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() && !MAI->doesDwarfRequireFrameSection())
602 if (MF->getFunction()->doesNotThrow())
608 void AsmPrinter::emitPrologLabel(const MachineInstr &MI) {
609 MCSymbol *Label = MI.getOperand(0).getMCSymbol();
611 if (MAI->doesDwarfRequireFrameSection() ||
612 MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
613 OutStreamer.EmitLabel(Label);
615 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
618 if (!needsCFIMoves())
621 MachineModuleInfo &MMI = MF->getMMI();
622 std::vector<MachineMove> &Moves = MMI.getFrameMoves();
623 bool FoundOne = false;
625 for (std::vector<MachineMove>::iterator I = Moves.begin(),
626 E = Moves.end(); I != E; ++I) {
627 if (I->getLabel() == Label) {
628 EmitCFIFrameMove(*I);
635 /// EmitFunctionBody - This method emits the body and trailer for a
637 void AsmPrinter::EmitFunctionBody() {
638 // Emit target-specific gunk before the function body.
639 EmitFunctionBodyStart();
641 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
643 // Print out code for the function.
644 bool HasAnyRealCode = false;
645 const MachineInstr *LastMI = 0;
646 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
648 // Print a label for the basic block.
649 EmitBasicBlockStart(I);
650 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
654 // Print the assembly for the instruction.
655 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
656 !II->isDebugValue()) {
657 HasAnyRealCode = true;
661 if (ShouldPrintDebugScopes) {
662 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
663 DD->beginInstruction(II);
667 EmitComments(*II, OutStreamer.GetCommentOS());
669 switch (II->getOpcode()) {
670 case TargetOpcode::PROLOG_LABEL:
671 emitPrologLabel(*II);
674 case TargetOpcode::EH_LABEL:
675 case TargetOpcode::GC_LABEL:
676 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
678 case TargetOpcode::INLINEASM:
681 case TargetOpcode::DBG_VALUE:
683 if (!EmitDebugValueComment(II, *this))
687 case TargetOpcode::IMPLICIT_DEF:
688 if (isVerbose()) EmitImplicitDef(II, *this);
690 case TargetOpcode::KILL:
691 if (isVerbose()) EmitKill(II, *this);
694 if (!TM.hasMCUseLoc())
695 MCLineEntry::Make(&OutStreamer, getCurrentSection());
701 if (ShouldPrintDebugScopes) {
702 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
703 DD->endInstruction(II);
708 // If the last instruction was a prolog label, then we have a situation where
709 // we emitted a prolog but no function body. This results in the ending prolog
710 // label equaling the end of function label and an invalid "row" in the
711 // FDE. We need to emit a noop in this situation so that the FDE's rows are
713 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
715 // If the function is empty and the object file uses .subsections_via_symbols,
716 // then we need to emit *something* to the function body to prevent the
717 // labels from collapsing together. Just emit a noop.
718 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
720 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
721 if (Noop.getOpcode()) {
722 OutStreamer.AddComment("avoids zero-length function");
723 OutStreamer.EmitInstruction(Noop);
724 } else // Target not mc-ized yet.
725 OutStreamer.EmitRawText(StringRef("\tnop\n"));
728 // Emit target-specific gunk after the function body.
729 EmitFunctionBodyEnd();
731 // If the target wants a .size directive for the size of the function, emit
733 if (MAI->hasDotTypeDotSizeDirective()) {
734 // Create a symbol for the end of function, so we can get the size as
735 // difference between the function label and the temp label.
736 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
737 OutStreamer.EmitLabel(FnEndLabel);
739 const MCExpr *SizeExp =
740 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
741 MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
743 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
746 // Emit post-function debug information.
748 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
752 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
757 // Print out jump tables referenced by the function.
760 OutStreamer.AddBlankLine();
763 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
765 MachineLocation AsmPrinter::
766 getDebugValueLocation(const MachineInstr *MI) const {
767 // Target specific DBG_VALUE instructions are handled by each target.
768 return MachineLocation();
771 /// getDwarfRegOpSize - get size required to emit given machine location using
773 unsigned AsmPrinter::getDwarfRegOpSize(const MachineLocation &MLoc) const {
774 const TargetRegisterInfo *RI = TM.getRegisterInfo();
775 unsigned DWReg = RI->getDwarfRegNum(MLoc.getReg(), false);
776 if (int Offset = MLoc.getOffset()) {
777 // If the value is at a certain offset from frame register then
780 return 1 + MCAsmInfo::getSLEB128Size(Offset);
782 return 1 + MCAsmInfo::getULEB128Size(MLoc.getReg())
783 + MCAsmInfo::getSLEB128Size(Offset);
788 return 1 + MCAsmInfo::getULEB128Size(DWReg);
791 /// EmitDwarfRegOp - Emit dwarf register operation.
792 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc) const {
793 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
794 unsigned Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
795 if (int Offset = MLoc.getOffset()) {
797 OutStreamer.AddComment(
798 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg));
799 EmitInt8(dwarf::DW_OP_breg0 + Reg);
801 OutStreamer.AddComment("DW_OP_bregx");
802 EmitInt8(dwarf::DW_OP_bregx);
803 OutStreamer.AddComment(Twine(Reg));
809 OutStreamer.AddComment(
810 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
811 EmitInt8(dwarf::DW_OP_reg0 + Reg);
813 OutStreamer.AddComment("DW_OP_regx");
814 EmitInt8(dwarf::DW_OP_regx);
815 OutStreamer.AddComment(Twine(Reg));
821 bool AsmPrinter::doFinalization(Module &M) {
822 // Emit global variables.
823 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
825 EmitGlobalVariable(I);
827 // Emit visibility info for declarations
828 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
829 const Function &F = *I;
830 if (!F.isDeclaration())
832 GlobalValue::VisibilityTypes V = F.getVisibility();
833 if (V == GlobalValue::DefaultVisibility)
836 MCSymbol *Name = Mang->getSymbol(&F);
837 EmitVisibility(Name, V, false);
840 // Finalize debug and EH information.
843 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
850 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
856 // If the target wants to know about weak references, print them all.
857 if (MAI->getWeakRefDirective()) {
858 // FIXME: This is not lazy, it would be nice to only print weak references
859 // to stuff that is actually used. Note that doing so would require targets
860 // to notice uses in operands (due to constant exprs etc). This should
861 // happen with the MC stuff eventually.
863 // Print out module-level global variables here.
864 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
866 if (!I->hasExternalWeakLinkage()) continue;
867 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
870 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
871 if (!I->hasExternalWeakLinkage()) continue;
872 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
876 if (MAI->hasSetDirective()) {
877 OutStreamer.AddBlankLine();
878 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
880 MCSymbol *Name = Mang->getSymbol(I);
882 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
883 MCSymbol *Target = Mang->getSymbol(GV);
885 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
886 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
887 else if (I->hasWeakLinkage())
888 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
890 assert(I->hasLocalLinkage() && "Invalid alias linkage");
892 EmitVisibility(Name, I->getVisibility());
894 // Emit the directives as assignments aka .set:
895 OutStreamer.EmitAssignment(Name,
896 MCSymbolRefExpr::Create(Target, OutContext));
900 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
901 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
902 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
903 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
904 MP->finishAssembly(*this);
906 // If we don't have any trampolines, then we don't require stack memory
907 // to be executable. Some targets have a directive to declare this.
908 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
909 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
910 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
911 OutStreamer.SwitchSection(S);
913 // Allow the target to emit any magic that it wants at the end of the file,
914 // after everything else has gone out.
917 delete Mang; Mang = 0;
920 OutStreamer.Finish();
924 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
926 // Get the function symbol.
927 CurrentFnSym = Mang->getSymbol(MF.getFunction());
930 LI = &getAnalysis<MachineLoopInfo>();
934 // SectionCPs - Keep track the alignment, constpool entries per Section.
938 SmallVector<unsigned, 4> CPEs;
939 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
943 /// EmitConstantPool - Print to the current output stream assembly
944 /// representations of the constants in the constant pool MCP. This is
945 /// used to print out constants which have been "spilled to memory" by
946 /// the code generator.
948 void AsmPrinter::EmitConstantPool() {
949 const MachineConstantPool *MCP = MF->getConstantPool();
950 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
951 if (CP.empty()) return;
953 // Calculate sections for constant pool entries. We collect entries to go into
954 // the same section together to reduce amount of section switch statements.
955 SmallVector<SectionCPs, 4> CPSections;
956 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
957 const MachineConstantPoolEntry &CPE = CP[i];
958 unsigned Align = CPE.getAlignment();
961 switch (CPE.getRelocationInfo()) {
962 default: llvm_unreachable("Unknown section kind");
963 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
965 Kind = SectionKind::getReadOnlyWithRelLocal();
968 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
969 case 4: Kind = SectionKind::getMergeableConst4(); break;
970 case 8: Kind = SectionKind::getMergeableConst8(); break;
971 case 16: Kind = SectionKind::getMergeableConst16();break;
972 default: Kind = SectionKind::getMergeableConst(); break;
976 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
978 // The number of sections are small, just do a linear search from the
979 // last section to the first.
981 unsigned SecIdx = CPSections.size();
982 while (SecIdx != 0) {
983 if (CPSections[--SecIdx].S == S) {
989 SecIdx = CPSections.size();
990 CPSections.push_back(SectionCPs(S, Align));
993 if (Align > CPSections[SecIdx].Alignment)
994 CPSections[SecIdx].Alignment = Align;
995 CPSections[SecIdx].CPEs.push_back(i);
998 // Now print stuff into the calculated sections.
999 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1000 OutStreamer.SwitchSection(CPSections[i].S);
1001 EmitAlignment(Log2_32(CPSections[i].Alignment));
1003 unsigned Offset = 0;
1004 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1005 unsigned CPI = CPSections[i].CPEs[j];
1006 MachineConstantPoolEntry CPE = CP[CPI];
1008 // Emit inter-object padding for alignment.
1009 unsigned AlignMask = CPE.getAlignment() - 1;
1010 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1011 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
1013 const Type *Ty = CPE.getType();
1014 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
1015 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1017 if (CPE.isMachineConstantPoolEntry())
1018 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1020 EmitGlobalConstant(CPE.Val.ConstVal);
1025 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1026 /// by the current function to the current output stream.
1028 void AsmPrinter::EmitJumpTableInfo() {
1029 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1030 if (MJTI == 0) return;
1031 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1032 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1033 if (JT.empty()) return;
1035 // Pick the directive to use to print the jump table entries, and switch to
1036 // the appropriate section.
1037 const Function *F = MF->getFunction();
1038 bool JTInDiffSection = false;
1039 if (// In PIC mode, we need to emit the jump table to the same section as the
1040 // function body itself, otherwise the label differences won't make sense.
1041 // FIXME: Need a better predicate for this: what about custom entries?
1042 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1043 // We should also do if the section name is NULL or function is declared
1044 // in discardable section
1045 // FIXME: this isn't the right predicate, should be based on the MCSection
1046 // for the function.
1047 F->isWeakForLinker()) {
1048 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
1050 // Otherwise, drop it in the readonly section.
1051 const MCSection *ReadOnlySection =
1052 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1053 OutStreamer.SwitchSection(ReadOnlySection);
1054 JTInDiffSection = true;
1057 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
1059 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1060 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1062 // If this jump table was deleted, ignore it.
1063 if (JTBBs.empty()) continue;
1065 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1066 // .set directive for each unique entry. This reduces the number of
1067 // relocations the assembler will generate for the jump table.
1068 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1069 MAI->hasSetDirective()) {
1070 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1071 const TargetLowering *TLI = TM.getTargetLowering();
1072 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1073 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1074 const MachineBasicBlock *MBB = JTBBs[ii];
1075 if (!EmittedSets.insert(MBB)) continue;
1077 // .set LJTSet, LBB32-base
1079 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1080 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1081 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1085 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1086 // before each jump table. The first label is never referenced, but tells
1087 // the assembler and linker the extents of the jump table object. The
1088 // second label is actually referenced by the code.
1089 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1090 // FIXME: This doesn't have to have any specific name, just any randomly
1091 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1092 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1094 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1096 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1097 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1101 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1103 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1104 const MachineBasicBlock *MBB,
1105 unsigned UID) const {
1106 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1107 const MCExpr *Value = 0;
1108 switch (MJTI->getEntryKind()) {
1109 case MachineJumpTableInfo::EK_Inline:
1110 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
1111 case MachineJumpTableInfo::EK_Custom32:
1112 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1115 case MachineJumpTableInfo::EK_BlockAddress:
1116 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1118 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1120 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1121 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1122 // with a relocation as gp-relative, e.g.:
1124 MCSymbol *MBBSym = MBB->getSymbol();
1125 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1129 case MachineJumpTableInfo::EK_LabelDifference32: {
1130 // EK_LabelDifference32 - Each entry is the address of the block minus
1131 // the address of the jump table. This is used for PIC jump tables where
1132 // gprel32 is not supported. e.g.:
1133 // .word LBB123 - LJTI1_2
1134 // If the .set directive is supported, this is emitted as:
1135 // .set L4_5_set_123, LBB123 - LJTI1_2
1136 // .word L4_5_set_123
1138 // If we have emitted set directives for the jump table entries, print
1139 // them rather than the entries themselves. If we're emitting PIC, then
1140 // emit the table entries as differences between two text section labels.
1141 if (MAI->hasSetDirective()) {
1142 // If we used .set, reference the .set's symbol.
1143 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1147 // Otherwise, use the difference as the jump table entry.
1148 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1149 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1150 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1155 assert(Value && "Unknown entry kind!");
1157 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
1158 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
1162 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1163 /// special global used by LLVM. If so, emit it and return true, otherwise
1164 /// do nothing and return false.
1165 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1166 if (GV->getName() == "llvm.used") {
1167 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1168 EmitLLVMUsedList(GV->getInitializer());
1172 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1173 if (GV->getSection() == "llvm.metadata" ||
1174 GV->hasAvailableExternallyLinkage())
1177 if (!GV->hasAppendingLinkage()) return false;
1179 assert(GV->hasInitializer() && "Not a special LLVM global!");
1181 const TargetData *TD = TM.getTargetData();
1182 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1183 if (GV->getName() == "llvm.global_ctors") {
1184 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
1185 EmitAlignment(Align);
1186 EmitXXStructorList(GV->getInitializer());
1188 if (TM.getRelocationModel() == Reloc::Static &&
1189 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1190 StringRef Sym(".constructors_used");
1191 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1197 if (GV->getName() == "llvm.global_dtors") {
1198 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
1199 EmitAlignment(Align);
1200 EmitXXStructorList(GV->getInitializer());
1202 if (TM.getRelocationModel() == Reloc::Static &&
1203 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1204 StringRef Sym(".destructors_used");
1205 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1214 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1215 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1216 /// is true, as being used with this directive.
1217 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
1218 // Should be an array of 'i8*'.
1219 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1220 if (InitList == 0) return;
1222 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1223 const GlobalValue *GV =
1224 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1225 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1226 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1230 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
1231 /// function pointers, ignoring the init priority.
1232 void AsmPrinter::EmitXXStructorList(Constant *List) {
1233 // Should be an array of '{ int, void ()* }' structs. The first value is the
1234 // init priority, which we ignore.
1235 if (!isa<ConstantArray>(List)) return;
1236 ConstantArray *InitList = cast<ConstantArray>(List);
1237 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
1238 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
1239 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
1241 if (CS->getOperand(1)->isNullValue())
1242 return; // Found a null terminator, exit printing.
1243 // Emit the function pointer.
1244 EmitGlobalConstant(CS->getOperand(1));
1248 //===--------------------------------------------------------------------===//
1249 // Emission and print routines
1252 /// EmitInt8 - Emit a byte directive and value.
1254 void AsmPrinter::EmitInt8(int Value) const {
1255 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
1258 /// EmitInt16 - Emit a short directive and value.
1260 void AsmPrinter::EmitInt16(int Value) const {
1261 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
1264 /// EmitInt32 - Emit a long directive and value.
1266 void AsmPrinter::EmitInt32(int Value) const {
1267 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
1270 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1271 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1272 /// labels. This implicitly uses .set if it is available.
1273 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1274 unsigned Size) const {
1275 // Get the Hi-Lo expression.
1276 const MCExpr *Diff =
1277 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1278 MCSymbolRefExpr::Create(Lo, OutContext),
1281 if (!MAI->hasSetDirective()) {
1282 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
1286 // Otherwise, emit with .set (aka assignment).
1287 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1288 OutStreamer.EmitAssignment(SetLabel, Diff);
1289 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
1292 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1293 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1294 /// specify the labels. This implicitly uses .set if it is available.
1295 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1296 const MCSymbol *Lo, unsigned Size)
1299 // Emit Hi+Offset - Lo
1300 // Get the Hi+Offset expression.
1301 const MCExpr *Plus =
1302 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1303 MCConstantExpr::Create(Offset, OutContext),
1306 // Get the Hi+Offset-Lo expression.
1307 const MCExpr *Diff =
1308 MCBinaryExpr::CreateSub(Plus,
1309 MCSymbolRefExpr::Create(Lo, OutContext),
1312 if (!MAI->hasSetDirective())
1313 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/);
1315 // Otherwise, emit with .set (aka assignment).
1316 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1317 OutStreamer.EmitAssignment(SetLabel, Diff);
1318 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/);
1322 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1323 /// where the size in bytes of the directive is specified by Size and Label
1324 /// specifies the label. This implicitly uses .set if it is available.
1325 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1329 // Emit Label+Offset
1330 const MCExpr *Plus =
1331 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext),
1332 MCConstantExpr::Create(Offset, OutContext),
1335 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/);
1339 //===----------------------------------------------------------------------===//
1341 // EmitAlignment - Emit an alignment directive to the specified power of
1342 // two boundary. For example, if you pass in 3 here, you will get an 8
1343 // byte alignment. If a global value is specified, and if that global has
1344 // an explicit alignment requested, it will override the alignment request
1345 // if required for correctness.
1347 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1348 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits);
1350 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1352 if (getCurrentSection()->getKind().isText())
1353 OutStreamer.EmitCodeAlignment(1 << NumBits);
1355 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1358 //===----------------------------------------------------------------------===//
1359 // Constant emission.
1360 //===----------------------------------------------------------------------===//
1362 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1364 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1365 MCContext &Ctx = AP.OutContext;
1367 if (CV->isNullValue() || isa<UndefValue>(CV))
1368 return MCConstantExpr::Create(0, Ctx);
1370 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1371 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1373 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1374 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1376 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1377 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1379 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1381 llvm_unreachable("Unknown constant value to lower!");
1382 return MCConstantExpr::Create(0, Ctx);
1385 switch (CE->getOpcode()) {
1387 // If the code isn't optimized, there may be outstanding folding
1388 // opportunities. Attempt to fold the expression using TargetData as a
1389 // last resort before giving up.
1391 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1393 return LowerConstant(C, AP);
1395 // Otherwise report the problem to the user.
1398 raw_string_ostream OS(S);
1399 OS << "Unsupported expression in static initializer: ";
1400 WriteAsOperand(OS, CE, /*PrintType=*/false,
1401 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1402 report_fatal_error(OS.str());
1404 return MCConstantExpr::Create(0, Ctx);
1405 case Instruction::GetElementPtr: {
1406 const TargetData &TD = *AP.TM.getTargetData();
1407 // Generate a symbolic expression for the byte address
1408 const Constant *PtrVal = CE->getOperand(0);
1409 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1410 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1413 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1417 // Truncate/sext the offset to the pointer size.
1418 if (TD.getPointerSizeInBits() != 64) {
1419 int SExtAmount = 64-TD.getPointerSizeInBits();
1420 Offset = (Offset << SExtAmount) >> SExtAmount;
1423 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1427 case Instruction::Trunc:
1428 // We emit the value and depend on the assembler to truncate the generated
1429 // expression properly. This is important for differences between
1430 // blockaddress labels. Since the two labels are in the same function, it
1431 // is reasonable to treat their delta as a 32-bit value.
1433 case Instruction::BitCast:
1434 return LowerConstant(CE->getOperand(0), AP);
1436 case Instruction::IntToPtr: {
1437 const TargetData &TD = *AP.TM.getTargetData();
1438 // Handle casts to pointers by changing them into casts to the appropriate
1439 // integer type. This promotes constant folding and simplifies this code.
1440 Constant *Op = CE->getOperand(0);
1441 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1443 return LowerConstant(Op, AP);
1446 case Instruction::PtrToInt: {
1447 const TargetData &TD = *AP.TM.getTargetData();
1448 // Support only foldable casts to/from pointers that can be eliminated by
1449 // changing the pointer to the appropriately sized integer type.
1450 Constant *Op = CE->getOperand(0);
1451 const Type *Ty = CE->getType();
1453 const MCExpr *OpExpr = LowerConstant(Op, AP);
1455 // We can emit the pointer value into this slot if the slot is an
1456 // integer slot equal to the size of the pointer.
1457 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1460 // Otherwise the pointer is smaller than the resultant integer, mask off
1461 // the high bits so we are sure to get a proper truncation if the input is
1463 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1464 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1465 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1468 // The MC library also has a right-shift operator, but it isn't consistently
1469 // signed or unsigned between different targets.
1470 case Instruction::Add:
1471 case Instruction::Sub:
1472 case Instruction::Mul:
1473 case Instruction::SDiv:
1474 case Instruction::SRem:
1475 case Instruction::Shl:
1476 case Instruction::And:
1477 case Instruction::Or:
1478 case Instruction::Xor: {
1479 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1480 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1481 switch (CE->getOpcode()) {
1482 default: llvm_unreachable("Unknown binary operator constant cast expr");
1483 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1484 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1485 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1486 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1487 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1488 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1489 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1490 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1491 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1497 static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace,
1500 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1502 if (AddrSpace != 0 || !CA->isString()) {
1503 // Not a string. Print the values in successive locations
1504 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1505 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP);
1509 // Otherwise, it can be emitted as .ascii.
1510 SmallVector<char, 128> TmpVec;
1511 TmpVec.reserve(CA->getNumOperands());
1512 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1513 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1515 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1518 static void EmitGlobalConstantVector(const ConstantVector *CV,
1519 unsigned AddrSpace, AsmPrinter &AP) {
1520 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1521 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP);
1524 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1525 unsigned AddrSpace, AsmPrinter &AP) {
1526 // Print the fields in successive locations. Pad to align if needed!
1527 const TargetData *TD = AP.TM.getTargetData();
1528 unsigned Size = TD->getTypeAllocSize(CS->getType());
1529 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1530 uint64_t SizeSoFar = 0;
1531 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1532 const Constant *Field = CS->getOperand(i);
1534 // Check if padding is needed and insert one or more 0s.
1535 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1536 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1537 - Layout->getElementOffset(i)) - FieldSize;
1538 SizeSoFar += FieldSize + PadSize;
1540 // Now print the actual field value.
1541 EmitGlobalConstantImpl(Field, AddrSpace, AP);
1543 // Insert padding - this may include padding to increase the size of the
1544 // current field up to the ABI size (if the struct is not packed) as well
1545 // as padding to ensure that the next field starts at the right offset.
1546 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1548 assert(SizeSoFar == Layout->getSizeInBytes() &&
1549 "Layout of constant struct may be incorrect!");
1552 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1554 // FP Constants are printed as integer constants to avoid losing
1556 if (CFP->getType()->isDoubleTy()) {
1557 if (AP.isVerbose()) {
1558 double Val = CFP->getValueAPF().convertToDouble();
1559 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1562 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1563 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1567 if (CFP->getType()->isFloatTy()) {
1568 if (AP.isVerbose()) {
1569 float Val = CFP->getValueAPF().convertToFloat();
1570 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1572 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1573 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1577 if (CFP->getType()->isX86_FP80Ty()) {
1578 // all long double variants are printed as hex
1579 // API needed to prevent premature destruction
1580 APInt API = CFP->getValueAPF().bitcastToAPInt();
1581 const uint64_t *p = API.getRawData();
1582 if (AP.isVerbose()) {
1583 // Convert to double so we can print the approximate val as a comment.
1584 APFloat DoubleVal = CFP->getValueAPF();
1586 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1588 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1589 << DoubleVal.convertToDouble() << '\n';
1592 if (AP.TM.getTargetData()->isBigEndian()) {
1593 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1594 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1596 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1597 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1600 // Emit the tail padding for the long double.
1601 const TargetData &TD = *AP.TM.getTargetData();
1602 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1603 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1607 assert(CFP->getType()->isPPC_FP128Ty() &&
1608 "Floating point constant type not handled");
1609 // All long double variants are printed as hex
1610 // API needed to prevent premature destruction.
1611 APInt API = CFP->getValueAPF().bitcastToAPInt();
1612 const uint64_t *p = API.getRawData();
1613 if (AP.TM.getTargetData()->isBigEndian()) {
1614 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1615 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1617 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1618 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1622 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1623 unsigned AddrSpace, AsmPrinter &AP) {
1624 const TargetData *TD = AP.TM.getTargetData();
1625 unsigned BitWidth = CI->getBitWidth();
1626 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1628 // We don't expect assemblers to support integer data directives
1629 // for more than 64 bits, so we emit the data in at most 64-bit
1630 // quantities at a time.
1631 const uint64_t *RawData = CI->getValue().getRawData();
1632 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1633 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1634 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1638 static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
1640 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1641 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1642 return AP.OutStreamer.EmitZeros(Size, AddrSpace);
1645 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1646 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1653 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1654 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1657 EmitGlobalConstantLargeInt(CI, AddrSpace, AP);
1662 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1663 return EmitGlobalConstantArray(CVA, AddrSpace, AP);
1665 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1666 return EmitGlobalConstantStruct(CVS, AddrSpace, AP);
1668 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1669 return EmitGlobalConstantFP(CFP, AddrSpace, AP);
1671 if (isa<ConstantPointerNull>(CV)) {
1672 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1673 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace);
1677 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1678 return EmitGlobalConstantVector(V, AddrSpace, AP);
1680 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1681 // thread the streamer with EmitValue.
1682 AP.OutStreamer.EmitValue(LowerConstant(CV, AP),
1683 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()),
1687 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1688 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1689 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1691 EmitGlobalConstantImpl(CV, AddrSpace, *this);
1692 else if (MAI->hasSubsectionsViaSymbols()) {
1693 // If the global has zero size, emit a single byte so that two labels don't
1694 // look like they are at the same location.
1695 OutStreamer.EmitIntValue(0, 1, AddrSpace);
1699 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1700 // Target doesn't support this yet!
1701 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1704 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1706 OS << '+' << Offset;
1707 else if (Offset < 0)
1711 //===----------------------------------------------------------------------===//
1712 // Symbol Lowering Routines.
1713 //===----------------------------------------------------------------------===//
1715 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1716 /// temporary label with the specified stem and unique ID.
1717 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1718 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1722 /// GetTempSymbol - Return an assembler temporary label with the specified
1724 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1725 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1730 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1731 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1734 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1735 return MMI->getAddrLabelSymbol(BB);
1738 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1739 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1740 return OutContext.GetOrCreateSymbol
1741 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1742 + "_" + Twine(CPID));
1745 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1746 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1747 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1750 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1751 /// FIXME: privatize to AsmPrinter.
1752 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1753 return OutContext.GetOrCreateSymbol
1754 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1755 Twine(UID) + "_set_" + Twine(MBBID));
1758 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1759 /// global value name as its base, with the specified suffix, and where the
1760 /// symbol is forced to have private linkage if ForcePrivate is true.
1761 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1763 bool ForcePrivate) const {
1764 SmallString<60> NameStr;
1765 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1766 NameStr.append(Suffix.begin(), Suffix.end());
1767 return OutContext.GetOrCreateSymbol(NameStr.str());
1770 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1772 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1773 SmallString<60> NameStr;
1774 Mang->getNameWithPrefix(NameStr, Sym);
1775 return OutContext.GetOrCreateSymbol(NameStr.str());
1780 /// PrintParentLoopComment - Print comments about parent loops of this one.
1781 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1782 unsigned FunctionNumber) {
1783 if (Loop == 0) return;
1784 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1785 OS.indent(Loop->getLoopDepth()*2)
1786 << "Parent Loop BB" << FunctionNumber << "_"
1787 << Loop->getHeader()->getNumber()
1788 << " Depth=" << Loop->getLoopDepth() << '\n';
1792 /// PrintChildLoopComment - Print comments about child loops within
1793 /// the loop for this basic block, with nesting.
1794 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1795 unsigned FunctionNumber) {
1796 // Add child loop information
1797 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1798 OS.indent((*CL)->getLoopDepth()*2)
1799 << "Child Loop BB" << FunctionNumber << "_"
1800 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1802 PrintChildLoopComment(OS, *CL, FunctionNumber);
1806 /// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks.
1807 static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB,
1808 const MachineLoopInfo *LI,
1809 const AsmPrinter &AP) {
1810 // Add loop depth information
1811 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1812 if (Loop == 0) return;
1814 MachineBasicBlock *Header = Loop->getHeader();
1815 assert(Header && "No header for loop");
1817 // If this block is not a loop header, just print out what is the loop header
1819 if (Header != &MBB) {
1820 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1821 Twine(AP.getFunctionNumber())+"_" +
1822 Twine(Loop->getHeader()->getNumber())+
1823 " Depth="+Twine(Loop->getLoopDepth()));
1827 // Otherwise, it is a loop header. Print out information about child and
1829 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1831 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1834 OS.indent(Loop->getLoopDepth()*2-2);
1839 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1841 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1845 /// EmitBasicBlockStart - This method prints the label for the specified
1846 /// MachineBasicBlock, an alignment (if present) and a comment describing
1847 /// it if appropriate.
1848 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1849 // Emit an alignment directive for this block, if needed.
1850 if (unsigned Align = MBB->getAlignment())
1851 EmitAlignment(Log2_32(Align));
1853 // If the block has its address taken, emit any labels that were used to
1854 // reference the block. It is possible that there is more than one label
1855 // here, because multiple LLVM BB's may have been RAUW'd to this block after
1856 // the references were generated.
1857 if (MBB->hasAddressTaken()) {
1858 const BasicBlock *BB = MBB->getBasicBlock();
1860 OutStreamer.AddComment("Block address taken");
1862 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1864 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1865 OutStreamer.EmitLabel(Syms[i]);
1868 // Print the main label for the block.
1869 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1870 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
1871 if (const BasicBlock *BB = MBB->getBasicBlock())
1873 OutStreamer.AddComment("%" + BB->getName());
1875 EmitBasicBlockLoopComments(*MBB, LI, *this);
1877 // NOTE: Want this comment at start of line, don't emit with AddComment.
1878 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1879 Twine(MBB->getNumber()) + ":");
1883 if (const BasicBlock *BB = MBB->getBasicBlock())
1885 OutStreamer.AddComment("%" + BB->getName());
1886 EmitBasicBlockLoopComments(*MBB, LI, *this);
1889 OutStreamer.EmitLabel(MBB->getSymbol());
1893 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
1894 bool IsDefinition) const {
1895 MCSymbolAttr Attr = MCSA_Invalid;
1897 switch (Visibility) {
1899 case GlobalValue::HiddenVisibility:
1901 Attr = MAI->getHiddenVisibilityAttr();
1903 Attr = MAI->getHiddenDeclarationVisibilityAttr();
1905 case GlobalValue::ProtectedVisibility:
1906 Attr = MAI->getProtectedVisibilityAttr();
1910 if (Attr != MCSA_Invalid)
1911 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1914 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1915 /// exactly one predecessor and the control transfer mechanism between
1916 /// the predecessor and this block is a fall-through.
1918 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1919 // If this is a landing pad, it isn't a fall through. If it has no preds,
1920 // then nothing falls through to it.
1921 if (MBB->isLandingPad() || MBB->pred_empty())
1924 // If there isn't exactly one predecessor, it can't be a fall through.
1925 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1927 if (PI2 != MBB->pred_end())
1930 // The predecessor has to be immediately before this block.
1931 const MachineBasicBlock *Pred = *PI;
1933 if (!Pred->isLayoutSuccessor(MBB))
1936 // If the block is completely empty, then it definitely does fall through.
1940 // Otherwise, check the last instruction.
1941 const MachineInstr &LastInst = Pred->back();
1942 return !LastInst.getDesc().isBarrier();
1947 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1948 if (!S->usesMetadata())
1951 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1952 gcp_map_type::iterator GCPI = GCMap.find(S);
1953 if (GCPI != GCMap.end())
1954 return GCPI->second;
1956 const char *Name = S->getName().c_str();
1958 for (GCMetadataPrinterRegistry::iterator
1959 I = GCMetadataPrinterRegistry::begin(),
1960 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1961 if (strcmp(Name, I->getName()) == 0) {
1962 GCMetadataPrinter *GMP = I->instantiate();
1964 GCMap.insert(std::make_pair(S, GMP));
1968 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));