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/TargetAsmInfo.h"
37 #include "llvm/Target/TargetData.h"
38 #include "llvm/Target/TargetInstrInfo.h"
39 #include "llvm/Target/TargetLowering.h"
40 #include "llvm/Target/TargetLoweringObjectFile.h"
41 #include "llvm/Target/TargetRegisterInfo.h"
42 #include "llvm/Assembly/Writer.h"
43 #include "llvm/ADT/SmallString.h"
44 #include "llvm/ADT/Statistic.h"
45 #include "llvm/Support/ErrorHandling.h"
46 #include "llvm/Support/Format.h"
47 #include "llvm/Support/Timer.h"
50 static const char *DWARFGroupName = "DWARF Emission";
51 static const char *DbgTimerName = "DWARF Debug Writer";
52 static const char *EHTimerName = "DWARF Exception Writer";
54 STATISTIC(EmittedInsts, "Number of machine instrs printed");
56 char AsmPrinter::ID = 0;
58 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
59 static gcp_map_type &getGCMap(void *&P) {
61 P = new gcp_map_type();
62 return *(gcp_map_type*)P;
66 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
67 /// value in log2 form. This rounds up to the preferred alignment if possible
69 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD,
70 unsigned InBits = 0) {
72 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
73 NumBits = TD.getPreferredAlignmentLog(GVar);
75 // If InBits is specified, round it to it.
79 // If the GV has a specified alignment, take it into account.
80 if (GV->getAlignment() == 0)
83 unsigned GVAlign = Log2_32(GV->getAlignment());
85 // If the GVAlign is larger than NumBits, or if we are required to obey
86 // NumBits because the GV has an assigned section, obey it.
87 if (GVAlign > NumBits || GV->hasSection())
95 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
96 : MachineFunctionPass(ID),
97 TM(tm), MAI(tm.getMCAsmInfo()),
98 OutContext(Streamer.getContext()),
99 OutStreamer(Streamer),
100 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
101 DD = 0; DE = 0; MMI = 0; LI = 0;
102 GCMetadataPrinters = 0;
103 VerboseAsm = Streamer.isVerboseAsm();
106 AsmPrinter::~AsmPrinter() {
107 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized");
109 if (GCMetadataPrinters != 0) {
110 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
112 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
115 GCMetadataPrinters = 0;
121 /// getFunctionNumber - Return a unique ID for the current function.
123 unsigned AsmPrinter::getFunctionNumber() const {
124 return MF->getFunctionNumber();
127 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
128 return TM.getTargetLowering()->getObjFileLowering();
132 /// getTargetData - Return information about data layout.
133 const TargetData &AsmPrinter::getTargetData() const {
134 return *TM.getTargetData();
137 /// getCurrentSection() - Return the current section we are emitting to.
138 const MCSection *AsmPrinter::getCurrentSection() const {
139 return OutStreamer.getCurrentSection();
144 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
145 AU.setPreservesAll();
146 MachineFunctionPass::getAnalysisUsage(AU);
147 AU.addRequired<MachineModuleInfo>();
148 AU.addRequired<GCModuleInfo>();
150 AU.addRequired<MachineLoopInfo>();
153 bool AsmPrinter::doInitialization(Module &M) {
154 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
155 MMI->AnalyzeModule(M);
157 // Initialize TargetLoweringObjectFile.
158 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
159 .Initialize(OutContext, TM);
161 Mang = new Mangler(OutContext, *TM.getTargetData());
163 // Allow the target to emit any magic that it wants at the start of the file.
164 EmitStartOfAsmFile(M);
166 // Very minimal debug info. It is ignored if we emit actual debug info. If we
167 // don't, this at least helps the user find where a global came from.
168 if (MAI->hasSingleParameterDotFile()) {
170 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
173 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
174 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
175 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
176 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
177 MP->beginAssembly(*this);
179 // Emit module-level inline asm if it exists.
180 if (!M.getModuleInlineAsm().empty()) {
181 OutStreamer.AddComment("Start of file scope inline assembly");
182 OutStreamer.AddBlankLine();
183 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
184 OutStreamer.AddComment("End of file scope inline assembly");
185 OutStreamer.AddBlankLine();
188 if (MAI->doesSupportDebugInformation())
189 DD = new DwarfDebug(this, &M);
191 if (MAI->doesSupportExceptionHandling())
192 switch (MAI->getExceptionHandlingType()) {
194 case ExceptionHandling::DwarfTable:
195 DE = new DwarfTableException(this);
197 case ExceptionHandling::DwarfCFI:
198 DE = new DwarfCFIException(this);
200 case ExceptionHandling::ARM:
201 DE = new ARMException(this);
208 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
209 switch ((GlobalValue::LinkageTypes)Linkage) {
210 case GlobalValue::CommonLinkage:
211 case GlobalValue::LinkOnceAnyLinkage:
212 case GlobalValue::LinkOnceODRLinkage:
213 case GlobalValue::WeakAnyLinkage:
214 case GlobalValue::WeakODRLinkage:
215 case GlobalValue::LinkerPrivateWeakLinkage:
216 case GlobalValue::LinkerPrivateWeakDefAutoLinkage:
217 if (MAI->getWeakDefDirective() != 0) {
219 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
221 if ((GlobalValue::LinkageTypes)Linkage !=
222 GlobalValue::LinkerPrivateWeakDefAutoLinkage)
223 // .weak_definition _foo
224 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
226 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
227 } else if (MAI->getLinkOnceDirective() != 0) {
229 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
230 //NOTE: linkonce is handled by the section the symbol was assigned to.
233 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
236 case GlobalValue::DLLExportLinkage:
237 case GlobalValue::AppendingLinkage:
238 // FIXME: appending linkage variables should go into a section of
239 // their name or something. For now, just emit them as external.
240 case GlobalValue::ExternalLinkage:
241 // If external or appending, declare as a global symbol.
243 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
245 case GlobalValue::PrivateLinkage:
246 case GlobalValue::InternalLinkage:
247 case GlobalValue::LinkerPrivateLinkage:
250 llvm_unreachable("Unknown linkage type!");
255 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
256 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
257 if (GV->hasInitializer()) {
258 // Check to see if this is a special global used by LLVM, if so, emit it.
259 if (EmitSpecialLLVMGlobal(GV))
263 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
264 /*PrintType=*/false, GV->getParent());
265 OutStreamer.GetCommentOS() << '\n';
269 MCSymbol *GVSym = Mang->getSymbol(GV);
270 EmitVisibility(GVSym, GV->getVisibility());
272 if (!GV->hasInitializer()) // External globals require no extra code.
275 if (MAI->hasDotTypeDotSizeDirective())
276 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
278 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
280 const TargetData *TD = TM.getTargetData();
281 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType());
283 // If the alignment is specified, we *must* obey it. Overaligning a global
284 // with a specified alignment is a prompt way to break globals emitted to
285 // sections and expected to be contiguous (e.g. ObjC metadata).
286 unsigned AlignLog = getGVAlignmentLog2(GV, *TD);
288 // Handle common and BSS local symbols (.lcomm).
289 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
290 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
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 /// EmitComments - Pretty-print comments for instructions.
484 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
485 const MachineFunction *MF = MI.getParent()->getParent();
486 const TargetMachine &TM = MF->getTarget();
488 // Check for spills and reloads
491 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
493 // We assume a single instruction only has a spill or reload, not
495 const MachineMemOperand *MMO;
496 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
497 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
498 MMO = *MI.memoperands_begin();
499 CommentOS << MMO->getSize() << "-byte Reload\n";
501 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
502 if (FrameInfo->isSpillSlotObjectIndex(FI))
503 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
504 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
505 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
506 MMO = *MI.memoperands_begin();
507 CommentOS << MMO->getSize() << "-byte Spill\n";
509 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
510 if (FrameInfo->isSpillSlotObjectIndex(FI))
511 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
514 // Check for spill-induced copies
515 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
516 CommentOS << " Reload Reuse\n";
519 /// EmitImplicitDef - This method emits the specified machine instruction
520 /// that is an implicit def.
521 static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
522 unsigned RegNo = MI->getOperand(0).getReg();
523 AP.OutStreamer.AddComment(Twine("implicit-def: ") +
524 AP.TM.getRegisterInfo()->getName(RegNo));
525 AP.OutStreamer.AddBlankLine();
528 static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) {
529 std::string Str = "kill:";
530 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
531 const MachineOperand &Op = MI->getOperand(i);
532 assert(Op.isReg() && "KILL instruction must have only register operands");
534 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
535 Str += (Op.isDef() ? "<def>" : "<kill>");
537 AP.OutStreamer.AddComment(Str);
538 AP.OutStreamer.AddBlankLine();
541 /// EmitDebugValueComment - This method handles the target-independent form
542 /// of DBG_VALUE, returning true if it was able to do so. A false return
543 /// means the target will need to handle MI in EmitInstruction.
544 static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
545 // This code handles only the 3-operand target-independent form.
546 if (MI->getNumOperands() != 3)
549 SmallString<128> Str;
550 raw_svector_ostream OS(Str);
551 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
553 // cast away const; DIetc do not take const operands for some reason.
554 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
555 if (V.getContext().isSubprogram())
556 OS << DISubprogram(V.getContext()).getDisplayName() << ":";
557 OS << V.getName() << " <- ";
559 // Register or immediate value. Register 0 means undef.
560 if (MI->getOperand(0).isFPImm()) {
561 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
562 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
563 OS << (double)APF.convertToFloat();
564 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
565 OS << APF.convertToDouble();
567 // There is no good way to print long double. Convert a copy to
568 // double. Ah well, it's only a comment.
570 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
572 OS << "(long double) " << APF.convertToDouble();
574 } else if (MI->getOperand(0).isImm()) {
575 OS << MI->getOperand(0).getImm();
577 assert(MI->getOperand(0).isReg() && "Unknown operand type");
578 if (MI->getOperand(0).getReg() == 0) {
579 // Suppress offset, it is not meaningful here.
581 // NOTE: Want this comment at start of line, don't emit with AddComment.
582 AP.OutStreamer.EmitRawText(OS.str());
585 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg());
588 OS << '+' << MI->getOperand(1).getImm();
589 // NOTE: Want this comment at start of line, don't emit with AddComment.
590 AP.OutStreamer.EmitRawText(OS.str());
594 void AsmPrinter::emitPrologLabel(const MachineInstr &MI) {
595 MCSymbol *Label = MI.getOperand(0).getMCSymbol();
596 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI) {
597 OutStreamer.EmitLabel(Label);
601 const MachineFunction &MF = *MI.getParent()->getParent();
602 MachineModuleInfo &MMI = MF.getMMI();
603 std::vector<MachineMove> &Moves = MMI.getFrameMoves();
604 bool FoundOne = false;
606 for (std::vector<MachineMove>::iterator I = Moves.begin(),
607 E = Moves.end(); I != E; ++I) {
608 if (I->getLabel() == Label) {
609 EmitCFIFrameMove(*I);
616 /// EmitFunctionBody - This method emits the body and trailer for a
618 void AsmPrinter::EmitFunctionBody() {
619 // Emit target-specific gunk before the function body.
620 EmitFunctionBodyStart();
622 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
624 // Print out code for the function.
625 bool HasAnyRealCode = false;
626 const MachineInstr *LastMI = 0;
627 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
629 // Print a label for the basic block.
630 EmitBasicBlockStart(I);
631 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
635 // Print the assembly for the instruction.
636 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
637 !II->isDebugValue()) {
638 HasAnyRealCode = true;
642 if (ShouldPrintDebugScopes) {
643 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
644 DD->beginInstruction(II);
648 EmitComments(*II, OutStreamer.GetCommentOS());
650 switch (II->getOpcode()) {
651 case TargetOpcode::PROLOG_LABEL:
652 emitPrologLabel(*II);
655 case TargetOpcode::EH_LABEL:
656 case TargetOpcode::GC_LABEL:
657 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
659 case TargetOpcode::INLINEASM:
662 case TargetOpcode::DBG_VALUE:
664 if (!EmitDebugValueComment(II, *this))
668 case TargetOpcode::IMPLICIT_DEF:
669 if (isVerbose()) EmitImplicitDef(II, *this);
671 case TargetOpcode::KILL:
672 if (isVerbose()) EmitKill(II, *this);
679 if (ShouldPrintDebugScopes) {
680 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
681 DD->endInstruction(II);
686 // If the last instruction was a prolog label, then we have a situation where
687 // we emitted a prolog but no function body. This results in the ending prolog
688 // label equaling the end of function label and an invalid "row" in the
689 // FDE. We need to emit a noop in this situation so that the FDE's rows are
691 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
693 // If the function is empty and the object file uses .subsections_via_symbols,
694 // then we need to emit *something* to the function body to prevent the
695 // labels from collapsing together. Just emit a noop.
696 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
698 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
699 if (Noop.getOpcode()) {
700 OutStreamer.AddComment("avoids zero-length function");
701 OutStreamer.EmitInstruction(Noop);
702 } else // Target not mc-ized yet.
703 OutStreamer.EmitRawText(StringRef("\tnop\n"));
706 // Emit target-specific gunk after the function body.
707 EmitFunctionBodyEnd();
709 // If the target wants a .size directive for the size of the function, emit
711 if (MAI->hasDotTypeDotSizeDirective()) {
712 // Create a symbol for the end of function, so we can get the size as
713 // difference between the function label and the temp label.
714 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
715 OutStreamer.EmitLabel(FnEndLabel);
717 const MCExpr *SizeExp =
718 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
719 MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
721 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
724 // Emit post-function debug information.
726 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
730 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
735 // Print out jump tables referenced by the function.
738 OutStreamer.AddBlankLine();
741 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
743 MachineLocation AsmPrinter::
744 getDebugValueLocation(const MachineInstr *MI) const {
745 // Target specific DBG_VALUE instructions are handled by each target.
746 return MachineLocation();
749 /// EmitDwarfRegOp - Emit dwarf register operation.
750 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc,
751 unsigned ExtraExprSize) const {
752 const TargetRegisterInfo *RI = TM.getRegisterInfo();
753 unsigned Reg = RI->getDwarfRegNum(MLoc.getReg(), false);
754 if (int Offset = MLoc.getOffset()) {
755 // If the value is at a certain offset from frame register then
757 unsigned OffsetSize = Offset ? MCAsmInfo::getSLEB128Size(Offset) : 1;
758 OutStreamer.AddComment("Loc expr size");
759 EmitInt16(1 + OffsetSize + ExtraExprSize);
760 OutStreamer.AddComment(
761 dwarf::OperationEncodingString(dwarf::DW_OP_fbreg));
762 EmitInt8(dwarf::DW_OP_fbreg);
763 OutStreamer.AddComment("Offset");
767 OutStreamer.AddComment("Loc expr size");
769 OutStreamer.AddComment(
770 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
771 EmitInt8(dwarf::DW_OP_reg0 + Reg);
773 OutStreamer.AddComment("Loc expr size");
774 EmitInt16(1 + MCAsmInfo::getULEB128Size(Reg) + ExtraExprSize);
775 OutStreamer.AddComment(
776 dwarf::OperationEncodingString(dwarf::DW_OP_regx));
777 EmitInt8(dwarf::DW_OP_regx);
778 OutStreamer.AddComment(Twine(Reg));
784 bool AsmPrinter::doFinalization(Module &M) {
785 // Emit global variables.
786 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
788 EmitGlobalVariable(I);
790 // Emit visibility info for declarations
791 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
792 const Function &F = *I;
793 if (!F.isDeclaration())
795 GlobalValue::VisibilityTypes V = F.getVisibility();
796 if (V == GlobalValue::DefaultVisibility)
799 MCSymbol *Name = Mang->getSymbol(&F);
800 EmitVisibility(Name, V, false);
803 // Finalize debug and EH information.
806 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
813 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
819 // If the target wants to know about weak references, print them all.
820 if (MAI->getWeakRefDirective()) {
821 // FIXME: This is not lazy, it would be nice to only print weak references
822 // to stuff that is actually used. Note that doing so would require targets
823 // to notice uses in operands (due to constant exprs etc). This should
824 // happen with the MC stuff eventually.
826 // Print out module-level global variables here.
827 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
829 if (!I->hasExternalWeakLinkage()) continue;
830 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
833 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
834 if (!I->hasExternalWeakLinkage()) continue;
835 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
839 if (MAI->hasSetDirective()) {
840 OutStreamer.AddBlankLine();
841 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
843 MCSymbol *Name = Mang->getSymbol(I);
845 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
846 MCSymbol *Target = Mang->getSymbol(GV);
848 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
849 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
850 else if (I->hasWeakLinkage())
851 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
853 assert(I->hasLocalLinkage() && "Invalid alias linkage");
855 EmitVisibility(Name, I->getVisibility());
857 // Emit the directives as assignments aka .set:
858 OutStreamer.EmitAssignment(Name,
859 MCSymbolRefExpr::Create(Target, OutContext));
863 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
864 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
865 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
866 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
867 MP->finishAssembly(*this);
869 // If we don't have any trampolines, then we don't require stack memory
870 // to be executable. Some targets have a directive to declare this.
871 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
872 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
873 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
874 OutStreamer.SwitchSection(S);
876 // Allow the target to emit any magic that it wants at the end of the file,
877 // after everything else has gone out.
880 delete Mang; Mang = 0;
883 OutStreamer.Finish();
887 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
889 // Get the function symbol.
890 CurrentFnSym = Mang->getSymbol(MF.getFunction());
893 LI = &getAnalysis<MachineLoopInfo>();
897 // SectionCPs - Keep track the alignment, constpool entries per Section.
901 SmallVector<unsigned, 4> CPEs;
902 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
906 /// EmitConstantPool - Print to the current output stream assembly
907 /// representations of the constants in the constant pool MCP. This is
908 /// used to print out constants which have been "spilled to memory" by
909 /// the code generator.
911 void AsmPrinter::EmitConstantPool() {
912 const MachineConstantPool *MCP = MF->getConstantPool();
913 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
914 if (CP.empty()) return;
916 // Calculate sections for constant pool entries. We collect entries to go into
917 // the same section together to reduce amount of section switch statements.
918 SmallVector<SectionCPs, 4> CPSections;
919 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
920 const MachineConstantPoolEntry &CPE = CP[i];
921 unsigned Align = CPE.getAlignment();
924 switch (CPE.getRelocationInfo()) {
925 default: llvm_unreachable("Unknown section kind");
926 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
928 Kind = SectionKind::getReadOnlyWithRelLocal();
931 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
932 case 4: Kind = SectionKind::getMergeableConst4(); break;
933 case 8: Kind = SectionKind::getMergeableConst8(); break;
934 case 16: Kind = SectionKind::getMergeableConst16();break;
935 default: Kind = SectionKind::getMergeableConst(); break;
939 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
941 // The number of sections are small, just do a linear search from the
942 // last section to the first.
944 unsigned SecIdx = CPSections.size();
945 while (SecIdx != 0) {
946 if (CPSections[--SecIdx].S == S) {
952 SecIdx = CPSections.size();
953 CPSections.push_back(SectionCPs(S, Align));
956 if (Align > CPSections[SecIdx].Alignment)
957 CPSections[SecIdx].Alignment = Align;
958 CPSections[SecIdx].CPEs.push_back(i);
961 // Now print stuff into the calculated sections.
962 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
963 OutStreamer.SwitchSection(CPSections[i].S);
964 EmitAlignment(Log2_32(CPSections[i].Alignment));
967 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
968 unsigned CPI = CPSections[i].CPEs[j];
969 MachineConstantPoolEntry CPE = CP[CPI];
971 // Emit inter-object padding for alignment.
972 unsigned AlignMask = CPE.getAlignment() - 1;
973 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
974 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
976 const Type *Ty = CPE.getType();
977 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
978 OutStreamer.EmitLabel(GetCPISymbol(CPI));
980 if (CPE.isMachineConstantPoolEntry())
981 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
983 EmitGlobalConstant(CPE.Val.ConstVal);
988 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
989 /// by the current function to the current output stream.
991 void AsmPrinter::EmitJumpTableInfo() {
992 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
993 if (MJTI == 0) return;
994 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
995 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
996 if (JT.empty()) return;
998 // Pick the directive to use to print the jump table entries, and switch to
999 // the appropriate section.
1000 const Function *F = MF->getFunction();
1001 bool JTInDiffSection = false;
1002 if (// In PIC mode, we need to emit the jump table to the same section as the
1003 // function body itself, otherwise the label differences won't make sense.
1004 // FIXME: Need a better predicate for this: what about custom entries?
1005 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1006 // We should also do if the section name is NULL or function is declared
1007 // in discardable section
1008 // FIXME: this isn't the right predicate, should be based on the MCSection
1009 // for the function.
1010 F->isWeakForLinker()) {
1011 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
1013 // Otherwise, drop it in the readonly section.
1014 const MCSection *ReadOnlySection =
1015 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1016 OutStreamer.SwitchSection(ReadOnlySection);
1017 JTInDiffSection = true;
1020 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
1022 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1023 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1025 // If this jump table was deleted, ignore it.
1026 if (JTBBs.empty()) continue;
1028 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1029 // .set directive for each unique entry. This reduces the number of
1030 // relocations the assembler will generate for the jump table.
1031 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1032 MAI->hasSetDirective()) {
1033 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1034 const TargetLowering *TLI = TM.getTargetLowering();
1035 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1036 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1037 const MachineBasicBlock *MBB = JTBBs[ii];
1038 if (!EmittedSets.insert(MBB)) continue;
1040 // .set LJTSet, LBB32-base
1042 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1043 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1044 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1048 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1049 // before each jump table. The first label is never referenced, but tells
1050 // the assembler and linker the extents of the jump table object. The
1051 // second label is actually referenced by the code.
1052 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1053 // FIXME: This doesn't have to have any specific name, just any randomly
1054 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1055 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1057 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1059 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1060 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1064 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1066 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1067 const MachineBasicBlock *MBB,
1068 unsigned UID) const {
1069 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1070 const MCExpr *Value = 0;
1071 switch (MJTI->getEntryKind()) {
1072 case MachineJumpTableInfo::EK_Inline:
1073 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
1074 case MachineJumpTableInfo::EK_Custom32:
1075 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1078 case MachineJumpTableInfo::EK_BlockAddress:
1079 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1081 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1083 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1084 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1085 // with a relocation as gp-relative, e.g.:
1087 MCSymbol *MBBSym = MBB->getSymbol();
1088 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1092 case MachineJumpTableInfo::EK_LabelDifference32: {
1093 // EK_LabelDifference32 - Each entry is the address of the block minus
1094 // the address of the jump table. This is used for PIC jump tables where
1095 // gprel32 is not supported. e.g.:
1096 // .word LBB123 - LJTI1_2
1097 // If the .set directive is supported, this is emitted as:
1098 // .set L4_5_set_123, LBB123 - LJTI1_2
1099 // .word L4_5_set_123
1101 // If we have emitted set directives for the jump table entries, print
1102 // them rather than the entries themselves. If we're emitting PIC, then
1103 // emit the table entries as differences between two text section labels.
1104 if (MAI->hasSetDirective()) {
1105 // If we used .set, reference the .set's symbol.
1106 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1110 // Otherwise, use the difference as the jump table entry.
1111 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1112 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1113 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1118 assert(Value && "Unknown entry kind!");
1120 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
1121 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
1125 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1126 /// special global used by LLVM. If so, emit it and return true, otherwise
1127 /// do nothing and return false.
1128 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1129 if (GV->getName() == "llvm.used") {
1130 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1131 EmitLLVMUsedList(GV->getInitializer());
1135 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1136 if (GV->getSection() == "llvm.metadata" ||
1137 GV->hasAvailableExternallyLinkage())
1140 if (!GV->hasAppendingLinkage()) return false;
1142 assert(GV->hasInitializer() && "Not a special LLVM global!");
1144 const TargetData *TD = TM.getTargetData();
1145 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1146 if (GV->getName() == "llvm.global_ctors") {
1147 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
1148 EmitAlignment(Align);
1149 EmitXXStructorList(GV->getInitializer());
1151 if (TM.getRelocationModel() == Reloc::Static &&
1152 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1153 StringRef Sym(".constructors_used");
1154 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1160 if (GV->getName() == "llvm.global_dtors") {
1161 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
1162 EmitAlignment(Align);
1163 EmitXXStructorList(GV->getInitializer());
1165 if (TM.getRelocationModel() == Reloc::Static &&
1166 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1167 StringRef Sym(".destructors_used");
1168 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1177 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1178 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1179 /// is true, as being used with this directive.
1180 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
1181 // Should be an array of 'i8*'.
1182 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1183 if (InitList == 0) return;
1185 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1186 const GlobalValue *GV =
1187 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1188 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1189 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1193 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
1194 /// function pointers, ignoring the init priority.
1195 void AsmPrinter::EmitXXStructorList(Constant *List) {
1196 // Should be an array of '{ int, void ()* }' structs. The first value is the
1197 // init priority, which we ignore.
1198 if (!isa<ConstantArray>(List)) return;
1199 ConstantArray *InitList = cast<ConstantArray>(List);
1200 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
1201 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
1202 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
1204 if (CS->getOperand(1)->isNullValue())
1205 return; // Found a null terminator, exit printing.
1206 // Emit the function pointer.
1207 EmitGlobalConstant(CS->getOperand(1));
1211 //===--------------------------------------------------------------------===//
1212 // Emission and print routines
1215 /// EmitInt8 - Emit a byte directive and value.
1217 void AsmPrinter::EmitInt8(int Value) const {
1218 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
1221 /// EmitInt16 - Emit a short directive and value.
1223 void AsmPrinter::EmitInt16(int Value) const {
1224 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
1227 /// EmitInt32 - Emit a long directive and value.
1229 void AsmPrinter::EmitInt32(int Value) const {
1230 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
1233 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1234 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1235 /// labels. This implicitly uses .set if it is available.
1236 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1237 unsigned Size) const {
1238 // Get the Hi-Lo expression.
1239 const MCExpr *Diff =
1240 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1241 MCSymbolRefExpr::Create(Lo, OutContext),
1244 if (!MAI->hasSetDirective()) {
1245 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
1249 // Otherwise, emit with .set (aka assignment).
1250 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1251 OutStreamer.EmitAssignment(SetLabel, Diff);
1252 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
1255 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1256 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1257 /// specify the labels. This implicitly uses .set if it is available.
1258 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1259 const MCSymbol *Lo, unsigned Size)
1262 // Emit Hi+Offset - Lo
1263 // Get the Hi+Offset expression.
1264 const MCExpr *Plus =
1265 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1266 MCConstantExpr::Create(Offset, OutContext),
1269 // Get the Hi+Offset-Lo expression.
1270 const MCExpr *Diff =
1271 MCBinaryExpr::CreateSub(Plus,
1272 MCSymbolRefExpr::Create(Lo, OutContext),
1275 if (!MAI->hasSetDirective())
1276 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/);
1278 // Otherwise, emit with .set (aka assignment).
1279 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1280 OutStreamer.EmitAssignment(SetLabel, Diff);
1281 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/);
1285 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1286 /// where the size in bytes of the directive is specified by Size and Label
1287 /// specifies the label. This implicitly uses .set if it is available.
1288 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1292 // Emit Label+Offset
1293 const MCExpr *Plus =
1294 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext),
1295 MCConstantExpr::Create(Offset, OutContext),
1298 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/);
1302 //===----------------------------------------------------------------------===//
1304 // EmitAlignment - Emit an alignment directive to the specified power of
1305 // two boundary. For example, if you pass in 3 here, you will get an 8
1306 // byte alignment. If a global value is specified, and if that global has
1307 // an explicit alignment requested, it will override the alignment request
1308 // if required for correctness.
1310 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1311 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits);
1313 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1315 if (getCurrentSection()->getKind().isText())
1316 OutStreamer.EmitCodeAlignment(1 << NumBits);
1318 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1321 //===----------------------------------------------------------------------===//
1322 // Constant emission.
1323 //===----------------------------------------------------------------------===//
1325 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1327 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1328 MCContext &Ctx = AP.OutContext;
1330 if (CV->isNullValue() || isa<UndefValue>(CV))
1331 return MCConstantExpr::Create(0, Ctx);
1333 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1334 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1336 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1337 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1339 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1340 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1342 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1344 llvm_unreachable("Unknown constant value to lower!");
1345 return MCConstantExpr::Create(0, Ctx);
1348 switch (CE->getOpcode()) {
1350 // If the code isn't optimized, there may be outstanding folding
1351 // opportunities. Attempt to fold the expression using TargetData as a
1352 // last resort before giving up.
1354 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1356 return LowerConstant(C, AP);
1358 // Otherwise report the problem to the user.
1361 raw_string_ostream OS(S);
1362 OS << "Unsupported expression in static initializer: ";
1363 WriteAsOperand(OS, CE, /*PrintType=*/false,
1364 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1365 report_fatal_error(OS.str());
1367 return MCConstantExpr::Create(0, Ctx);
1368 case Instruction::GetElementPtr: {
1369 const TargetData &TD = *AP.TM.getTargetData();
1370 // Generate a symbolic expression for the byte address
1371 const Constant *PtrVal = CE->getOperand(0);
1372 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1373 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1376 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1380 // Truncate/sext the offset to the pointer size.
1381 if (TD.getPointerSizeInBits() != 64) {
1382 int SExtAmount = 64-TD.getPointerSizeInBits();
1383 Offset = (Offset << SExtAmount) >> SExtAmount;
1386 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1390 case Instruction::Trunc:
1391 // We emit the value and depend on the assembler to truncate the generated
1392 // expression properly. This is important for differences between
1393 // blockaddress labels. Since the two labels are in the same function, it
1394 // is reasonable to treat their delta as a 32-bit value.
1396 case Instruction::BitCast:
1397 return LowerConstant(CE->getOperand(0), AP);
1399 case Instruction::IntToPtr: {
1400 const TargetData &TD = *AP.TM.getTargetData();
1401 // Handle casts to pointers by changing them into casts to the appropriate
1402 // integer type. This promotes constant folding and simplifies this code.
1403 Constant *Op = CE->getOperand(0);
1404 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1406 return LowerConstant(Op, AP);
1409 case Instruction::PtrToInt: {
1410 const TargetData &TD = *AP.TM.getTargetData();
1411 // Support only foldable casts to/from pointers that can be eliminated by
1412 // changing the pointer to the appropriately sized integer type.
1413 Constant *Op = CE->getOperand(0);
1414 const Type *Ty = CE->getType();
1416 const MCExpr *OpExpr = LowerConstant(Op, AP);
1418 // We can emit the pointer value into this slot if the slot is an
1419 // integer slot equal to the size of the pointer.
1420 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1423 // Otherwise the pointer is smaller than the resultant integer, mask off
1424 // the high bits so we are sure to get a proper truncation if the input is
1426 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1427 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1428 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1431 // The MC library also has a right-shift operator, but it isn't consistently
1432 // signed or unsigned between different targets.
1433 case Instruction::Add:
1434 case Instruction::Sub:
1435 case Instruction::Mul:
1436 case Instruction::SDiv:
1437 case Instruction::SRem:
1438 case Instruction::Shl:
1439 case Instruction::And:
1440 case Instruction::Or:
1441 case Instruction::Xor: {
1442 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1443 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1444 switch (CE->getOpcode()) {
1445 default: llvm_unreachable("Unknown binary operator constant cast expr");
1446 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1447 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1448 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1449 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1450 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1451 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1452 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1453 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1454 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1460 static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace,
1463 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1465 if (AddrSpace != 0 || !CA->isString()) {
1466 // Not a string. Print the values in successive locations
1467 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1468 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP);
1472 // Otherwise, it can be emitted as .ascii.
1473 SmallVector<char, 128> TmpVec;
1474 TmpVec.reserve(CA->getNumOperands());
1475 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1476 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1478 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1481 static void EmitGlobalConstantVector(const ConstantVector *CV,
1482 unsigned AddrSpace, AsmPrinter &AP) {
1483 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1484 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP);
1487 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1488 unsigned AddrSpace, AsmPrinter &AP) {
1489 // Print the fields in successive locations. Pad to align if needed!
1490 const TargetData *TD = AP.TM.getTargetData();
1491 unsigned Size = TD->getTypeAllocSize(CS->getType());
1492 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1493 uint64_t SizeSoFar = 0;
1494 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1495 const Constant *Field = CS->getOperand(i);
1497 // Check if padding is needed and insert one or more 0s.
1498 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1499 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1500 - Layout->getElementOffset(i)) - FieldSize;
1501 SizeSoFar += FieldSize + PadSize;
1503 // Now print the actual field value.
1504 EmitGlobalConstantImpl(Field, AddrSpace, AP);
1506 // Insert padding - this may include padding to increase the size of the
1507 // current field up to the ABI size (if the struct is not packed) as well
1508 // as padding to ensure that the next field starts at the right offset.
1509 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1511 assert(SizeSoFar == Layout->getSizeInBytes() &&
1512 "Layout of constant struct may be incorrect!");
1515 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1517 // FP Constants are printed as integer constants to avoid losing
1519 if (CFP->getType()->isDoubleTy()) {
1520 if (AP.isVerbose()) {
1521 double Val = CFP->getValueAPF().convertToDouble();
1522 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1525 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1526 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1530 if (CFP->getType()->isFloatTy()) {
1531 if (AP.isVerbose()) {
1532 float Val = CFP->getValueAPF().convertToFloat();
1533 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1535 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1536 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1540 if (CFP->getType()->isX86_FP80Ty()) {
1541 // all long double variants are printed as hex
1542 // API needed to prevent premature destruction
1543 APInt API = CFP->getValueAPF().bitcastToAPInt();
1544 const uint64_t *p = API.getRawData();
1545 if (AP.isVerbose()) {
1546 // Convert to double so we can print the approximate val as a comment.
1547 APFloat DoubleVal = CFP->getValueAPF();
1549 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1551 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1552 << DoubleVal.convertToDouble() << '\n';
1555 if (AP.TM.getTargetData()->isBigEndian()) {
1556 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1557 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1559 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1560 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1563 // Emit the tail padding for the long double.
1564 const TargetData &TD = *AP.TM.getTargetData();
1565 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1566 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1570 assert(CFP->getType()->isPPC_FP128Ty() &&
1571 "Floating point constant type not handled");
1572 // All long double variants are printed as hex
1573 // API needed to prevent premature destruction.
1574 APInt API = CFP->getValueAPF().bitcastToAPInt();
1575 const uint64_t *p = API.getRawData();
1576 if (AP.TM.getTargetData()->isBigEndian()) {
1577 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1578 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1580 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1581 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1585 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1586 unsigned AddrSpace, AsmPrinter &AP) {
1587 const TargetData *TD = AP.TM.getTargetData();
1588 unsigned BitWidth = CI->getBitWidth();
1589 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1591 // We don't expect assemblers to support integer data directives
1592 // for more than 64 bits, so we emit the data in at most 64-bit
1593 // quantities at a time.
1594 const uint64_t *RawData = CI->getValue().getRawData();
1595 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1596 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1597 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1601 static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
1603 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1604 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1605 return AP.OutStreamer.EmitZeros(Size, AddrSpace);
1608 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1609 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1616 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1617 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1620 EmitGlobalConstantLargeInt(CI, AddrSpace, AP);
1625 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1626 return EmitGlobalConstantArray(CVA, AddrSpace, AP);
1628 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1629 return EmitGlobalConstantStruct(CVS, AddrSpace, AP);
1631 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1632 return EmitGlobalConstantFP(CFP, AddrSpace, AP);
1634 if (isa<ConstantPointerNull>(CV)) {
1635 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1636 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace);
1640 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1641 return EmitGlobalConstantVector(V, AddrSpace, AP);
1643 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1644 // thread the streamer with EmitValue.
1645 AP.OutStreamer.EmitValue(LowerConstant(CV, AP),
1646 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()),
1650 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1651 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1652 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1654 EmitGlobalConstantImpl(CV, AddrSpace, *this);
1655 else if (MAI->hasSubsectionsViaSymbols()) {
1656 // If the global has zero size, emit a single byte so that two labels don't
1657 // look like they are at the same location.
1658 OutStreamer.EmitIntValue(0, 1, AddrSpace);
1662 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1663 // Target doesn't support this yet!
1664 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1667 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1669 OS << '+' << Offset;
1670 else if (Offset < 0)
1674 //===----------------------------------------------------------------------===//
1675 // Symbol Lowering Routines.
1676 //===----------------------------------------------------------------------===//
1678 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1679 /// temporary label with the specified stem and unique ID.
1680 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1681 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1685 /// GetTempSymbol - Return an assembler temporary label with the specified
1687 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1688 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1693 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1694 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1697 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1698 return MMI->getAddrLabelSymbol(BB);
1701 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1702 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1703 return OutContext.GetOrCreateSymbol
1704 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1705 + "_" + Twine(CPID));
1708 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1709 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1710 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1713 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1714 /// FIXME: privatize to AsmPrinter.
1715 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1716 return OutContext.GetOrCreateSymbol
1717 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1718 Twine(UID) + "_set_" + Twine(MBBID));
1721 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1722 /// global value name as its base, with the specified suffix, and where the
1723 /// symbol is forced to have private linkage if ForcePrivate is true.
1724 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1726 bool ForcePrivate) const {
1727 SmallString<60> NameStr;
1728 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1729 NameStr.append(Suffix.begin(), Suffix.end());
1730 return OutContext.GetOrCreateSymbol(NameStr.str());
1733 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1735 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1736 SmallString<60> NameStr;
1737 Mang->getNameWithPrefix(NameStr, Sym);
1738 return OutContext.GetOrCreateSymbol(NameStr.str());
1743 /// PrintParentLoopComment - Print comments about parent loops of this one.
1744 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1745 unsigned FunctionNumber) {
1746 if (Loop == 0) return;
1747 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1748 OS.indent(Loop->getLoopDepth()*2)
1749 << "Parent Loop BB" << FunctionNumber << "_"
1750 << Loop->getHeader()->getNumber()
1751 << " Depth=" << Loop->getLoopDepth() << '\n';
1755 /// PrintChildLoopComment - Print comments about child loops within
1756 /// the loop for this basic block, with nesting.
1757 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1758 unsigned FunctionNumber) {
1759 // Add child loop information
1760 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1761 OS.indent((*CL)->getLoopDepth()*2)
1762 << "Child Loop BB" << FunctionNumber << "_"
1763 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1765 PrintChildLoopComment(OS, *CL, FunctionNumber);
1769 /// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks.
1770 static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB,
1771 const MachineLoopInfo *LI,
1772 const AsmPrinter &AP) {
1773 // Add loop depth information
1774 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1775 if (Loop == 0) return;
1777 MachineBasicBlock *Header = Loop->getHeader();
1778 assert(Header && "No header for loop");
1780 // If this block is not a loop header, just print out what is the loop header
1782 if (Header != &MBB) {
1783 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1784 Twine(AP.getFunctionNumber())+"_" +
1785 Twine(Loop->getHeader()->getNumber())+
1786 " Depth="+Twine(Loop->getLoopDepth()));
1790 // Otherwise, it is a loop header. Print out information about child and
1792 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1794 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1797 OS.indent(Loop->getLoopDepth()*2-2);
1802 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1804 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1808 /// EmitBasicBlockStart - This method prints the label for the specified
1809 /// MachineBasicBlock, an alignment (if present) and a comment describing
1810 /// it if appropriate.
1811 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1812 // Emit an alignment directive for this block, if needed.
1813 if (unsigned Align = MBB->getAlignment())
1814 EmitAlignment(Log2_32(Align));
1816 // If the block has its address taken, emit any labels that were used to
1817 // reference the block. It is possible that there is more than one label
1818 // here, because multiple LLVM BB's may have been RAUW'd to this block after
1819 // the references were generated.
1820 if (MBB->hasAddressTaken()) {
1821 const BasicBlock *BB = MBB->getBasicBlock();
1823 OutStreamer.AddComment("Block address taken");
1825 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1827 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1828 OutStreamer.EmitLabel(Syms[i]);
1831 // Print the main label for the block.
1832 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1833 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
1834 if (const BasicBlock *BB = MBB->getBasicBlock())
1836 OutStreamer.AddComment("%" + BB->getName());
1838 EmitBasicBlockLoopComments(*MBB, LI, *this);
1840 // NOTE: Want this comment at start of line, don't emit with AddComment.
1841 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1842 Twine(MBB->getNumber()) + ":");
1846 if (const BasicBlock *BB = MBB->getBasicBlock())
1848 OutStreamer.AddComment("%" + BB->getName());
1849 EmitBasicBlockLoopComments(*MBB, LI, *this);
1852 OutStreamer.EmitLabel(MBB->getSymbol());
1856 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
1857 bool IsDefinition) const {
1858 MCSymbolAttr Attr = MCSA_Invalid;
1860 switch (Visibility) {
1862 case GlobalValue::HiddenVisibility:
1864 Attr = MAI->getHiddenVisibilityAttr();
1866 Attr = MAI->getHiddenDeclarationVisibilityAttr();
1868 case GlobalValue::ProtectedVisibility:
1869 Attr = MAI->getProtectedVisibilityAttr();
1873 if (Attr != MCSA_Invalid)
1874 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1877 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1878 /// exactly one predecessor and the control transfer mechanism between
1879 /// the predecessor and this block is a fall-through.
1881 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1882 // If this is a landing pad, it isn't a fall through. If it has no preds,
1883 // then nothing falls through to it.
1884 if (MBB->isLandingPad() || MBB->pred_empty())
1887 // If there isn't exactly one predecessor, it can't be a fall through.
1888 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1890 if (PI2 != MBB->pred_end())
1893 // The predecessor has to be immediately before this block.
1894 const MachineBasicBlock *Pred = *PI;
1896 if (!Pred->isLayoutSuccessor(MBB))
1899 // If the block is completely empty, then it definitely does fall through.
1903 // Otherwise, check the last instruction.
1904 const MachineInstr &LastInst = Pred->back();
1905 return !LastInst.getDesc().isBarrier();
1910 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1911 if (!S->usesMetadata())
1914 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1915 gcp_map_type::iterator GCPI = GCMap.find(S);
1916 if (GCPI != GCMap.end())
1917 return GCPI->second;
1919 const char *Name = S->getName().c_str();
1921 for (GCMetadataPrinterRegistry::iterator
1922 I = GCMetadataPrinterRegistry::begin(),
1923 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1924 if (strcmp(Name, I->getName()) == 0) {
1925 GCMetadataPrinter *GMP = I->instantiate();
1927 GCMap.insert(std::make_pair(S, GMP));
1931 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));