1 //===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the AsmPrinter class.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "asm-printer"
15 #include "llvm/CodeGen/AsmPrinter.h"
16 #include "DwarfDebug.h"
17 #include "DwarfException.h"
18 #include "llvm/Module.h"
19 #include "llvm/CodeGen/GCMetadataPrinter.h"
20 #include "llvm/CodeGen/MachineConstantPool.h"
21 #include "llvm/CodeGen/MachineFrameInfo.h"
22 #include "llvm/CodeGen/MachineFunction.h"
23 #include "llvm/CodeGen/MachineJumpTableInfo.h"
24 #include "llvm/CodeGen/MachineLoopInfo.h"
25 #include "llvm/CodeGen/MachineModuleInfo.h"
26 #include "llvm/Analysis/ConstantFolding.h"
27 #include "llvm/Analysis/DebugInfo.h"
28 #include "llvm/MC/MCAsmInfo.h"
29 #include "llvm/MC/MCContext.h"
30 #include "llvm/MC/MCExpr.h"
31 #include "llvm/MC/MCInst.h"
32 #include "llvm/MC/MCSection.h"
33 #include "llvm/MC/MCStreamer.h"
34 #include "llvm/MC/MCSymbol.h"
35 #include "llvm/Target/Mangler.h"
36 #include "llvm/Target/TargetData.h"
37 #include "llvm/Target/TargetInstrInfo.h"
38 #include "llvm/Target/TargetLowering.h"
39 #include "llvm/Target/TargetLoweringObjectFile.h"
40 #include "llvm/Target/TargetRegisterInfo.h"
41 #include "llvm/Assembly/Writer.h"
42 #include "llvm/ADT/SmallString.h"
43 #include "llvm/ADT/Statistic.h"
44 #include "llvm/Support/ErrorHandling.h"
45 #include "llvm/Support/Format.h"
46 #include "llvm/Support/Timer.h"
49 static const char *DWARFGroupName = "DWARF Emission";
50 static const char *DbgTimerName = "DWARF Debug Writer";
51 static const char *EHTimerName = "DWARF Exception Writer";
53 STATISTIC(EmittedInsts, "Number of machine instrs printed");
55 char AsmPrinter::ID = 0;
57 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
58 static gcp_map_type &getGCMap(void *&P) {
60 P = new gcp_map_type();
61 return *(gcp_map_type*)P;
65 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
66 /// value in log2 form. This rounds up to the preferred alignment if possible
68 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD,
69 unsigned InBits = 0) {
71 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
72 NumBits = TD.getPreferredAlignmentLog(GVar);
74 // If InBits is specified, round it to it.
78 // If the GV has a specified alignment, take it into account.
79 if (GV->getAlignment() == 0)
82 unsigned GVAlign = Log2_32(GV->getAlignment());
84 // If the GVAlign is larger than NumBits, or if we are required to obey
85 // NumBits because the GV has an assigned section, obey it.
86 if (GVAlign > NumBits || GV->hasSection())
94 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
95 : MachineFunctionPass(ID),
96 TM(tm), MAI(tm.getMCAsmInfo()),
97 OutContext(Streamer.getContext()),
98 OutStreamer(Streamer),
99 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
100 DD = 0; DE = 0; MMI = 0; LI = 0;
101 GCMetadataPrinters = 0;
102 VerboseAsm = Streamer.isVerboseAsm();
105 AsmPrinter::~AsmPrinter() {
106 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized");
108 if (GCMetadataPrinters != 0) {
109 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
111 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
114 GCMetadataPrinters = 0;
120 /// getFunctionNumber - Return a unique ID for the current function.
122 unsigned AsmPrinter::getFunctionNumber() const {
123 return MF->getFunctionNumber();
126 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
127 return TM.getTargetLowering()->getObjFileLowering();
131 /// getTargetData - Return information about data layout.
132 const TargetData &AsmPrinter::getTargetData() const {
133 return *TM.getTargetData();
136 /// getCurrentSection() - Return the current section we are emitting to.
137 const MCSection *AsmPrinter::getCurrentSection() const {
138 return OutStreamer.getCurrentSection();
143 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
144 AU.setPreservesAll();
145 MachineFunctionPass::getAnalysisUsage(AU);
146 AU.addRequired<MachineModuleInfo>();
147 AU.addRequired<GCModuleInfo>();
149 AU.addRequired<MachineLoopInfo>();
152 bool AsmPrinter::doInitialization(Module &M) {
153 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
154 MMI->AnalyzeModule(M);
156 // Initialize TargetLoweringObjectFile.
157 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
158 .Initialize(OutContext, TM);
160 Mang = new Mangler(OutContext, *TM.getTargetData());
162 // Allow the target to emit any magic that it wants at the start of the file.
163 EmitStartOfAsmFile(M);
165 // Very minimal debug info. It is ignored if we emit actual debug info. If we
166 // don't, this at least helps the user find where a global came from.
167 if (MAI->hasSingleParameterDotFile()) {
169 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
172 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
173 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
174 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
175 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
176 MP->beginAssembly(*this);
178 // Emit module-level inline asm if it exists.
179 if (!M.getModuleInlineAsm().empty()) {
180 OutStreamer.AddComment("Start of file scope inline assembly");
181 OutStreamer.AddBlankLine();
182 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
183 OutStreamer.AddComment("End of file scope inline assembly");
184 OutStreamer.AddBlankLine();
187 if (MAI->doesSupportDebugInformation())
188 DD = new DwarfDebug(this, &M);
190 if (MAI->doesSupportExceptionHandling())
191 switch (MAI->getExceptionHandlingType()) {
193 case ExceptionHandling::DwarfTable:
194 DE = new DwarfTableException(this);
196 case ExceptionHandling::DwarfCFI:
197 DE = new DwarfCFIException(this);
199 case ExceptionHandling::ARM:
200 DE = new ARMException(this);
207 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
208 switch ((GlobalValue::LinkageTypes)Linkage) {
209 case GlobalValue::CommonLinkage:
210 case GlobalValue::LinkOnceAnyLinkage:
211 case GlobalValue::LinkOnceODRLinkage:
212 case GlobalValue::WeakAnyLinkage:
213 case GlobalValue::WeakODRLinkage:
214 case GlobalValue::LinkerPrivateWeakLinkage:
215 case GlobalValue::LinkerPrivateWeakDefAutoLinkage:
216 if (MAI->getWeakDefDirective() != 0) {
218 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
220 if ((GlobalValue::LinkageTypes)Linkage !=
221 GlobalValue::LinkerPrivateWeakDefAutoLinkage)
222 // .weak_definition _foo
223 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
225 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
226 } else if (MAI->getLinkOnceDirective() != 0) {
228 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
229 //NOTE: linkonce is handled by the section the symbol was assigned to.
232 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
235 case GlobalValue::DLLExportLinkage:
236 case GlobalValue::AppendingLinkage:
237 // FIXME: appending linkage variables should go into a section of
238 // their name or something. For now, just emit them as external.
239 case GlobalValue::ExternalLinkage:
240 // If external or appending, declare as a global symbol.
242 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
244 case GlobalValue::PrivateLinkage:
245 case GlobalValue::InternalLinkage:
246 case GlobalValue::LinkerPrivateLinkage:
249 llvm_unreachable("Unknown linkage type!");
254 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
255 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
256 if (!GV->hasInitializer()) // External globals require no code.
259 // Check to see if this is a special global used by LLVM, if so, emit it.
260 if (EmitSpecialLLVMGlobal(GV))
264 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
265 /*PrintType=*/false, GV->getParent());
266 OutStreamer.GetCommentOS() << '\n';
269 MCSymbol *GVSym = Mang->getSymbol(GV);
270 EmitVisibility(GVSym, GV->getVisibility());
272 if (MAI->hasDotTypeDotSizeDirective())
273 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
275 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
277 const TargetData *TD = TM.getTargetData();
278 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType());
280 // If the alignment is specified, we *must* obey it. Overaligning a global
281 // with a specified alignment is a prompt way to break globals emitted to
282 // sections and expected to be contiguous (e.g. ObjC metadata).
283 unsigned AlignLog = getGVAlignmentLog2(GV, *TD);
285 // Handle common and BSS local symbols (.lcomm).
286 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
287 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
290 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
291 /*PrintType=*/false, GV->getParent());
292 OutStreamer.GetCommentOS() << '\n';
295 // Handle common symbols.
296 if (GVKind.isCommon()) {
297 unsigned Align = 1 << AlignLog;
298 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
302 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
306 // Handle local BSS symbols.
307 if (MAI->hasMachoZeroFillDirective()) {
308 const MCSection *TheSection =
309 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
310 // .zerofill __DATA, __bss, _foo, 400, 5
311 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
315 if (MAI->hasLCOMMDirective()) {
317 OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
321 unsigned Align = 1 << AlignLog;
322 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
326 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
328 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
332 const MCSection *TheSection =
333 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
335 // Handle the zerofill directive on darwin, which is a special form of BSS
337 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
338 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
341 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
342 // .zerofill __DATA, __common, _foo, 400, 5
343 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
347 // Handle thread local data for mach-o which requires us to output an
348 // additional structure of data and mangle the original symbol so that we
349 // can reference it later.
351 // TODO: This should become an "emit thread local global" method on TLOF.
352 // All of this macho specific stuff should be sunk down into TLOFMachO and
353 // stuff like "TLSExtraDataSection" should no longer be part of the parent
354 // TLOF class. This will also make it more obvious that stuff like
355 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
357 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
358 // Emit the .tbss symbol
360 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
362 if (GVKind.isThreadBSS())
363 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
364 else if (GVKind.isThreadData()) {
365 OutStreamer.SwitchSection(TheSection);
367 EmitAlignment(AlignLog, GV);
368 OutStreamer.EmitLabel(MangSym);
370 EmitGlobalConstant(GV->getInitializer());
373 OutStreamer.AddBlankLine();
375 // Emit the variable struct for the runtime.
376 const MCSection *TLVSect
377 = getObjFileLowering().getTLSExtraDataSection();
379 OutStreamer.SwitchSection(TLVSect);
380 // Emit the linkage here.
381 EmitLinkage(GV->getLinkage(), GVSym);
382 OutStreamer.EmitLabel(GVSym);
384 // Three pointers in size:
385 // - __tlv_bootstrap - used to make sure support exists
386 // - spare pointer, used when mapped by the runtime
387 // - pointer to mangled symbol above with initializer
388 unsigned PtrSize = TD->getPointerSizeInBits()/8;
389 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
391 OutStreamer.EmitIntValue(0, PtrSize, 0);
392 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0);
394 OutStreamer.AddBlankLine();
398 OutStreamer.SwitchSection(TheSection);
400 EmitLinkage(GV->getLinkage(), GVSym);
401 EmitAlignment(AlignLog, GV);
403 OutStreamer.EmitLabel(GVSym);
405 EmitGlobalConstant(GV->getInitializer());
407 if (MAI->hasDotTypeDotSizeDirective())
409 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
411 OutStreamer.AddBlankLine();
414 /// EmitFunctionHeader - This method emits the header for the current
416 void AsmPrinter::EmitFunctionHeader() {
417 // Print out constants referenced by the function
420 // Print the 'header' of function.
421 const Function *F = MF->getFunction();
423 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
424 EmitVisibility(CurrentFnSym, F->getVisibility());
426 EmitLinkage(F->getLinkage(), CurrentFnSym);
427 EmitAlignment(MF->getAlignment(), F);
429 if (MAI->hasDotTypeDotSizeDirective())
430 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
433 WriteAsOperand(OutStreamer.GetCommentOS(), F,
434 /*PrintType=*/false, F->getParent());
435 OutStreamer.GetCommentOS() << '\n';
438 // Emit the CurrentFnSym. This is a virtual function to allow targets to
439 // do their wild and crazy things as required.
440 EmitFunctionEntryLabel();
442 // If the function had address-taken blocks that got deleted, then we have
443 // references to the dangling symbols. Emit them at the start of the function
444 // so that we don't get references to undefined symbols.
445 std::vector<MCSymbol*> DeadBlockSyms;
446 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
447 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
448 OutStreamer.AddComment("Address taken block that was later removed");
449 OutStreamer.EmitLabel(DeadBlockSyms[i]);
452 // Add some workaround for linkonce linkage on Cygwin\MinGW.
453 if (MAI->getLinkOnceDirective() != 0 &&
454 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
455 // FIXME: What is this?
457 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
458 CurrentFnSym->getName());
459 OutStreamer.EmitLabel(FakeStub);
462 // Emit pre-function debug and/or EH information.
464 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
465 DE->BeginFunction(MF);
468 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
469 DD->beginFunction(MF);
473 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
474 /// function. This can be overridden by targets as required to do custom stuff.
475 void AsmPrinter::EmitFunctionEntryLabel() {
476 // The function label could have already been emitted if two symbols end up
477 // conflicting due to asm renaming. Detect this and emit an error.
478 if (CurrentFnSym->isUndefined())
479 return OutStreamer.EmitLabel(CurrentFnSym);
481 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
482 "' label emitted multiple times to assembly file");
486 static void EmitDebugLoc(DebugLoc DL, const MachineFunction *MF,
487 raw_ostream &CommentOS) {
488 const LLVMContext &Ctx = MF->getFunction()->getContext();
489 if (!DL.isUnknown()) { // Print source line info.
490 DIScope Scope(DL.getScope(Ctx));
491 // Omit the directory, because it's likely to be long and uninteresting.
493 CommentOS << Scope.getFilename();
495 CommentOS << "<unknown>";
496 CommentOS << ':' << DL.getLine();
497 if (DL.getCol() != 0)
498 CommentOS << ':' << DL.getCol();
499 DebugLoc InlinedAtDL = DebugLoc::getFromDILocation(DL.getInlinedAt(Ctx));
500 if (!InlinedAtDL.isUnknown()) {
502 EmitDebugLoc(InlinedAtDL, MF, CommentOS);
508 /// EmitComments - Pretty-print comments for instructions.
509 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
510 const MachineFunction *MF = MI.getParent()->getParent();
511 const TargetMachine &TM = MF->getTarget();
513 DebugLoc DL = MI.getDebugLoc();
514 if (!DL.isUnknown()) { // Print source line info.
515 EmitDebugLoc(DL, MF, CommentOS);
519 // Check for spills and reloads
522 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
524 // We assume a single instruction only has a spill or reload, not
526 const MachineMemOperand *MMO;
527 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
528 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
529 MMO = *MI.memoperands_begin();
530 CommentOS << MMO->getSize() << "-byte Reload\n";
532 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
533 if (FrameInfo->isSpillSlotObjectIndex(FI))
534 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
535 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
536 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
537 MMO = *MI.memoperands_begin();
538 CommentOS << MMO->getSize() << "-byte Spill\n";
540 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
541 if (FrameInfo->isSpillSlotObjectIndex(FI))
542 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
545 // Check for spill-induced copies
546 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
547 CommentOS << " Reload Reuse\n";
550 /// EmitImplicitDef - This method emits the specified machine instruction
551 /// that is an implicit def.
552 static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
553 unsigned RegNo = MI->getOperand(0).getReg();
554 AP.OutStreamer.AddComment(Twine("implicit-def: ") +
555 AP.TM.getRegisterInfo()->getName(RegNo));
556 AP.OutStreamer.AddBlankLine();
559 static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) {
560 std::string Str = "kill:";
561 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
562 const MachineOperand &Op = MI->getOperand(i);
563 assert(Op.isReg() && "KILL instruction must have only register operands");
565 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
566 Str += (Op.isDef() ? "<def>" : "<kill>");
568 AP.OutStreamer.AddComment(Str);
569 AP.OutStreamer.AddBlankLine();
572 /// EmitDebugValueComment - This method handles the target-independent form
573 /// of DBG_VALUE, returning true if it was able to do so. A false return
574 /// means the target will need to handle MI in EmitInstruction.
575 static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
576 // This code handles only the 3-operand target-independent form.
577 if (MI->getNumOperands() != 3)
580 SmallString<128> Str;
581 raw_svector_ostream OS(Str);
582 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
584 // cast away const; DIetc do not take const operands for some reason.
585 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
586 if (V.getContext().isSubprogram())
587 OS << DISubprogram(V.getContext()).getDisplayName() << ":";
588 OS << V.getName() << " <- ";
590 // Register or immediate value. Register 0 means undef.
591 if (MI->getOperand(0).isFPImm()) {
592 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
593 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
594 OS << (double)APF.convertToFloat();
595 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
596 OS << APF.convertToDouble();
598 // There is no good way to print long double. Convert a copy to
599 // double. Ah well, it's only a comment.
601 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
603 OS << "(long double) " << APF.convertToDouble();
605 } else if (MI->getOperand(0).isImm()) {
606 OS << MI->getOperand(0).getImm();
608 assert(MI->getOperand(0).isReg() && "Unknown operand type");
609 if (MI->getOperand(0).getReg() == 0) {
610 // Suppress offset, it is not meaningful here.
612 // NOTE: Want this comment at start of line, don't emit with AddComment.
613 AP.OutStreamer.EmitRawText(OS.str());
616 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg());
619 OS << '+' << MI->getOperand(1).getImm();
620 // NOTE: Want this comment at start of line, don't emit with AddComment.
621 AP.OutStreamer.EmitRawText(OS.str());
625 /// EmitFunctionBody - This method emits the body and trailer for a
627 void AsmPrinter::EmitFunctionBody() {
628 // Emit target-specific gunk before the function body.
629 EmitFunctionBodyStart();
631 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
633 // Print out code for the function.
634 bool HasAnyRealCode = false;
635 const MachineInstr *LastMI = 0;
636 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
638 // Print a label for the basic block.
639 EmitBasicBlockStart(I);
640 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
644 // Print the assembly for the instruction.
645 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
646 !II->isDebugValue()) {
647 HasAnyRealCode = true;
651 if (ShouldPrintDebugScopes) {
652 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
653 DD->beginInstruction(II);
657 EmitComments(*II, OutStreamer.GetCommentOS());
659 switch (II->getOpcode()) {
660 case TargetOpcode::PROLOG_LABEL:
661 case TargetOpcode::EH_LABEL:
662 case TargetOpcode::GC_LABEL:
663 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
665 case TargetOpcode::INLINEASM:
668 case TargetOpcode::DBG_VALUE:
670 if (!EmitDebugValueComment(II, *this))
674 case TargetOpcode::IMPLICIT_DEF:
675 if (isVerbose()) EmitImplicitDef(II, *this);
677 case TargetOpcode::KILL:
678 if (isVerbose()) EmitKill(II, *this);
685 if (ShouldPrintDebugScopes) {
686 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
687 DD->endInstruction(II);
692 // If the last instruction was a prolog label, then we have a situation where
693 // we emitted a prolog but no function body. This results in the ending prolog
694 // label equaling the end of function label and an invalid "row" in the
695 // FDE. We need to emit a noop in this situation so that the FDE's rows are
697 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
699 // If the function is empty and the object file uses .subsections_via_symbols,
700 // then we need to emit *something* to the function body to prevent the
701 // labels from collapsing together. Just emit a noop.
702 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
704 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
705 if (Noop.getOpcode()) {
706 OutStreamer.AddComment("avoids zero-length function");
707 OutStreamer.EmitInstruction(Noop);
708 } else // Target not mc-ized yet.
709 OutStreamer.EmitRawText(StringRef("\tnop\n"));
712 // Emit target-specific gunk after the function body.
713 EmitFunctionBodyEnd();
715 // If the target wants a .size directive for the size of the function, emit
717 if (MAI->hasDotTypeDotSizeDirective()) {
718 // Create a symbol for the end of function, so we can get the size as
719 // difference between the function label and the temp label.
720 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
721 OutStreamer.EmitLabel(FnEndLabel);
723 const MCExpr *SizeExp =
724 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
725 MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
727 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
730 // Emit post-function debug information.
732 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
736 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
741 // Print out jump tables referenced by the function.
744 OutStreamer.AddBlankLine();
747 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
749 MachineLocation AsmPrinter::
750 getDebugValueLocation(const MachineInstr *MI) const {
751 // Target specific DBG_VALUE instructions are handled by each target.
752 return MachineLocation();
755 bool AsmPrinter::doFinalization(Module &M) {
756 // Emit global variables.
757 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
759 EmitGlobalVariable(I);
761 // Emit visibility info for declarations
762 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
763 const Function &F = *I;
764 if (!F.isDeclaration())
766 GlobalValue::VisibilityTypes V = F.getVisibility();
767 if (V == GlobalValue::DefaultVisibility)
770 MCSymbol *Name = Mang->getSymbol(&F);
771 EmitVisibility(Name, V, false);
774 // Finalize debug and EH information.
777 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
784 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
790 // If the target wants to know about weak references, print them all.
791 if (MAI->getWeakRefDirective()) {
792 // FIXME: This is not lazy, it would be nice to only print weak references
793 // to stuff that is actually used. Note that doing so would require targets
794 // to notice uses in operands (due to constant exprs etc). This should
795 // happen with the MC stuff eventually.
797 // Print out module-level global variables here.
798 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
800 if (!I->hasExternalWeakLinkage()) continue;
801 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
804 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
805 if (!I->hasExternalWeakLinkage()) continue;
806 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
810 if (MAI->hasSetDirective()) {
811 OutStreamer.AddBlankLine();
812 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
814 MCSymbol *Name = Mang->getSymbol(I);
816 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
817 MCSymbol *Target = Mang->getSymbol(GV);
819 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
820 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
821 else if (I->hasWeakLinkage())
822 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
824 assert(I->hasLocalLinkage() && "Invalid alias linkage");
826 EmitVisibility(Name, I->getVisibility());
828 // Emit the directives as assignments aka .set:
829 OutStreamer.EmitAssignment(Name,
830 MCSymbolRefExpr::Create(Target, OutContext));
834 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
835 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
836 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
837 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
838 MP->finishAssembly(*this);
840 // If we don't have any trampolines, then we don't require stack memory
841 // to be executable. Some targets have a directive to declare this.
842 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
843 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
844 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
845 OutStreamer.SwitchSection(S);
847 // Allow the target to emit any magic that it wants at the end of the file,
848 // after everything else has gone out.
851 delete Mang; Mang = 0;
854 OutStreamer.Finish();
858 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
860 // Get the function symbol.
861 CurrentFnSym = Mang->getSymbol(MF.getFunction());
864 LI = &getAnalysis<MachineLoopInfo>();
868 // SectionCPs - Keep track the alignment, constpool entries per Section.
872 SmallVector<unsigned, 4> CPEs;
873 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
877 /// EmitConstantPool - Print to the current output stream assembly
878 /// representations of the constants in the constant pool MCP. This is
879 /// used to print out constants which have been "spilled to memory" by
880 /// the code generator.
882 void AsmPrinter::EmitConstantPool() {
883 const MachineConstantPool *MCP = MF->getConstantPool();
884 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
885 if (CP.empty()) return;
887 // Calculate sections for constant pool entries. We collect entries to go into
888 // the same section together to reduce amount of section switch statements.
889 SmallVector<SectionCPs, 4> CPSections;
890 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
891 const MachineConstantPoolEntry &CPE = CP[i];
892 unsigned Align = CPE.getAlignment();
895 switch (CPE.getRelocationInfo()) {
896 default: llvm_unreachable("Unknown section kind");
897 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
899 Kind = SectionKind::getReadOnlyWithRelLocal();
902 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
903 case 4: Kind = SectionKind::getMergeableConst4(); break;
904 case 8: Kind = SectionKind::getMergeableConst8(); break;
905 case 16: Kind = SectionKind::getMergeableConst16();break;
906 default: Kind = SectionKind::getMergeableConst(); break;
910 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
912 // The number of sections are small, just do a linear search from the
913 // last section to the first.
915 unsigned SecIdx = CPSections.size();
916 while (SecIdx != 0) {
917 if (CPSections[--SecIdx].S == S) {
923 SecIdx = CPSections.size();
924 CPSections.push_back(SectionCPs(S, Align));
927 if (Align > CPSections[SecIdx].Alignment)
928 CPSections[SecIdx].Alignment = Align;
929 CPSections[SecIdx].CPEs.push_back(i);
932 // Now print stuff into the calculated sections.
933 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
934 OutStreamer.SwitchSection(CPSections[i].S);
935 EmitAlignment(Log2_32(CPSections[i].Alignment));
938 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
939 unsigned CPI = CPSections[i].CPEs[j];
940 MachineConstantPoolEntry CPE = CP[CPI];
942 // Emit inter-object padding for alignment.
943 unsigned AlignMask = CPE.getAlignment() - 1;
944 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
945 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
947 const Type *Ty = CPE.getType();
948 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
949 OutStreamer.EmitLabel(GetCPISymbol(CPI));
951 if (CPE.isMachineConstantPoolEntry())
952 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
954 EmitGlobalConstant(CPE.Val.ConstVal);
959 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
960 /// by the current function to the current output stream.
962 void AsmPrinter::EmitJumpTableInfo() {
963 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
964 if (MJTI == 0) return;
965 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
966 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
967 if (JT.empty()) return;
969 // Pick the directive to use to print the jump table entries, and switch to
970 // the appropriate section.
971 const Function *F = MF->getFunction();
972 bool JTInDiffSection = false;
973 if (// In PIC mode, we need to emit the jump table to the same section as the
974 // function body itself, otherwise the label differences won't make sense.
975 // FIXME: Need a better predicate for this: what about custom entries?
976 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
977 // We should also do if the section name is NULL or function is declared
978 // in discardable section
979 // FIXME: this isn't the right predicate, should be based on the MCSection
981 F->isWeakForLinker()) {
982 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
984 // Otherwise, drop it in the readonly section.
985 const MCSection *ReadOnlySection =
986 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
987 OutStreamer.SwitchSection(ReadOnlySection);
988 JTInDiffSection = true;
991 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
993 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
994 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
996 // If this jump table was deleted, ignore it.
997 if (JTBBs.empty()) continue;
999 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1000 // .set directive for each unique entry. This reduces the number of
1001 // relocations the assembler will generate for the jump table.
1002 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1003 MAI->hasSetDirective()) {
1004 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1005 const TargetLowering *TLI = TM.getTargetLowering();
1006 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1007 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1008 const MachineBasicBlock *MBB = JTBBs[ii];
1009 if (!EmittedSets.insert(MBB)) continue;
1011 // .set LJTSet, LBB32-base
1013 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1014 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1015 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1019 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1020 // before each jump table. The first label is never referenced, but tells
1021 // the assembler and linker the extents of the jump table object. The
1022 // second label is actually referenced by the code.
1023 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1024 // FIXME: This doesn't have to have any specific name, just any randomly
1025 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1026 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1028 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1030 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1031 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1035 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1037 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1038 const MachineBasicBlock *MBB,
1039 unsigned UID) const {
1040 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1041 const MCExpr *Value = 0;
1042 switch (MJTI->getEntryKind()) {
1043 case MachineJumpTableInfo::EK_Inline:
1044 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
1045 case MachineJumpTableInfo::EK_Custom32:
1046 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1049 case MachineJumpTableInfo::EK_BlockAddress:
1050 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1052 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1054 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1055 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1056 // with a relocation as gp-relative, e.g.:
1058 MCSymbol *MBBSym = MBB->getSymbol();
1059 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1063 case MachineJumpTableInfo::EK_LabelDifference32: {
1064 // EK_LabelDifference32 - Each entry is the address of the block minus
1065 // the address of the jump table. This is used for PIC jump tables where
1066 // gprel32 is not supported. e.g.:
1067 // .word LBB123 - LJTI1_2
1068 // If the .set directive is supported, this is emitted as:
1069 // .set L4_5_set_123, LBB123 - LJTI1_2
1070 // .word L4_5_set_123
1072 // If we have emitted set directives for the jump table entries, print
1073 // them rather than the entries themselves. If we're emitting PIC, then
1074 // emit the table entries as differences between two text section labels.
1075 if (MAI->hasSetDirective()) {
1076 // If we used .set, reference the .set's symbol.
1077 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1081 // Otherwise, use the difference as the jump table entry.
1082 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1083 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1084 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1089 assert(Value && "Unknown entry kind!");
1091 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
1092 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
1096 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1097 /// special global used by LLVM. If so, emit it and return true, otherwise
1098 /// do nothing and return false.
1099 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1100 if (GV->getName() == "llvm.used") {
1101 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1102 EmitLLVMUsedList(GV->getInitializer());
1106 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1107 if (GV->getSection() == "llvm.metadata" ||
1108 GV->hasAvailableExternallyLinkage())
1111 if (!GV->hasAppendingLinkage()) return false;
1113 assert(GV->hasInitializer() && "Not a special LLVM global!");
1115 const TargetData *TD = TM.getTargetData();
1116 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1117 if (GV->getName() == "llvm.global_ctors") {
1118 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
1119 EmitAlignment(Align);
1120 EmitXXStructorList(GV->getInitializer());
1122 if (TM.getRelocationModel() == Reloc::Static &&
1123 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1124 StringRef Sym(".constructors_used");
1125 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1131 if (GV->getName() == "llvm.global_dtors") {
1132 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
1133 EmitAlignment(Align);
1134 EmitXXStructorList(GV->getInitializer());
1136 if (TM.getRelocationModel() == Reloc::Static &&
1137 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1138 StringRef Sym(".destructors_used");
1139 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1148 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1149 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1150 /// is true, as being used with this directive.
1151 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
1152 // Should be an array of 'i8*'.
1153 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1154 if (InitList == 0) return;
1156 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1157 const GlobalValue *GV =
1158 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1159 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1160 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1164 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
1165 /// function pointers, ignoring the init priority.
1166 void AsmPrinter::EmitXXStructorList(Constant *List) {
1167 // Should be an array of '{ int, void ()* }' structs. The first value is the
1168 // init priority, which we ignore.
1169 if (!isa<ConstantArray>(List)) return;
1170 ConstantArray *InitList = cast<ConstantArray>(List);
1171 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
1172 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
1173 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
1175 if (CS->getOperand(1)->isNullValue())
1176 return; // Found a null terminator, exit printing.
1177 // Emit the function pointer.
1178 EmitGlobalConstant(CS->getOperand(1));
1182 //===--------------------------------------------------------------------===//
1183 // Emission and print routines
1186 /// EmitInt8 - Emit a byte directive and value.
1188 void AsmPrinter::EmitInt8(int Value) const {
1189 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
1192 /// EmitInt16 - Emit a short directive and value.
1194 void AsmPrinter::EmitInt16(int Value) const {
1195 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
1198 /// EmitInt32 - Emit a long directive and value.
1200 void AsmPrinter::EmitInt32(int Value) const {
1201 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
1204 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1205 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1206 /// labels. This implicitly uses .set if it is available.
1207 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1208 unsigned Size) const {
1209 // Get the Hi-Lo expression.
1210 const MCExpr *Diff =
1211 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1212 MCSymbolRefExpr::Create(Lo, OutContext),
1215 if (!MAI->hasSetDirective()) {
1216 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
1220 // Otherwise, emit with .set (aka assignment).
1221 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1222 OutStreamer.EmitAssignment(SetLabel, Diff);
1223 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
1226 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1227 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1228 /// specify the labels. This implicitly uses .set if it is available.
1229 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1230 const MCSymbol *Lo, unsigned Size)
1233 // Emit Hi+Offset - Lo
1234 // Get the Hi+Offset expression.
1235 const MCExpr *Plus =
1236 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1237 MCConstantExpr::Create(Offset, OutContext),
1240 // Get the Hi+Offset-Lo expression.
1241 const MCExpr *Diff =
1242 MCBinaryExpr::CreateSub(Plus,
1243 MCSymbolRefExpr::Create(Lo, OutContext),
1246 if (!MAI->hasSetDirective())
1247 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/);
1249 // Otherwise, emit with .set (aka assignment).
1250 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1251 OutStreamer.EmitAssignment(SetLabel, Diff);
1252 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/);
1256 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1257 /// where the size in bytes of the directive is specified by Size and Label
1258 /// specifies the label. This implicitly uses .set if it is available.
1259 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1263 // Emit Label+Offset
1264 const MCExpr *Plus =
1265 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext),
1266 MCConstantExpr::Create(Offset, OutContext),
1269 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/);
1273 //===----------------------------------------------------------------------===//
1275 // EmitAlignment - Emit an alignment directive to the specified power of
1276 // two boundary. For example, if you pass in 3 here, you will get an 8
1277 // byte alignment. If a global value is specified, and if that global has
1278 // an explicit alignment requested, it will override the alignment request
1279 // if required for correctness.
1281 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1282 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits);
1284 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1286 if (getCurrentSection()->getKind().isText())
1287 OutStreamer.EmitCodeAlignment(1 << NumBits);
1289 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1292 //===----------------------------------------------------------------------===//
1293 // Constant emission.
1294 //===----------------------------------------------------------------------===//
1296 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1298 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1299 MCContext &Ctx = AP.OutContext;
1301 if (CV->isNullValue() || isa<UndefValue>(CV))
1302 return MCConstantExpr::Create(0, Ctx);
1304 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1305 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1307 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1308 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1310 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1311 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1313 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1315 llvm_unreachable("Unknown constant value to lower!");
1316 return MCConstantExpr::Create(0, Ctx);
1319 switch (CE->getOpcode()) {
1321 // If the code isn't optimized, there may be outstanding folding
1322 // opportunities. Attempt to fold the expression using TargetData as a
1323 // last resort before giving up.
1325 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1327 return LowerConstant(C, AP);
1329 // Otherwise report the problem to the user.
1332 raw_string_ostream OS(S);
1333 OS << "Unsupported expression in static initializer: ";
1334 WriteAsOperand(OS, CE, /*PrintType=*/false,
1335 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1336 report_fatal_error(OS.str());
1338 return MCConstantExpr::Create(0, Ctx);
1339 case Instruction::GetElementPtr: {
1340 const TargetData &TD = *AP.TM.getTargetData();
1341 // Generate a symbolic expression for the byte address
1342 const Constant *PtrVal = CE->getOperand(0);
1343 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1344 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1347 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1351 // Truncate/sext the offset to the pointer size.
1352 if (TD.getPointerSizeInBits() != 64) {
1353 int SExtAmount = 64-TD.getPointerSizeInBits();
1354 Offset = (Offset << SExtAmount) >> SExtAmount;
1357 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1361 case Instruction::Trunc:
1362 // We emit the value and depend on the assembler to truncate the generated
1363 // expression properly. This is important for differences between
1364 // blockaddress labels. Since the two labels are in the same function, it
1365 // is reasonable to treat their delta as a 32-bit value.
1367 case Instruction::BitCast:
1368 return LowerConstant(CE->getOperand(0), AP);
1370 case Instruction::IntToPtr: {
1371 const TargetData &TD = *AP.TM.getTargetData();
1372 // Handle casts to pointers by changing them into casts to the appropriate
1373 // integer type. This promotes constant folding and simplifies this code.
1374 Constant *Op = CE->getOperand(0);
1375 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1377 return LowerConstant(Op, AP);
1380 case Instruction::PtrToInt: {
1381 const TargetData &TD = *AP.TM.getTargetData();
1382 // Support only foldable casts to/from pointers that can be eliminated by
1383 // changing the pointer to the appropriately sized integer type.
1384 Constant *Op = CE->getOperand(0);
1385 const Type *Ty = CE->getType();
1387 const MCExpr *OpExpr = LowerConstant(Op, AP);
1389 // We can emit the pointer value into this slot if the slot is an
1390 // integer slot equal to the size of the pointer.
1391 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1394 // Otherwise the pointer is smaller than the resultant integer, mask off
1395 // the high bits so we are sure to get a proper truncation if the input is
1397 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1398 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1399 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1402 // The MC library also has a right-shift operator, but it isn't consistently
1403 // signed or unsigned between different targets.
1404 case Instruction::Add:
1405 case Instruction::Sub:
1406 case Instruction::Mul:
1407 case Instruction::SDiv:
1408 case Instruction::SRem:
1409 case Instruction::Shl:
1410 case Instruction::And:
1411 case Instruction::Or:
1412 case Instruction::Xor: {
1413 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1414 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1415 switch (CE->getOpcode()) {
1416 default: llvm_unreachable("Unknown binary operator constant cast expr");
1417 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1418 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1419 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1420 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1421 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1422 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1423 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1424 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1425 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1431 static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace,
1434 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1436 if (AddrSpace != 0 || !CA->isString()) {
1437 // Not a string. Print the values in successive locations
1438 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1439 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP);
1443 // Otherwise, it can be emitted as .ascii.
1444 SmallVector<char, 128> TmpVec;
1445 TmpVec.reserve(CA->getNumOperands());
1446 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1447 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1449 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1452 static void EmitGlobalConstantVector(const ConstantVector *CV,
1453 unsigned AddrSpace, AsmPrinter &AP) {
1454 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1455 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP);
1458 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1459 unsigned AddrSpace, AsmPrinter &AP) {
1460 // Print the fields in successive locations. Pad to align if needed!
1461 const TargetData *TD = AP.TM.getTargetData();
1462 unsigned Size = TD->getTypeAllocSize(CS->getType());
1463 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1464 uint64_t SizeSoFar = 0;
1465 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1466 const Constant *Field = CS->getOperand(i);
1468 // Check if padding is needed and insert one or more 0s.
1469 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1470 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1471 - Layout->getElementOffset(i)) - FieldSize;
1472 SizeSoFar += FieldSize + PadSize;
1474 // Now print the actual field value.
1475 EmitGlobalConstantImpl(Field, AddrSpace, AP);
1477 // Insert padding - this may include padding to increase the size of the
1478 // current field up to the ABI size (if the struct is not packed) as well
1479 // as padding to ensure that the next field starts at the right offset.
1480 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1482 assert(SizeSoFar == Layout->getSizeInBytes() &&
1483 "Layout of constant struct may be incorrect!");
1486 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1488 // FP Constants are printed as integer constants to avoid losing
1490 if (CFP->getType()->isDoubleTy()) {
1491 if (AP.isVerbose()) {
1492 double Val = CFP->getValueAPF().convertToDouble();
1493 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1496 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1497 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1501 if (CFP->getType()->isFloatTy()) {
1502 if (AP.isVerbose()) {
1503 float Val = CFP->getValueAPF().convertToFloat();
1504 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1506 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1507 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1511 if (CFP->getType()->isX86_FP80Ty()) {
1512 // all long double variants are printed as hex
1513 // API needed to prevent premature destruction
1514 APInt API = CFP->getValueAPF().bitcastToAPInt();
1515 const uint64_t *p = API.getRawData();
1516 if (AP.isVerbose()) {
1517 // Convert to double so we can print the approximate val as a comment.
1518 APFloat DoubleVal = CFP->getValueAPF();
1520 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1522 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1523 << DoubleVal.convertToDouble() << '\n';
1526 if (AP.TM.getTargetData()->isBigEndian()) {
1527 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1528 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1530 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1531 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1534 // Emit the tail padding for the long double.
1535 const TargetData &TD = *AP.TM.getTargetData();
1536 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1537 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1541 assert(CFP->getType()->isPPC_FP128Ty() &&
1542 "Floating point constant type not handled");
1543 // All long double variants are printed as hex
1544 // API needed to prevent premature destruction.
1545 APInt API = CFP->getValueAPF().bitcastToAPInt();
1546 const uint64_t *p = API.getRawData();
1547 if (AP.TM.getTargetData()->isBigEndian()) {
1548 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1549 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1551 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1552 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1556 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1557 unsigned AddrSpace, AsmPrinter &AP) {
1558 const TargetData *TD = AP.TM.getTargetData();
1559 unsigned BitWidth = CI->getBitWidth();
1560 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1562 // We don't expect assemblers to support integer data directives
1563 // for more than 64 bits, so we emit the data in at most 64-bit
1564 // quantities at a time.
1565 const uint64_t *RawData = CI->getValue().getRawData();
1566 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1567 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1568 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1572 static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
1574 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1575 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1576 return AP.OutStreamer.EmitZeros(Size, AddrSpace);
1579 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1580 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1587 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1588 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1591 EmitGlobalConstantLargeInt(CI, AddrSpace, AP);
1596 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1597 return EmitGlobalConstantArray(CVA, AddrSpace, AP);
1599 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1600 return EmitGlobalConstantStruct(CVS, AddrSpace, AP);
1602 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1603 return EmitGlobalConstantFP(CFP, AddrSpace, AP);
1605 if (isa<ConstantPointerNull>(CV)) {
1606 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1607 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace);
1611 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1612 return EmitGlobalConstantVector(V, AddrSpace, AP);
1614 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1615 // thread the streamer with EmitValue.
1616 AP.OutStreamer.EmitValue(LowerConstant(CV, AP),
1617 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()),
1621 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1622 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1623 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1625 EmitGlobalConstantImpl(CV, AddrSpace, *this);
1626 else if (MAI->hasSubsectionsViaSymbols()) {
1627 // If the global has zero size, emit a single byte so that two labels don't
1628 // look like they are at the same location.
1629 OutStreamer.EmitIntValue(0, 1, AddrSpace);
1633 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1634 // Target doesn't support this yet!
1635 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1638 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1640 OS << '+' << Offset;
1641 else if (Offset < 0)
1645 //===----------------------------------------------------------------------===//
1646 // Symbol Lowering Routines.
1647 //===----------------------------------------------------------------------===//
1649 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1650 /// temporary label with the specified stem and unique ID.
1651 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1652 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1656 /// GetTempSymbol - Return an assembler temporary label with the specified
1658 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1659 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1664 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1665 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1668 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1669 return MMI->getAddrLabelSymbol(BB);
1672 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1673 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1674 return OutContext.GetOrCreateSymbol
1675 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1676 + "_" + Twine(CPID));
1679 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1680 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1681 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1684 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1685 /// FIXME: privatize to AsmPrinter.
1686 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1687 return OutContext.GetOrCreateSymbol
1688 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1689 Twine(UID) + "_set_" + Twine(MBBID));
1692 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1693 /// global value name as its base, with the specified suffix, and where the
1694 /// symbol is forced to have private linkage if ForcePrivate is true.
1695 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1697 bool ForcePrivate) const {
1698 SmallString<60> NameStr;
1699 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1700 NameStr.append(Suffix.begin(), Suffix.end());
1701 return OutContext.GetOrCreateSymbol(NameStr.str());
1704 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1706 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1707 SmallString<60> NameStr;
1708 Mang->getNameWithPrefix(NameStr, Sym);
1709 return OutContext.GetOrCreateSymbol(NameStr.str());
1714 /// PrintParentLoopComment - Print comments about parent loops of this one.
1715 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1716 unsigned FunctionNumber) {
1717 if (Loop == 0) return;
1718 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1719 OS.indent(Loop->getLoopDepth()*2)
1720 << "Parent Loop BB" << FunctionNumber << "_"
1721 << Loop->getHeader()->getNumber()
1722 << " Depth=" << Loop->getLoopDepth() << '\n';
1726 /// PrintChildLoopComment - Print comments about child loops within
1727 /// the loop for this basic block, with nesting.
1728 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1729 unsigned FunctionNumber) {
1730 // Add child loop information
1731 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1732 OS.indent((*CL)->getLoopDepth()*2)
1733 << "Child Loop BB" << FunctionNumber << "_"
1734 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1736 PrintChildLoopComment(OS, *CL, FunctionNumber);
1740 /// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks.
1741 static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB,
1742 const MachineLoopInfo *LI,
1743 const AsmPrinter &AP) {
1744 // Add loop depth information
1745 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1746 if (Loop == 0) return;
1748 MachineBasicBlock *Header = Loop->getHeader();
1749 assert(Header && "No header for loop");
1751 // If this block is not a loop header, just print out what is the loop header
1753 if (Header != &MBB) {
1754 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1755 Twine(AP.getFunctionNumber())+"_" +
1756 Twine(Loop->getHeader()->getNumber())+
1757 " Depth="+Twine(Loop->getLoopDepth()));
1761 // Otherwise, it is a loop header. Print out information about child and
1763 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1765 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1768 OS.indent(Loop->getLoopDepth()*2-2);
1773 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1775 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1779 /// EmitBasicBlockStart - This method prints the label for the specified
1780 /// MachineBasicBlock, an alignment (if present) and a comment describing
1781 /// it if appropriate.
1782 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1783 // Emit an alignment directive for this block, if needed.
1784 if (unsigned Align = MBB->getAlignment())
1785 EmitAlignment(Log2_32(Align));
1787 // If the block has its address taken, emit any labels that were used to
1788 // reference the block. It is possible that there is more than one label
1789 // here, because multiple LLVM BB's may have been RAUW'd to this block after
1790 // the references were generated.
1791 if (MBB->hasAddressTaken()) {
1792 const BasicBlock *BB = MBB->getBasicBlock();
1794 OutStreamer.AddComment("Block address taken");
1796 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1798 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1799 OutStreamer.EmitLabel(Syms[i]);
1802 // Print the main label for the block.
1803 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1804 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
1805 if (const BasicBlock *BB = MBB->getBasicBlock())
1807 OutStreamer.AddComment("%" + BB->getName());
1809 EmitBasicBlockLoopComments(*MBB, LI, *this);
1811 // NOTE: Want this comment at start of line, don't emit with AddComment.
1812 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1813 Twine(MBB->getNumber()) + ":");
1817 if (const BasicBlock *BB = MBB->getBasicBlock())
1819 OutStreamer.AddComment("%" + BB->getName());
1820 EmitBasicBlockLoopComments(*MBB, LI, *this);
1823 OutStreamer.EmitLabel(MBB->getSymbol());
1827 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
1828 bool IsDefinition) const {
1829 MCSymbolAttr Attr = MCSA_Invalid;
1831 switch (Visibility) {
1833 case GlobalValue::HiddenVisibility:
1835 Attr = MAI->getHiddenVisibilityAttr();
1837 Attr = MAI->getHiddenDeclarationVisibilityAttr();
1839 case GlobalValue::ProtectedVisibility:
1840 Attr = MAI->getProtectedVisibilityAttr();
1844 if (Attr != MCSA_Invalid)
1845 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1848 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1849 /// exactly one predecessor and the control transfer mechanism between
1850 /// the predecessor and this block is a fall-through.
1852 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1853 // If this is a landing pad, it isn't a fall through. If it has no preds,
1854 // then nothing falls through to it.
1855 if (MBB->isLandingPad() || MBB->pred_empty())
1858 // If there isn't exactly one predecessor, it can't be a fall through.
1859 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1861 if (PI2 != MBB->pred_end())
1864 // The predecessor has to be immediately before this block.
1865 const MachineBasicBlock *Pred = *PI;
1867 if (!Pred->isLayoutSuccessor(MBB))
1870 // If the block is completely empty, then it definitely does fall through.
1874 // Otherwise, check the last instruction.
1875 const MachineInstr &LastInst = Pred->back();
1876 return !LastInst.getDesc().isBarrier();
1881 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1882 if (!S->usesMetadata())
1885 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1886 gcp_map_type::iterator GCPI = GCMap.find(S);
1887 if (GCPI != GCMap.end())
1888 return GCPI->second;
1890 const char *Name = S->getName().c_str();
1892 for (GCMetadataPrinterRegistry::iterator
1893 I = GCMetadataPrinterRegistry::begin(),
1894 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1895 if (strcmp(Name, I->getName()) == 0) {
1896 GCMetadataPrinter *GMP = I->instantiate();
1898 GCMap.insert(std::make_pair(S, GMP));
1902 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));