1 //===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the AsmPrinter class.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "asm-printer"
15 #include "llvm/CodeGen/AsmPrinter.h"
16 #include "DwarfDebug.h"
17 #include "DwarfException.h"
18 #include "llvm/Module.h"
19 #include "llvm/CodeGen/GCMetadataPrinter.h"
20 #include "llvm/CodeGen/MachineConstantPool.h"
21 #include "llvm/CodeGen/MachineFrameInfo.h"
22 #include "llvm/CodeGen/MachineFunction.h"
23 #include "llvm/CodeGen/MachineJumpTableInfo.h"
24 #include "llvm/CodeGen/MachineLoopInfo.h"
25 #include "llvm/CodeGen/MachineModuleInfo.h"
26 #include "llvm/Analysis/ConstantFolding.h"
27 #include "llvm/Analysis/DebugInfo.h"
28 #include "llvm/MC/MCAsmInfo.h"
29 #include "llvm/MC/MCContext.h"
30 #include "llvm/MC/MCExpr.h"
31 #include "llvm/MC/MCInst.h"
32 #include "llvm/MC/MCSection.h"
33 #include "llvm/MC/MCStreamer.h"
34 #include "llvm/MC/MCSymbol.h"
35 #include "llvm/Target/Mangler.h"
36 #include "llvm/Target/TargetData.h"
37 #include "llvm/Target/TargetInstrInfo.h"
38 #include "llvm/Target/TargetLowering.h"
39 #include "llvm/Target/TargetLoweringObjectFile.h"
40 #include "llvm/Target/TargetRegisterInfo.h"
41 #include "llvm/Assembly/Writer.h"
42 #include "llvm/ADT/SmallString.h"
43 #include "llvm/ADT/Statistic.h"
44 #include "llvm/Support/ErrorHandling.h"
45 #include "llvm/Support/Format.h"
46 #include "llvm/Support/Timer.h"
49 static const char *DWARFGroupName = "DWARF Emission";
50 static const char *DbgTimerName = "DWARF Debug Writer";
51 static const char *EHTimerName = "DWARF Exception Writer";
53 STATISTIC(EmittedInsts, "Number of machine instrs printed");
55 char AsmPrinter::ID = 0;
57 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
58 static gcp_map_type &getGCMap(void *&P) {
60 P = new gcp_map_type();
61 return *(gcp_map_type*)P;
65 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
66 /// value in log2 form. This rounds up to the preferred alignment if possible
68 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD,
69 unsigned InBits = 0) {
71 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
72 NumBits = TD.getPreferredAlignmentLog(GVar);
74 // If InBits is specified, round it to it.
78 // If the GV has a specified alignment, take it into account.
79 if (GV->getAlignment() == 0)
82 unsigned GVAlign = Log2_32(GV->getAlignment());
84 // If the GVAlign is larger than NumBits, or if we are required to obey
85 // NumBits because the GV has an assigned section, obey it.
86 if (GVAlign > NumBits || GV->hasSection())
94 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
95 : MachineFunctionPass(ID),
96 TM(tm), MAI(tm.getMCAsmInfo()),
97 OutContext(Streamer.getContext()),
98 OutStreamer(Streamer),
99 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
100 DD = 0; DE = 0; MMI = 0; LI = 0;
101 GCMetadataPrinters = 0;
102 VerboseAsm = Streamer.isVerboseAsm();
105 AsmPrinter::~AsmPrinter() {
106 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized");
108 if (GCMetadataPrinters != 0) {
109 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
111 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
114 GCMetadataPrinters = 0;
120 /// getFunctionNumber - Return a unique ID for the current function.
122 unsigned AsmPrinter::getFunctionNumber() const {
123 return MF->getFunctionNumber();
126 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
127 return TM.getTargetLowering()->getObjFileLowering();
131 /// getTargetData - Return information about data layout.
132 const TargetData &AsmPrinter::getTargetData() const {
133 return *TM.getTargetData();
136 /// getCurrentSection() - Return the current section we are emitting to.
137 const MCSection *AsmPrinter::getCurrentSection() const {
138 return OutStreamer.getCurrentSection();
143 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
144 AU.setPreservesAll();
145 MachineFunctionPass::getAnalysisUsage(AU);
146 AU.addRequired<MachineModuleInfo>();
147 AU.addRequired<GCModuleInfo>();
149 AU.addRequired<MachineLoopInfo>();
152 bool AsmPrinter::doInitialization(Module &M) {
153 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
154 MMI->AnalyzeModule(M);
156 // Initialize TargetLoweringObjectFile.
157 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
158 .Initialize(OutContext, TM);
160 Mang = new Mangler(OutContext, *TM.getTargetData());
162 // Allow the target to emit any magic that it wants at the start of the file.
163 EmitStartOfAsmFile(M);
165 // Very minimal debug info. It is ignored if we emit actual debug info. If we
166 // don't, this at least helps the user find where a global came from.
167 if (MAI->hasSingleParameterDotFile()) {
169 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
172 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
173 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
174 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
175 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
176 MP->beginAssembly(*this);
178 // Emit module-level inline asm if it exists.
179 if (!M.getModuleInlineAsm().empty()) {
180 OutStreamer.AddComment("Start of file scope inline assembly");
181 OutStreamer.AddBlankLine();
182 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
183 OutStreamer.AddComment("End of file scope inline assembly");
184 OutStreamer.AddBlankLine();
187 if (MAI->doesSupportDebugInformation())
188 DD = new DwarfDebug(this, &M);
190 if (MAI->doesSupportExceptionHandling())
191 switch (MAI->getExceptionHandlingType()) {
193 case ExceptionHandling::DwarfTable:
194 DE = new DwarfTableException(this);
196 case ExceptionHandling::DwarfCFI:
197 DE = new DwarfCFIException(this);
199 case ExceptionHandling::ARM:
200 DE = new ARMException(this);
207 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
208 switch ((GlobalValue::LinkageTypes)Linkage) {
209 case GlobalValue::CommonLinkage:
210 case GlobalValue::LinkOnceAnyLinkage:
211 case GlobalValue::LinkOnceODRLinkage:
212 case GlobalValue::WeakAnyLinkage:
213 case GlobalValue::WeakODRLinkage:
214 case GlobalValue::LinkerPrivateWeakLinkage:
215 case GlobalValue::LinkerPrivateWeakDefAutoLinkage:
216 if (MAI->getWeakDefDirective() != 0) {
218 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
220 if ((GlobalValue::LinkageTypes)Linkage !=
221 GlobalValue::LinkerPrivateWeakDefAutoLinkage)
222 // .weak_definition _foo
223 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
225 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
226 } else if (MAI->getLinkOnceDirective() != 0) {
228 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
229 //NOTE: linkonce is handled by the section the symbol was assigned to.
232 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
235 case GlobalValue::DLLExportLinkage:
236 case GlobalValue::AppendingLinkage:
237 // FIXME: appending linkage variables should go into a section of
238 // their name or something. For now, just emit them as external.
239 case GlobalValue::ExternalLinkage:
240 // If external or appending, declare as a global symbol.
242 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
244 case GlobalValue::PrivateLinkage:
245 case GlobalValue::InternalLinkage:
246 case GlobalValue::LinkerPrivateLinkage:
249 llvm_unreachable("Unknown linkage type!");
254 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
255 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
256 if (GV->hasInitializer()) {
257 // Check to see if this is a special global used by LLVM, if so, emit it.
258 if (EmitSpecialLLVMGlobal(GV))
262 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
263 /*PrintType=*/false, GV->getParent());
264 OutStreamer.GetCommentOS() << '\n';
268 MCSymbol *GVSym = Mang->getSymbol(GV);
269 EmitVisibility(GVSym, GV->getVisibility());
271 if (!GV->hasInitializer()) // External globals require no extra code.
274 if (MAI->hasDotTypeDotSizeDirective())
275 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
277 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
279 const TargetData *TD = TM.getTargetData();
280 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType());
282 // If the alignment is specified, we *must* obey it. Overaligning a global
283 // with a specified alignment is a prompt way to break globals emitted to
284 // sections and expected to be contiguous (e.g. ObjC metadata).
285 unsigned AlignLog = getGVAlignmentLog2(GV, *TD);
287 // Handle common and BSS local symbols (.lcomm).
288 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
289 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
292 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
293 /*PrintType=*/false, GV->getParent());
294 OutStreamer.GetCommentOS() << '\n';
297 // Handle common symbols.
298 if (GVKind.isCommon()) {
299 unsigned Align = 1 << AlignLog;
300 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
304 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
308 // Handle local BSS symbols.
309 if (MAI->hasMachoZeroFillDirective()) {
310 const MCSection *TheSection =
311 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
312 // .zerofill __DATA, __bss, _foo, 400, 5
313 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
317 if (MAI->hasLCOMMDirective()) {
319 OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
323 unsigned Align = 1 << AlignLog;
324 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
328 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
330 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
334 const MCSection *TheSection =
335 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
337 // Handle the zerofill directive on darwin, which is a special form of BSS
339 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
340 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
343 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
344 // .zerofill __DATA, __common, _foo, 400, 5
345 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
349 // Handle thread local data for mach-o which requires us to output an
350 // additional structure of data and mangle the original symbol so that we
351 // can reference it later.
353 // TODO: This should become an "emit thread local global" method on TLOF.
354 // All of this macho specific stuff should be sunk down into TLOFMachO and
355 // stuff like "TLSExtraDataSection" should no longer be part of the parent
356 // TLOF class. This will also make it more obvious that stuff like
357 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
359 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
360 // Emit the .tbss symbol
362 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
364 if (GVKind.isThreadBSS())
365 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
366 else if (GVKind.isThreadData()) {
367 OutStreamer.SwitchSection(TheSection);
369 EmitAlignment(AlignLog, GV);
370 OutStreamer.EmitLabel(MangSym);
372 EmitGlobalConstant(GV->getInitializer());
375 OutStreamer.AddBlankLine();
377 // Emit the variable struct for the runtime.
378 const MCSection *TLVSect
379 = getObjFileLowering().getTLSExtraDataSection();
381 OutStreamer.SwitchSection(TLVSect);
382 // Emit the linkage here.
383 EmitLinkage(GV->getLinkage(), GVSym);
384 OutStreamer.EmitLabel(GVSym);
386 // Three pointers in size:
387 // - __tlv_bootstrap - used to make sure support exists
388 // - spare pointer, used when mapped by the runtime
389 // - pointer to mangled symbol above with initializer
390 unsigned PtrSize = TD->getPointerSizeInBits()/8;
391 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
393 OutStreamer.EmitIntValue(0, PtrSize, 0);
394 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0);
396 OutStreamer.AddBlankLine();
400 OutStreamer.SwitchSection(TheSection);
402 EmitLinkage(GV->getLinkage(), GVSym);
403 EmitAlignment(AlignLog, GV);
405 OutStreamer.EmitLabel(GVSym);
407 EmitGlobalConstant(GV->getInitializer());
409 if (MAI->hasDotTypeDotSizeDirective())
411 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
413 OutStreamer.AddBlankLine();
416 /// EmitFunctionHeader - This method emits the header for the current
418 void AsmPrinter::EmitFunctionHeader() {
419 // Print out constants referenced by the function
422 // Print the 'header' of function.
423 const Function *F = MF->getFunction();
425 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
426 EmitVisibility(CurrentFnSym, F->getVisibility());
428 EmitLinkage(F->getLinkage(), CurrentFnSym);
429 EmitAlignment(MF->getAlignment(), F);
431 if (MAI->hasDotTypeDotSizeDirective())
432 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
435 WriteAsOperand(OutStreamer.GetCommentOS(), F,
436 /*PrintType=*/false, F->getParent());
437 OutStreamer.GetCommentOS() << '\n';
440 // Emit the CurrentFnSym. This is a virtual function to allow targets to
441 // do their wild and crazy things as required.
442 EmitFunctionEntryLabel();
444 // If the function had address-taken blocks that got deleted, then we have
445 // references to the dangling symbols. Emit them at the start of the function
446 // so that we don't get references to undefined symbols.
447 std::vector<MCSymbol*> DeadBlockSyms;
448 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
449 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
450 OutStreamer.AddComment("Address taken block that was later removed");
451 OutStreamer.EmitLabel(DeadBlockSyms[i]);
454 // Add some workaround for linkonce linkage on Cygwin\MinGW.
455 if (MAI->getLinkOnceDirective() != 0 &&
456 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
457 // FIXME: What is this?
459 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
460 CurrentFnSym->getName());
461 OutStreamer.EmitLabel(FakeStub);
464 // Emit pre-function debug and/or EH information.
466 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
467 DE->BeginFunction(MF);
470 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
471 DD->beginFunction(MF);
475 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
476 /// function. This can be overridden by targets as required to do custom stuff.
477 void AsmPrinter::EmitFunctionEntryLabel() {
478 // The function label could have already been emitted if two symbols end up
479 // conflicting due to asm renaming. Detect this and emit an error.
480 if (CurrentFnSym->isUndefined())
481 return OutStreamer.EmitLabel(CurrentFnSym);
483 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
484 "' label emitted multiple times to assembly file");
488 static void EmitDebugLoc(DebugLoc DL, const MachineFunction *MF,
489 raw_ostream &CommentOS) {
490 const LLVMContext &Ctx = MF->getFunction()->getContext();
491 if (!DL.isUnknown()) { // Print source line info.
492 DIScope Scope(DL.getScope(Ctx));
493 // Omit the directory, because it's likely to be long and uninteresting.
495 CommentOS << Scope.getFilename();
497 CommentOS << "<unknown>";
498 CommentOS << ':' << DL.getLine();
499 if (DL.getCol() != 0)
500 CommentOS << ':' << DL.getCol();
501 DebugLoc InlinedAtDL = DebugLoc::getFromDILocation(DL.getInlinedAt(Ctx));
502 if (!InlinedAtDL.isUnknown()) {
504 EmitDebugLoc(InlinedAtDL, MF, CommentOS);
510 /// EmitComments - Pretty-print comments for instructions.
511 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
512 const MachineFunction *MF = MI.getParent()->getParent();
513 const TargetMachine &TM = MF->getTarget();
515 DebugLoc DL = MI.getDebugLoc();
516 if (!DL.isUnknown()) { // Print source line info.
517 EmitDebugLoc(DL, MF, CommentOS);
521 // Check for spills and reloads
524 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
526 // We assume a single instruction only has a spill or reload, not
528 const MachineMemOperand *MMO;
529 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
530 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
531 MMO = *MI.memoperands_begin();
532 CommentOS << MMO->getSize() << "-byte Reload\n";
534 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
535 if (FrameInfo->isSpillSlotObjectIndex(FI))
536 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
537 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
538 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
539 MMO = *MI.memoperands_begin();
540 CommentOS << MMO->getSize() << "-byte Spill\n";
542 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
543 if (FrameInfo->isSpillSlotObjectIndex(FI))
544 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
547 // Check for spill-induced copies
548 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
549 CommentOS << " Reload Reuse\n";
552 /// EmitImplicitDef - This method emits the specified machine instruction
553 /// that is an implicit def.
554 static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
555 unsigned RegNo = MI->getOperand(0).getReg();
556 AP.OutStreamer.AddComment(Twine("implicit-def: ") +
557 AP.TM.getRegisterInfo()->getName(RegNo));
558 AP.OutStreamer.AddBlankLine();
561 static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) {
562 std::string Str = "kill:";
563 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
564 const MachineOperand &Op = MI->getOperand(i);
565 assert(Op.isReg() && "KILL instruction must have only register operands");
567 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
568 Str += (Op.isDef() ? "<def>" : "<kill>");
570 AP.OutStreamer.AddComment(Str);
571 AP.OutStreamer.AddBlankLine();
574 /// EmitDebugValueComment - This method handles the target-independent form
575 /// of DBG_VALUE, returning true if it was able to do so. A false return
576 /// means the target will need to handle MI in EmitInstruction.
577 static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
578 // This code handles only the 3-operand target-independent form.
579 if (MI->getNumOperands() != 3)
582 SmallString<128> Str;
583 raw_svector_ostream OS(Str);
584 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
586 // cast away const; DIetc do not take const operands for some reason.
587 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
588 if (V.getContext().isSubprogram())
589 OS << DISubprogram(V.getContext()).getDisplayName() << ":";
590 OS << V.getName() << " <- ";
592 // Register or immediate value. Register 0 means undef.
593 if (MI->getOperand(0).isFPImm()) {
594 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
595 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
596 OS << (double)APF.convertToFloat();
597 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
598 OS << APF.convertToDouble();
600 // There is no good way to print long double. Convert a copy to
601 // double. Ah well, it's only a comment.
603 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
605 OS << "(long double) " << APF.convertToDouble();
607 } else if (MI->getOperand(0).isImm()) {
608 OS << MI->getOperand(0).getImm();
610 assert(MI->getOperand(0).isReg() && "Unknown operand type");
611 if (MI->getOperand(0).getReg() == 0) {
612 // Suppress offset, it is not meaningful here.
614 // NOTE: Want this comment at start of line, don't emit with AddComment.
615 AP.OutStreamer.EmitRawText(OS.str());
618 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg());
621 OS << '+' << MI->getOperand(1).getImm();
622 // NOTE: Want this comment at start of line, don't emit with AddComment.
623 AP.OutStreamer.EmitRawText(OS.str());
627 /// EmitFunctionBody - This method emits the body and trailer for a
629 void AsmPrinter::EmitFunctionBody() {
630 // Emit target-specific gunk before the function body.
631 EmitFunctionBodyStart();
633 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
635 // Print out code for the function.
636 bool HasAnyRealCode = false;
637 const MachineInstr *LastMI = 0;
638 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
640 // Print a label for the basic block.
641 EmitBasicBlockStart(I);
642 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
646 // Print the assembly for the instruction.
647 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
648 !II->isDebugValue()) {
649 HasAnyRealCode = true;
653 if (ShouldPrintDebugScopes) {
654 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
655 DD->beginInstruction(II);
659 EmitComments(*II, OutStreamer.GetCommentOS());
661 switch (II->getOpcode()) {
662 case TargetOpcode::PROLOG_LABEL:
663 case TargetOpcode::EH_LABEL:
664 case TargetOpcode::GC_LABEL:
665 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
667 case TargetOpcode::INLINEASM:
670 case TargetOpcode::DBG_VALUE:
672 if (!EmitDebugValueComment(II, *this))
676 case TargetOpcode::IMPLICIT_DEF:
677 if (isVerbose()) EmitImplicitDef(II, *this);
679 case TargetOpcode::KILL:
680 if (isVerbose()) EmitKill(II, *this);
687 if (ShouldPrintDebugScopes) {
688 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
689 DD->endInstruction(II);
694 // If the last instruction was a prolog label, then we have a situation where
695 // we emitted a prolog but no function body. This results in the ending prolog
696 // label equaling the end of function label and an invalid "row" in the
697 // FDE. We need to emit a noop in this situation so that the FDE's rows are
699 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
701 // If the function is empty and the object file uses .subsections_via_symbols,
702 // then we need to emit *something* to the function body to prevent the
703 // labels from collapsing together. Just emit a noop.
704 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
706 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
707 if (Noop.getOpcode()) {
708 OutStreamer.AddComment("avoids zero-length function");
709 OutStreamer.EmitInstruction(Noop);
710 } else // Target not mc-ized yet.
711 OutStreamer.EmitRawText(StringRef("\tnop\n"));
714 // Emit target-specific gunk after the function body.
715 EmitFunctionBodyEnd();
717 // If the target wants a .size directive for the size of the function, emit
719 if (MAI->hasDotTypeDotSizeDirective()) {
720 // Create a symbol for the end of function, so we can get the size as
721 // difference between the function label and the temp label.
722 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
723 OutStreamer.EmitLabel(FnEndLabel);
725 const MCExpr *SizeExp =
726 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
727 MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
729 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
732 // Emit post-function debug information.
734 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
738 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
743 // Print out jump tables referenced by the function.
746 OutStreamer.AddBlankLine();
749 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
751 MachineLocation AsmPrinter::
752 getDebugValueLocation(const MachineInstr *MI) const {
753 // Target specific DBG_VALUE instructions are handled by each target.
754 return MachineLocation();
757 bool AsmPrinter::doFinalization(Module &M) {
758 // Emit global variables.
759 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
761 EmitGlobalVariable(I);
763 // Emit visibility info for declarations
764 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
765 const Function &F = *I;
766 if (!F.isDeclaration())
768 GlobalValue::VisibilityTypes V = F.getVisibility();
769 if (V == GlobalValue::DefaultVisibility)
772 MCSymbol *Name = Mang->getSymbol(&F);
773 EmitVisibility(Name, V, false);
776 // Finalize debug and EH information.
779 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
786 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
792 // If the target wants to know about weak references, print them all.
793 if (MAI->getWeakRefDirective()) {
794 // FIXME: This is not lazy, it would be nice to only print weak references
795 // to stuff that is actually used. Note that doing so would require targets
796 // to notice uses in operands (due to constant exprs etc). This should
797 // happen with the MC stuff eventually.
799 // Print out module-level global variables here.
800 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
802 if (!I->hasExternalWeakLinkage()) continue;
803 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
806 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
807 if (!I->hasExternalWeakLinkage()) continue;
808 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
812 if (MAI->hasSetDirective()) {
813 OutStreamer.AddBlankLine();
814 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
816 MCSymbol *Name = Mang->getSymbol(I);
818 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
819 MCSymbol *Target = Mang->getSymbol(GV);
821 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
822 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
823 else if (I->hasWeakLinkage())
824 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
826 assert(I->hasLocalLinkage() && "Invalid alias linkage");
828 EmitVisibility(Name, I->getVisibility());
830 // Emit the directives as assignments aka .set:
831 OutStreamer.EmitAssignment(Name,
832 MCSymbolRefExpr::Create(Target, OutContext));
836 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
837 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
838 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
839 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
840 MP->finishAssembly(*this);
842 // If we don't have any trampolines, then we don't require stack memory
843 // to be executable. Some targets have a directive to declare this.
844 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
845 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
846 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
847 OutStreamer.SwitchSection(S);
849 // Allow the target to emit any magic that it wants at the end of the file,
850 // after everything else has gone out.
853 delete Mang; Mang = 0;
856 OutStreamer.Finish();
860 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
862 // Get the function symbol.
863 CurrentFnSym = Mang->getSymbol(MF.getFunction());
866 LI = &getAnalysis<MachineLoopInfo>();
870 // SectionCPs - Keep track the alignment, constpool entries per Section.
874 SmallVector<unsigned, 4> CPEs;
875 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
879 /// EmitConstantPool - Print to the current output stream assembly
880 /// representations of the constants in the constant pool MCP. This is
881 /// used to print out constants which have been "spilled to memory" by
882 /// the code generator.
884 void AsmPrinter::EmitConstantPool() {
885 const MachineConstantPool *MCP = MF->getConstantPool();
886 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
887 if (CP.empty()) return;
889 // Calculate sections for constant pool entries. We collect entries to go into
890 // the same section together to reduce amount of section switch statements.
891 SmallVector<SectionCPs, 4> CPSections;
892 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
893 const MachineConstantPoolEntry &CPE = CP[i];
894 unsigned Align = CPE.getAlignment();
897 switch (CPE.getRelocationInfo()) {
898 default: llvm_unreachable("Unknown section kind");
899 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
901 Kind = SectionKind::getReadOnlyWithRelLocal();
904 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
905 case 4: Kind = SectionKind::getMergeableConst4(); break;
906 case 8: Kind = SectionKind::getMergeableConst8(); break;
907 case 16: Kind = SectionKind::getMergeableConst16();break;
908 default: Kind = SectionKind::getMergeableConst(); break;
912 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
914 // The number of sections are small, just do a linear search from the
915 // last section to the first.
917 unsigned SecIdx = CPSections.size();
918 while (SecIdx != 0) {
919 if (CPSections[--SecIdx].S == S) {
925 SecIdx = CPSections.size();
926 CPSections.push_back(SectionCPs(S, Align));
929 if (Align > CPSections[SecIdx].Alignment)
930 CPSections[SecIdx].Alignment = Align;
931 CPSections[SecIdx].CPEs.push_back(i);
934 // Now print stuff into the calculated sections.
935 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
936 OutStreamer.SwitchSection(CPSections[i].S);
937 EmitAlignment(Log2_32(CPSections[i].Alignment));
940 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
941 unsigned CPI = CPSections[i].CPEs[j];
942 MachineConstantPoolEntry CPE = CP[CPI];
944 // Emit inter-object padding for alignment.
945 unsigned AlignMask = CPE.getAlignment() - 1;
946 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
947 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
949 const Type *Ty = CPE.getType();
950 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
951 OutStreamer.EmitLabel(GetCPISymbol(CPI));
953 if (CPE.isMachineConstantPoolEntry())
954 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
956 EmitGlobalConstant(CPE.Val.ConstVal);
961 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
962 /// by the current function to the current output stream.
964 void AsmPrinter::EmitJumpTableInfo() {
965 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
966 if (MJTI == 0) return;
967 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
968 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
969 if (JT.empty()) return;
971 // Pick the directive to use to print the jump table entries, and switch to
972 // the appropriate section.
973 const Function *F = MF->getFunction();
974 bool JTInDiffSection = false;
975 if (// In PIC mode, we need to emit the jump table to the same section as the
976 // function body itself, otherwise the label differences won't make sense.
977 // FIXME: Need a better predicate for this: what about custom entries?
978 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
979 // We should also do if the section name is NULL or function is declared
980 // in discardable section
981 // FIXME: this isn't the right predicate, should be based on the MCSection
983 F->isWeakForLinker()) {
984 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
986 // Otherwise, drop it in the readonly section.
987 const MCSection *ReadOnlySection =
988 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
989 OutStreamer.SwitchSection(ReadOnlySection);
990 JTInDiffSection = true;
993 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
995 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
996 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
998 // If this jump table was deleted, ignore it.
999 if (JTBBs.empty()) continue;
1001 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1002 // .set directive for each unique entry. This reduces the number of
1003 // relocations the assembler will generate for the jump table.
1004 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1005 MAI->hasSetDirective()) {
1006 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1007 const TargetLowering *TLI = TM.getTargetLowering();
1008 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1009 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1010 const MachineBasicBlock *MBB = JTBBs[ii];
1011 if (!EmittedSets.insert(MBB)) continue;
1013 // .set LJTSet, LBB32-base
1015 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1016 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1017 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1021 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1022 // before each jump table. The first label is never referenced, but tells
1023 // the assembler and linker the extents of the jump table object. The
1024 // second label is actually referenced by the code.
1025 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1026 // FIXME: This doesn't have to have any specific name, just any randomly
1027 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1028 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1030 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1032 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1033 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1037 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1039 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1040 const MachineBasicBlock *MBB,
1041 unsigned UID) const {
1042 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1043 const MCExpr *Value = 0;
1044 switch (MJTI->getEntryKind()) {
1045 case MachineJumpTableInfo::EK_Inline:
1046 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
1047 case MachineJumpTableInfo::EK_Custom32:
1048 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1051 case MachineJumpTableInfo::EK_BlockAddress:
1052 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1054 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1056 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1057 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1058 // with a relocation as gp-relative, e.g.:
1060 MCSymbol *MBBSym = MBB->getSymbol();
1061 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1065 case MachineJumpTableInfo::EK_LabelDifference32: {
1066 // EK_LabelDifference32 - Each entry is the address of the block minus
1067 // the address of the jump table. This is used for PIC jump tables where
1068 // gprel32 is not supported. e.g.:
1069 // .word LBB123 - LJTI1_2
1070 // If the .set directive is supported, this is emitted as:
1071 // .set L4_5_set_123, LBB123 - LJTI1_2
1072 // .word L4_5_set_123
1074 // If we have emitted set directives for the jump table entries, print
1075 // them rather than the entries themselves. If we're emitting PIC, then
1076 // emit the table entries as differences between two text section labels.
1077 if (MAI->hasSetDirective()) {
1078 // If we used .set, reference the .set's symbol.
1079 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1083 // Otherwise, use the difference as the jump table entry.
1084 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1085 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1086 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1091 assert(Value && "Unknown entry kind!");
1093 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
1094 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
1098 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1099 /// special global used by LLVM. If so, emit it and return true, otherwise
1100 /// do nothing and return false.
1101 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1102 if (GV->getName() == "llvm.used") {
1103 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1104 EmitLLVMUsedList(GV->getInitializer());
1108 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1109 if (GV->getSection() == "llvm.metadata" ||
1110 GV->hasAvailableExternallyLinkage())
1113 if (!GV->hasAppendingLinkage()) return false;
1115 assert(GV->hasInitializer() && "Not a special LLVM global!");
1117 const TargetData *TD = TM.getTargetData();
1118 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1119 if (GV->getName() == "llvm.global_ctors") {
1120 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
1121 EmitAlignment(Align);
1122 EmitXXStructorList(GV->getInitializer());
1124 if (TM.getRelocationModel() == Reloc::Static &&
1125 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1126 StringRef Sym(".constructors_used");
1127 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1133 if (GV->getName() == "llvm.global_dtors") {
1134 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
1135 EmitAlignment(Align);
1136 EmitXXStructorList(GV->getInitializer());
1138 if (TM.getRelocationModel() == Reloc::Static &&
1139 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1140 StringRef Sym(".destructors_used");
1141 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1150 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1151 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1152 /// is true, as being used with this directive.
1153 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
1154 // Should be an array of 'i8*'.
1155 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1156 if (InitList == 0) return;
1158 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1159 const GlobalValue *GV =
1160 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1161 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1162 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1166 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
1167 /// function pointers, ignoring the init priority.
1168 void AsmPrinter::EmitXXStructorList(Constant *List) {
1169 // Should be an array of '{ int, void ()* }' structs. The first value is the
1170 // init priority, which we ignore.
1171 if (!isa<ConstantArray>(List)) return;
1172 ConstantArray *InitList = cast<ConstantArray>(List);
1173 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
1174 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
1175 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
1177 if (CS->getOperand(1)->isNullValue())
1178 return; // Found a null terminator, exit printing.
1179 // Emit the function pointer.
1180 EmitGlobalConstant(CS->getOperand(1));
1184 //===--------------------------------------------------------------------===//
1185 // Emission and print routines
1188 /// EmitInt8 - Emit a byte directive and value.
1190 void AsmPrinter::EmitInt8(int Value) const {
1191 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
1194 /// EmitInt16 - Emit a short directive and value.
1196 void AsmPrinter::EmitInt16(int Value) const {
1197 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
1200 /// EmitInt32 - Emit a long directive and value.
1202 void AsmPrinter::EmitInt32(int Value) const {
1203 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
1206 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1207 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1208 /// labels. This implicitly uses .set if it is available.
1209 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1210 unsigned Size) const {
1211 // Get the Hi-Lo expression.
1212 const MCExpr *Diff =
1213 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1214 MCSymbolRefExpr::Create(Lo, OutContext),
1217 if (!MAI->hasSetDirective()) {
1218 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
1222 // Otherwise, emit with .set (aka assignment).
1223 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1224 OutStreamer.EmitAssignment(SetLabel, Diff);
1225 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
1228 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1229 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1230 /// specify the labels. This implicitly uses .set if it is available.
1231 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1232 const MCSymbol *Lo, unsigned Size)
1235 // Emit Hi+Offset - Lo
1236 // Get the Hi+Offset expression.
1237 const MCExpr *Plus =
1238 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1239 MCConstantExpr::Create(Offset, OutContext),
1242 // Get the Hi+Offset-Lo expression.
1243 const MCExpr *Diff =
1244 MCBinaryExpr::CreateSub(Plus,
1245 MCSymbolRefExpr::Create(Lo, OutContext),
1248 if (!MAI->hasSetDirective())
1249 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/);
1251 // Otherwise, emit with .set (aka assignment).
1252 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1253 OutStreamer.EmitAssignment(SetLabel, Diff);
1254 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/);
1258 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1259 /// where the size in bytes of the directive is specified by Size and Label
1260 /// specifies the label. This implicitly uses .set if it is available.
1261 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1265 // Emit Label+Offset
1266 const MCExpr *Plus =
1267 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext),
1268 MCConstantExpr::Create(Offset, OutContext),
1271 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/);
1275 //===----------------------------------------------------------------------===//
1277 // EmitAlignment - Emit an alignment directive to the specified power of
1278 // two boundary. For example, if you pass in 3 here, you will get an 8
1279 // byte alignment. If a global value is specified, and if that global has
1280 // an explicit alignment requested, it will override the alignment request
1281 // if required for correctness.
1283 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1284 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits);
1286 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1288 if (getCurrentSection()->getKind().isText())
1289 OutStreamer.EmitCodeAlignment(1 << NumBits);
1291 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1294 //===----------------------------------------------------------------------===//
1295 // Constant emission.
1296 //===----------------------------------------------------------------------===//
1298 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1300 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1301 MCContext &Ctx = AP.OutContext;
1303 if (CV->isNullValue() || isa<UndefValue>(CV))
1304 return MCConstantExpr::Create(0, Ctx);
1306 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1307 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1309 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1310 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1312 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1313 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1315 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1317 llvm_unreachable("Unknown constant value to lower!");
1318 return MCConstantExpr::Create(0, Ctx);
1321 switch (CE->getOpcode()) {
1323 // If the code isn't optimized, there may be outstanding folding
1324 // opportunities. Attempt to fold the expression using TargetData as a
1325 // last resort before giving up.
1327 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1329 return LowerConstant(C, AP);
1331 // Otherwise report the problem to the user.
1334 raw_string_ostream OS(S);
1335 OS << "Unsupported expression in static initializer: ";
1336 WriteAsOperand(OS, CE, /*PrintType=*/false,
1337 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1338 report_fatal_error(OS.str());
1340 return MCConstantExpr::Create(0, Ctx);
1341 case Instruction::GetElementPtr: {
1342 const TargetData &TD = *AP.TM.getTargetData();
1343 // Generate a symbolic expression for the byte address
1344 const Constant *PtrVal = CE->getOperand(0);
1345 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1346 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1349 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1353 // Truncate/sext the offset to the pointer size.
1354 if (TD.getPointerSizeInBits() != 64) {
1355 int SExtAmount = 64-TD.getPointerSizeInBits();
1356 Offset = (Offset << SExtAmount) >> SExtAmount;
1359 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1363 case Instruction::Trunc:
1364 // We emit the value and depend on the assembler to truncate the generated
1365 // expression properly. This is important for differences between
1366 // blockaddress labels. Since the two labels are in the same function, it
1367 // is reasonable to treat their delta as a 32-bit value.
1369 case Instruction::BitCast:
1370 return LowerConstant(CE->getOperand(0), AP);
1372 case Instruction::IntToPtr: {
1373 const TargetData &TD = *AP.TM.getTargetData();
1374 // Handle casts to pointers by changing them into casts to the appropriate
1375 // integer type. This promotes constant folding and simplifies this code.
1376 Constant *Op = CE->getOperand(0);
1377 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1379 return LowerConstant(Op, AP);
1382 case Instruction::PtrToInt: {
1383 const TargetData &TD = *AP.TM.getTargetData();
1384 // Support only foldable casts to/from pointers that can be eliminated by
1385 // changing the pointer to the appropriately sized integer type.
1386 Constant *Op = CE->getOperand(0);
1387 const Type *Ty = CE->getType();
1389 const MCExpr *OpExpr = LowerConstant(Op, AP);
1391 // We can emit the pointer value into this slot if the slot is an
1392 // integer slot equal to the size of the pointer.
1393 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1396 // Otherwise the pointer is smaller than the resultant integer, mask off
1397 // the high bits so we are sure to get a proper truncation if the input is
1399 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1400 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1401 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1404 // The MC library also has a right-shift operator, but it isn't consistently
1405 // signed or unsigned between different targets.
1406 case Instruction::Add:
1407 case Instruction::Sub:
1408 case Instruction::Mul:
1409 case Instruction::SDiv:
1410 case Instruction::SRem:
1411 case Instruction::Shl:
1412 case Instruction::And:
1413 case Instruction::Or:
1414 case Instruction::Xor: {
1415 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1416 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1417 switch (CE->getOpcode()) {
1418 default: llvm_unreachable("Unknown binary operator constant cast expr");
1419 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1420 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1421 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1422 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1423 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1424 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1425 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1426 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1427 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1433 static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace,
1436 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1438 if (AddrSpace != 0 || !CA->isString()) {
1439 // Not a string. Print the values in successive locations
1440 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1441 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP);
1445 // Otherwise, it can be emitted as .ascii.
1446 SmallVector<char, 128> TmpVec;
1447 TmpVec.reserve(CA->getNumOperands());
1448 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1449 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1451 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1454 static void EmitGlobalConstantVector(const ConstantVector *CV,
1455 unsigned AddrSpace, AsmPrinter &AP) {
1456 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1457 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP);
1460 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1461 unsigned AddrSpace, AsmPrinter &AP) {
1462 // Print the fields in successive locations. Pad to align if needed!
1463 const TargetData *TD = AP.TM.getTargetData();
1464 unsigned Size = TD->getTypeAllocSize(CS->getType());
1465 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1466 uint64_t SizeSoFar = 0;
1467 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1468 const Constant *Field = CS->getOperand(i);
1470 // Check if padding is needed and insert one or more 0s.
1471 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1472 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1473 - Layout->getElementOffset(i)) - FieldSize;
1474 SizeSoFar += FieldSize + PadSize;
1476 // Now print the actual field value.
1477 EmitGlobalConstantImpl(Field, AddrSpace, AP);
1479 // Insert padding - this may include padding to increase the size of the
1480 // current field up to the ABI size (if the struct is not packed) as well
1481 // as padding to ensure that the next field starts at the right offset.
1482 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1484 assert(SizeSoFar == Layout->getSizeInBytes() &&
1485 "Layout of constant struct may be incorrect!");
1488 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1490 // FP Constants are printed as integer constants to avoid losing
1492 if (CFP->getType()->isDoubleTy()) {
1493 if (AP.isVerbose()) {
1494 double Val = CFP->getValueAPF().convertToDouble();
1495 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1498 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1499 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1503 if (CFP->getType()->isFloatTy()) {
1504 if (AP.isVerbose()) {
1505 float Val = CFP->getValueAPF().convertToFloat();
1506 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1508 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1509 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1513 if (CFP->getType()->isX86_FP80Ty()) {
1514 // all long double variants are printed as hex
1515 // API needed to prevent premature destruction
1516 APInt API = CFP->getValueAPF().bitcastToAPInt();
1517 const uint64_t *p = API.getRawData();
1518 if (AP.isVerbose()) {
1519 // Convert to double so we can print the approximate val as a comment.
1520 APFloat DoubleVal = CFP->getValueAPF();
1522 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1524 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1525 << DoubleVal.convertToDouble() << '\n';
1528 if (AP.TM.getTargetData()->isBigEndian()) {
1529 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1530 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1532 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1533 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1536 // Emit the tail padding for the long double.
1537 const TargetData &TD = *AP.TM.getTargetData();
1538 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1539 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1543 assert(CFP->getType()->isPPC_FP128Ty() &&
1544 "Floating point constant type not handled");
1545 // All long double variants are printed as hex
1546 // API needed to prevent premature destruction.
1547 APInt API = CFP->getValueAPF().bitcastToAPInt();
1548 const uint64_t *p = API.getRawData();
1549 if (AP.TM.getTargetData()->isBigEndian()) {
1550 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1551 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1553 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1554 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1558 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1559 unsigned AddrSpace, AsmPrinter &AP) {
1560 const TargetData *TD = AP.TM.getTargetData();
1561 unsigned BitWidth = CI->getBitWidth();
1562 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1564 // We don't expect assemblers to support integer data directives
1565 // for more than 64 bits, so we emit the data in at most 64-bit
1566 // quantities at a time.
1567 const uint64_t *RawData = CI->getValue().getRawData();
1568 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1569 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1570 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1574 static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
1576 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1577 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1578 return AP.OutStreamer.EmitZeros(Size, AddrSpace);
1581 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1582 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1589 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1590 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1593 EmitGlobalConstantLargeInt(CI, AddrSpace, AP);
1598 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1599 return EmitGlobalConstantArray(CVA, AddrSpace, AP);
1601 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1602 return EmitGlobalConstantStruct(CVS, AddrSpace, AP);
1604 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1605 return EmitGlobalConstantFP(CFP, AddrSpace, AP);
1607 if (isa<ConstantPointerNull>(CV)) {
1608 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1609 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace);
1613 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1614 return EmitGlobalConstantVector(V, AddrSpace, AP);
1616 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1617 // thread the streamer with EmitValue.
1618 AP.OutStreamer.EmitValue(LowerConstant(CV, AP),
1619 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()),
1623 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1624 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1625 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1627 EmitGlobalConstantImpl(CV, AddrSpace, *this);
1628 else if (MAI->hasSubsectionsViaSymbols()) {
1629 // If the global has zero size, emit a single byte so that two labels don't
1630 // look like they are at the same location.
1631 OutStreamer.EmitIntValue(0, 1, AddrSpace);
1635 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1636 // Target doesn't support this yet!
1637 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1640 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1642 OS << '+' << Offset;
1643 else if (Offset < 0)
1647 //===----------------------------------------------------------------------===//
1648 // Symbol Lowering Routines.
1649 //===----------------------------------------------------------------------===//
1651 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1652 /// temporary label with the specified stem and unique ID.
1653 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1654 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1658 /// GetTempSymbol - Return an assembler temporary label with the specified
1660 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1661 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1666 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1667 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1670 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1671 return MMI->getAddrLabelSymbol(BB);
1674 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1675 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1676 return OutContext.GetOrCreateSymbol
1677 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1678 + "_" + Twine(CPID));
1681 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1682 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1683 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1686 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1687 /// FIXME: privatize to AsmPrinter.
1688 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1689 return OutContext.GetOrCreateSymbol
1690 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1691 Twine(UID) + "_set_" + Twine(MBBID));
1694 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1695 /// global value name as its base, with the specified suffix, and where the
1696 /// symbol is forced to have private linkage if ForcePrivate is true.
1697 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1699 bool ForcePrivate) const {
1700 SmallString<60> NameStr;
1701 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1702 NameStr.append(Suffix.begin(), Suffix.end());
1703 return OutContext.GetOrCreateSymbol(NameStr.str());
1706 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1708 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1709 SmallString<60> NameStr;
1710 Mang->getNameWithPrefix(NameStr, Sym);
1711 return OutContext.GetOrCreateSymbol(NameStr.str());
1716 /// PrintParentLoopComment - Print comments about parent loops of this one.
1717 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1718 unsigned FunctionNumber) {
1719 if (Loop == 0) return;
1720 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1721 OS.indent(Loop->getLoopDepth()*2)
1722 << "Parent Loop BB" << FunctionNumber << "_"
1723 << Loop->getHeader()->getNumber()
1724 << " Depth=" << Loop->getLoopDepth() << '\n';
1728 /// PrintChildLoopComment - Print comments about child loops within
1729 /// the loop for this basic block, with nesting.
1730 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1731 unsigned FunctionNumber) {
1732 // Add child loop information
1733 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1734 OS.indent((*CL)->getLoopDepth()*2)
1735 << "Child Loop BB" << FunctionNumber << "_"
1736 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1738 PrintChildLoopComment(OS, *CL, FunctionNumber);
1742 /// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks.
1743 static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB,
1744 const MachineLoopInfo *LI,
1745 const AsmPrinter &AP) {
1746 // Add loop depth information
1747 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1748 if (Loop == 0) return;
1750 MachineBasicBlock *Header = Loop->getHeader();
1751 assert(Header && "No header for loop");
1753 // If this block is not a loop header, just print out what is the loop header
1755 if (Header != &MBB) {
1756 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1757 Twine(AP.getFunctionNumber())+"_" +
1758 Twine(Loop->getHeader()->getNumber())+
1759 " Depth="+Twine(Loop->getLoopDepth()));
1763 // Otherwise, it is a loop header. Print out information about child and
1765 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1767 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1770 OS.indent(Loop->getLoopDepth()*2-2);
1775 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1777 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1781 /// EmitBasicBlockStart - This method prints the label for the specified
1782 /// MachineBasicBlock, an alignment (if present) and a comment describing
1783 /// it if appropriate.
1784 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1785 // Emit an alignment directive for this block, if needed.
1786 if (unsigned Align = MBB->getAlignment())
1787 EmitAlignment(Log2_32(Align));
1789 // If the block has its address taken, emit any labels that were used to
1790 // reference the block. It is possible that there is more than one label
1791 // here, because multiple LLVM BB's may have been RAUW'd to this block after
1792 // the references were generated.
1793 if (MBB->hasAddressTaken()) {
1794 const BasicBlock *BB = MBB->getBasicBlock();
1796 OutStreamer.AddComment("Block address taken");
1798 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1800 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1801 OutStreamer.EmitLabel(Syms[i]);
1804 // Print the main label for the block.
1805 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1806 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
1807 if (const BasicBlock *BB = MBB->getBasicBlock())
1809 OutStreamer.AddComment("%" + BB->getName());
1811 EmitBasicBlockLoopComments(*MBB, LI, *this);
1813 // NOTE: Want this comment at start of line, don't emit with AddComment.
1814 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1815 Twine(MBB->getNumber()) + ":");
1819 if (const BasicBlock *BB = MBB->getBasicBlock())
1821 OutStreamer.AddComment("%" + BB->getName());
1822 EmitBasicBlockLoopComments(*MBB, LI, *this);
1825 OutStreamer.EmitLabel(MBB->getSymbol());
1829 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
1830 bool IsDefinition) const {
1831 MCSymbolAttr Attr = MCSA_Invalid;
1833 switch (Visibility) {
1835 case GlobalValue::HiddenVisibility:
1837 Attr = MAI->getHiddenVisibilityAttr();
1839 Attr = MAI->getHiddenDeclarationVisibilityAttr();
1841 case GlobalValue::ProtectedVisibility:
1842 Attr = MAI->getProtectedVisibilityAttr();
1846 if (Attr != MCSA_Invalid)
1847 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1850 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1851 /// exactly one predecessor and the control transfer mechanism between
1852 /// the predecessor and this block is a fall-through.
1854 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1855 // If this is a landing pad, it isn't a fall through. If it has no preds,
1856 // then nothing falls through to it.
1857 if (MBB->isLandingPad() || MBB->pred_empty())
1860 // If there isn't exactly one predecessor, it can't be a fall through.
1861 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1863 if (PI2 != MBB->pred_end())
1866 // The predecessor has to be immediately before this block.
1867 const MachineBasicBlock *Pred = *PI;
1869 if (!Pred->isLayoutSuccessor(MBB))
1872 // If the block is completely empty, then it definitely does fall through.
1876 // Otherwise, check the last instruction.
1877 const MachineInstr &LastInst = Pred->back();
1878 return !LastInst.getDesc().isBarrier();
1883 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1884 if (!S->usesMetadata())
1887 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1888 gcp_map_type::iterator GCPI = GCMap.find(S);
1889 if (GCPI != GCMap.end())
1890 return GCPI->second;
1892 const char *Name = S->getName().c_str();
1894 for (GCMetadataPrinterRegistry::iterator
1895 I = GCMetadataPrinterRegistry::begin(),
1896 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1897 if (strcmp(Name, I->getName()) == 0) {
1898 GCMetadataPrinter *GMP = I->instantiate();
1900 GCMap.insert(std::make_pair(S, GMP));
1904 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));