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);
204 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
205 switch ((GlobalValue::LinkageTypes)Linkage) {
206 case GlobalValue::CommonLinkage:
207 case GlobalValue::LinkOnceAnyLinkage:
208 case GlobalValue::LinkOnceODRLinkage:
209 case GlobalValue::WeakAnyLinkage:
210 case GlobalValue::WeakODRLinkage:
211 case GlobalValue::LinkerPrivateWeakLinkage:
212 case GlobalValue::LinkerPrivateWeakDefAutoLinkage:
213 if (MAI->getWeakDefDirective() != 0) {
215 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
217 if ((GlobalValue::LinkageTypes)Linkage !=
218 GlobalValue::LinkerPrivateWeakDefAutoLinkage)
219 // .weak_definition _foo
220 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
222 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
223 } else if (MAI->getLinkOnceDirective() != 0) {
225 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
226 //NOTE: linkonce is handled by the section the symbol was assigned to.
229 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
232 case GlobalValue::DLLExportLinkage:
233 case GlobalValue::AppendingLinkage:
234 // FIXME: appending linkage variables should go into a section of
235 // their name or something. For now, just emit them as external.
236 case GlobalValue::ExternalLinkage:
237 // If external or appending, declare as a global symbol.
239 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
241 case GlobalValue::PrivateLinkage:
242 case GlobalValue::InternalLinkage:
243 case GlobalValue::LinkerPrivateLinkage:
246 llvm_unreachable("Unknown linkage type!");
251 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
252 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
253 if (!GV->hasInitializer()) // External globals require no code.
256 // Check to see if this is a special global used by LLVM, if so, emit it.
257 if (EmitSpecialLLVMGlobal(GV))
261 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
262 /*PrintType=*/false, GV->getParent());
263 OutStreamer.GetCommentOS() << '\n';
266 MCSymbol *GVSym = Mang->getSymbol(GV);
267 EmitVisibility(GVSym, GV->getVisibility());
269 if (MAI->hasDotTypeDotSizeDirective())
270 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
272 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
274 const TargetData *TD = TM.getTargetData();
275 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType());
277 // If the alignment is specified, we *must* obey it. Overaligning a global
278 // with a specified alignment is a prompt way to break globals emitted to
279 // sections and expected to be contiguous (e.g. ObjC metadata).
280 unsigned AlignLog = getGVAlignmentLog2(GV, *TD);
282 // Handle common and BSS local symbols (.lcomm).
283 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
284 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
287 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
288 /*PrintType=*/false, GV->getParent());
289 OutStreamer.GetCommentOS() << '\n';
292 // Handle common symbols.
293 if (GVKind.isCommon()) {
294 unsigned Align = 1 << AlignLog;
295 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
299 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
303 // Handle local BSS symbols.
304 if (MAI->hasMachoZeroFillDirective()) {
305 const MCSection *TheSection =
306 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
307 // .zerofill __DATA, __bss, _foo, 400, 5
308 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
312 if (MAI->hasLCOMMDirective()) {
314 OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
318 unsigned Align = 1 << AlignLog;
319 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
323 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
325 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
329 const MCSection *TheSection =
330 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
332 // Handle the zerofill directive on darwin, which is a special form of BSS
334 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
335 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
338 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
339 // .zerofill __DATA, __common, _foo, 400, 5
340 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
344 // Handle thread local data for mach-o which requires us to output an
345 // additional structure of data and mangle the original symbol so that we
346 // can reference it later.
348 // TODO: This should become an "emit thread local global" method on TLOF.
349 // All of this macho specific stuff should be sunk down into TLOFMachO and
350 // stuff like "TLSExtraDataSection" should no longer be part of the parent
351 // TLOF class. This will also make it more obvious that stuff like
352 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
354 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
355 // Emit the .tbss symbol
357 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
359 if (GVKind.isThreadBSS())
360 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
361 else if (GVKind.isThreadData()) {
362 OutStreamer.SwitchSection(TheSection);
364 EmitAlignment(AlignLog, GV);
365 OutStreamer.EmitLabel(MangSym);
367 EmitGlobalConstant(GV->getInitializer());
370 OutStreamer.AddBlankLine();
372 // Emit the variable struct for the runtime.
373 const MCSection *TLVSect
374 = getObjFileLowering().getTLSExtraDataSection();
376 OutStreamer.SwitchSection(TLVSect);
377 // Emit the linkage here.
378 EmitLinkage(GV->getLinkage(), GVSym);
379 OutStreamer.EmitLabel(GVSym);
381 // Three pointers in size:
382 // - __tlv_bootstrap - used to make sure support exists
383 // - spare pointer, used when mapped by the runtime
384 // - pointer to mangled symbol above with initializer
385 unsigned PtrSize = TD->getPointerSizeInBits()/8;
386 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
388 OutStreamer.EmitIntValue(0, PtrSize, 0);
389 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0);
391 OutStreamer.AddBlankLine();
395 OutStreamer.SwitchSection(TheSection);
397 EmitLinkage(GV->getLinkage(), GVSym);
398 EmitAlignment(AlignLog, GV);
400 OutStreamer.EmitLabel(GVSym);
402 EmitGlobalConstant(GV->getInitializer());
404 if (MAI->hasDotTypeDotSizeDirective())
406 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
408 OutStreamer.AddBlankLine();
411 /// EmitFunctionHeader - This method emits the header for the current
413 void AsmPrinter::EmitFunctionHeader() {
414 // Print out constants referenced by the function
417 // Print the 'header' of function.
418 const Function *F = MF->getFunction();
420 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
421 EmitVisibility(CurrentFnSym, F->getVisibility());
423 EmitLinkage(F->getLinkage(), CurrentFnSym);
424 EmitAlignment(MF->getAlignment(), F);
426 if (MAI->hasDotTypeDotSizeDirective())
427 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
430 WriteAsOperand(OutStreamer.GetCommentOS(), F,
431 /*PrintType=*/false, F->getParent());
432 OutStreamer.GetCommentOS() << '\n';
435 // Emit the CurrentFnSym. This is a virtual function to allow targets to
436 // do their wild and crazy things as required.
437 EmitFunctionEntryLabel();
439 // If the function had address-taken blocks that got deleted, then we have
440 // references to the dangling symbols. Emit them at the start of the function
441 // so that we don't get references to undefined symbols.
442 std::vector<MCSymbol*> DeadBlockSyms;
443 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
444 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
445 OutStreamer.AddComment("Address taken block that was later removed");
446 OutStreamer.EmitLabel(DeadBlockSyms[i]);
449 // Add some workaround for linkonce linkage on Cygwin\MinGW.
450 if (MAI->getLinkOnceDirective() != 0 &&
451 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
452 // FIXME: What is this?
454 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
455 CurrentFnSym->getName());
456 OutStreamer.EmitLabel(FakeStub);
459 // Emit pre-function debug and/or EH information.
461 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
462 DE->BeginFunction(MF);
465 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
466 DD->beginFunction(MF);
470 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
471 /// function. This can be overridden by targets as required to do custom stuff.
472 void AsmPrinter::EmitFunctionEntryLabel() {
473 // The function label could have already been emitted if two symbols end up
474 // conflicting due to asm renaming. Detect this and emit an error.
475 if (CurrentFnSym->isUndefined())
476 return OutStreamer.EmitLabel(CurrentFnSym);
478 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
479 "' label emitted multiple times to assembly file");
483 static void EmitDebugLoc(DebugLoc DL, const MachineFunction *MF,
484 raw_ostream &CommentOS) {
485 const LLVMContext &Ctx = MF->getFunction()->getContext();
486 if (!DL.isUnknown()) { // Print source line info.
487 DIScope Scope(DL.getScope(Ctx));
488 // Omit the directory, because it's likely to be long and uninteresting.
490 CommentOS << Scope.getFilename();
492 CommentOS << "<unknown>";
493 CommentOS << ':' << DL.getLine();
494 if (DL.getCol() != 0)
495 CommentOS << ':' << DL.getCol();
496 DebugLoc InlinedAtDL = DebugLoc::getFromDILocation(DL.getInlinedAt(Ctx));
497 if (!InlinedAtDL.isUnknown()) {
499 EmitDebugLoc(InlinedAtDL, MF, CommentOS);
505 /// EmitComments - Pretty-print comments for instructions.
506 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
507 const MachineFunction *MF = MI.getParent()->getParent();
508 const TargetMachine &TM = MF->getTarget();
510 DebugLoc DL = MI.getDebugLoc();
511 if (!DL.isUnknown()) { // Print source line info.
512 EmitDebugLoc(DL, MF, CommentOS);
516 // Check for spills and reloads
519 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
521 // We assume a single instruction only has a spill or reload, not
523 const MachineMemOperand *MMO;
524 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
525 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
526 MMO = *MI.memoperands_begin();
527 CommentOS << MMO->getSize() << "-byte Reload\n";
529 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
530 if (FrameInfo->isSpillSlotObjectIndex(FI))
531 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
532 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
533 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
534 MMO = *MI.memoperands_begin();
535 CommentOS << MMO->getSize() << "-byte Spill\n";
537 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
538 if (FrameInfo->isSpillSlotObjectIndex(FI))
539 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
542 // Check for spill-induced copies
543 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
544 CommentOS << " Reload Reuse\n";
547 /// EmitImplicitDef - This method emits the specified machine instruction
548 /// that is an implicit def.
549 static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
550 unsigned RegNo = MI->getOperand(0).getReg();
551 AP.OutStreamer.AddComment(Twine("implicit-def: ") +
552 AP.TM.getRegisterInfo()->getName(RegNo));
553 AP.OutStreamer.AddBlankLine();
556 static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) {
557 std::string Str = "kill:";
558 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
559 const MachineOperand &Op = MI->getOperand(i);
560 assert(Op.isReg() && "KILL instruction must have only register operands");
562 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
563 Str += (Op.isDef() ? "<def>" : "<kill>");
565 AP.OutStreamer.AddComment(Str);
566 AP.OutStreamer.AddBlankLine();
569 /// EmitDebugValueComment - This method handles the target-independent form
570 /// of DBG_VALUE, returning true if it was able to do so. A false return
571 /// means the target will need to handle MI in EmitInstruction.
572 static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
573 // This code handles only the 3-operand target-independent form.
574 if (MI->getNumOperands() != 3)
577 SmallString<128> Str;
578 raw_svector_ostream OS(Str);
579 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
581 // cast away const; DIetc do not take const operands for some reason.
582 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
583 if (V.getContext().isSubprogram())
584 OS << DISubprogram(V.getContext()).getDisplayName() << ":";
585 OS << V.getName() << " <- ";
587 // Register or immediate value. Register 0 means undef.
588 if (MI->getOperand(0).isFPImm()) {
589 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
590 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
591 OS << (double)APF.convertToFloat();
592 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
593 OS << APF.convertToDouble();
595 // There is no good way to print long double. Convert a copy to
596 // double. Ah well, it's only a comment.
598 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
600 OS << "(long double) " << APF.convertToDouble();
602 } else if (MI->getOperand(0).isImm()) {
603 OS << MI->getOperand(0).getImm();
605 assert(MI->getOperand(0).isReg() && "Unknown operand type");
606 if (MI->getOperand(0).getReg() == 0) {
607 // Suppress offset, it is not meaningful here.
609 // NOTE: Want this comment at start of line, don't emit with AddComment.
610 AP.OutStreamer.EmitRawText(OS.str());
613 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg());
616 OS << '+' << MI->getOperand(1).getImm();
617 // NOTE: Want this comment at start of line, don't emit with AddComment.
618 AP.OutStreamer.EmitRawText(OS.str());
622 /// EmitFunctionBody - This method emits the body and trailer for a
624 void AsmPrinter::EmitFunctionBody() {
625 // Emit target-specific gunk before the function body.
626 EmitFunctionBodyStart();
628 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
630 // Print out code for the function.
631 bool HasAnyRealCode = false;
632 const MachineInstr *LastMI = 0;
633 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
635 // Print a label for the basic block.
636 EmitBasicBlockStart(I);
637 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
641 // Print the assembly for the instruction.
642 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
643 !II->isDebugValue()) {
644 HasAnyRealCode = true;
648 if (ShouldPrintDebugScopes) {
649 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
650 DD->beginInstruction(II);
654 EmitComments(*II, OutStreamer.GetCommentOS());
656 switch (II->getOpcode()) {
657 case TargetOpcode::PROLOG_LABEL:
658 case TargetOpcode::EH_LABEL:
659 case TargetOpcode::GC_LABEL:
660 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
662 case TargetOpcode::INLINEASM:
665 case TargetOpcode::DBG_VALUE:
667 if (!EmitDebugValueComment(II, *this))
671 case TargetOpcode::IMPLICIT_DEF:
672 if (isVerbose()) EmitImplicitDef(II, *this);
674 case TargetOpcode::KILL:
675 if (isVerbose()) EmitKill(II, *this);
682 if (ShouldPrintDebugScopes) {
683 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
684 DD->endInstruction(II);
689 // If the last instruction was a prolog label, then we have a situation where
690 // we emitted a prolog but no function body. This results in the ending prolog
691 // label equaling the end of function label and an invalid "row" in the
692 // FDE. We need to emit a noop in this situation so that the FDE's rows are
694 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
696 // If the function is empty and the object file uses .subsections_via_symbols,
697 // then we need to emit *something* to the function body to prevent the
698 // labels from collapsing together. Just emit a noop.
699 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
701 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
702 if (Noop.getOpcode()) {
703 OutStreamer.AddComment("avoids zero-length function");
704 OutStreamer.EmitInstruction(Noop);
705 } else // Target not mc-ized yet.
706 OutStreamer.EmitRawText(StringRef("\tnop\n"));
709 // Emit target-specific gunk after the function body.
710 EmitFunctionBodyEnd();
712 // If the target wants a .size directive for the size of the function, emit
714 if (MAI->hasDotTypeDotSizeDirective()) {
715 // Create a symbol for the end of function, so we can get the size as
716 // difference between the function label and the temp label.
717 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
718 OutStreamer.EmitLabel(FnEndLabel);
720 const MCExpr *SizeExp =
721 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
722 MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
724 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
727 // Emit post-function debug information.
729 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
733 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
738 // Print out jump tables referenced by the function.
741 OutStreamer.AddBlankLine();
744 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
746 MachineLocation AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const {
747 // Target specific DBG_VALUE instructions are handled by each target.
748 return MachineLocation();
751 bool AsmPrinter::doFinalization(Module &M) {
752 // Emit global variables.
753 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
755 EmitGlobalVariable(I);
757 // Emit visibility info for declarations
758 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
759 const Function &F = *I;
760 if (!F.isDeclaration())
762 GlobalValue::VisibilityTypes V = F.getVisibility();
763 if (V == GlobalValue::DefaultVisibility)
766 MCSymbol *Name = Mang->getSymbol(&F);
767 EmitVisibility(Name, V);
770 // Finalize debug and EH information.
773 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
780 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
786 // If the target wants to know about weak references, print them all.
787 if (MAI->getWeakRefDirective()) {
788 // FIXME: This is not lazy, it would be nice to only print weak references
789 // to stuff that is actually used. Note that doing so would require targets
790 // to notice uses in operands (due to constant exprs etc). This should
791 // happen with the MC stuff eventually.
793 // Print out module-level global variables here.
794 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
796 if (!I->hasExternalWeakLinkage()) continue;
797 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
800 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
801 if (!I->hasExternalWeakLinkage()) continue;
802 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
806 if (MAI->hasSetDirective()) {
807 OutStreamer.AddBlankLine();
808 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
810 MCSymbol *Name = Mang->getSymbol(I);
812 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
813 MCSymbol *Target = Mang->getSymbol(GV);
815 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
816 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
817 else if (I->hasWeakLinkage())
818 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
820 assert(I->hasLocalLinkage() && "Invalid alias linkage");
822 EmitVisibility(Name, I->getVisibility());
824 // Emit the directives as assignments aka .set:
825 OutStreamer.EmitAssignment(Name,
826 MCSymbolRefExpr::Create(Target, OutContext));
830 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
831 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
832 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
833 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
834 MP->finishAssembly(*this);
836 // If we don't have any trampolines, then we don't require stack memory
837 // to be executable. Some targets have a directive to declare this.
838 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
839 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
840 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
841 OutStreamer.SwitchSection(S);
843 // Allow the target to emit any magic that it wants at the end of the file,
844 // after everything else has gone out.
847 delete Mang; Mang = 0;
850 OutStreamer.Finish();
854 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
856 // Get the function symbol.
857 CurrentFnSym = Mang->getSymbol(MF.getFunction());
860 LI = &getAnalysis<MachineLoopInfo>();
864 // SectionCPs - Keep track the alignment, constpool entries per Section.
868 SmallVector<unsigned, 4> CPEs;
869 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
873 /// EmitConstantPool - Print to the current output stream assembly
874 /// representations of the constants in the constant pool MCP. This is
875 /// used to print out constants which have been "spilled to memory" by
876 /// the code generator.
878 void AsmPrinter::EmitConstantPool() {
879 const MachineConstantPool *MCP = MF->getConstantPool();
880 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
881 if (CP.empty()) return;
883 // Calculate sections for constant pool entries. We collect entries to go into
884 // the same section together to reduce amount of section switch statements.
885 SmallVector<SectionCPs, 4> CPSections;
886 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
887 const MachineConstantPoolEntry &CPE = CP[i];
888 unsigned Align = CPE.getAlignment();
891 switch (CPE.getRelocationInfo()) {
892 default: llvm_unreachable("Unknown section kind");
893 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
895 Kind = SectionKind::getReadOnlyWithRelLocal();
898 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
899 case 4: Kind = SectionKind::getMergeableConst4(); break;
900 case 8: Kind = SectionKind::getMergeableConst8(); break;
901 case 16: Kind = SectionKind::getMergeableConst16();break;
902 default: Kind = SectionKind::getMergeableConst(); break;
906 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
908 // The number of sections are small, just do a linear search from the
909 // last section to the first.
911 unsigned SecIdx = CPSections.size();
912 while (SecIdx != 0) {
913 if (CPSections[--SecIdx].S == S) {
919 SecIdx = CPSections.size();
920 CPSections.push_back(SectionCPs(S, Align));
923 if (Align > CPSections[SecIdx].Alignment)
924 CPSections[SecIdx].Alignment = Align;
925 CPSections[SecIdx].CPEs.push_back(i);
928 // Now print stuff into the calculated sections.
929 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
930 OutStreamer.SwitchSection(CPSections[i].S);
931 EmitAlignment(Log2_32(CPSections[i].Alignment));
934 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
935 unsigned CPI = CPSections[i].CPEs[j];
936 MachineConstantPoolEntry CPE = CP[CPI];
938 // Emit inter-object padding for alignment.
939 unsigned AlignMask = CPE.getAlignment() - 1;
940 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
941 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
943 const Type *Ty = CPE.getType();
944 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
945 OutStreamer.EmitLabel(GetCPISymbol(CPI));
947 if (CPE.isMachineConstantPoolEntry())
948 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
950 EmitGlobalConstant(CPE.Val.ConstVal);
955 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
956 /// by the current function to the current output stream.
958 void AsmPrinter::EmitJumpTableInfo() {
959 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
960 if (MJTI == 0) return;
961 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
962 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
963 if (JT.empty()) return;
965 // Pick the directive to use to print the jump table entries, and switch to
966 // the appropriate section.
967 const Function *F = MF->getFunction();
968 bool JTInDiffSection = false;
969 if (// In PIC mode, we need to emit the jump table to the same section as the
970 // function body itself, otherwise the label differences won't make sense.
971 // FIXME: Need a better predicate for this: what about custom entries?
972 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
973 // We should also do if the section name is NULL or function is declared
974 // in discardable section
975 // FIXME: this isn't the right predicate, should be based on the MCSection
977 F->isWeakForLinker()) {
978 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
980 // Otherwise, drop it in the readonly section.
981 const MCSection *ReadOnlySection =
982 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
983 OutStreamer.SwitchSection(ReadOnlySection);
984 JTInDiffSection = true;
987 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
989 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
990 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
992 // If this jump table was deleted, ignore it.
993 if (JTBBs.empty()) continue;
995 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
996 // .set directive for each unique entry. This reduces the number of
997 // relocations the assembler will generate for the jump table.
998 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
999 MAI->hasSetDirective()) {
1000 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1001 const TargetLowering *TLI = TM.getTargetLowering();
1002 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1003 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1004 const MachineBasicBlock *MBB = JTBBs[ii];
1005 if (!EmittedSets.insert(MBB)) continue;
1007 // .set LJTSet, LBB32-base
1009 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1010 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1011 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1015 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1016 // before each jump table. The first label is never referenced, but tells
1017 // the assembler and linker the extents of the jump table object. The
1018 // second label is actually referenced by the code.
1019 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1020 // FIXME: This doesn't have to have any specific name, just any randomly
1021 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1022 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1024 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1026 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1027 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1031 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1033 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1034 const MachineBasicBlock *MBB,
1035 unsigned UID) const {
1036 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1037 const MCExpr *Value = 0;
1038 switch (MJTI->getEntryKind()) {
1039 case MachineJumpTableInfo::EK_Inline:
1040 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
1041 case MachineJumpTableInfo::EK_Custom32:
1042 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1045 case MachineJumpTableInfo::EK_BlockAddress:
1046 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1048 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1050 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1051 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1052 // with a relocation as gp-relative, e.g.:
1054 MCSymbol *MBBSym = MBB->getSymbol();
1055 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1059 case MachineJumpTableInfo::EK_LabelDifference32: {
1060 // EK_LabelDifference32 - Each entry is the address of the block minus
1061 // the address of the jump table. This is used for PIC jump tables where
1062 // gprel32 is not supported. e.g.:
1063 // .word LBB123 - LJTI1_2
1064 // If the .set directive is supported, this is emitted as:
1065 // .set L4_5_set_123, LBB123 - LJTI1_2
1066 // .word L4_5_set_123
1068 // If we have emitted set directives for the jump table entries, print
1069 // them rather than the entries themselves. If we're emitting PIC, then
1070 // emit the table entries as differences between two text section labels.
1071 if (MAI->hasSetDirective()) {
1072 // If we used .set, reference the .set's symbol.
1073 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1077 // Otherwise, use the difference as the jump table entry.
1078 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1079 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1080 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1085 assert(Value && "Unknown entry kind!");
1087 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
1088 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
1092 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1093 /// special global used by LLVM. If so, emit it and return true, otherwise
1094 /// do nothing and return false.
1095 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1096 if (GV->getName() == "llvm.used") {
1097 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1098 EmitLLVMUsedList(GV->getInitializer());
1102 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1103 if (GV->getSection() == "llvm.metadata" ||
1104 GV->hasAvailableExternallyLinkage())
1107 if (!GV->hasAppendingLinkage()) return false;
1109 assert(GV->hasInitializer() && "Not a special LLVM global!");
1111 const TargetData *TD = TM.getTargetData();
1112 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1113 if (GV->getName() == "llvm.global_ctors") {
1114 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
1115 EmitAlignment(Align);
1116 EmitXXStructorList(GV->getInitializer());
1118 if (TM.getRelocationModel() == Reloc::Static &&
1119 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1120 StringRef Sym(".constructors_used");
1121 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1127 if (GV->getName() == "llvm.global_dtors") {
1128 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
1129 EmitAlignment(Align);
1130 EmitXXStructorList(GV->getInitializer());
1132 if (TM.getRelocationModel() == Reloc::Static &&
1133 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1134 StringRef Sym(".destructors_used");
1135 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1144 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1145 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1146 /// is true, as being used with this directive.
1147 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
1148 // Should be an array of 'i8*'.
1149 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1150 if (InitList == 0) return;
1152 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1153 const GlobalValue *GV =
1154 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1155 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1156 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1160 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
1161 /// function pointers, ignoring the init priority.
1162 void AsmPrinter::EmitXXStructorList(Constant *List) {
1163 // Should be an array of '{ int, void ()* }' structs. The first value is the
1164 // init priority, which we ignore.
1165 if (!isa<ConstantArray>(List)) return;
1166 ConstantArray *InitList = cast<ConstantArray>(List);
1167 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
1168 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
1169 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
1171 if (CS->getOperand(1)->isNullValue())
1172 return; // Found a null terminator, exit printing.
1173 // Emit the function pointer.
1174 EmitGlobalConstant(CS->getOperand(1));
1178 //===--------------------------------------------------------------------===//
1179 // Emission and print routines
1182 /// EmitInt8 - Emit a byte directive and value.
1184 void AsmPrinter::EmitInt8(int Value) const {
1185 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
1188 /// EmitInt16 - Emit a short directive and value.
1190 void AsmPrinter::EmitInt16(int Value) const {
1191 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
1194 /// EmitInt32 - Emit a long directive and value.
1196 void AsmPrinter::EmitInt32(int Value) const {
1197 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
1200 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1201 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1202 /// labels. This implicitly uses .set if it is available.
1203 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1204 unsigned Size) const {
1205 // Get the Hi-Lo expression.
1206 const MCExpr *Diff =
1207 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1208 MCSymbolRefExpr::Create(Lo, OutContext),
1211 if (!MAI->hasSetDirective()) {
1212 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
1216 // Otherwise, emit with .set (aka assignment).
1217 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1218 OutStreamer.EmitAssignment(SetLabel, Diff);
1219 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
1222 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1223 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1224 /// specify the labels. This implicitly uses .set if it is available.
1225 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1226 const MCSymbol *Lo, unsigned Size)
1229 // Emit Hi+Offset - Lo
1230 // Get the Hi+Offset expression.
1231 const MCExpr *Plus =
1232 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1233 MCConstantExpr::Create(Offset, OutContext),
1236 // Get the Hi+Offset-Lo expression.
1237 const MCExpr *Diff =
1238 MCBinaryExpr::CreateSub(Plus,
1239 MCSymbolRefExpr::Create(Lo, OutContext),
1242 if (!MAI->hasSetDirective())
1243 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/);
1245 // Otherwise, emit with .set (aka assignment).
1246 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1247 OutStreamer.EmitAssignment(SetLabel, Diff);
1248 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/);
1252 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1253 /// where the size in bytes of the directive is specified by Size and Label
1254 /// specifies the label. This implicitly uses .set if it is available.
1255 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1259 // Emit Label+Offset
1260 const MCExpr *Plus =
1261 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext),
1262 MCConstantExpr::Create(Offset, OutContext),
1265 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/);
1269 //===----------------------------------------------------------------------===//
1271 // EmitAlignment - Emit an alignment directive to the specified power of
1272 // two boundary. For example, if you pass in 3 here, you will get an 8
1273 // byte alignment. If a global value is specified, and if that global has
1274 // an explicit alignment requested, it will override the alignment request
1275 // if required for correctness.
1277 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1278 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits);
1280 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1282 if (getCurrentSection()->getKind().isText())
1283 OutStreamer.EmitCodeAlignment(1 << NumBits);
1285 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1288 //===----------------------------------------------------------------------===//
1289 // Constant emission.
1290 //===----------------------------------------------------------------------===//
1292 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1294 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1295 MCContext &Ctx = AP.OutContext;
1297 if (CV->isNullValue() || isa<UndefValue>(CV))
1298 return MCConstantExpr::Create(0, Ctx);
1300 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1301 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1303 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1304 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1306 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1307 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1309 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1311 llvm_unreachable("Unknown constant value to lower!");
1312 return MCConstantExpr::Create(0, Ctx);
1315 switch (CE->getOpcode()) {
1317 // If the code isn't optimized, there may be outstanding folding
1318 // opportunities. Attempt to fold the expression using TargetData as a
1319 // last resort before giving up.
1321 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1323 return LowerConstant(C, AP);
1325 // Otherwise report the problem to the user.
1328 raw_string_ostream OS(S);
1329 OS << "Unsupported expression in static initializer: ";
1330 WriteAsOperand(OS, CE, /*PrintType=*/false,
1331 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1332 report_fatal_error(OS.str());
1334 return MCConstantExpr::Create(0, Ctx);
1335 case Instruction::GetElementPtr: {
1336 const TargetData &TD = *AP.TM.getTargetData();
1337 // Generate a symbolic expression for the byte address
1338 const Constant *PtrVal = CE->getOperand(0);
1339 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1340 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1343 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1347 // Truncate/sext the offset to the pointer size.
1348 if (TD.getPointerSizeInBits() != 64) {
1349 int SExtAmount = 64-TD.getPointerSizeInBits();
1350 Offset = (Offset << SExtAmount) >> SExtAmount;
1353 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1357 case Instruction::Trunc:
1358 // We emit the value and depend on the assembler to truncate the generated
1359 // expression properly. This is important for differences between
1360 // blockaddress labels. Since the two labels are in the same function, it
1361 // is reasonable to treat their delta as a 32-bit value.
1363 case Instruction::BitCast:
1364 return LowerConstant(CE->getOperand(0), AP);
1366 case Instruction::IntToPtr: {
1367 const TargetData &TD = *AP.TM.getTargetData();
1368 // Handle casts to pointers by changing them into casts to the appropriate
1369 // integer type. This promotes constant folding and simplifies this code.
1370 Constant *Op = CE->getOperand(0);
1371 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1373 return LowerConstant(Op, AP);
1376 case Instruction::PtrToInt: {
1377 const TargetData &TD = *AP.TM.getTargetData();
1378 // Support only foldable casts to/from pointers that can be eliminated by
1379 // changing the pointer to the appropriately sized integer type.
1380 Constant *Op = CE->getOperand(0);
1381 const Type *Ty = CE->getType();
1383 const MCExpr *OpExpr = LowerConstant(Op, AP);
1385 // We can emit the pointer value into this slot if the slot is an
1386 // integer slot equal to the size of the pointer.
1387 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1390 // Otherwise the pointer is smaller than the resultant integer, mask off
1391 // the high bits so we are sure to get a proper truncation if the input is
1393 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1394 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1395 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1398 // The MC library also has a right-shift operator, but it isn't consistently
1399 // signed or unsigned between different targets.
1400 case Instruction::Add:
1401 case Instruction::Sub:
1402 case Instruction::Mul:
1403 case Instruction::SDiv:
1404 case Instruction::SRem:
1405 case Instruction::Shl:
1406 case Instruction::And:
1407 case Instruction::Or:
1408 case Instruction::Xor: {
1409 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1410 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1411 switch (CE->getOpcode()) {
1412 default: llvm_unreachable("Unknown binary operator constant cast expr");
1413 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1414 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1415 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1416 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1417 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1418 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1419 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1420 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1421 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1427 static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace,
1430 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1432 if (AddrSpace != 0 || !CA->isString()) {
1433 // Not a string. Print the values in successive locations
1434 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1435 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP);
1439 // Otherwise, it can be emitted as .ascii.
1440 SmallVector<char, 128> TmpVec;
1441 TmpVec.reserve(CA->getNumOperands());
1442 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1443 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1445 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1448 static void EmitGlobalConstantVector(const ConstantVector *CV,
1449 unsigned AddrSpace, AsmPrinter &AP) {
1450 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1451 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP);
1454 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1455 unsigned AddrSpace, AsmPrinter &AP) {
1456 // Print the fields in successive locations. Pad to align if needed!
1457 const TargetData *TD = AP.TM.getTargetData();
1458 unsigned Size = TD->getTypeAllocSize(CS->getType());
1459 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1460 uint64_t SizeSoFar = 0;
1461 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1462 const Constant *Field = CS->getOperand(i);
1464 // Check if padding is needed and insert one or more 0s.
1465 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1466 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1467 - Layout->getElementOffset(i)) - FieldSize;
1468 SizeSoFar += FieldSize + PadSize;
1470 // Now print the actual field value.
1471 EmitGlobalConstantImpl(Field, AddrSpace, AP);
1473 // Insert padding - this may include padding to increase the size of the
1474 // current field up to the ABI size (if the struct is not packed) as well
1475 // as padding to ensure that the next field starts at the right offset.
1476 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1478 assert(SizeSoFar == Layout->getSizeInBytes() &&
1479 "Layout of constant struct may be incorrect!");
1482 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1484 // FP Constants are printed as integer constants to avoid losing
1486 if (CFP->getType()->isDoubleTy()) {
1487 if (AP.isVerbose()) {
1488 double Val = CFP->getValueAPF().convertToDouble();
1489 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1492 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1493 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1497 if (CFP->getType()->isFloatTy()) {
1498 if (AP.isVerbose()) {
1499 float Val = CFP->getValueAPF().convertToFloat();
1500 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1502 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1503 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1507 if (CFP->getType()->isX86_FP80Ty()) {
1508 // all long double variants are printed as hex
1509 // API needed to prevent premature destruction
1510 APInt API = CFP->getValueAPF().bitcastToAPInt();
1511 const uint64_t *p = API.getRawData();
1512 if (AP.isVerbose()) {
1513 // Convert to double so we can print the approximate val as a comment.
1514 APFloat DoubleVal = CFP->getValueAPF();
1516 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1518 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1519 << DoubleVal.convertToDouble() << '\n';
1522 if (AP.TM.getTargetData()->isBigEndian()) {
1523 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1524 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1526 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1527 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1530 // Emit the tail padding for the long double.
1531 const TargetData &TD = *AP.TM.getTargetData();
1532 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1533 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1537 assert(CFP->getType()->isPPC_FP128Ty() &&
1538 "Floating point constant type not handled");
1539 // All long double variants are printed as hex
1540 // API needed to prevent premature destruction.
1541 APInt API = CFP->getValueAPF().bitcastToAPInt();
1542 const uint64_t *p = API.getRawData();
1543 if (AP.TM.getTargetData()->isBigEndian()) {
1544 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1545 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1547 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1548 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1552 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1553 unsigned AddrSpace, AsmPrinter &AP) {
1554 const TargetData *TD = AP.TM.getTargetData();
1555 unsigned BitWidth = CI->getBitWidth();
1556 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1558 // We don't expect assemblers to support integer data directives
1559 // for more than 64 bits, so we emit the data in at most 64-bit
1560 // quantities at a time.
1561 const uint64_t *RawData = CI->getValue().getRawData();
1562 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1563 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1564 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1568 static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
1570 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1571 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1572 return AP.OutStreamer.EmitZeros(Size, AddrSpace);
1575 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1576 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1583 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1584 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1587 EmitGlobalConstantLargeInt(CI, AddrSpace, AP);
1592 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1593 return EmitGlobalConstantArray(CVA, AddrSpace, AP);
1595 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1596 return EmitGlobalConstantStruct(CVS, AddrSpace, AP);
1598 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1599 return EmitGlobalConstantFP(CFP, AddrSpace, AP);
1601 if (isa<ConstantPointerNull>(CV)) {
1602 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1603 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace);
1607 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1608 return EmitGlobalConstantVector(V, AddrSpace, AP);
1610 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1611 // thread the streamer with EmitValue.
1612 AP.OutStreamer.EmitValue(LowerConstant(CV, AP),
1613 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()),
1617 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1618 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1619 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1621 EmitGlobalConstantImpl(CV, AddrSpace, *this);
1622 else if (MAI->hasSubsectionsViaSymbols()) {
1623 // If the global has zero size, emit a single byte so that two labels don't
1624 // look like they are at the same location.
1625 OutStreamer.EmitIntValue(0, 1, AddrSpace);
1629 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1630 // Target doesn't support this yet!
1631 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1634 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1636 OS << '+' << Offset;
1637 else if (Offset < 0)
1641 //===----------------------------------------------------------------------===//
1642 // Symbol Lowering Routines.
1643 //===----------------------------------------------------------------------===//
1645 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1646 /// temporary label with the specified stem and unique ID.
1647 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1648 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1652 /// GetTempSymbol - Return an assembler temporary label with the specified
1654 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1655 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1660 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1661 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1664 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1665 return MMI->getAddrLabelSymbol(BB);
1668 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1669 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1670 return OutContext.GetOrCreateSymbol
1671 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1672 + "_" + Twine(CPID));
1675 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1676 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1677 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1680 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1681 /// FIXME: privatize to AsmPrinter.
1682 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1683 return OutContext.GetOrCreateSymbol
1684 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1685 Twine(UID) + "_set_" + Twine(MBBID));
1688 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1689 /// global value name as its base, with the specified suffix, and where the
1690 /// symbol is forced to have private linkage if ForcePrivate is true.
1691 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1693 bool ForcePrivate) const {
1694 SmallString<60> NameStr;
1695 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1696 NameStr.append(Suffix.begin(), Suffix.end());
1697 return OutContext.GetOrCreateSymbol(NameStr.str());
1700 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1702 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1703 SmallString<60> NameStr;
1704 Mang->getNameWithPrefix(NameStr, Sym);
1705 return OutContext.GetOrCreateSymbol(NameStr.str());
1710 /// PrintParentLoopComment - Print comments about parent loops of this one.
1711 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1712 unsigned FunctionNumber) {
1713 if (Loop == 0) return;
1714 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1715 OS.indent(Loop->getLoopDepth()*2)
1716 << "Parent Loop BB" << FunctionNumber << "_"
1717 << Loop->getHeader()->getNumber()
1718 << " Depth=" << Loop->getLoopDepth() << '\n';
1722 /// PrintChildLoopComment - Print comments about child loops within
1723 /// the loop for this basic block, with nesting.
1724 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1725 unsigned FunctionNumber) {
1726 // Add child loop information
1727 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1728 OS.indent((*CL)->getLoopDepth()*2)
1729 << "Child Loop BB" << FunctionNumber << "_"
1730 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1732 PrintChildLoopComment(OS, *CL, FunctionNumber);
1736 /// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks.
1737 static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB,
1738 const MachineLoopInfo *LI,
1739 const AsmPrinter &AP) {
1740 // Add loop depth information
1741 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1742 if (Loop == 0) return;
1744 MachineBasicBlock *Header = Loop->getHeader();
1745 assert(Header && "No header for loop");
1747 // If this block is not a loop header, just print out what is the loop header
1749 if (Header != &MBB) {
1750 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1751 Twine(AP.getFunctionNumber())+"_" +
1752 Twine(Loop->getHeader()->getNumber())+
1753 " Depth="+Twine(Loop->getLoopDepth()));
1757 // Otherwise, it is a loop header. Print out information about child and
1759 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1761 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1764 OS.indent(Loop->getLoopDepth()*2-2);
1769 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1771 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1775 /// EmitBasicBlockStart - This method prints the label for the specified
1776 /// MachineBasicBlock, an alignment (if present) and a comment describing
1777 /// it if appropriate.
1778 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1779 // Emit an alignment directive for this block, if needed.
1780 if (unsigned Align = MBB->getAlignment())
1781 EmitAlignment(Log2_32(Align));
1783 // If the block has its address taken, emit any labels that were used to
1784 // reference the block. It is possible that there is more than one label
1785 // here, because multiple LLVM BB's may have been RAUW'd to this block after
1786 // the references were generated.
1787 if (MBB->hasAddressTaken()) {
1788 const BasicBlock *BB = MBB->getBasicBlock();
1790 OutStreamer.AddComment("Block address taken");
1792 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1794 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1795 OutStreamer.EmitLabel(Syms[i]);
1798 // Print the main label for the block.
1799 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1800 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
1801 if (const BasicBlock *BB = MBB->getBasicBlock())
1803 OutStreamer.AddComment("%" + BB->getName());
1805 EmitBasicBlockLoopComments(*MBB, LI, *this);
1807 // NOTE: Want this comment at start of line, don't emit with AddComment.
1808 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1809 Twine(MBB->getNumber()) + ":");
1813 if (const BasicBlock *BB = MBB->getBasicBlock())
1815 OutStreamer.AddComment("%" + BB->getName());
1816 EmitBasicBlockLoopComments(*MBB, LI, *this);
1819 OutStreamer.EmitLabel(MBB->getSymbol());
1823 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1824 MCSymbolAttr Attr = MCSA_Invalid;
1826 switch (Visibility) {
1828 case GlobalValue::HiddenVisibility:
1829 Attr = MAI->getHiddenVisibilityAttr();
1831 case GlobalValue::ProtectedVisibility:
1832 Attr = MAI->getProtectedVisibilityAttr();
1836 if (Attr != MCSA_Invalid)
1837 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1840 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1841 /// exactly one predecessor and the control transfer mechanism between
1842 /// the predecessor and this block is a fall-through.
1844 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1845 // If this is a landing pad, it isn't a fall through. If it has no preds,
1846 // then nothing falls through to it.
1847 if (MBB->isLandingPad() || MBB->pred_empty())
1850 // If there isn't exactly one predecessor, it can't be a fall through.
1851 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1853 if (PI2 != MBB->pred_end())
1856 // The predecessor has to be immediately before this block.
1857 const MachineBasicBlock *Pred = *PI;
1859 if (!Pred->isLayoutSuccessor(MBB))
1862 // If the block is completely empty, then it definitely does fall through.
1866 // Otherwise, check the last instruction.
1867 const MachineInstr &LastInst = Pred->back();
1868 return !LastInst.getDesc().isBarrier();
1873 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1874 if (!S->usesMetadata())
1877 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1878 gcp_map_type::iterator GCPI = GCMap.find(S);
1879 if (GCPI != GCMap.end())
1880 return GCPI->second;
1882 const char *Name = S->getName().c_str();
1884 for (GCMetadataPrinterRegistry::iterator
1885 I = GCMetadataPrinterRegistry::begin(),
1886 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1887 if (strcmp(Name, I->getName()) == 0) {
1888 GCMetadataPrinter *GMP = I->instantiate();
1890 GCMap.insert(std::make_pair(S, GMP));
1894 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));