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::DwarfCFI:
199 DE = new DwarfCFIException(this);
201 case ExceptionHandling::ARM:
202 DE = new ARMException(this);
206 llvm_unreachable("Unknown exception type.");
209 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
210 switch ((GlobalValue::LinkageTypes)Linkage) {
211 case GlobalValue::CommonLinkage:
212 case GlobalValue::LinkOnceAnyLinkage:
213 case GlobalValue::LinkOnceODRLinkage:
214 case GlobalValue::WeakAnyLinkage:
215 case GlobalValue::WeakODRLinkage:
216 case GlobalValue::LinkerPrivateWeakLinkage:
217 case GlobalValue::LinkerPrivateWeakDefAutoLinkage:
218 if (MAI->getWeakDefDirective() != 0) {
220 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
222 if ((GlobalValue::LinkageTypes)Linkage !=
223 GlobalValue::LinkerPrivateWeakDefAutoLinkage)
224 // .weak_definition _foo
225 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
227 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
228 } else if (MAI->getLinkOnceDirective() != 0) {
230 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
231 //NOTE: linkonce is handled by the section the symbol was assigned to.
234 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
237 case GlobalValue::DLLExportLinkage:
238 case GlobalValue::AppendingLinkage:
239 // FIXME: appending linkage variables should go into a section of
240 // their name or something. For now, just emit them as external.
241 case GlobalValue::ExternalLinkage:
242 // If external or appending, declare as a global symbol.
244 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
246 case GlobalValue::PrivateLinkage:
247 case GlobalValue::InternalLinkage:
248 case GlobalValue::LinkerPrivateLinkage:
251 llvm_unreachable("Unknown linkage type!");
256 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
257 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
258 if (GV->hasInitializer()) {
259 // Check to see if this is a special global used by LLVM, if so, emit it.
260 if (EmitSpecialLLVMGlobal(GV))
264 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
265 /*PrintType=*/false, GV->getParent());
266 OutStreamer.GetCommentOS() << '\n';
270 MCSymbol *GVSym = Mang->getSymbol(GV);
271 EmitVisibility(GVSym, GV->getVisibility());
273 if (!GV->hasInitializer()) // External globals require no extra code.
276 if (MAI->hasDotTypeDotSizeDirective())
277 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
279 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
281 const TargetData *TD = TM.getTargetData();
282 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType());
284 // If the alignment is specified, we *must* obey it. Overaligning a global
285 // with a specified alignment is a prompt way to break globals emitted to
286 // sections and expected to be contiguous (e.g. ObjC metadata).
287 unsigned AlignLog = getGVAlignmentLog2(GV, *TD);
289 // Handle common and BSS local symbols (.lcomm).
290 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
291 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
293 // Handle common symbols.
294 if (GVKind.isCommon()) {
295 unsigned Align = 1 << AlignLog;
296 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
300 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
304 // Handle local BSS symbols.
305 if (MAI->hasMachoZeroFillDirective()) {
306 const MCSection *TheSection =
307 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
308 // .zerofill __DATA, __bss, _foo, 400, 5
309 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
313 if (MAI->hasLCOMMDirective()) {
315 OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
319 unsigned Align = 1 << AlignLog;
320 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
324 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
326 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
330 const MCSection *TheSection =
331 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
333 // Handle the zerofill directive on darwin, which is a special form of BSS
335 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
336 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
339 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
340 // .zerofill __DATA, __common, _foo, 400, 5
341 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
345 // Handle thread local data for mach-o which requires us to output an
346 // additional structure of data and mangle the original symbol so that we
347 // can reference it later.
349 // TODO: This should become an "emit thread local global" method on TLOF.
350 // All of this macho specific stuff should be sunk down into TLOFMachO and
351 // stuff like "TLSExtraDataSection" should no longer be part of the parent
352 // TLOF class. This will also make it more obvious that stuff like
353 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
355 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
356 // Emit the .tbss symbol
358 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
360 if (GVKind.isThreadBSS())
361 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
362 else if (GVKind.isThreadData()) {
363 OutStreamer.SwitchSection(TheSection);
365 EmitAlignment(AlignLog, GV);
366 OutStreamer.EmitLabel(MangSym);
368 EmitGlobalConstant(GV->getInitializer());
371 OutStreamer.AddBlankLine();
373 // Emit the variable struct for the runtime.
374 const MCSection *TLVSect
375 = getObjFileLowering().getTLSExtraDataSection();
377 OutStreamer.SwitchSection(TLVSect);
378 // Emit the linkage here.
379 EmitLinkage(GV->getLinkage(), GVSym);
380 OutStreamer.EmitLabel(GVSym);
382 // Three pointers in size:
383 // - __tlv_bootstrap - used to make sure support exists
384 // - spare pointer, used when mapped by the runtime
385 // - pointer to mangled symbol above with initializer
386 unsigned PtrSize = TD->getPointerSizeInBits()/8;
387 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
389 OutStreamer.EmitIntValue(0, PtrSize, 0);
390 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0);
392 OutStreamer.AddBlankLine();
396 OutStreamer.SwitchSection(TheSection);
398 EmitLinkage(GV->getLinkage(), GVSym);
399 EmitAlignment(AlignLog, GV);
401 OutStreamer.EmitLabel(GVSym);
403 EmitGlobalConstant(GV->getInitializer());
405 if (MAI->hasDotTypeDotSizeDirective())
407 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
409 OutStreamer.AddBlankLine();
412 /// EmitFunctionHeader - This method emits the header for the current
414 void AsmPrinter::EmitFunctionHeader() {
415 // Print out constants referenced by the function
418 // Print the 'header' of function.
419 const Function *F = MF->getFunction();
421 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
422 EmitVisibility(CurrentFnSym, F->getVisibility());
424 EmitLinkage(F->getLinkage(), CurrentFnSym);
425 EmitAlignment(MF->getAlignment(), F);
427 if (MAI->hasDotTypeDotSizeDirective())
428 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
431 WriteAsOperand(OutStreamer.GetCommentOS(), F,
432 /*PrintType=*/false, F->getParent());
433 OutStreamer.GetCommentOS() << '\n';
436 // Emit the CurrentFnSym. This is a virtual function to allow targets to
437 // do their wild and crazy things as required.
438 EmitFunctionEntryLabel();
440 // If the function had address-taken blocks that got deleted, then we have
441 // references to the dangling symbols. Emit them at the start of the function
442 // so that we don't get references to undefined symbols.
443 std::vector<MCSymbol*> DeadBlockSyms;
444 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
445 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
446 OutStreamer.AddComment("Address taken block that was later removed");
447 OutStreamer.EmitLabel(DeadBlockSyms[i]);
450 // Add some workaround for linkonce linkage on Cygwin\MinGW.
451 if (MAI->getLinkOnceDirective() != 0 &&
452 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
453 // FIXME: What is this?
455 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
456 CurrentFnSym->getName());
457 OutStreamer.EmitLabel(FakeStub);
460 // Emit pre-function debug and/or EH information.
462 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
463 DE->BeginFunction(MF);
466 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
467 DD->beginFunction(MF);
471 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
472 /// function. This can be overridden by targets as required to do custom stuff.
473 void AsmPrinter::EmitFunctionEntryLabel() {
474 // The function label could have already been emitted if two symbols end up
475 // conflicting due to asm renaming. Detect this and emit an error.
476 if (CurrentFnSym->isUndefined())
477 return OutStreamer.EmitLabel(CurrentFnSym);
479 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
480 "' label emitted multiple times to assembly file");
484 /// EmitComments - Pretty-print comments for instructions.
485 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
486 const MachineFunction *MF = MI.getParent()->getParent();
487 const TargetMachine &TM = MF->getTarget();
489 // Check for spills and reloads
492 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
494 // We assume a single instruction only has a spill or reload, not
496 const MachineMemOperand *MMO;
497 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
498 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
499 MMO = *MI.memoperands_begin();
500 CommentOS << MMO->getSize() << "-byte Reload\n";
502 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
503 if (FrameInfo->isSpillSlotObjectIndex(FI))
504 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
505 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
506 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
507 MMO = *MI.memoperands_begin();
508 CommentOS << MMO->getSize() << "-byte Spill\n";
510 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
511 if (FrameInfo->isSpillSlotObjectIndex(FI))
512 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
515 // Check for spill-induced copies
516 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
517 CommentOS << " Reload Reuse\n";
520 /// EmitImplicitDef - This method emits the specified machine instruction
521 /// that is an implicit def.
522 static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
523 unsigned RegNo = MI->getOperand(0).getReg();
524 AP.OutStreamer.AddComment(Twine("implicit-def: ") +
525 AP.TM.getRegisterInfo()->getName(RegNo));
526 AP.OutStreamer.AddBlankLine();
529 static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) {
530 std::string Str = "kill:";
531 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
532 const MachineOperand &Op = MI->getOperand(i);
533 assert(Op.isReg() && "KILL instruction must have only register operands");
535 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
536 Str += (Op.isDef() ? "<def>" : "<kill>");
538 AP.OutStreamer.AddComment(Str);
539 AP.OutStreamer.AddBlankLine();
542 /// EmitDebugValueComment - This method handles the target-independent form
543 /// of DBG_VALUE, returning true if it was able to do so. A false return
544 /// means the target will need to handle MI in EmitInstruction.
545 static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
546 // This code handles only the 3-operand target-independent form.
547 if (MI->getNumOperands() != 3)
550 SmallString<128> Str;
551 raw_svector_ostream OS(Str);
552 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
554 // cast away const; DIetc do not take const operands for some reason.
555 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
556 if (V.getContext().isSubprogram())
557 OS << DISubprogram(V.getContext()).getDisplayName() << ":";
558 OS << V.getName() << " <- ";
560 // Register or immediate value. Register 0 means undef.
561 if (MI->getOperand(0).isFPImm()) {
562 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
563 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
564 OS << (double)APF.convertToFloat();
565 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
566 OS << APF.convertToDouble();
568 // There is no good way to print long double. Convert a copy to
569 // double. Ah well, it's only a comment.
571 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
573 OS << "(long double) " << APF.convertToDouble();
575 } else if (MI->getOperand(0).isImm()) {
576 OS << MI->getOperand(0).getImm();
578 assert(MI->getOperand(0).isReg() && "Unknown operand type");
579 if (MI->getOperand(0).getReg() == 0) {
580 // Suppress offset, it is not meaningful here.
582 // NOTE: Want this comment at start of line, don't emit with AddComment.
583 AP.OutStreamer.EmitRawText(OS.str());
586 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg());
589 OS << '+' << MI->getOperand(1).getImm();
590 // NOTE: Want this comment at start of line, don't emit with AddComment.
591 AP.OutStreamer.EmitRawText(OS.str());
595 bool AsmPrinter::needsCFIMoves() {
596 if (UnwindTablesMandatory)
599 if (MMI->hasDebugInfo())
602 if (MF->getFunction()->doesNotThrow())
608 void AsmPrinter::emitPrologLabel(const MachineInstr &MI) {
609 MCSymbol *Label = MI.getOperand(0).getMCSymbol();
611 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
612 OutStreamer.EmitLabel(Label);
614 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
617 if (!needsCFIMoves())
620 MachineModuleInfo &MMI = MF->getMMI();
621 std::vector<MachineMove> &Moves = MMI.getFrameMoves();
622 bool FoundOne = false;
624 for (std::vector<MachineMove>::iterator I = Moves.begin(),
625 E = Moves.end(); I != E; ++I) {
626 if (I->getLabel() == Label) {
627 EmitCFIFrameMove(*I);
634 /// EmitFunctionBody - This method emits the body and trailer for a
636 void AsmPrinter::EmitFunctionBody() {
637 // Emit target-specific gunk before the function body.
638 EmitFunctionBodyStart();
640 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
642 // Print out code for the function.
643 bool HasAnyRealCode = false;
644 const MachineInstr *LastMI = 0;
645 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
647 // Print a label for the basic block.
648 EmitBasicBlockStart(I);
649 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
653 // Print the assembly for the instruction.
654 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
655 !II->isDebugValue()) {
656 HasAnyRealCode = true;
660 if (ShouldPrintDebugScopes) {
661 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
662 DD->beginInstruction(II);
666 EmitComments(*II, OutStreamer.GetCommentOS());
668 switch (II->getOpcode()) {
669 case TargetOpcode::PROLOG_LABEL:
670 emitPrologLabel(*II);
673 case TargetOpcode::EH_LABEL:
674 case TargetOpcode::GC_LABEL:
675 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
677 case TargetOpcode::INLINEASM:
680 case TargetOpcode::DBG_VALUE:
682 if (!EmitDebugValueComment(II, *this))
686 case TargetOpcode::IMPLICIT_DEF:
687 if (isVerbose()) EmitImplicitDef(II, *this);
689 case TargetOpcode::KILL:
690 if (isVerbose()) EmitKill(II, *this);
693 if (!TM.hasMCUseLoc())
694 MCLineEntry::Make(&OutStreamer, getCurrentSection());
700 if (ShouldPrintDebugScopes) {
701 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
702 DD->endInstruction(II);
707 // If the last instruction was a prolog label, then we have a situation where
708 // we emitted a prolog but no function body. This results in the ending prolog
709 // label equaling the end of function label and an invalid "row" in the
710 // FDE. We need to emit a noop in this situation so that the FDE's rows are
712 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
714 // If the function is empty and the object file uses .subsections_via_symbols,
715 // then we need to emit *something* to the function body to prevent the
716 // labels from collapsing together. Just emit a noop.
717 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
719 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
720 if (Noop.getOpcode()) {
721 OutStreamer.AddComment("avoids zero-length function");
722 OutStreamer.EmitInstruction(Noop);
723 } else // Target not mc-ized yet.
724 OutStreamer.EmitRawText(StringRef("\tnop\n"));
727 // Emit target-specific gunk after the function body.
728 EmitFunctionBodyEnd();
730 // If the target wants a .size directive for the size of the function, emit
732 if (MAI->hasDotTypeDotSizeDirective()) {
733 // Create a symbol for the end of function, so we can get the size as
734 // difference between the function label and the temp label.
735 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
736 OutStreamer.EmitLabel(FnEndLabel);
738 const MCExpr *SizeExp =
739 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
740 MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
742 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
745 // Emit post-function debug information.
747 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
751 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
756 // Print out jump tables referenced by the function.
759 OutStreamer.AddBlankLine();
762 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
764 MachineLocation AsmPrinter::
765 getDebugValueLocation(const MachineInstr *MI) const {
766 // Target specific DBG_VALUE instructions are handled by each target.
767 return MachineLocation();
770 /// getDwarfRegOpSize - get size required to emit given machine location using
772 unsigned AsmPrinter::getDwarfRegOpSize(const MachineLocation &MLoc) const {
773 const TargetRegisterInfo *RI = TM.getRegisterInfo();
774 unsigned DWReg = RI->getDwarfRegNum(MLoc.getReg(), false);
775 if (int Offset = MLoc.getOffset()) {
776 // If the value is at a certain offset from frame register then
779 return 1 + MCAsmInfo::getSLEB128Size(Offset);
781 return 1 + MCAsmInfo::getULEB128Size(MLoc.getReg())
782 + MCAsmInfo::getSLEB128Size(Offset);
787 return 1 + MCAsmInfo::getULEB128Size(DWReg);
790 /// EmitDwarfRegOp - Emit dwarf register operation.
791 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc) const {
792 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
793 unsigned Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
794 if (int Offset = MLoc.getOffset()) {
796 OutStreamer.AddComment(
797 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg));
798 EmitInt8(dwarf::DW_OP_breg0 + Reg);
800 OutStreamer.AddComment("DW_OP_bregx");
801 EmitInt8(dwarf::DW_OP_bregx);
802 OutStreamer.AddComment(Twine(Reg));
808 OutStreamer.AddComment(
809 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
810 EmitInt8(dwarf::DW_OP_reg0 + Reg);
812 OutStreamer.AddComment("DW_OP_regx");
813 EmitInt8(dwarf::DW_OP_regx);
814 OutStreamer.AddComment(Twine(Reg));
820 bool AsmPrinter::doFinalization(Module &M) {
821 // Emit global variables.
822 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
824 EmitGlobalVariable(I);
826 // Emit visibility info for declarations
827 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
828 const Function &F = *I;
829 if (!F.isDeclaration())
831 GlobalValue::VisibilityTypes V = F.getVisibility();
832 if (V == GlobalValue::DefaultVisibility)
835 MCSymbol *Name = Mang->getSymbol(&F);
836 EmitVisibility(Name, V, false);
839 // Finalize debug and EH information.
842 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
849 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
855 // If the target wants to know about weak references, print them all.
856 if (MAI->getWeakRefDirective()) {
857 // FIXME: This is not lazy, it would be nice to only print weak references
858 // to stuff that is actually used. Note that doing so would require targets
859 // to notice uses in operands (due to constant exprs etc). This should
860 // happen with the MC stuff eventually.
862 // Print out module-level global variables here.
863 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
865 if (!I->hasExternalWeakLinkage()) continue;
866 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
869 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
870 if (!I->hasExternalWeakLinkage()) continue;
871 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
875 if (MAI->hasSetDirective()) {
876 OutStreamer.AddBlankLine();
877 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
879 MCSymbol *Name = Mang->getSymbol(I);
881 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
882 MCSymbol *Target = Mang->getSymbol(GV);
884 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
885 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
886 else if (I->hasWeakLinkage())
887 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
889 assert(I->hasLocalLinkage() && "Invalid alias linkage");
891 EmitVisibility(Name, I->getVisibility());
893 // Emit the directives as assignments aka .set:
894 OutStreamer.EmitAssignment(Name,
895 MCSymbolRefExpr::Create(Target, OutContext));
899 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
900 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
901 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
902 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
903 MP->finishAssembly(*this);
905 // If we don't have any trampolines, then we don't require stack memory
906 // to be executable. Some targets have a directive to declare this.
907 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
908 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
909 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
910 OutStreamer.SwitchSection(S);
912 // Allow the target to emit any magic that it wants at the end of the file,
913 // after everything else has gone out.
916 delete Mang; Mang = 0;
919 OutStreamer.Finish();
923 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
925 // Get the function symbol.
926 CurrentFnSym = Mang->getSymbol(MF.getFunction());
929 LI = &getAnalysis<MachineLoopInfo>();
933 // SectionCPs - Keep track the alignment, constpool entries per Section.
937 SmallVector<unsigned, 4> CPEs;
938 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
942 /// EmitConstantPool - Print to the current output stream assembly
943 /// representations of the constants in the constant pool MCP. This is
944 /// used to print out constants which have been "spilled to memory" by
945 /// the code generator.
947 void AsmPrinter::EmitConstantPool() {
948 const MachineConstantPool *MCP = MF->getConstantPool();
949 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
950 if (CP.empty()) return;
952 // Calculate sections for constant pool entries. We collect entries to go into
953 // the same section together to reduce amount of section switch statements.
954 SmallVector<SectionCPs, 4> CPSections;
955 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
956 const MachineConstantPoolEntry &CPE = CP[i];
957 unsigned Align = CPE.getAlignment();
960 switch (CPE.getRelocationInfo()) {
961 default: llvm_unreachable("Unknown section kind");
962 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
964 Kind = SectionKind::getReadOnlyWithRelLocal();
967 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
968 case 4: Kind = SectionKind::getMergeableConst4(); break;
969 case 8: Kind = SectionKind::getMergeableConst8(); break;
970 case 16: Kind = SectionKind::getMergeableConst16();break;
971 default: Kind = SectionKind::getMergeableConst(); break;
975 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
977 // The number of sections are small, just do a linear search from the
978 // last section to the first.
980 unsigned SecIdx = CPSections.size();
981 while (SecIdx != 0) {
982 if (CPSections[--SecIdx].S == S) {
988 SecIdx = CPSections.size();
989 CPSections.push_back(SectionCPs(S, Align));
992 if (Align > CPSections[SecIdx].Alignment)
993 CPSections[SecIdx].Alignment = Align;
994 CPSections[SecIdx].CPEs.push_back(i);
997 // Now print stuff into the calculated sections.
998 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
999 OutStreamer.SwitchSection(CPSections[i].S);
1000 EmitAlignment(Log2_32(CPSections[i].Alignment));
1002 unsigned Offset = 0;
1003 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1004 unsigned CPI = CPSections[i].CPEs[j];
1005 MachineConstantPoolEntry CPE = CP[CPI];
1007 // Emit inter-object padding for alignment.
1008 unsigned AlignMask = CPE.getAlignment() - 1;
1009 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1010 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
1012 const Type *Ty = CPE.getType();
1013 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
1014 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1016 if (CPE.isMachineConstantPoolEntry())
1017 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1019 EmitGlobalConstant(CPE.Val.ConstVal);
1024 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1025 /// by the current function to the current output stream.
1027 void AsmPrinter::EmitJumpTableInfo() {
1028 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1029 if (MJTI == 0) return;
1030 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1031 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1032 if (JT.empty()) return;
1034 // Pick the directive to use to print the jump table entries, and switch to
1035 // the appropriate section.
1036 const Function *F = MF->getFunction();
1037 bool JTInDiffSection = false;
1038 if (// In PIC mode, we need to emit the jump table to the same section as the
1039 // function body itself, otherwise the label differences won't make sense.
1040 // FIXME: Need a better predicate for this: what about custom entries?
1041 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1042 // We should also do if the section name is NULL or function is declared
1043 // in discardable section
1044 // FIXME: this isn't the right predicate, should be based on the MCSection
1045 // for the function.
1046 F->isWeakForLinker()) {
1047 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
1049 // Otherwise, drop it in the readonly section.
1050 const MCSection *ReadOnlySection =
1051 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1052 OutStreamer.SwitchSection(ReadOnlySection);
1053 JTInDiffSection = true;
1056 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
1058 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1059 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1061 // If this jump table was deleted, ignore it.
1062 if (JTBBs.empty()) continue;
1064 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1065 // .set directive for each unique entry. This reduces the number of
1066 // relocations the assembler will generate for the jump table.
1067 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1068 MAI->hasSetDirective()) {
1069 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1070 const TargetLowering *TLI = TM.getTargetLowering();
1071 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1072 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1073 const MachineBasicBlock *MBB = JTBBs[ii];
1074 if (!EmittedSets.insert(MBB)) continue;
1076 // .set LJTSet, LBB32-base
1078 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1079 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1080 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1084 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1085 // before each jump table. The first label is never referenced, but tells
1086 // the assembler and linker the extents of the jump table object. The
1087 // second label is actually referenced by the code.
1088 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1089 // FIXME: This doesn't have to have any specific name, just any randomly
1090 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1091 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1093 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1095 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1096 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1100 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1102 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1103 const MachineBasicBlock *MBB,
1104 unsigned UID) const {
1105 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1106 const MCExpr *Value = 0;
1107 switch (MJTI->getEntryKind()) {
1108 case MachineJumpTableInfo::EK_Inline:
1109 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
1110 case MachineJumpTableInfo::EK_Custom32:
1111 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1114 case MachineJumpTableInfo::EK_BlockAddress:
1115 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1117 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1119 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1120 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1121 // with a relocation as gp-relative, e.g.:
1123 MCSymbol *MBBSym = MBB->getSymbol();
1124 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1128 case MachineJumpTableInfo::EK_LabelDifference32: {
1129 // EK_LabelDifference32 - Each entry is the address of the block minus
1130 // the address of the jump table. This is used for PIC jump tables where
1131 // gprel32 is not supported. e.g.:
1132 // .word LBB123 - LJTI1_2
1133 // If the .set directive is supported, this is emitted as:
1134 // .set L4_5_set_123, LBB123 - LJTI1_2
1135 // .word L4_5_set_123
1137 // If we have emitted set directives for the jump table entries, print
1138 // them rather than the entries themselves. If we're emitting PIC, then
1139 // emit the table entries as differences between two text section labels.
1140 if (MAI->hasSetDirective()) {
1141 // If we used .set, reference the .set's symbol.
1142 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1146 // Otherwise, use the difference as the jump table entry.
1147 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1148 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1149 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1154 assert(Value && "Unknown entry kind!");
1156 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
1157 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
1161 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1162 /// special global used by LLVM. If so, emit it and return true, otherwise
1163 /// do nothing and return false.
1164 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1165 if (GV->getName() == "llvm.used") {
1166 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1167 EmitLLVMUsedList(GV->getInitializer());
1171 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1172 if (GV->getSection() == "llvm.metadata" ||
1173 GV->hasAvailableExternallyLinkage())
1176 if (!GV->hasAppendingLinkage()) return false;
1178 assert(GV->hasInitializer() && "Not a special LLVM global!");
1180 const TargetData *TD = TM.getTargetData();
1181 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1182 if (GV->getName() == "llvm.global_ctors") {
1183 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
1184 EmitAlignment(Align);
1185 EmitXXStructorList(GV->getInitializer());
1187 if (TM.getRelocationModel() == Reloc::Static &&
1188 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1189 StringRef Sym(".constructors_used");
1190 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1196 if (GV->getName() == "llvm.global_dtors") {
1197 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
1198 EmitAlignment(Align);
1199 EmitXXStructorList(GV->getInitializer());
1201 if (TM.getRelocationModel() == Reloc::Static &&
1202 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1203 StringRef Sym(".destructors_used");
1204 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1213 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1214 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1215 /// is true, as being used with this directive.
1216 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
1217 // Should be an array of 'i8*'.
1218 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1219 if (InitList == 0) return;
1221 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1222 const GlobalValue *GV =
1223 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1224 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1225 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1229 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
1230 /// function pointers, ignoring the init priority.
1231 void AsmPrinter::EmitXXStructorList(Constant *List) {
1232 // Should be an array of '{ int, void ()* }' structs. The first value is the
1233 // init priority, which we ignore.
1234 if (!isa<ConstantArray>(List)) return;
1235 ConstantArray *InitList = cast<ConstantArray>(List);
1236 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
1237 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
1238 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
1240 if (CS->getOperand(1)->isNullValue())
1241 return; // Found a null terminator, exit printing.
1242 // Emit the function pointer.
1243 EmitGlobalConstant(CS->getOperand(1));
1247 //===--------------------------------------------------------------------===//
1248 // Emission and print routines
1251 /// EmitInt8 - Emit a byte directive and value.
1253 void AsmPrinter::EmitInt8(int Value) const {
1254 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
1257 /// EmitInt16 - Emit a short directive and value.
1259 void AsmPrinter::EmitInt16(int Value) const {
1260 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
1263 /// EmitInt32 - Emit a long directive and value.
1265 void AsmPrinter::EmitInt32(int Value) const {
1266 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
1269 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1270 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1271 /// labels. This implicitly uses .set if it is available.
1272 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1273 unsigned Size) const {
1274 // Get the Hi-Lo expression.
1275 const MCExpr *Diff =
1276 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1277 MCSymbolRefExpr::Create(Lo, OutContext),
1280 if (!MAI->hasSetDirective()) {
1281 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
1285 // Otherwise, emit with .set (aka assignment).
1286 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1287 OutStreamer.EmitAssignment(SetLabel, Diff);
1288 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
1291 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1292 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1293 /// specify the labels. This implicitly uses .set if it is available.
1294 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1295 const MCSymbol *Lo, unsigned Size)
1298 // Emit Hi+Offset - Lo
1299 // Get the Hi+Offset expression.
1300 const MCExpr *Plus =
1301 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1302 MCConstantExpr::Create(Offset, OutContext),
1305 // Get the Hi+Offset-Lo expression.
1306 const MCExpr *Diff =
1307 MCBinaryExpr::CreateSub(Plus,
1308 MCSymbolRefExpr::Create(Lo, OutContext),
1311 if (!MAI->hasSetDirective())
1312 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/);
1314 // Otherwise, emit with .set (aka assignment).
1315 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1316 OutStreamer.EmitAssignment(SetLabel, Diff);
1317 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/);
1321 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1322 /// where the size in bytes of the directive is specified by Size and Label
1323 /// specifies the label. This implicitly uses .set if it is available.
1324 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1328 // Emit Label+Offset
1329 const MCExpr *Plus =
1330 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext),
1331 MCConstantExpr::Create(Offset, OutContext),
1334 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/);
1338 //===----------------------------------------------------------------------===//
1340 // EmitAlignment - Emit an alignment directive to the specified power of
1341 // two boundary. For example, if you pass in 3 here, you will get an 8
1342 // byte alignment. If a global value is specified, and if that global has
1343 // an explicit alignment requested, it will override the alignment request
1344 // if required for correctness.
1346 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1347 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits);
1349 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1351 if (getCurrentSection()->getKind().isText())
1352 OutStreamer.EmitCodeAlignment(1 << NumBits);
1354 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1357 //===----------------------------------------------------------------------===//
1358 // Constant emission.
1359 //===----------------------------------------------------------------------===//
1361 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1363 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1364 MCContext &Ctx = AP.OutContext;
1366 if (CV->isNullValue() || isa<UndefValue>(CV))
1367 return MCConstantExpr::Create(0, Ctx);
1369 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1370 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1372 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1373 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1375 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1376 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1378 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1380 llvm_unreachable("Unknown constant value to lower!");
1381 return MCConstantExpr::Create(0, Ctx);
1384 switch (CE->getOpcode()) {
1386 // If the code isn't optimized, there may be outstanding folding
1387 // opportunities. Attempt to fold the expression using TargetData as a
1388 // last resort before giving up.
1390 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1392 return LowerConstant(C, AP);
1394 // Otherwise report the problem to the user.
1397 raw_string_ostream OS(S);
1398 OS << "Unsupported expression in static initializer: ";
1399 WriteAsOperand(OS, CE, /*PrintType=*/false,
1400 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1401 report_fatal_error(OS.str());
1403 return MCConstantExpr::Create(0, Ctx);
1404 case Instruction::GetElementPtr: {
1405 const TargetData &TD = *AP.TM.getTargetData();
1406 // Generate a symbolic expression for the byte address
1407 const Constant *PtrVal = CE->getOperand(0);
1408 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1409 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1412 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1416 // Truncate/sext the offset to the pointer size.
1417 if (TD.getPointerSizeInBits() != 64) {
1418 int SExtAmount = 64-TD.getPointerSizeInBits();
1419 Offset = (Offset << SExtAmount) >> SExtAmount;
1422 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1426 case Instruction::Trunc:
1427 // We emit the value and depend on the assembler to truncate the generated
1428 // expression properly. This is important for differences between
1429 // blockaddress labels. Since the two labels are in the same function, it
1430 // is reasonable to treat their delta as a 32-bit value.
1432 case Instruction::BitCast:
1433 return LowerConstant(CE->getOperand(0), AP);
1435 case Instruction::IntToPtr: {
1436 const TargetData &TD = *AP.TM.getTargetData();
1437 // Handle casts to pointers by changing them into casts to the appropriate
1438 // integer type. This promotes constant folding and simplifies this code.
1439 Constant *Op = CE->getOperand(0);
1440 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1442 return LowerConstant(Op, AP);
1445 case Instruction::PtrToInt: {
1446 const TargetData &TD = *AP.TM.getTargetData();
1447 // Support only foldable casts to/from pointers that can be eliminated by
1448 // changing the pointer to the appropriately sized integer type.
1449 Constant *Op = CE->getOperand(0);
1450 const Type *Ty = CE->getType();
1452 const MCExpr *OpExpr = LowerConstant(Op, AP);
1454 // We can emit the pointer value into this slot if the slot is an
1455 // integer slot equal to the size of the pointer.
1456 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1459 // Otherwise the pointer is smaller than the resultant integer, mask off
1460 // the high bits so we are sure to get a proper truncation if the input is
1462 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1463 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1464 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1467 // The MC library also has a right-shift operator, but it isn't consistently
1468 // signed or unsigned between different targets.
1469 case Instruction::Add:
1470 case Instruction::Sub:
1471 case Instruction::Mul:
1472 case Instruction::SDiv:
1473 case Instruction::SRem:
1474 case Instruction::Shl:
1475 case Instruction::And:
1476 case Instruction::Or:
1477 case Instruction::Xor: {
1478 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1479 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1480 switch (CE->getOpcode()) {
1481 default: llvm_unreachable("Unknown binary operator constant cast expr");
1482 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1483 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1484 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1485 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1486 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1487 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1488 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1489 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1490 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1496 static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace,
1499 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1501 if (AddrSpace != 0 || !CA->isString()) {
1502 // Not a string. Print the values in successive locations
1503 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1504 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP);
1508 // Otherwise, it can be emitted as .ascii.
1509 SmallVector<char, 128> TmpVec;
1510 TmpVec.reserve(CA->getNumOperands());
1511 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1512 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1514 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1517 static void EmitGlobalConstantVector(const ConstantVector *CV,
1518 unsigned AddrSpace, AsmPrinter &AP) {
1519 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1520 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP);
1523 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1524 unsigned AddrSpace, AsmPrinter &AP) {
1525 // Print the fields in successive locations. Pad to align if needed!
1526 const TargetData *TD = AP.TM.getTargetData();
1527 unsigned Size = TD->getTypeAllocSize(CS->getType());
1528 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1529 uint64_t SizeSoFar = 0;
1530 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1531 const Constant *Field = CS->getOperand(i);
1533 // Check if padding is needed and insert one or more 0s.
1534 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1535 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1536 - Layout->getElementOffset(i)) - FieldSize;
1537 SizeSoFar += FieldSize + PadSize;
1539 // Now print the actual field value.
1540 EmitGlobalConstantImpl(Field, AddrSpace, AP);
1542 // Insert padding - this may include padding to increase the size of the
1543 // current field up to the ABI size (if the struct is not packed) as well
1544 // as padding to ensure that the next field starts at the right offset.
1545 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1547 assert(SizeSoFar == Layout->getSizeInBytes() &&
1548 "Layout of constant struct may be incorrect!");
1551 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1553 // FP Constants are printed as integer constants to avoid losing
1555 if (CFP->getType()->isDoubleTy()) {
1556 if (AP.isVerbose()) {
1557 double Val = CFP->getValueAPF().convertToDouble();
1558 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1561 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1562 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1566 if (CFP->getType()->isFloatTy()) {
1567 if (AP.isVerbose()) {
1568 float Val = CFP->getValueAPF().convertToFloat();
1569 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1571 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1572 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1576 if (CFP->getType()->isX86_FP80Ty()) {
1577 // all long double variants are printed as hex
1578 // API needed to prevent premature destruction
1579 APInt API = CFP->getValueAPF().bitcastToAPInt();
1580 const uint64_t *p = API.getRawData();
1581 if (AP.isVerbose()) {
1582 // Convert to double so we can print the approximate val as a comment.
1583 APFloat DoubleVal = CFP->getValueAPF();
1585 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1587 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1588 << DoubleVal.convertToDouble() << '\n';
1591 if (AP.TM.getTargetData()->isBigEndian()) {
1592 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1593 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1595 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1596 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1599 // Emit the tail padding for the long double.
1600 const TargetData &TD = *AP.TM.getTargetData();
1601 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1602 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1606 assert(CFP->getType()->isPPC_FP128Ty() &&
1607 "Floating point constant type not handled");
1608 // All long double variants are printed as hex
1609 // API needed to prevent premature destruction.
1610 APInt API = CFP->getValueAPF().bitcastToAPInt();
1611 const uint64_t *p = API.getRawData();
1612 if (AP.TM.getTargetData()->isBigEndian()) {
1613 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1614 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1616 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1617 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1621 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1622 unsigned AddrSpace, AsmPrinter &AP) {
1623 const TargetData *TD = AP.TM.getTargetData();
1624 unsigned BitWidth = CI->getBitWidth();
1625 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1627 // We don't expect assemblers to support integer data directives
1628 // for more than 64 bits, so we emit the data in at most 64-bit
1629 // quantities at a time.
1630 const uint64_t *RawData = CI->getValue().getRawData();
1631 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1632 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1633 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1637 static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
1639 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1640 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1641 return AP.OutStreamer.EmitZeros(Size, AddrSpace);
1644 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1645 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1652 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1653 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1656 EmitGlobalConstantLargeInt(CI, AddrSpace, AP);
1661 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1662 return EmitGlobalConstantArray(CVA, AddrSpace, AP);
1664 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1665 return EmitGlobalConstantStruct(CVS, AddrSpace, AP);
1667 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1668 return EmitGlobalConstantFP(CFP, AddrSpace, AP);
1670 if (isa<ConstantPointerNull>(CV)) {
1671 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1672 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace);
1676 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1677 return EmitGlobalConstantVector(V, AddrSpace, AP);
1679 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1680 // thread the streamer with EmitValue.
1681 AP.OutStreamer.EmitValue(LowerConstant(CV, AP),
1682 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()),
1686 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1687 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1688 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1690 EmitGlobalConstantImpl(CV, AddrSpace, *this);
1691 else if (MAI->hasSubsectionsViaSymbols()) {
1692 // If the global has zero size, emit a single byte so that two labels don't
1693 // look like they are at the same location.
1694 OutStreamer.EmitIntValue(0, 1, AddrSpace);
1698 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1699 // Target doesn't support this yet!
1700 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1703 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1705 OS << '+' << Offset;
1706 else if (Offset < 0)
1710 //===----------------------------------------------------------------------===//
1711 // Symbol Lowering Routines.
1712 //===----------------------------------------------------------------------===//
1714 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1715 /// temporary label with the specified stem and unique ID.
1716 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1717 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1721 /// GetTempSymbol - Return an assembler temporary label with the specified
1723 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1724 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1729 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1730 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1733 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1734 return MMI->getAddrLabelSymbol(BB);
1737 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1738 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1739 return OutContext.GetOrCreateSymbol
1740 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1741 + "_" + Twine(CPID));
1744 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1745 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1746 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1749 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1750 /// FIXME: privatize to AsmPrinter.
1751 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1752 return OutContext.GetOrCreateSymbol
1753 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1754 Twine(UID) + "_set_" + Twine(MBBID));
1757 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1758 /// global value name as its base, with the specified suffix, and where the
1759 /// symbol is forced to have private linkage if ForcePrivate is true.
1760 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1762 bool ForcePrivate) const {
1763 SmallString<60> NameStr;
1764 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1765 NameStr.append(Suffix.begin(), Suffix.end());
1766 return OutContext.GetOrCreateSymbol(NameStr.str());
1769 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1771 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1772 SmallString<60> NameStr;
1773 Mang->getNameWithPrefix(NameStr, Sym);
1774 return OutContext.GetOrCreateSymbol(NameStr.str());
1779 /// PrintParentLoopComment - Print comments about parent loops of this one.
1780 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1781 unsigned FunctionNumber) {
1782 if (Loop == 0) return;
1783 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1784 OS.indent(Loop->getLoopDepth()*2)
1785 << "Parent Loop BB" << FunctionNumber << "_"
1786 << Loop->getHeader()->getNumber()
1787 << " Depth=" << Loop->getLoopDepth() << '\n';
1791 /// PrintChildLoopComment - Print comments about child loops within
1792 /// the loop for this basic block, with nesting.
1793 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1794 unsigned FunctionNumber) {
1795 // Add child loop information
1796 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1797 OS.indent((*CL)->getLoopDepth()*2)
1798 << "Child Loop BB" << FunctionNumber << "_"
1799 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1801 PrintChildLoopComment(OS, *CL, FunctionNumber);
1805 /// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks.
1806 static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB,
1807 const MachineLoopInfo *LI,
1808 const AsmPrinter &AP) {
1809 // Add loop depth information
1810 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1811 if (Loop == 0) return;
1813 MachineBasicBlock *Header = Loop->getHeader();
1814 assert(Header && "No header for loop");
1816 // If this block is not a loop header, just print out what is the loop header
1818 if (Header != &MBB) {
1819 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1820 Twine(AP.getFunctionNumber())+"_" +
1821 Twine(Loop->getHeader()->getNumber())+
1822 " Depth="+Twine(Loop->getLoopDepth()));
1826 // Otherwise, it is a loop header. Print out information about child and
1828 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1830 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1833 OS.indent(Loop->getLoopDepth()*2-2);
1838 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1840 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1844 /// EmitBasicBlockStart - This method prints the label for the specified
1845 /// MachineBasicBlock, an alignment (if present) and a comment describing
1846 /// it if appropriate.
1847 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1848 // Emit an alignment directive for this block, if needed.
1849 if (unsigned Align = MBB->getAlignment())
1850 EmitAlignment(Log2_32(Align));
1852 // If the block has its address taken, emit any labels that were used to
1853 // reference the block. It is possible that there is more than one label
1854 // here, because multiple LLVM BB's may have been RAUW'd to this block after
1855 // the references were generated.
1856 if (MBB->hasAddressTaken()) {
1857 const BasicBlock *BB = MBB->getBasicBlock();
1859 OutStreamer.AddComment("Block address taken");
1861 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1863 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1864 OutStreamer.EmitLabel(Syms[i]);
1867 // Print the main label for the block.
1868 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1869 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
1870 if (const BasicBlock *BB = MBB->getBasicBlock())
1872 OutStreamer.AddComment("%" + BB->getName());
1874 EmitBasicBlockLoopComments(*MBB, LI, *this);
1876 // NOTE: Want this comment at start of line, don't emit with AddComment.
1877 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1878 Twine(MBB->getNumber()) + ":");
1882 if (const BasicBlock *BB = MBB->getBasicBlock())
1884 OutStreamer.AddComment("%" + BB->getName());
1885 EmitBasicBlockLoopComments(*MBB, LI, *this);
1888 OutStreamer.EmitLabel(MBB->getSymbol());
1892 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
1893 bool IsDefinition) const {
1894 MCSymbolAttr Attr = MCSA_Invalid;
1896 switch (Visibility) {
1898 case GlobalValue::HiddenVisibility:
1900 Attr = MAI->getHiddenVisibilityAttr();
1902 Attr = MAI->getHiddenDeclarationVisibilityAttr();
1904 case GlobalValue::ProtectedVisibility:
1905 Attr = MAI->getProtectedVisibilityAttr();
1909 if (Attr != MCSA_Invalid)
1910 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1913 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1914 /// exactly one predecessor and the control transfer mechanism between
1915 /// the predecessor and this block is a fall-through.
1917 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1918 // If this is a landing pad, it isn't a fall through. If it has no preds,
1919 // then nothing falls through to it.
1920 if (MBB->isLandingPad() || MBB->pred_empty())
1923 // If there isn't exactly one predecessor, it can't be a fall through.
1924 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1926 if (PI2 != MBB->pred_end())
1929 // The predecessor has to be immediately before this block.
1930 const MachineBasicBlock *Pred = *PI;
1932 if (!Pred->isLayoutSuccessor(MBB))
1935 // If the block is completely empty, then it definitely does fall through.
1939 // Otherwise, check the last instruction.
1940 const MachineInstr &LastInst = Pred->back();
1941 return !LastInst.getDesc().isBarrier();
1946 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1947 if (!S->usesMetadata())
1950 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1951 gcp_map_type::iterator GCPI = GCMap.find(S);
1952 if (GCPI != GCMap.end())
1953 return GCPI->second;
1955 const char *Name = S->getName().c_str();
1957 for (GCMetadataPrinterRegistry::iterator
1958 I = GCMetadataPrinterRegistry::begin(),
1959 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1960 if (strcmp(Name, I->getName()) == 0) {
1961 GCMetadataPrinter *GMP = I->instantiate();
1963 GCMap.insert(std::make_pair(S, GMP));
1967 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));