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/TargetOptions.h"
42 #include "llvm/Target/TargetRegisterInfo.h"
43 #include "llvm/Assembly/Writer.h"
44 #include "llvm/ADT/SmallString.h"
45 #include "llvm/ADT/Statistic.h"
46 #include "llvm/Support/ErrorHandling.h"
47 #include "llvm/Support/Format.h"
48 #include "llvm/Support/Timer.h"
51 static const char *DWARFGroupName = "DWARF Emission";
52 static const char *DbgTimerName = "DWARF Debug Writer";
53 static const char *EHTimerName = "DWARF Exception Writer";
55 STATISTIC(EmittedInsts, "Number of machine instrs printed");
57 char AsmPrinter::ID = 0;
59 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
60 static gcp_map_type &getGCMap(void *&P) {
62 P = new gcp_map_type();
63 return *(gcp_map_type*)P;
67 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
68 /// value in log2 form. This rounds up to the preferred alignment if possible
70 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD,
71 unsigned InBits = 0) {
73 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
74 NumBits = TD.getPreferredAlignmentLog(GVar);
76 // If InBits is specified, round it to it.
80 // If the GV has a specified alignment, take it into account.
81 if (GV->getAlignment() == 0)
84 unsigned GVAlign = Log2_32(GV->getAlignment());
86 // If the GVAlign is larger than NumBits, or if we are required to obey
87 // NumBits because the GV has an assigned section, obey it.
88 if (GVAlign > NumBits || GV->hasSection())
96 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
97 : MachineFunctionPass(ID),
98 TM(tm), MAI(tm.getMCAsmInfo()),
99 OutContext(Streamer.getContext()),
100 OutStreamer(Streamer),
101 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
102 DD = 0; DE = 0; MMI = 0; LI = 0;
103 GCMetadataPrinters = 0;
104 VerboseAsm = Streamer.isVerboseAsm();
107 AsmPrinter::~AsmPrinter() {
108 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized");
110 if (GCMetadataPrinters != 0) {
111 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
113 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
116 GCMetadataPrinters = 0;
122 /// getFunctionNumber - Return a unique ID for the current function.
124 unsigned AsmPrinter::getFunctionNumber() const {
125 return MF->getFunctionNumber();
128 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
129 return TM.getTargetLowering()->getObjFileLowering();
133 /// getTargetData - Return information about data layout.
134 const TargetData &AsmPrinter::getTargetData() const {
135 return *TM.getTargetData();
138 /// getCurrentSection() - Return the current section we are emitting to.
139 const MCSection *AsmPrinter::getCurrentSection() const {
140 return OutStreamer.getCurrentSection();
145 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
146 AU.setPreservesAll();
147 MachineFunctionPass::getAnalysisUsage(AU);
148 AU.addRequired<MachineModuleInfo>();
149 AU.addRequired<GCModuleInfo>();
151 AU.addRequired<MachineLoopInfo>();
154 bool AsmPrinter::doInitialization(Module &M) {
155 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
156 MMI->AnalyzeModule(M);
158 // Initialize TargetLoweringObjectFile.
159 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
160 .Initialize(OutContext, TM);
162 Mang = new Mangler(OutContext, *TM.getTargetData());
164 // Allow the target to emit any magic that it wants at the start of the file.
165 EmitStartOfAsmFile(M);
167 // Very minimal debug info. It is ignored if we emit actual debug info. If we
168 // don't, this at least helps the user find where a global came from.
169 if (MAI->hasSingleParameterDotFile()) {
171 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
174 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
175 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
176 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
177 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
178 MP->beginAssembly(*this);
180 // Emit module-level inline asm if it exists.
181 if (!M.getModuleInlineAsm().empty()) {
182 OutStreamer.AddComment("Start of file scope inline assembly");
183 OutStreamer.AddBlankLine();
184 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
185 OutStreamer.AddComment("End of file scope inline assembly");
186 OutStreamer.AddBlankLine();
189 if (MAI->doesSupportDebugInformation())
190 DD = new DwarfDebug(this, &M);
192 switch (MAI->getExceptionHandlingType()) {
193 case ExceptionHandling::None:
195 case ExceptionHandling::SjLj:
196 DE = new DwarfSjLjException(this);
198 case ExceptionHandling::DwarfTable:
199 DE = new DwarfTableException(this);
201 case ExceptionHandling::DwarfCFI:
202 DE = new DwarfCFIException(this);
204 case ExceptionHandling::ARM:
205 DE = new ARMException(this);
209 llvm_unreachable("Unknown exception type.");
212 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
213 switch ((GlobalValue::LinkageTypes)Linkage) {
214 case GlobalValue::CommonLinkage:
215 case GlobalValue::LinkOnceAnyLinkage:
216 case GlobalValue::LinkOnceODRLinkage:
217 case GlobalValue::WeakAnyLinkage:
218 case GlobalValue::WeakODRLinkage:
219 case GlobalValue::LinkerPrivateWeakLinkage:
220 case GlobalValue::LinkerPrivateWeakDefAutoLinkage:
221 if (MAI->getWeakDefDirective() != 0) {
223 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
225 if ((GlobalValue::LinkageTypes)Linkage !=
226 GlobalValue::LinkerPrivateWeakDefAutoLinkage)
227 // .weak_definition _foo
228 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
230 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
231 } else if (MAI->getLinkOnceDirective() != 0) {
233 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
234 //NOTE: linkonce is handled by the section the symbol was assigned to.
237 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
240 case GlobalValue::DLLExportLinkage:
241 case GlobalValue::AppendingLinkage:
242 // FIXME: appending linkage variables should go into a section of
243 // their name or something. For now, just emit them as external.
244 case GlobalValue::ExternalLinkage:
245 // If external or appending, declare as a global symbol.
247 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
249 case GlobalValue::PrivateLinkage:
250 case GlobalValue::InternalLinkage:
251 case GlobalValue::LinkerPrivateLinkage:
254 llvm_unreachable("Unknown linkage type!");
259 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
260 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
261 if (GV->hasInitializer()) {
262 // Check to see if this is a special global used by LLVM, if so, emit it.
263 if (EmitSpecialLLVMGlobal(GV))
267 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
268 /*PrintType=*/false, GV->getParent());
269 OutStreamer.GetCommentOS() << '\n';
273 MCSymbol *GVSym = Mang->getSymbol(GV);
274 EmitVisibility(GVSym, GV->getVisibility());
276 if (!GV->hasInitializer()) // External globals require no extra code.
279 if (MAI->hasDotTypeDotSizeDirective())
280 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
282 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
284 const TargetData *TD = TM.getTargetData();
285 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType());
287 // If the alignment is specified, we *must* obey it. Overaligning a global
288 // with a specified alignment is a prompt way to break globals emitted to
289 // sections and expected to be contiguous (e.g. ObjC metadata).
290 unsigned AlignLog = getGVAlignmentLog2(GV, *TD);
292 // Handle common and BSS local symbols (.lcomm).
293 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
294 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
296 // Handle common symbols.
297 if (GVKind.isCommon()) {
298 unsigned Align = 1 << AlignLog;
299 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
303 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
307 // Handle local BSS symbols.
308 if (MAI->hasMachoZeroFillDirective()) {
309 const MCSection *TheSection =
310 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
311 // .zerofill __DATA, __bss, _foo, 400, 5
312 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
316 if (MAI->hasLCOMMDirective()) {
318 OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
322 unsigned Align = 1 << AlignLog;
323 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
327 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
329 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
333 const MCSection *TheSection =
334 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
336 // Handle the zerofill directive on darwin, which is a special form of BSS
338 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
339 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
342 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
343 // .zerofill __DATA, __common, _foo, 400, 5
344 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
348 // Handle thread local data for mach-o which requires us to output an
349 // additional structure of data and mangle the original symbol so that we
350 // can reference it later.
352 // TODO: This should become an "emit thread local global" method on TLOF.
353 // All of this macho specific stuff should be sunk down into TLOFMachO and
354 // stuff like "TLSExtraDataSection" should no longer be part of the parent
355 // TLOF class. This will also make it more obvious that stuff like
356 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
358 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
359 // Emit the .tbss symbol
361 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
363 if (GVKind.isThreadBSS())
364 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
365 else if (GVKind.isThreadData()) {
366 OutStreamer.SwitchSection(TheSection);
368 EmitAlignment(AlignLog, GV);
369 OutStreamer.EmitLabel(MangSym);
371 EmitGlobalConstant(GV->getInitializer());
374 OutStreamer.AddBlankLine();
376 // Emit the variable struct for the runtime.
377 const MCSection *TLVSect
378 = getObjFileLowering().getTLSExtraDataSection();
380 OutStreamer.SwitchSection(TLVSect);
381 // Emit the linkage here.
382 EmitLinkage(GV->getLinkage(), GVSym);
383 OutStreamer.EmitLabel(GVSym);
385 // Three pointers in size:
386 // - __tlv_bootstrap - used to make sure support exists
387 // - spare pointer, used when mapped by the runtime
388 // - pointer to mangled symbol above with initializer
389 unsigned PtrSize = TD->getPointerSizeInBits()/8;
390 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
392 OutStreamer.EmitIntValue(0, PtrSize, 0);
393 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0);
395 OutStreamer.AddBlankLine();
399 OutStreamer.SwitchSection(TheSection);
401 EmitLinkage(GV->getLinkage(), GVSym);
402 EmitAlignment(AlignLog, GV);
404 OutStreamer.EmitLabel(GVSym);
406 EmitGlobalConstant(GV->getInitializer());
408 if (MAI->hasDotTypeDotSizeDirective())
410 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
412 OutStreamer.AddBlankLine();
415 /// EmitFunctionHeader - This method emits the header for the current
417 void AsmPrinter::EmitFunctionHeader() {
418 // Print out constants referenced by the function
421 // Print the 'header' of function.
422 const Function *F = MF->getFunction();
424 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
425 EmitVisibility(CurrentFnSym, F->getVisibility());
427 EmitLinkage(F->getLinkage(), CurrentFnSym);
428 EmitAlignment(MF->getAlignment(), F);
430 if (MAI->hasDotTypeDotSizeDirective())
431 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
434 WriteAsOperand(OutStreamer.GetCommentOS(), F,
435 /*PrintType=*/false, F->getParent());
436 OutStreamer.GetCommentOS() << '\n';
439 // Emit the CurrentFnSym. This is a virtual function to allow targets to
440 // do their wild and crazy things as required.
441 EmitFunctionEntryLabel();
443 // If the function had address-taken blocks that got deleted, then we have
444 // references to the dangling symbols. Emit them at the start of the function
445 // so that we don't get references to undefined symbols.
446 std::vector<MCSymbol*> DeadBlockSyms;
447 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
448 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
449 OutStreamer.AddComment("Address taken block that was later removed");
450 OutStreamer.EmitLabel(DeadBlockSyms[i]);
453 // Add some workaround for linkonce linkage on Cygwin\MinGW.
454 if (MAI->getLinkOnceDirective() != 0 &&
455 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
456 // FIXME: What is this?
458 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
459 CurrentFnSym->getName());
460 OutStreamer.EmitLabel(FakeStub);
463 // Emit pre-function debug and/or EH information.
465 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
466 DE->BeginFunction(MF);
469 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
470 DD->beginFunction(MF);
474 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
475 /// function. This can be overridden by targets as required to do custom stuff.
476 void AsmPrinter::EmitFunctionEntryLabel() {
477 // The function label could have already been emitted if two symbols end up
478 // conflicting due to asm renaming. Detect this and emit an error.
479 if (CurrentFnSym->isUndefined())
480 return OutStreamer.EmitLabel(CurrentFnSym);
482 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
483 "' label emitted multiple times to assembly file");
487 /// EmitComments - Pretty-print comments for instructions.
488 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
489 const MachineFunction *MF = MI.getParent()->getParent();
490 const TargetMachine &TM = MF->getTarget();
492 // Check for spills and reloads
495 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
497 // We assume a single instruction only has a spill or reload, not
499 const MachineMemOperand *MMO;
500 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
501 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
502 MMO = *MI.memoperands_begin();
503 CommentOS << MMO->getSize() << "-byte Reload\n";
505 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
506 if (FrameInfo->isSpillSlotObjectIndex(FI))
507 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
508 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
509 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
510 MMO = *MI.memoperands_begin();
511 CommentOS << MMO->getSize() << "-byte Spill\n";
513 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
514 if (FrameInfo->isSpillSlotObjectIndex(FI))
515 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
518 // Check for spill-induced copies
519 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
520 CommentOS << " Reload Reuse\n";
523 /// EmitImplicitDef - This method emits the specified machine instruction
524 /// that is an implicit def.
525 static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
526 unsigned RegNo = MI->getOperand(0).getReg();
527 AP.OutStreamer.AddComment(Twine("implicit-def: ") +
528 AP.TM.getRegisterInfo()->getName(RegNo));
529 AP.OutStreamer.AddBlankLine();
532 static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) {
533 std::string Str = "kill:";
534 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
535 const MachineOperand &Op = MI->getOperand(i);
536 assert(Op.isReg() && "KILL instruction must have only register operands");
538 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
539 Str += (Op.isDef() ? "<def>" : "<kill>");
541 AP.OutStreamer.AddComment(Str);
542 AP.OutStreamer.AddBlankLine();
545 /// EmitDebugValueComment - This method handles the target-independent form
546 /// of DBG_VALUE, returning true if it was able to do so. A false return
547 /// means the target will need to handle MI in EmitInstruction.
548 static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
549 // This code handles only the 3-operand target-independent form.
550 if (MI->getNumOperands() != 3)
553 SmallString<128> Str;
554 raw_svector_ostream OS(Str);
555 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
557 // cast away const; DIetc do not take const operands for some reason.
558 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
559 if (V.getContext().isSubprogram())
560 OS << DISubprogram(V.getContext()).getDisplayName() << ":";
561 OS << V.getName() << " <- ";
563 // Register or immediate value. Register 0 means undef.
564 if (MI->getOperand(0).isFPImm()) {
565 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
566 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
567 OS << (double)APF.convertToFloat();
568 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
569 OS << APF.convertToDouble();
571 // There is no good way to print long double. Convert a copy to
572 // double. Ah well, it's only a comment.
574 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
576 OS << "(long double) " << APF.convertToDouble();
578 } else if (MI->getOperand(0).isImm()) {
579 OS << MI->getOperand(0).getImm();
581 assert(MI->getOperand(0).isReg() && "Unknown operand type");
582 if (MI->getOperand(0).getReg() == 0) {
583 // Suppress offset, it is not meaningful here.
585 // NOTE: Want this comment at start of line, don't emit with AddComment.
586 AP.OutStreamer.EmitRawText(OS.str());
589 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg());
592 OS << '+' << MI->getOperand(1).getImm();
593 // NOTE: Want this comment at start of line, don't emit with AddComment.
594 AP.OutStreamer.EmitRawText(OS.str());
598 bool AsmPrinter::needsCFIMoves() {
599 if (UnwindTablesMandatory)
602 if (MMI->hasDebugInfo() && !MAI->doesDwarfRequireFrameSection())
605 if (MF->getFunction()->doesNotThrow())
611 void AsmPrinter::emitPrologLabel(const MachineInstr &MI) {
612 MCSymbol *Label = MI.getOperand(0).getMCSymbol();
614 if (MAI->doesDwarfRequireFrameSection() ||
615 MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
616 OutStreamer.EmitLabel(Label);
618 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
621 if (!needsCFIMoves())
624 MachineModuleInfo &MMI = MF->getMMI();
625 std::vector<MachineMove> &Moves = MMI.getFrameMoves();
626 bool FoundOne = false;
628 for (std::vector<MachineMove>::iterator I = Moves.begin(),
629 E = Moves.end(); I != E; ++I) {
630 if (I->getLabel() == Label) {
631 EmitCFIFrameMove(*I);
638 /// EmitFunctionBody - This method emits the body and trailer for a
640 void AsmPrinter::EmitFunctionBody() {
641 // Emit target-specific gunk before the function body.
642 EmitFunctionBodyStart();
644 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
646 // Print out code for the function.
647 bool HasAnyRealCode = false;
648 const MachineInstr *LastMI = 0;
649 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
651 // Print a label for the basic block.
652 EmitBasicBlockStart(I);
653 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
657 // Print the assembly for the instruction.
658 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
659 !II->isDebugValue()) {
660 HasAnyRealCode = true;
664 if (ShouldPrintDebugScopes) {
665 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
666 DD->beginInstruction(II);
670 EmitComments(*II, OutStreamer.GetCommentOS());
672 switch (II->getOpcode()) {
673 case TargetOpcode::PROLOG_LABEL:
674 emitPrologLabel(*II);
677 case TargetOpcode::EH_LABEL:
678 case TargetOpcode::GC_LABEL:
679 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
681 case TargetOpcode::INLINEASM:
684 case TargetOpcode::DBG_VALUE:
686 if (!EmitDebugValueComment(II, *this))
690 case TargetOpcode::IMPLICIT_DEF:
691 if (isVerbose()) EmitImplicitDef(II, *this);
693 case TargetOpcode::KILL:
694 if (isVerbose()) EmitKill(II, *this);
697 if (!TM.hasMCUseLoc())
698 MCLineEntry::Make(&OutStreamer, getCurrentSection());
704 if (ShouldPrintDebugScopes) {
705 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
706 DD->endInstruction(II);
711 // If the last instruction was a prolog label, then we have a situation where
712 // we emitted a prolog but no function body. This results in the ending prolog
713 // label equaling the end of function label and an invalid "row" in the
714 // FDE. We need to emit a noop in this situation so that the FDE's rows are
716 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
718 // If the function is empty and the object file uses .subsections_via_symbols,
719 // then we need to emit *something* to the function body to prevent the
720 // labels from collapsing together. Just emit a noop.
721 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
723 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
724 if (Noop.getOpcode()) {
725 OutStreamer.AddComment("avoids zero-length function");
726 OutStreamer.EmitInstruction(Noop);
727 } else // Target not mc-ized yet.
728 OutStreamer.EmitRawText(StringRef("\tnop\n"));
731 // Emit target-specific gunk after the function body.
732 EmitFunctionBodyEnd();
734 // If the target wants a .size directive for the size of the function, emit
736 if (MAI->hasDotTypeDotSizeDirective()) {
737 // Create a symbol for the end of function, so we can get the size as
738 // difference between the function label and the temp label.
739 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
740 OutStreamer.EmitLabel(FnEndLabel);
742 const MCExpr *SizeExp =
743 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
744 MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
746 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
749 // Emit post-function debug information.
751 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
755 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
760 // Print out jump tables referenced by the function.
763 OutStreamer.AddBlankLine();
766 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
768 MachineLocation AsmPrinter::
769 getDebugValueLocation(const MachineInstr *MI) const {
770 // Target specific DBG_VALUE instructions are handled by each target.
771 return MachineLocation();
774 /// getDwarfRegOpSize - get size required to emit given machine location using
776 unsigned AsmPrinter::getDwarfRegOpSize(const MachineLocation &MLoc) const {
777 const TargetRegisterInfo *RI = TM.getRegisterInfo();
778 unsigned DWReg = RI->getDwarfRegNum(MLoc.getReg(), false);
779 if (int Offset = MLoc.getOffset()) {
780 // If the value is at a certain offset from frame register then
783 return 1 + MCAsmInfo::getSLEB128Size(Offset);
785 return 1 + MCAsmInfo::getULEB128Size(MLoc.getReg())
786 + MCAsmInfo::getSLEB128Size(Offset);
791 return 1 + MCAsmInfo::getULEB128Size(DWReg);
794 /// EmitDwarfRegOp - Emit dwarf register operation.
795 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc) const {
796 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
797 unsigned Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
798 if (int Offset = MLoc.getOffset()) {
800 OutStreamer.AddComment(
801 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg));
802 EmitInt8(dwarf::DW_OP_breg0 + Reg);
804 OutStreamer.AddComment("DW_OP_bregx");
805 EmitInt8(dwarf::DW_OP_bregx);
806 OutStreamer.AddComment(Twine(Reg));
812 OutStreamer.AddComment(
813 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
814 EmitInt8(dwarf::DW_OP_reg0 + Reg);
816 OutStreamer.AddComment("DW_OP_regx");
817 EmitInt8(dwarf::DW_OP_regx);
818 OutStreamer.AddComment(Twine(Reg));
824 bool AsmPrinter::doFinalization(Module &M) {
825 // Emit global variables.
826 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
828 EmitGlobalVariable(I);
830 // Emit visibility info for declarations
831 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
832 const Function &F = *I;
833 if (!F.isDeclaration())
835 GlobalValue::VisibilityTypes V = F.getVisibility();
836 if (V == GlobalValue::DefaultVisibility)
839 MCSymbol *Name = Mang->getSymbol(&F);
840 EmitVisibility(Name, V, false);
843 // Finalize debug and EH information.
846 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
853 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
859 // If the target wants to know about weak references, print them all.
860 if (MAI->getWeakRefDirective()) {
861 // FIXME: This is not lazy, it would be nice to only print weak references
862 // to stuff that is actually used. Note that doing so would require targets
863 // to notice uses in operands (due to constant exprs etc). This should
864 // happen with the MC stuff eventually.
866 // Print out module-level global variables here.
867 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
869 if (!I->hasExternalWeakLinkage()) continue;
870 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
873 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
874 if (!I->hasExternalWeakLinkage()) continue;
875 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
879 if (MAI->hasSetDirective()) {
880 OutStreamer.AddBlankLine();
881 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
883 MCSymbol *Name = Mang->getSymbol(I);
885 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
886 MCSymbol *Target = Mang->getSymbol(GV);
888 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
889 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
890 else if (I->hasWeakLinkage())
891 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
893 assert(I->hasLocalLinkage() && "Invalid alias linkage");
895 EmitVisibility(Name, I->getVisibility());
897 // Emit the directives as assignments aka .set:
898 OutStreamer.EmitAssignment(Name,
899 MCSymbolRefExpr::Create(Target, OutContext));
903 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
904 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
905 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
906 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
907 MP->finishAssembly(*this);
909 // If we don't have any trampolines, then we don't require stack memory
910 // to be executable. Some targets have a directive to declare this.
911 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
912 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
913 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
914 OutStreamer.SwitchSection(S);
916 // Allow the target to emit any magic that it wants at the end of the file,
917 // after everything else has gone out.
920 delete Mang; Mang = 0;
923 OutStreamer.Finish();
927 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
929 // Get the function symbol.
930 CurrentFnSym = Mang->getSymbol(MF.getFunction());
933 LI = &getAnalysis<MachineLoopInfo>();
937 // SectionCPs - Keep track the alignment, constpool entries per Section.
941 SmallVector<unsigned, 4> CPEs;
942 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
946 /// EmitConstantPool - Print to the current output stream assembly
947 /// representations of the constants in the constant pool MCP. This is
948 /// used to print out constants which have been "spilled to memory" by
949 /// the code generator.
951 void AsmPrinter::EmitConstantPool() {
952 const MachineConstantPool *MCP = MF->getConstantPool();
953 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
954 if (CP.empty()) return;
956 // Calculate sections for constant pool entries. We collect entries to go into
957 // the same section together to reduce amount of section switch statements.
958 SmallVector<SectionCPs, 4> CPSections;
959 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
960 const MachineConstantPoolEntry &CPE = CP[i];
961 unsigned Align = CPE.getAlignment();
964 switch (CPE.getRelocationInfo()) {
965 default: llvm_unreachable("Unknown section kind");
966 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
968 Kind = SectionKind::getReadOnlyWithRelLocal();
971 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
972 case 4: Kind = SectionKind::getMergeableConst4(); break;
973 case 8: Kind = SectionKind::getMergeableConst8(); break;
974 case 16: Kind = SectionKind::getMergeableConst16();break;
975 default: Kind = SectionKind::getMergeableConst(); break;
979 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
981 // The number of sections are small, just do a linear search from the
982 // last section to the first.
984 unsigned SecIdx = CPSections.size();
985 while (SecIdx != 0) {
986 if (CPSections[--SecIdx].S == S) {
992 SecIdx = CPSections.size();
993 CPSections.push_back(SectionCPs(S, Align));
996 if (Align > CPSections[SecIdx].Alignment)
997 CPSections[SecIdx].Alignment = Align;
998 CPSections[SecIdx].CPEs.push_back(i);
1001 // Now print stuff into the calculated sections.
1002 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1003 OutStreamer.SwitchSection(CPSections[i].S);
1004 EmitAlignment(Log2_32(CPSections[i].Alignment));
1006 unsigned Offset = 0;
1007 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1008 unsigned CPI = CPSections[i].CPEs[j];
1009 MachineConstantPoolEntry CPE = CP[CPI];
1011 // Emit inter-object padding for alignment.
1012 unsigned AlignMask = CPE.getAlignment() - 1;
1013 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1014 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
1016 const Type *Ty = CPE.getType();
1017 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
1018 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1020 if (CPE.isMachineConstantPoolEntry())
1021 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1023 EmitGlobalConstant(CPE.Val.ConstVal);
1028 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1029 /// by the current function to the current output stream.
1031 void AsmPrinter::EmitJumpTableInfo() {
1032 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1033 if (MJTI == 0) return;
1034 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1035 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1036 if (JT.empty()) return;
1038 // Pick the directive to use to print the jump table entries, and switch to
1039 // the appropriate section.
1040 const Function *F = MF->getFunction();
1041 bool JTInDiffSection = false;
1042 if (// In PIC mode, we need to emit the jump table to the same section as the
1043 // function body itself, otherwise the label differences won't make sense.
1044 // FIXME: Need a better predicate for this: what about custom entries?
1045 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1046 // We should also do if the section name is NULL or function is declared
1047 // in discardable section
1048 // FIXME: this isn't the right predicate, should be based on the MCSection
1049 // for the function.
1050 F->isWeakForLinker()) {
1051 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
1053 // Otherwise, drop it in the readonly section.
1054 const MCSection *ReadOnlySection =
1055 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1056 OutStreamer.SwitchSection(ReadOnlySection);
1057 JTInDiffSection = true;
1060 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
1062 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1063 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1065 // If this jump table was deleted, ignore it.
1066 if (JTBBs.empty()) continue;
1068 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1069 // .set directive for each unique entry. This reduces the number of
1070 // relocations the assembler will generate for the jump table.
1071 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1072 MAI->hasSetDirective()) {
1073 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1074 const TargetLowering *TLI = TM.getTargetLowering();
1075 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1076 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1077 const MachineBasicBlock *MBB = JTBBs[ii];
1078 if (!EmittedSets.insert(MBB)) continue;
1080 // .set LJTSet, LBB32-base
1082 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1083 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1084 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1088 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1089 // before each jump table. The first label is never referenced, but tells
1090 // the assembler and linker the extents of the jump table object. The
1091 // second label is actually referenced by the code.
1092 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1093 // FIXME: This doesn't have to have any specific name, just any randomly
1094 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1095 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1097 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1099 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1100 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1104 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1106 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1107 const MachineBasicBlock *MBB,
1108 unsigned UID) const {
1109 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1110 const MCExpr *Value = 0;
1111 switch (MJTI->getEntryKind()) {
1112 case MachineJumpTableInfo::EK_Inline:
1113 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
1114 case MachineJumpTableInfo::EK_Custom32:
1115 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1118 case MachineJumpTableInfo::EK_BlockAddress:
1119 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1121 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1123 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1124 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1125 // with a relocation as gp-relative, e.g.:
1127 MCSymbol *MBBSym = MBB->getSymbol();
1128 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1132 case MachineJumpTableInfo::EK_LabelDifference32: {
1133 // EK_LabelDifference32 - Each entry is the address of the block minus
1134 // the address of the jump table. This is used for PIC jump tables where
1135 // gprel32 is not supported. e.g.:
1136 // .word LBB123 - LJTI1_2
1137 // If the .set directive is supported, this is emitted as:
1138 // .set L4_5_set_123, LBB123 - LJTI1_2
1139 // .word L4_5_set_123
1141 // If we have emitted set directives for the jump table entries, print
1142 // them rather than the entries themselves. If we're emitting PIC, then
1143 // emit the table entries as differences between two text section labels.
1144 if (MAI->hasSetDirective()) {
1145 // If we used .set, reference the .set's symbol.
1146 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1150 // Otherwise, use the difference as the jump table entry.
1151 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1152 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1153 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1158 assert(Value && "Unknown entry kind!");
1160 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
1161 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
1165 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1166 /// special global used by LLVM. If so, emit it and return true, otherwise
1167 /// do nothing and return false.
1168 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1169 if (GV->getName() == "llvm.used") {
1170 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1171 EmitLLVMUsedList(GV->getInitializer());
1175 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1176 if (GV->getSection() == "llvm.metadata" ||
1177 GV->hasAvailableExternallyLinkage())
1180 if (!GV->hasAppendingLinkage()) return false;
1182 assert(GV->hasInitializer() && "Not a special LLVM global!");
1184 const TargetData *TD = TM.getTargetData();
1185 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1186 if (GV->getName() == "llvm.global_ctors") {
1187 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
1188 EmitAlignment(Align);
1189 EmitXXStructorList(GV->getInitializer());
1191 if (TM.getRelocationModel() == Reloc::Static &&
1192 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1193 StringRef Sym(".constructors_used");
1194 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1200 if (GV->getName() == "llvm.global_dtors") {
1201 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
1202 EmitAlignment(Align);
1203 EmitXXStructorList(GV->getInitializer());
1205 if (TM.getRelocationModel() == Reloc::Static &&
1206 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1207 StringRef Sym(".destructors_used");
1208 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1217 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1218 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1219 /// is true, as being used with this directive.
1220 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
1221 // Should be an array of 'i8*'.
1222 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1223 if (InitList == 0) return;
1225 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1226 const GlobalValue *GV =
1227 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1228 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1229 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1233 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
1234 /// function pointers, ignoring the init priority.
1235 void AsmPrinter::EmitXXStructorList(Constant *List) {
1236 // Should be an array of '{ int, void ()* }' structs. The first value is the
1237 // init priority, which we ignore.
1238 if (!isa<ConstantArray>(List)) return;
1239 ConstantArray *InitList = cast<ConstantArray>(List);
1240 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
1241 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
1242 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
1244 if (CS->getOperand(1)->isNullValue())
1245 return; // Found a null terminator, exit printing.
1246 // Emit the function pointer.
1247 EmitGlobalConstant(CS->getOperand(1));
1251 //===--------------------------------------------------------------------===//
1252 // Emission and print routines
1255 /// EmitInt8 - Emit a byte directive and value.
1257 void AsmPrinter::EmitInt8(int Value) const {
1258 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
1261 /// EmitInt16 - Emit a short directive and value.
1263 void AsmPrinter::EmitInt16(int Value) const {
1264 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
1267 /// EmitInt32 - Emit a long directive and value.
1269 void AsmPrinter::EmitInt32(int Value) const {
1270 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
1273 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1274 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1275 /// labels. This implicitly uses .set if it is available.
1276 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1277 unsigned Size) const {
1278 // Get the Hi-Lo expression.
1279 const MCExpr *Diff =
1280 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1281 MCSymbolRefExpr::Create(Lo, OutContext),
1284 if (!MAI->hasSetDirective()) {
1285 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
1289 // Otherwise, emit with .set (aka assignment).
1290 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1291 OutStreamer.EmitAssignment(SetLabel, Diff);
1292 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
1295 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1296 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1297 /// specify the labels. This implicitly uses .set if it is available.
1298 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1299 const MCSymbol *Lo, unsigned Size)
1302 // Emit Hi+Offset - Lo
1303 // Get the Hi+Offset expression.
1304 const MCExpr *Plus =
1305 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1306 MCConstantExpr::Create(Offset, OutContext),
1309 // Get the Hi+Offset-Lo expression.
1310 const MCExpr *Diff =
1311 MCBinaryExpr::CreateSub(Plus,
1312 MCSymbolRefExpr::Create(Lo, OutContext),
1315 if (!MAI->hasSetDirective())
1316 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/);
1318 // Otherwise, emit with .set (aka assignment).
1319 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1320 OutStreamer.EmitAssignment(SetLabel, Diff);
1321 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/);
1325 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1326 /// where the size in bytes of the directive is specified by Size and Label
1327 /// specifies the label. This implicitly uses .set if it is available.
1328 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1332 // Emit Label+Offset
1333 const MCExpr *Plus =
1334 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext),
1335 MCConstantExpr::Create(Offset, OutContext),
1338 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/);
1342 //===----------------------------------------------------------------------===//
1344 // EmitAlignment - Emit an alignment directive to the specified power of
1345 // two boundary. For example, if you pass in 3 here, you will get an 8
1346 // byte alignment. If a global value is specified, and if that global has
1347 // an explicit alignment requested, it will override the alignment request
1348 // if required for correctness.
1350 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1351 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits);
1353 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1355 if (getCurrentSection()->getKind().isText())
1356 OutStreamer.EmitCodeAlignment(1 << NumBits);
1358 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1361 //===----------------------------------------------------------------------===//
1362 // Constant emission.
1363 //===----------------------------------------------------------------------===//
1365 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1367 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1368 MCContext &Ctx = AP.OutContext;
1370 if (CV->isNullValue() || isa<UndefValue>(CV))
1371 return MCConstantExpr::Create(0, Ctx);
1373 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1374 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1376 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1377 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1379 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1380 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1382 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1384 llvm_unreachable("Unknown constant value to lower!");
1385 return MCConstantExpr::Create(0, Ctx);
1388 switch (CE->getOpcode()) {
1390 // If the code isn't optimized, there may be outstanding folding
1391 // opportunities. Attempt to fold the expression using TargetData as a
1392 // last resort before giving up.
1394 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1396 return LowerConstant(C, AP);
1398 // Otherwise report the problem to the user.
1401 raw_string_ostream OS(S);
1402 OS << "Unsupported expression in static initializer: ";
1403 WriteAsOperand(OS, CE, /*PrintType=*/false,
1404 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1405 report_fatal_error(OS.str());
1407 return MCConstantExpr::Create(0, Ctx);
1408 case Instruction::GetElementPtr: {
1409 const TargetData &TD = *AP.TM.getTargetData();
1410 // Generate a symbolic expression for the byte address
1411 const Constant *PtrVal = CE->getOperand(0);
1412 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1413 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1416 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1420 // Truncate/sext the offset to the pointer size.
1421 if (TD.getPointerSizeInBits() != 64) {
1422 int SExtAmount = 64-TD.getPointerSizeInBits();
1423 Offset = (Offset << SExtAmount) >> SExtAmount;
1426 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1430 case Instruction::Trunc:
1431 // We emit the value and depend on the assembler to truncate the generated
1432 // expression properly. This is important for differences between
1433 // blockaddress labels. Since the two labels are in the same function, it
1434 // is reasonable to treat their delta as a 32-bit value.
1436 case Instruction::BitCast:
1437 return LowerConstant(CE->getOperand(0), AP);
1439 case Instruction::IntToPtr: {
1440 const TargetData &TD = *AP.TM.getTargetData();
1441 // Handle casts to pointers by changing them into casts to the appropriate
1442 // integer type. This promotes constant folding and simplifies this code.
1443 Constant *Op = CE->getOperand(0);
1444 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1446 return LowerConstant(Op, AP);
1449 case Instruction::PtrToInt: {
1450 const TargetData &TD = *AP.TM.getTargetData();
1451 // Support only foldable casts to/from pointers that can be eliminated by
1452 // changing the pointer to the appropriately sized integer type.
1453 Constant *Op = CE->getOperand(0);
1454 const Type *Ty = CE->getType();
1456 const MCExpr *OpExpr = LowerConstant(Op, AP);
1458 // We can emit the pointer value into this slot if the slot is an
1459 // integer slot equal to the size of the pointer.
1460 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1463 // Otherwise the pointer is smaller than the resultant integer, mask off
1464 // the high bits so we are sure to get a proper truncation if the input is
1466 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1467 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1468 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1471 // The MC library also has a right-shift operator, but it isn't consistently
1472 // signed or unsigned between different targets.
1473 case Instruction::Add:
1474 case Instruction::Sub:
1475 case Instruction::Mul:
1476 case Instruction::SDiv:
1477 case Instruction::SRem:
1478 case Instruction::Shl:
1479 case Instruction::And:
1480 case Instruction::Or:
1481 case Instruction::Xor: {
1482 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1483 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1484 switch (CE->getOpcode()) {
1485 default: llvm_unreachable("Unknown binary operator constant cast expr");
1486 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1487 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1488 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1489 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1490 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1491 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1492 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1493 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1494 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1500 static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace,
1503 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1505 if (AddrSpace != 0 || !CA->isString()) {
1506 // Not a string. Print the values in successive locations
1507 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1508 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP);
1512 // Otherwise, it can be emitted as .ascii.
1513 SmallVector<char, 128> TmpVec;
1514 TmpVec.reserve(CA->getNumOperands());
1515 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1516 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1518 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1521 static void EmitGlobalConstantVector(const ConstantVector *CV,
1522 unsigned AddrSpace, AsmPrinter &AP) {
1523 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1524 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP);
1527 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1528 unsigned AddrSpace, AsmPrinter &AP) {
1529 // Print the fields in successive locations. Pad to align if needed!
1530 const TargetData *TD = AP.TM.getTargetData();
1531 unsigned Size = TD->getTypeAllocSize(CS->getType());
1532 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1533 uint64_t SizeSoFar = 0;
1534 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1535 const Constant *Field = CS->getOperand(i);
1537 // Check if padding is needed and insert one or more 0s.
1538 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1539 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1540 - Layout->getElementOffset(i)) - FieldSize;
1541 SizeSoFar += FieldSize + PadSize;
1543 // Now print the actual field value.
1544 EmitGlobalConstantImpl(Field, AddrSpace, AP);
1546 // Insert padding - this may include padding to increase the size of the
1547 // current field up to the ABI size (if the struct is not packed) as well
1548 // as padding to ensure that the next field starts at the right offset.
1549 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1551 assert(SizeSoFar == Layout->getSizeInBytes() &&
1552 "Layout of constant struct may be incorrect!");
1555 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1557 // FP Constants are printed as integer constants to avoid losing
1559 if (CFP->getType()->isDoubleTy()) {
1560 if (AP.isVerbose()) {
1561 double Val = CFP->getValueAPF().convertToDouble();
1562 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1565 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1566 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1570 if (CFP->getType()->isFloatTy()) {
1571 if (AP.isVerbose()) {
1572 float Val = CFP->getValueAPF().convertToFloat();
1573 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1575 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1576 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1580 if (CFP->getType()->isX86_FP80Ty()) {
1581 // all long double variants are printed as hex
1582 // API needed to prevent premature destruction
1583 APInt API = CFP->getValueAPF().bitcastToAPInt();
1584 const uint64_t *p = API.getRawData();
1585 if (AP.isVerbose()) {
1586 // Convert to double so we can print the approximate val as a comment.
1587 APFloat DoubleVal = CFP->getValueAPF();
1589 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1591 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1592 << DoubleVal.convertToDouble() << '\n';
1595 if (AP.TM.getTargetData()->isBigEndian()) {
1596 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1597 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1599 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1600 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1603 // Emit the tail padding for the long double.
1604 const TargetData &TD = *AP.TM.getTargetData();
1605 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1606 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1610 assert(CFP->getType()->isPPC_FP128Ty() &&
1611 "Floating point constant type not handled");
1612 // All long double variants are printed as hex
1613 // API needed to prevent premature destruction.
1614 APInt API = CFP->getValueAPF().bitcastToAPInt();
1615 const uint64_t *p = API.getRawData();
1616 if (AP.TM.getTargetData()->isBigEndian()) {
1617 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1618 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1620 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1621 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1625 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1626 unsigned AddrSpace, AsmPrinter &AP) {
1627 const TargetData *TD = AP.TM.getTargetData();
1628 unsigned BitWidth = CI->getBitWidth();
1629 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1631 // We don't expect assemblers to support integer data directives
1632 // for more than 64 bits, so we emit the data in at most 64-bit
1633 // quantities at a time.
1634 const uint64_t *RawData = CI->getValue().getRawData();
1635 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1636 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1637 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1641 static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
1643 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1644 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1645 return AP.OutStreamer.EmitZeros(Size, AddrSpace);
1648 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1649 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1656 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1657 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1660 EmitGlobalConstantLargeInt(CI, AddrSpace, AP);
1665 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1666 return EmitGlobalConstantArray(CVA, AddrSpace, AP);
1668 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1669 return EmitGlobalConstantStruct(CVS, AddrSpace, AP);
1671 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1672 return EmitGlobalConstantFP(CFP, AddrSpace, AP);
1674 if (isa<ConstantPointerNull>(CV)) {
1675 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1676 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace);
1680 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1681 return EmitGlobalConstantVector(V, AddrSpace, AP);
1683 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1684 // thread the streamer with EmitValue.
1685 AP.OutStreamer.EmitValue(LowerConstant(CV, AP),
1686 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()),
1690 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1691 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1692 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1694 EmitGlobalConstantImpl(CV, AddrSpace, *this);
1695 else if (MAI->hasSubsectionsViaSymbols()) {
1696 // If the global has zero size, emit a single byte so that two labels don't
1697 // look like they are at the same location.
1698 OutStreamer.EmitIntValue(0, 1, AddrSpace);
1702 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1703 // Target doesn't support this yet!
1704 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1707 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1709 OS << '+' << Offset;
1710 else if (Offset < 0)
1714 //===----------------------------------------------------------------------===//
1715 // Symbol Lowering Routines.
1716 //===----------------------------------------------------------------------===//
1718 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1719 /// temporary label with the specified stem and unique ID.
1720 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1721 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1725 /// GetTempSymbol - Return an assembler temporary label with the specified
1727 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1728 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1733 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1734 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1737 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1738 return MMI->getAddrLabelSymbol(BB);
1741 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1742 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1743 return OutContext.GetOrCreateSymbol
1744 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1745 + "_" + Twine(CPID));
1748 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1749 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1750 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1753 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1754 /// FIXME: privatize to AsmPrinter.
1755 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1756 return OutContext.GetOrCreateSymbol
1757 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1758 Twine(UID) + "_set_" + Twine(MBBID));
1761 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1762 /// global value name as its base, with the specified suffix, and where the
1763 /// symbol is forced to have private linkage if ForcePrivate is true.
1764 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1766 bool ForcePrivate) const {
1767 SmallString<60> NameStr;
1768 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1769 NameStr.append(Suffix.begin(), Suffix.end());
1770 return OutContext.GetOrCreateSymbol(NameStr.str());
1773 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1775 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1776 SmallString<60> NameStr;
1777 Mang->getNameWithPrefix(NameStr, Sym);
1778 return OutContext.GetOrCreateSymbol(NameStr.str());
1783 /// PrintParentLoopComment - Print comments about parent loops of this one.
1784 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1785 unsigned FunctionNumber) {
1786 if (Loop == 0) return;
1787 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1788 OS.indent(Loop->getLoopDepth()*2)
1789 << "Parent Loop BB" << FunctionNumber << "_"
1790 << Loop->getHeader()->getNumber()
1791 << " Depth=" << Loop->getLoopDepth() << '\n';
1795 /// PrintChildLoopComment - Print comments about child loops within
1796 /// the loop for this basic block, with nesting.
1797 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1798 unsigned FunctionNumber) {
1799 // Add child loop information
1800 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1801 OS.indent((*CL)->getLoopDepth()*2)
1802 << "Child Loop BB" << FunctionNumber << "_"
1803 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1805 PrintChildLoopComment(OS, *CL, FunctionNumber);
1809 /// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks.
1810 static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB,
1811 const MachineLoopInfo *LI,
1812 const AsmPrinter &AP) {
1813 // Add loop depth information
1814 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1815 if (Loop == 0) return;
1817 MachineBasicBlock *Header = Loop->getHeader();
1818 assert(Header && "No header for loop");
1820 // If this block is not a loop header, just print out what is the loop header
1822 if (Header != &MBB) {
1823 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1824 Twine(AP.getFunctionNumber())+"_" +
1825 Twine(Loop->getHeader()->getNumber())+
1826 " Depth="+Twine(Loop->getLoopDepth()));
1830 // Otherwise, it is a loop header. Print out information about child and
1832 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1834 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1837 OS.indent(Loop->getLoopDepth()*2-2);
1842 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1844 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1848 /// EmitBasicBlockStart - This method prints the label for the specified
1849 /// MachineBasicBlock, an alignment (if present) and a comment describing
1850 /// it if appropriate.
1851 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1852 // Emit an alignment directive for this block, if needed.
1853 if (unsigned Align = MBB->getAlignment())
1854 EmitAlignment(Log2_32(Align));
1856 // If the block has its address taken, emit any labels that were used to
1857 // reference the block. It is possible that there is more than one label
1858 // here, because multiple LLVM BB's may have been RAUW'd to this block after
1859 // the references were generated.
1860 if (MBB->hasAddressTaken()) {
1861 const BasicBlock *BB = MBB->getBasicBlock();
1863 OutStreamer.AddComment("Block address taken");
1865 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1867 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1868 OutStreamer.EmitLabel(Syms[i]);
1871 // Print the main label for the block.
1872 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1873 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
1874 if (const BasicBlock *BB = MBB->getBasicBlock())
1876 OutStreamer.AddComment("%" + BB->getName());
1878 EmitBasicBlockLoopComments(*MBB, LI, *this);
1880 // NOTE: Want this comment at start of line, don't emit with AddComment.
1881 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1882 Twine(MBB->getNumber()) + ":");
1886 if (const BasicBlock *BB = MBB->getBasicBlock())
1888 OutStreamer.AddComment("%" + BB->getName());
1889 EmitBasicBlockLoopComments(*MBB, LI, *this);
1892 OutStreamer.EmitLabel(MBB->getSymbol());
1896 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
1897 bool IsDefinition) const {
1898 MCSymbolAttr Attr = MCSA_Invalid;
1900 switch (Visibility) {
1902 case GlobalValue::HiddenVisibility:
1904 Attr = MAI->getHiddenVisibilityAttr();
1906 Attr = MAI->getHiddenDeclarationVisibilityAttr();
1908 case GlobalValue::ProtectedVisibility:
1909 Attr = MAI->getProtectedVisibilityAttr();
1913 if (Attr != MCSA_Invalid)
1914 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1917 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1918 /// exactly one predecessor and the control transfer mechanism between
1919 /// the predecessor and this block is a fall-through.
1921 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1922 // If this is a landing pad, it isn't a fall through. If it has no preds,
1923 // then nothing falls through to it.
1924 if (MBB->isLandingPad() || MBB->pred_empty())
1927 // If there isn't exactly one predecessor, it can't be a fall through.
1928 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1930 if (PI2 != MBB->pred_end())
1933 // The predecessor has to be immediately before this block.
1934 const MachineBasicBlock *Pred = *PI;
1936 if (!Pred->isLayoutSuccessor(MBB))
1939 // If the block is completely empty, then it definitely does fall through.
1943 // Otherwise, check the last instruction.
1944 const MachineInstr &LastInst = Pred->back();
1945 return !LastInst.getDesc().isBarrier();
1950 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1951 if (!S->usesMetadata())
1954 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1955 gcp_map_type::iterator GCPI = GCMap.find(S);
1956 if (GCPI != GCMap.end())
1957 return GCPI->second;
1959 const char *Name = S->getName().c_str();
1961 for (GCMetadataPrinterRegistry::iterator
1962 I = GCMetadataPrinterRegistry::begin(),
1963 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1964 if (strcmp(Name, I->getName()) == 0) {
1965 GCMetadataPrinter *GMP = I->instantiate();
1967 GCMap.insert(std::make_pair(S, GMP));
1971 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));