Str);
917    return;
918  }
919
920  errs() << "Inline asm not supported by this streamer!\n";
921}
922
923
924//===--------------------------------------------------------------------===//
925// Emission and print routines
926//
927
928/// EmitInt8 - Emit a byte directive and value.
929///
930void AsmPrinter::EmitInt8(int Value) const {
931  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
932}
933
934/// EmitInt16 - Emit a short directive and value.
935///
936void AsmPrinter::EmitInt16(int Value) const {
937  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
938}
939
940/// EmitInt32 - Emit a long directive and value.
941///
942void AsmPrinter::EmitInt32(int Value) const {
943  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
944}
945
946/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
947/// in bytes of the directive is specified by Size and Hi/Lo specify the
948/// labels.  This implicitly uses .set if it is available.
949void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
950                                     unsigned Size) const {
951  // Get the Hi-Lo expression.
952  const MCExpr *Diff =
953    MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
954                            MCSymbolRefExpr::Create(Lo, OutContext),
955                            OutContext);
956
957  if (!MAI->hasSetDirective()) {
958    OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
959    return;
960  }
961
962  // Otherwise, emit with .set (aka assignment).
963  MCSymbol *SetLabel =
964    OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
965                                 "set" + Twine(SetCounter++));
966  OutStreamer.EmitAssignment(SetLabel, Diff);
967  OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
968}
969
970
971//===----------------------------------------------------------------------===//
972
973// EmitAlignment - Emit an alignment directive to the specified power of
974// two boundary.  For example, if you pass in 3 here, you will get an 8
975// byte alignment.  If a global value is specified, and if that global has
976// an explicit alignment requested, it will unconditionally override the
977// alignment request.  However, if ForcedAlignBits is specified, this value
978// has final say: the ultimate alignment will be the max of ForcedAlignBits
979// and the alignment computed with NumBits and the global.
980//
981// The algorithm is:
982//     Align = NumBits;
983//     if (GV && GV->hasalignment) Align = GV->getalignment();
984//     Align = std::max(Align, ForcedAlignBits);
985//
986void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
987                               unsigned ForcedAlignBits,
988                               bool UseFillExpr) const {
989  if (GV && GV->getAlignment())
990    NumBits = Log2_32(GV->getAlignment());
991  NumBits = std::max(NumBits, ForcedAlignBits);
992
993  if (NumBits == 0) return;   // No need to emit alignment.
994
995  if (getCurrentSection()->getKind().isText())
996    OutStreamer.EmitCodeAlignment(1 << NumBits);
997  else
998    OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
999}
1000
1001/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1002///
1003static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1004  MCContext &Ctx = AP.OutContext;
1005
1006  if (CV->isNullValue() || isa<UndefValue>(CV))
1007    return MCConstantExpr::Create(0, Ctx);
1008
1009  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1010    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1011
1012  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1013    return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1014  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1015    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1016
1017  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1018  if (CE == 0) {
1019    llvm_unreachable("Unknown constant value to lower!");
1020    return MCConstantExpr::Create(0, Ctx);
1021  }
1022
1023  switch (CE->getOpcode()) {
1024  default:
1025    // If the code isn't optimized, there may be outstanding folding
1026    // opportunities. Attempt to fold the expression using TargetData as a
1027    // last resort before giving up.
1028    if (Constant *C =
1029          ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1030      if (C != CE)
1031        return LowerConstant(C, AP);
1032#ifndef NDEBUG
1033    CE->dump();
1034#endif
1035    llvm_unreachable("FIXME: Don't support this constant expr");
1036  case Instruction::GetElementPtr: {
1037    const TargetData &TD = *AP.TM.getTargetData();
1038    // Generate a symbolic expression for the byte address
1039    const Constant *PtrVal = CE->getOperand(0);
1040    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1041    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1042                                         IdxVec.size());
1043
1044    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1045    if (Offset == 0)
1046      return Base;
1047
1048    // Truncate/sext the offset to the pointer size.
1049    if (TD.getPointerSizeInBits() != 64) {
1050      int SExtAmount = 64-TD.getPointerSizeInBits();
1051      Offset = (Offset << SExtAmount) >> SExtAmount;
1052    }
1053
1054    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1055                                   Ctx);
1056  }
1057
1058  case Instruction::Trunc:
1059    // We emit the value and depend on the assembler to truncate the generated
1060    // expression properly.  This is important for differences between
1061    // blockaddress labels.  Since the two labels are in the same function, it
1062    // is reasonable to treat their delta as a 32-bit value.
1063    // FALL THROUGH.
1064  case Instruction::BitCast:
1065    return LowerConstant(CE->getOperand(0), AP);
1066
1067  case Instruction::IntToPtr: {
1068    const TargetData &TD = *AP.TM.getTargetData();
1069    // Handle casts to pointers by changing them into casts to the appropriate
1070    // integer type.  This promotes constant folding and simplifies this code.
1071    Constant *Op = CE->getOperand(0);
1072    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1073                                      false/*ZExt*/);
1074    return LowerConstant(Op, AP);
1075  }
1076
1077  case Instruction::PtrToInt: {
1078    const TargetData &TD = *AP.TM.getTargetData();
1079    // Support only foldable casts to/from pointers that can be eliminated by
1080    // changing the pointer to the appropriately sized integer type.
1081    Constant *Op = CE->getOperand(0);
1082    const Type *Ty = CE->getType();
1083
1084    const MCExpr *OpExpr = LowerConstant(Op, AP);
1085
1086    // We can emit the pointer value into this slot if the slot is an
1087    // integer slot equal to the size of the pointer.
1088    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1089      return OpExpr;
1090
1091    // Otherwise the pointer is smaller than the resultant integer, mask off
1092    // the high bits so we are sure to get a proper truncation if the input is
1093    // a constant expr.
1094    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1095    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1096    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1097  }
1098
1099  // The MC library also has a right-shift operator, but it isn't consistently
1100  // signed or unsigned between different targets.
1101  case Instruction::Add:
1102  case Instruction::Sub:
1103  case Instruction::Mul:
1104  case Instruction::SDiv:
1105  case Instruction::SRem:
1106  case Instruction::Shl:
1107  case Instruction::And:
1108  case Instruction::Or:
1109  case Instruction::Xor: {
1110    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1111    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1112    switch (CE->getOpcode()) {
1113    default: llvm_unreachable("Unknown binary operator constant cast expr");
1114    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1115    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1116    case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1117    case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1118    case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1119    case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1120    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1121    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1122    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1123    }
1124  }
1125  }
1126}
1127
1128static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1129                                    AsmPrinter &AP) {
1130  if (AddrSpace != 0 || !CA->isString()) {
1131    // Not a string.  Print the values in successive locations
1132    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1133      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
1134    return;
1135  }
1136
1137  // Otherwise, it can be emitted as .ascii.
1138  SmallVector<char, 128> TmpVec;
1139  TmpVec.reserve(CA->getNumOperands());
1140  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1141    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1142
1143  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1144}
1145
1146static void EmitGlobalConstantVector(const ConstantVector *CV,
1147                                     unsigned AddrSpace, AsmPrinter &AP) {
1148  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1149    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1150}
1151
1152static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1153                                     unsigned AddrSpace, AsmPrinter &AP) {
1154  // Print the fields in successive locations. Pad to align if needed!
1155  const TargetData *TD = AP.TM.getTargetData();
1156  unsigned Size = TD->getTypeAllocSize(CS->getType());
1157  const StructLayout *Layout = TD->getStructLayout(CS->getType());
1158  uint64_t SizeSoFar = 0;
1159  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1160    const Constant *Field = CS->getOperand(i);
1161
1162    // Check if padding is needed and insert one or more 0s.
1163    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1164    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1165                        - Layout->getElementOffset(i)) - FieldSize;
1166    SizeSoFar += FieldSize + PadSize;
1167
1168    // Now print the actual field value.
1169    AP.EmitGlobalConstant(Field, AddrSpace);
1170
1171    // Insert padding - this may include padding to increase the size of the
1172    // current field up to the ABI size (if the struct is not packed) as well
1173    // as padding to ensure that the next field starts at the right offset.
1174    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1175  }
1176  assert(SizeSoFar == Layout->getSizeInBytes() &&
1177         "Layout of constant struct may be incorrect!");
1178}
1179
1180static void EmitGlobalConstantUnion(const ConstantUnion *CU,
1181                                    unsigned AddrSpace, AsmPrinter &AP) {
1182  const TargetData *TD = AP.TM.getTargetData();
1183  unsigned Size = TD->getTypeAllocSize(CU->getType());
1184
1185  const Constant *Contents = CU->getOperand(0);
1186  unsigned FilledSize = TD->getTypeAllocSize(Contents->getType());
1187
1188  // Print the actually filled part
1189  AP.EmitGlobalConstant(Contents, AddrSpace);
1190
1191  // And pad with enough zeroes
1192  AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace);
1193}
1194
1195static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1196                                 AsmPrinter &AP) {
1197  // FP Constants are printed as integer constants to avoid losing
1198  // precision.
1199  if (CFP->getType()->isDoubleTy()) {
1200    if (AP.VerboseAsm) {
1201      double Val = CFP->getValueAPF().convertToDouble();
1202      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1203    }
1204
1205    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1206    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1207    return;
1208  }
1209
1210  if (CFP->getType()->isFloatTy()) {
1211    if (AP.VerboseAsm) {
1212      float Val = CFP->getValueAPF().convertToFloat();
1213      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1214    }
1215    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1216    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1217    return;
1218  }
1219
1220  if (CFP->getType()->isX86_FP80Ty()) {
1221    // all long double variants are printed as hex
1222    // api needed to prevent premature destruction
1223    APInt API = CFP->getValueAPF().bitcastToAPInt();
1224    const uint64_t *p = API.getRawData();
1225    if (AP.VerboseAsm) {
1226      // Convert to double so we can print the approximate val as a comment.
1227      APFloat DoubleVal = CFP->getValueAPF();
1228      bool ignored;
1229      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1230                        &ignored);
1231      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1232        << DoubleVal.convertToDouble() << '\n';
1233    }
1234
1235    if (AP.TM.getTargetData()->isBigEndian()) {
1236      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1237      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1238    } else {
1239      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1240      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1241    }
1242
1243    // Emit the tail padding for the long double.
1244    const TargetData &TD = *AP.TM.getTargetData();
1245    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1246                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1247    return;
1248  }
1249
1250  assert(CFP->getType()->isPPC_FP128Ty() &&
1251         "Floating point constant type not handled");
1252  // All long double variants are printed as hex api needed to prevent
1253  // premature destruction.
1254  APInt API = CFP->getValueAPF().bitcastToAPInt();
1255  const uint64_t *p = API.getRawData();
1256  if (AP.TM.getTargetData()->isBigEndian()) {
1257    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1258    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1259  } else {
1260    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1261    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1262  }
1263}
1264
1265static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1266                                       unsigned AddrSpace, AsmPrinter &AP) {
1267  const TargetData *TD = AP.TM.getTargetData();
1268  unsigned BitWidth = CI->getBitWidth();
1269  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1270
1271  // We don't expect assemblers to support integer data directives
1272  // for more than 64 bits, so we emit the data in at most 64-bit
1273  // quantities at a time.
1274  const uint64_t *RawData = CI->getValue().getRawData();
1275  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1276    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1277    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1278  }
1279}
1280
1281/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1282void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1283  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1284    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1285    if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef.
1286    return OutStreamer.EmitZeros(Size, AddrSpace);
1287  }
1288
1289  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1290    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1291    switch (Size) {
1292    case 1:
1293    case 2:
1294    case 4:
1295    case 8:
1296      if (VerboseAsm)
1297        OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1298      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1299      return;
1300    default:
1301      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1302      return;
1303    }
1304  }
1305
1306  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1307    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1308
1309  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1310    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1311
1312  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1313    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1314
1315  if (isa<ConstantPointerNull>(CV)) {
1316    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1317    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1318    return;
1319  }
1320
1321  if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV))
1322    return EmitGlobalConstantUnion(CVU, AddrSpace, *this);
1323
1324  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1325    return EmitGlobalConstantVector(V, AddrSpace, *this);
1326
1327  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1328  // thread the streamer with EmitValue.
1329  OutStreamer.EmitValue(LowerConstant(CV, *this),
1330                        TM.getTargetData()->getTypeAllocSize(CV->getType()),
1331                        AddrSpace);
1332}
1333
1334void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1335  // Target doesn't support this yet!
1336  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1337}
1338
1339/// PrintSpecial - Print information related to the specified machine instr
1340/// that is independent of the operand, and may be independent of the instr
1341/// itself.  This can be useful for portably encoding the comment character
1342/// or other bits of target-specific knowledge into the asmstrings.  The
1343/// syntax used is ${:comment}.  Targets can override this to add support
1344/// for their own strange codes.
1345void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
1346                              const char *Code) const {
1347  if (!strcmp(Code, "private")) {
1348    OS << MAI->getPrivateGlobalPrefix();
1349  } else if (!strcmp(Code, "comment")) {
1350    OS << MAI->getCommentString();
1351  } else if (!strcmp(Code, "uid")) {
1352    // Comparing the address of MI isn't sufficient, because machineinstrs may
1353    // be allocated to the same address across functions.
1354    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1355
1356    // If this is a new LastFn instruction, bump the counter.
1357    if (LastMI != MI || LastFn != ThisF) {
1358      ++Counter;
1359      LastMI = MI;
1360      LastFn = ThisF;
1361    }
1362    OS << Counter;
1363  } else {
1364    std::string msg;
1365    raw_string_ostream Msg(msg);
1366    Msg << "Unknown special formatter '" << Code
1367         << "' for machine instr: " << *MI;
1368    llvm_report_error(Msg.str());
1369  }
1370}
1371
1372/// processDebugLoc - Processes the debug information of each machine
1373/// instruction's DebugLoc.
1374void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1375                                 bool BeforePrintingInsn) {
1376  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1377      || !DW->ShouldEmitDwarfDebug())
1378    return;
1379
1380  if (!BeforePrintingInsn)
1381    // After printing instruction
1382    DW->EndScope(MI);
1383  else
1384    DW->BeginScope(MI);
1385}
1386
1387
1388/// EmitInlineAsm - This method formats and emits the specified machine
1389/// instruction that is an inline asm.
1390void AsmPrinter::EmitInlineAsm(const MachineInstr *MI) const {
1391  assert(MI->isInlineAsm() && "printInlineAsm only works on inline asms");
1392
1393  unsigned NumOperands = MI->getNumOperands();
1394
1395  // Count the number of register definitions to find the asm string.
1396  unsigned NumDefs = 0;
1397  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1398       ++NumDefs)
1399    assert(NumDefs != NumOperands-1 && "No asm string?");
1400
1401  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1402
1403  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1404  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1405
1406  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1407  // These are useful to see where empty asm's wound up.
1408  if (AsmStr[0] == 0) {
1409    if (!OutStreamer.hasRawTextSupport()) return;
1410
1411    OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1412                            MAI->getInlineAsmStart());
1413    OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1414                            MAI->getInlineAsmEnd());
1415    return;
1416  }
1417
1418  // Emit the #APP start marker.  This has to happen even if verbose-asm isn't
1419  // enabled, so we use EmitRawText.
1420  if (OutStreamer.hasRawTextSupport())
1421    OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1422                            MAI->getInlineAsmStart());
1423
1424  // Emit the inline asm to a temporary string so we can emit it through
1425  // EmitInlineAsm.
1426  SmallString<256> StringData;
1427  raw_svector_ostream OS(StringData);
1428
1429  OS << '\t';
1430
1431  // The variant of the current asmprinter.
1432  int AsmPrinterVariant = MAI->getAssemblerDialect();
1433
1434  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1435  const char *LastEmitted = AsmStr; // One past the last character emitted.
1436
1437  while (*LastEmitted) {
1438    switch (*LastEmitted) {
1439    default: {
1440      // Not a special case, emit the string section literally.
1441      const char *LiteralEnd = LastEmitted+1;
1442      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1443             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1444        ++LiteralEnd;
1445      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1446        OS.write(LastEmitted, LiteralEnd-LastEmitted);
1447      LastEmitted = LiteralEnd;
1448      break;
1449    }
1450    case '\n':
1451      ++LastEmitted;   // Consume newline character.
1452      OS << '\n';       // Indent code with newline.
1453      break;
1454    case '$': {
1455      ++LastEmitted;   // Consume '$' character.
1456      bool Done = true;
1457
1458      // Handle escapes.
1459      switch (*LastEmitted) {
1460      default: Done = false; break;
1461      case '$':     // $$ -> $
1462        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1463          OS << '$';
1464        ++LastEmitted;  // Consume second '$' character.
1465        break;
1466      case '(':             // $( -> same as GCC's { character.
1467        ++LastEmitted;      // Consume '(' character.
1468        if (CurVariant != -1) {
1469          llvm_report_error("Nested variants found in inline asm string: '"
1470                            + std::string(AsmStr) + "'");
1471        }
1472        CurVariant = 0;     // We're in the first variant now.
1473        break;
1474      case '|':
1475        ++LastEmitted;  // consume '|' character.
1476        if (CurVariant == -1)
1477          OS << '|';       // this is gcc's behavior for | outside a variant
1478        else
1479          ++CurVariant;   // We're in the next variant.
1480        break;
1481      case ')':         // $) -> same as GCC's } char.
1482        ++LastEmitted;  // consume ')' character.
1483        if (CurVariant == -1)
1484          OS << '}';     // this is gcc's behavior for } outside a variant
1485        else
1486          CurVariant = -1;
1487        break;
1488      }
1489      if (Done) break;
1490
1491      bool HasCurlyBraces = false;
1492      if (*LastEmitted == '{') {     // ${variable}
1493        ++LastEmitted;               // Consume '{' character.
1494        HasCurlyBraces = true;
1495      }
1496
1497      // If we have ${:foo}, then this is not a real operand reference, it is a
1498      // "magic" string reference, just like in .td files.  Arrange to call
1499      // PrintSpecial.
1500      if (HasCurlyBraces && *LastEmitted == ':') {
1501        ++LastEmitted;
1502        const char *StrStart = LastEmitted;
1503        const char *StrEnd = strchr(StrStart, '}');
1504        if (StrEnd == 0)
1505          llvm_report_error(Twine("Unterminated ${:foo} operand in inline asm"
1506                                  " string: '") + Twine(AsmStr) + "'");
1507
1508        std::string Val(StrStart, StrEnd);
1509        PrintSpecial(MI, OS, Val.c_str());
1510        LastEmitted = StrEnd+1;
1511        break;
1512      }
1513
1514      const char *IDStart = LastEmitted;
1515      char *IDEnd;
1516      errno = 0;
1517      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1518      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1519        llvm_report_error("Bad $ operand number in inline asm string: '"
1520                          + std::string(AsmStr) + "'");
1521      }
1522      LastEmitted = IDEnd;
1523
1524      char Modifier[2] = { 0, 0 };
1525
1526      if (HasCurlyBraces) {
1527        // If we have curly braces, check for a modifier character.  This
1528        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1529        if (*LastEmitted == ':') {
1530          ++LastEmitted;    // Consume ':' character.
1531          if (*LastEmitted == 0) {
1532            llvm_report_error("Bad ${:} expression in inline asm string: '"
1533                              + std::string(AsmStr) + "'");
1534          }
1535
1536          Modifier[0] = *LastEmitted;
1537          ++LastEmitted;    // Consume modifier character.
1538        }
1539
1540        if (*LastEmitted != '}') {
1541          llvm_report_error("Bad ${} expression in inline asm string: '"
1542                            + std::string(AsmStr) + "'");
1543        }
1544        ++LastEmitted;    // Consume '}' character.
1545      }
1546
1547      if ((unsigned)Val >= NumOperands-1) {
1548        llvm_report_error("Invalid $ operand number in inline asm string: '"
1549                          + std::string(AsmStr) + "'");
1550      }
1551
1552      // Okay, we finally have a value number.  Ask the target to print this
1553      // operand!
1554      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1555        unsigned OpNo = 1;
1556
1557        bool Error = false;
1558
1559        // Scan to find the machine operand number for the operand.
1560        for (; Val; --Val) {
1561          if (OpNo >= MI->getNumOperands()) break;
1562          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1563          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1564        }
1565
1566        if (OpNo >= MI->getNumOperands()) {
1567          Error = true;
1568        } else {
1569          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1570          ++OpNo;  // Skip over the ID number.
1571
1572          if (Modifier[0] == 'l')  // labels are target independent
1573            OS << *MI->getOperand(OpNo).getMBB()->getSymbol();
1574          else {
1575            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1576            if ((OpFlags & 7) == 4) {
1577              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1578                                                Modifier[0] ? Modifier : 0,
1579                                                OS);
1580            } else {
1581              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1582                                          Modifier[0] ? Modifier : 0, OS);
1583            }
1584          }
1585        }
1586        if (Error) {
1587          std::string msg;
1588          raw_string_ostream Msg(msg);
1589          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1590          MI->print(Msg);
1591          llvm_report_error(Msg.str());
1592        }
1593      }
1594      break;
1595    }
1596    }
1597  }
1598  OS << "\n";
1599
1600  EmitInlineAsm(OS.str());
1601
1602  // Emit the #NOAPP end marker.  This has to happen even if verbose-asm isn't
1603  // enabled, so we use EmitRawText.
1604  if (OutStreamer.hasRawTextSupport())
1605    OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1606                            MAI->getInlineAsmEnd());
1607}
1608
1609/// EmitImplicitDef - This method emits the specified machine instruction
1610/// that is an implicit def.
1611void AsmPrinter::EmitImplicitDef(const MachineInstr *MI) const {
1612  if (!VerboseAsm) return;
1613  unsigned RegNo = MI->getOperand(0).getReg();
1614  OutStreamer.AddComment(Twine("implicit-def: ") +
1615                         TM.getRegisterInfo()->getName(RegNo));
1616  OutStreamer.AddBlankLine();
1617}
1618
1619void AsmPrinter::EmitKill(const MachineInstr *MI) const {
1620  if (!VerboseAsm) return;
1621
1622  std::string Str = "kill:";
1623  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1624    const MachineOperand &Op = MI->getOperand(n);
1625    assert(Op.isReg() && "KILL instruction must have only register operands");
1626    Str += ' ';
1627    Str += TM.getRegisterInfo()->getName(Op.getReg());
1628    Str += (Op.isDef() ? "<def>" : "<kill>");
1629  }
1630  OutStreamer.AddComment(Str);
1631  OutStreamer.AddBlankLine();
1632}
1633
1634/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1635/// instruction, using the specified assembler variant.  Targets should
1636/// override this to format as appropriate.
1637bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1638                                 unsigned AsmVariant, const char *ExtraCode,
1639                                 raw_ostream &O) {
1640  // Target doesn't support this yet!
1641  return true;
1642}
1643
1644bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1645                                       unsigned AsmVariant,
1646                                       const char *ExtraCode, raw_ostream &O) {
1647  // Target doesn't support this yet!
1648  return true;
1649}
1650
1651MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1652  return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1653}
1654
1655MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1656  return MMI->getAddrLabelSymbol(BB);
1657}
1658
1659/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1660MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1661  return OutContext.GetOrCreateSymbol
1662    (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1663     + "_" + Twine(CPID));
1664}
1665
1666/// GetJTISymbol - Return the symbol for the specified jump table entry.
1667MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1668  return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1669}
1670
1671/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1672/// FIXME: privatize to AsmPrinter.
1673MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1674  return OutContext.GetOrCreateSymbol
1675  (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1676   Twine(UID) + "_set_" + Twine(MBBID));
1677}
1678
1679/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1680/// global value name as its base, with the specified suffix, and where the
1681/// symbol is forced to have private linkage if ForcePrivate is true.
1682MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1683                                                   StringRef Suffix,
1684                                                   bool ForcePrivate) const {
1685  SmallString<60> NameStr;
1686  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1687  NameStr.append(Suffix.begin(), Suffix.end());
1688  return OutContext.GetOrCreateSymbol(NameStr.str());
1689}
1690
1691/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1692/// ExternalSymbol.
1693MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1694  SmallString<60> NameStr;
1695  Mang->getNameWithPrefix(NameStr, Sym);
1696  return OutContext.GetOrCreateSymbol(NameStr.str());
1697}
1698
1699
1700
1701/// PrintParentLoopComment - Print comments about parent loops of this one.
1702static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1703                                   unsigned FunctionNumber) {
1704  if (Loop == 0) return;
1705  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1706  OS.indent(Loop->getLoopDepth()*2)
1707    << "Parent Loop BB" << FunctionNumber << "_"
1708    << Loop->getHeader()->getNumber()
1709    << " Depth=" << Loop->getLoopDepth() << '\n';
1710}
1711
1712
1713/// PrintChildLoopComment - Print comments about child loops within
1714/// the loop for this basic block, with nesting.
1715static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1716                                  unsigned FunctionNumber) {
1717  // Add child loop information
1718  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1719    OS.indent((*CL)->getLoopDepth()*2)
1720      << "Child Loop BB" << FunctionNumber << "_"
1721      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1722      << '\n';
1723    PrintChildLoopComment(OS, *CL, FunctionNumber);
1724  }
1725}
1726
1727/// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks.
1728static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1729                                        const MachineLoopInfo *LI,
1730                                        const AsmPrinter &AP) {
1731  // Add loop depth information
1732  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1733  if (Loop == 0) return;
1734
1735  MachineBasicBlock *Header = Loop->getHeader();
1736  assert(Header && "No header for loop");
1737
1738  // If this block is not a loop header, just print out what is the loop header
1739  // and return.
1740  if (Header != &MBB) {
1741    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1742                              Twine(AP.getFunctionNumber())+"_" +
1743                              Twine(Loop->getHeader()->getNumber())+
1744                              " Depth="+Twine(Loop->getLoopDepth()));
1745    return;
1746  }
1747
1748  // Otherwise, it is a loop header.  Print out information about child and
1749  // parent loops.
1750  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1751
1752  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1753
1754  OS << "=>";
1755  OS.indent(Loop->getLoopDepth()*2-2);
1756
1757  OS << "This ";
1758  if (Loop->empty())
1759    OS << "Inner ";
1760  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1761
1762  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1763}
1764
1765
1766/// EmitBasicBlockStart - This method prints the label for the specified
1767/// MachineBasicBlock, an alignment (if present) and a comment describing
1768/// it if appropriate.
1769void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1770  // Emit an alignment directive for this block, if needed.
1771  if (unsigned Align = MBB->getAlignment())
1772    EmitAlignment(Log2_32(Align));
1773
1774  // If the block has its address taken, emit any labels that were used to
1775  // reference the block.  It is possible that there is more than one label
1776  // here, because multiple LLVM BB's may have been RAUW'd to this block after
1777  // the references were generated.
1778  if (MBB->hasAddressTaken()) {
1779    const BasicBlock *BB = MBB->getBasicBlock();
1780    if (VerboseAsm)
1781      OutStreamer.AddComment("Block address taken");
1782
1783    std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1784
1785    for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1786      OutStreamer.EmitLabel(Syms[i]);
1787  }
1788
1789  // Print the main label for the block.
1790  if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1791    if (VerboseAsm && OutStreamer.hasRawTextSupport()) {
1792      if (const BasicBlock *BB = MBB->getBasicBlock())
1793        if (BB->hasName())
1794          OutStreamer.AddComment("%" + BB->getName());
1795
1796      PrintBasicBlockLoopComments(*MBB, LI, *this);
1797
1798      // NOTE: Want this comment at start of line, don't emit with AddComment.
1799      OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1800                              Twine(MBB->getNumber()) + ":");
1801    }
1802  } else {
1803    if (VerboseAsm) {
1804      if (const BasicBlock *BB = MBB->getBasicBlock())
1805        if (BB->hasName())
1806          OutStreamer.AddComment("%" + BB->getName());
1807      PrintBasicBlockLoopComments(*MBB, LI, *this);
1808    }
1809
1810    OutStreamer.EmitLabel(MBB->getSymbol());
1811  }
1812}
1813
1814void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1815  MCSymbolAttr Attr = MCSA_Invalid;
1816
1817  switch (Visibility) {
1818  default: break;
1819  case GlobalValue::HiddenVisibility:
1820    Attr = MAI->getHiddenVisibilityAttr();
1821    break;
1822  case GlobalValue::ProtectedVisibility:
1823    Attr = MAI->getProtectedVisibilityAttr();
1824    break;
1825  }
1826
1827  if (Attr != MCSA_Invalid)
1828    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1829}
1830
1831void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1832  if (Offset > 0)
1833    OS << '+' << Offset;
1834  else if (Offset < 0)
1835    OS << Offset;
1836}
1837
1838/// isBlockOnlyReachableByFallthough - Return true if the basic block has
1839/// exactly one predecessor and the control transfer mechanism between
1840/// the predecessor and this block is a fall-through.
1841bool AsmPrinter::
1842isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1843  // If this is a landing pad, it isn't a fall through.  If it has no preds,
1844  // then nothing falls through to it.
1845  if (MBB->isLandingPad() || MBB->pred_empty())
1846    return false;
1847
1848  // If there isn't exactly one predecessor, it can't be a fall through.
1849  MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1850  ++PI2;
1851  if (PI2 != MBB->pred_end())
1852    return false;
1853
1854  // The predecessor has to be immediately before this block.
1855  const MachineBasicBlock *Pred = *PI;
1856
1857  if (!Pred->isLayoutSuccessor(MBB))
1858    return false;
1859
1860  // If the block is completely empty, then it definitely does fall through.
1861  if (Pred->empty())
1862    return true;
1863
1864  // Otherwise, check the last instruction.
1865  const MachineInstr &LastInst = Pred->back();
1866  return !LastInst.getDesc().isBarrier();
1867}
1868
1869
1870
1871GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1872  if (!S->usesMetadata())
1873    return 0;
1874
1875  gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1876  gcp_map_type::iterator GCPI = GCMap.find(S);
1877  if (GCPI != GCMap.end())
1878    return GCPI->second;
1879
1880  const char *Name = S->getName().c_str();
1881
1882  for (GCMetadataPrinterRegistry::iterator
1883         I = GCMetadataPrinterRegistry::begin(),
1884         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1885    if (strcmp(Name, I->getName()) == 0) {
1886      GCMetadataPrinter *GMP = I->instantiate();
1887      GMP->S = S;
1888      GCMap.insert(std::make_pair(S, GMP));
1889      return GMP;
1890    }
1891
1892  llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1893  return 0;
1894}
1895
1896