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/ADT/SmallString.h"
42 #include "llvm/ADT/Statistic.h"
43 #include "llvm/Support/ErrorHandling.h"
44 #include "llvm/Support/Format.h"
45 #include "llvm/Support/Timer.h"
48 static const char *DWARFGroupName = "DWARF Emission";
49 static const char *DbgTimerName = "DWARF Debug Writer";
50 static const char *EHTimerName = "DWARF Exception Writer";
52 STATISTIC(EmittedInsts, "Number of machine instrs printed");
54 char AsmPrinter::ID = 0;
56 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
57 static gcp_map_type &getGCMap(void *&P) {
59 P = new gcp_map_type();
60 return *(gcp_map_type*)P;
64 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
65 /// value in log2 form. This rounds up to the preferred alignment if possible
67 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD,
68 unsigned InBits = 0) {
70 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
71 NumBits = TD.getPreferredAlignmentLog(GVar);
73 // If InBits is specified, round it to it.
77 // If the GV has a specified alignment, take it into account.
78 if (GV->getAlignment() == 0)
81 unsigned GVAlign = Log2_32(GV->getAlignment());
83 // If the GVAlign is larger than NumBits, or if we are required to obey
84 // NumBits because the GV has an assigned section, obey it.
85 if (GVAlign > NumBits || GV->hasSection())
93 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
94 : MachineFunctionPass(ID),
95 TM(tm), MAI(tm.getMCAsmInfo()),
96 OutContext(Streamer.getContext()),
97 OutStreamer(Streamer),
98 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
99 DD = 0; DE = 0; MMI = 0; LI = 0;
100 GCMetadataPrinters = 0;
101 VerboseAsm = Streamer.isVerboseAsm();
104 AsmPrinter::~AsmPrinter() {
105 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized");
107 if (GCMetadataPrinters != 0) {
108 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
110 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
113 GCMetadataPrinters = 0;
119 /// getFunctionNumber - Return a unique ID for the current function.
121 unsigned AsmPrinter::getFunctionNumber() const {
122 return MF->getFunctionNumber();
125 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
126 return TM.getTargetLowering()->getObjFileLowering();
130 /// getTargetData - Return information about data layout.
131 const TargetData &AsmPrinter::getTargetData() const {
132 return *TM.getTargetData();
135 /// getCurrentSection() - Return the current section we are emitting to.
136 const MCSection *AsmPrinter::getCurrentSection() const {
137 return OutStreamer.getCurrentSection();
142 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
143 AU.setPreservesAll();
144 MachineFunctionPass::getAnalysisUsage(AU);
145 AU.addRequired<MachineModuleInfo>();
146 AU.addRequired<GCModuleInfo>();
148 AU.addRequired<MachineLoopInfo>();
151 bool AsmPrinter::doInitialization(Module &M) {
152 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
153 MMI->AnalyzeModule(M);
155 // Initialize TargetLoweringObjectFile.
156 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
157 .Initialize(OutContext, TM);
159 Mang = new Mangler(OutContext, *TM.getTargetData());
161 // Allow the target to emit any magic that it wants at the start of the file.
162 EmitStartOfAsmFile(M);
164 // Very minimal debug info. It is ignored if we emit actual debug info. If we
165 // don't, this at least helps the user find where a global came from.
166 if (MAI->hasSingleParameterDotFile()) {
168 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
171 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
172 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
173 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
174 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
175 MP->beginAssembly(*this);
177 // Emit module-level inline asm if it exists.
178 if (!M.getModuleInlineAsm().empty()) {
179 OutStreamer.AddComment("Start of file scope inline assembly");
180 OutStreamer.AddBlankLine();
181 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
182 OutStreamer.AddComment("End of file scope inline assembly");
183 OutStreamer.AddBlankLine();
186 if (MAI->doesSupportDebugInformation())
187 DD = new DwarfDebug(this, &M);
189 if (MAI->doesSupportExceptionHandling())
190 DE = new DwarfException(this);
195 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
196 switch ((GlobalValue::LinkageTypes)Linkage) {
197 case GlobalValue::CommonLinkage:
198 case GlobalValue::LinkOnceAnyLinkage:
199 case GlobalValue::LinkOnceODRLinkage:
200 case GlobalValue::WeakAnyLinkage:
201 case GlobalValue::WeakODRLinkage:
202 case GlobalValue::LinkerPrivateWeakLinkage:
203 case GlobalValue::LinkerPrivateWeakDefAutoLinkage:
204 if (MAI->getWeakDefDirective() != 0) {
206 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
208 if ((GlobalValue::LinkageTypes)Linkage !=
209 GlobalValue::LinkerPrivateWeakDefAutoLinkage)
210 // .weak_definition _foo
211 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
213 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
214 } else if (MAI->getLinkOnceDirective() != 0) {
216 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
217 //NOTE: linkonce is handled by the section the symbol was assigned to.
220 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
223 case GlobalValue::DLLExportLinkage:
224 case GlobalValue::AppendingLinkage:
225 // FIXME: appending linkage variables should go into a section of
226 // their name or something. For now, just emit them as external.
227 case GlobalValue::ExternalLinkage:
228 // If external or appending, declare as a global symbol.
230 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
232 case GlobalValue::PrivateLinkage:
233 case GlobalValue::InternalLinkage:
234 case GlobalValue::LinkerPrivateLinkage:
237 llvm_unreachable("Unknown linkage type!");
242 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
243 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
244 if (!GV->hasInitializer()) // External globals require no code.
247 // Check to see if this is a special global used by LLVM, if so, emit it.
248 if (EmitSpecialLLVMGlobal(GV))
252 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
253 /*PrintType=*/false, GV->getParent());
254 OutStreamer.GetCommentOS() << '\n';
257 MCSymbol *GVSym = Mang->getSymbol(GV);
258 EmitVisibility(GVSym, GV->getVisibility());
260 if (MAI->hasDotTypeDotSizeDirective())
261 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
263 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
265 const TargetData *TD = TM.getTargetData();
266 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType());
268 // If the alignment is specified, we *must* obey it. Overaligning a global
269 // with a specified alignment is a prompt way to break globals emitted to
270 // sections and expected to be contiguous (e.g. ObjC metadata).
271 unsigned AlignLog = getGVAlignmentLog2(GV, *TD);
273 // Handle common and BSS local symbols (.lcomm).
274 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
275 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
278 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
279 /*PrintType=*/false, GV->getParent());
280 OutStreamer.GetCommentOS() << '\n';
283 // Handle common symbols.
284 if (GVKind.isCommon()) {
285 unsigned Align = 1 << AlignLog;
286 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
290 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
294 // Handle local BSS symbols.
295 if (MAI->hasMachoZeroFillDirective()) {
296 const MCSection *TheSection =
297 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
298 // .zerofill __DATA, __bss, _foo, 400, 5
299 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
303 if (MAI->hasLCOMMDirective()) {
305 OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
309 unsigned Align = 1 << AlignLog;
310 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
314 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
316 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
320 const MCSection *TheSection =
321 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
323 // Handle the zerofill directive on darwin, which is a special form of BSS
325 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
326 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
329 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
330 // .zerofill __DATA, __common, _foo, 400, 5
331 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
335 // Handle thread local data for mach-o which requires us to output an
336 // additional structure of data and mangle the original symbol so that we
337 // can reference it later.
339 // TODO: This should become an "emit thread local global" method on TLOF.
340 // All of this macho specific stuff should be sunk down into TLOFMachO and
341 // stuff like "TLSExtraDataSection" should no longer be part of the parent
342 // TLOF class. This will also make it more obvious that stuff like
343 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
345 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
346 // Emit the .tbss symbol
348 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
350 if (GVKind.isThreadBSS())
351 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
352 else if (GVKind.isThreadData()) {
353 OutStreamer.SwitchSection(TheSection);
355 EmitAlignment(AlignLog, GV);
356 OutStreamer.EmitLabel(MangSym);
358 EmitGlobalConstant(GV->getInitializer());
361 OutStreamer.AddBlankLine();
363 // Emit the variable struct for the runtime.
364 const MCSection *TLVSect
365 = getObjFileLowering().getTLSExtraDataSection();
367 OutStreamer.SwitchSection(TLVSect);
368 // Emit the linkage here.
369 EmitLinkage(GV->getLinkage(), GVSym);
370 OutStreamer.EmitLabel(GVSym);
372 // Three pointers in size:
373 // - __tlv_bootstrap - used to make sure support exists
374 // - spare pointer, used when mapped by the runtime
375 // - pointer to mangled symbol above with initializer
376 unsigned PtrSize = TD->getPointerSizeInBits()/8;
377 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
379 OutStreamer.EmitIntValue(0, PtrSize, 0);
380 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0);
382 OutStreamer.AddBlankLine();
386 OutStreamer.SwitchSection(TheSection);
388 EmitLinkage(GV->getLinkage(), GVSym);
389 EmitAlignment(AlignLog, GV);
391 OutStreamer.EmitLabel(GVSym);
393 EmitGlobalConstant(GV->getInitializer());
395 if (MAI->hasDotTypeDotSizeDirective())
397 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
399 OutStreamer.AddBlankLine();
402 /// EmitFunctionHeader - This method emits the header for the current
404 void AsmPrinter::EmitFunctionHeader() {
405 // Print out constants referenced by the function
408 // Print the 'header' of function.
409 const Function *F = MF->getFunction();
411 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
412 EmitVisibility(CurrentFnSym, F->getVisibility());
414 EmitLinkage(F->getLinkage(), CurrentFnSym);
415 EmitAlignment(MF->getAlignment(), F);
417 if (MAI->hasDotTypeDotSizeDirective())
418 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
421 WriteAsOperand(OutStreamer.GetCommentOS(), F,
422 /*PrintType=*/false, F->getParent());
423 OutStreamer.GetCommentOS() << '\n';
426 // Emit the CurrentFnSym. This is a virtual function to allow targets to
427 // do their wild and crazy things as required.
428 EmitFunctionEntryLabel();
430 // If the function had address-taken blocks that got deleted, then we have
431 // references to the dangling symbols. Emit them at the start of the function
432 // so that we don't get references to undefined symbols.
433 std::vector<MCSymbol*> DeadBlockSyms;
434 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
435 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
436 OutStreamer.AddComment("Address taken block that was later removed");
437 OutStreamer.EmitLabel(DeadBlockSyms[i]);
440 // Add some workaround for linkonce linkage on Cygwin\MinGW.
441 if (MAI->getLinkOnceDirective() != 0 &&
442 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
443 // FIXME: What is this?
445 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
446 CurrentFnSym->getName());
447 OutStreamer.EmitLabel(FakeStub);
450 // Emit pre-function debug and/or EH information.
452 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
453 DE->BeginFunction(MF);
456 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
457 DD->beginFunction(MF);
461 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
462 /// function. This can be overridden by targets as required to do custom stuff.
463 void AsmPrinter::EmitFunctionEntryLabel() {
464 // The function label could have already been emitted if two symbols end up
465 // conflicting due to asm renaming. Detect this and emit an error.
466 if (CurrentFnSym->isUndefined())
467 return OutStreamer.EmitLabel(CurrentFnSym);
469 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
470 "' label emitted multiple times to assembly file");
474 static void EmitDebugLoc(DebugLoc DL, const MachineFunction *MF,
475 raw_ostream &CommentOS) {
476 const LLVMContext &Ctx = MF->getFunction()->getContext();
477 if (!DL.isUnknown()) { // Print source line info.
478 DIScope Scope(DL.getScope(Ctx));
479 // Omit the directory, because it's likely to be long and uninteresting.
481 CommentOS << Scope.getFilename();
483 CommentOS << "<unknown>";
484 CommentOS << ':' << DL.getLine();
485 if (DL.getCol() != 0)
486 CommentOS << ':' << DL.getCol();
487 DebugLoc InlinedAtDL = DebugLoc::getFromDILocation(DL.getInlinedAt(Ctx));
488 if (!InlinedAtDL.isUnknown()) {
490 EmitDebugLoc(InlinedAtDL, MF, CommentOS);
496 /// EmitComments - Pretty-print comments for instructions.
497 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
498 const MachineFunction *MF = MI.getParent()->getParent();
499 const TargetMachine &TM = MF->getTarget();
501 DebugLoc DL = MI.getDebugLoc();
502 if (!DL.isUnknown()) { // Print source line info.
503 EmitDebugLoc(DL, MF, CommentOS);
507 // Check for spills and reloads
510 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
512 // We assume a single instruction only has a spill or reload, not
514 const MachineMemOperand *MMO;
515 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
516 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
517 MMO = *MI.memoperands_begin();
518 CommentOS << MMO->getSize() << "-byte Reload\n";
520 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
521 if (FrameInfo->isSpillSlotObjectIndex(FI))
522 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
523 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
524 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
525 MMO = *MI.memoperands_begin();
526 CommentOS << MMO->getSize() << "-byte Spill\n";
528 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
529 if (FrameInfo->isSpillSlotObjectIndex(FI))
530 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
533 // Check for spill-induced copies
534 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
535 CommentOS << " Reload Reuse\n";
538 /// EmitImplicitDef - This method emits the specified machine instruction
539 /// that is an implicit def.
540 static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
541 unsigned RegNo = MI->getOperand(0).getReg();
542 AP.OutStreamer.AddComment(Twine("implicit-def: ") +
543 AP.TM.getRegisterInfo()->getName(RegNo));
544 AP.OutStreamer.AddBlankLine();
547 static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) {
548 std::string Str = "kill:";
549 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
550 const MachineOperand &Op = MI->getOperand(i);
551 assert(Op.isReg() && "KILL instruction must have only register operands");
553 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
554 Str += (Op.isDef() ? "<def>" : "<kill>");
556 AP.OutStreamer.AddComment(Str);
557 AP.OutStreamer.AddBlankLine();
560 /// EmitDebugValueComment - This method handles the target-independent form
561 /// of DBG_VALUE, returning true if it was able to do so. A false return
562 /// means the target will need to handle MI in EmitInstruction.
563 static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
564 // This code handles only the 3-operand target-independent form.
565 if (MI->getNumOperands() != 3)
568 SmallString<128> Str;
569 raw_svector_ostream OS(Str);
570 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
572 // cast away const; DIetc do not take const operands for some reason.
573 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
574 if (V.getContext().isSubprogram())
575 OS << DISubprogram(V.getContext()).getDisplayName() << ":";
576 OS << V.getName() << " <- ";
578 // Register or immediate value. Register 0 means undef.
579 if (MI->getOperand(0).isFPImm()) {
580 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
581 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
582 OS << (double)APF.convertToFloat();
583 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
584 OS << APF.convertToDouble();
586 // There is no good way to print long double. Convert a copy to
587 // double. Ah well, it's only a comment.
589 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
591 OS << "(long double) " << APF.convertToDouble();
593 } else if (MI->getOperand(0).isImm()) {
594 OS << MI->getOperand(0).getImm();
596 assert(MI->getOperand(0).isReg() && "Unknown operand type");
597 if (MI->getOperand(0).getReg() == 0) {
598 // Suppress offset, it is not meaningful here.
600 // NOTE: Want this comment at start of line, don't emit with AddComment.
601 AP.OutStreamer.EmitRawText(OS.str());
604 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg());
607 OS << '+' << MI->getOperand(1).getImm();
608 // NOTE: Want this comment at start of line, don't emit with AddComment.
609 AP.OutStreamer.EmitRawText(OS.str());
613 /// EmitFunctionBody - This method emits the body and trailer for a
615 void AsmPrinter::EmitFunctionBody() {
616 // Emit target-specific gunk before the function body.
617 EmitFunctionBodyStart();
619 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
621 // Print out code for the function.
622 bool HasAnyRealCode = false;
623 const MachineInstr *LastMI = 0;
624 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
626 // Print a label for the basic block.
627 EmitBasicBlockStart(I);
628 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
632 // Print the assembly for the instruction.
633 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
634 !II->isDebugValue()) {
635 HasAnyRealCode = true;
639 if (ShouldPrintDebugScopes) {
640 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
641 DD->beginInstruction(II);
645 EmitComments(*II, OutStreamer.GetCommentOS());
647 switch (II->getOpcode()) {
648 case TargetOpcode::PROLOG_LABEL:
649 case TargetOpcode::EH_LABEL:
650 case TargetOpcode::GC_LABEL:
651 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
653 case TargetOpcode::INLINEASM:
656 case TargetOpcode::DBG_VALUE:
658 if (!EmitDebugValueComment(II, *this))
662 case TargetOpcode::IMPLICIT_DEF:
663 if (isVerbose()) EmitImplicitDef(II, *this);
665 case TargetOpcode::KILL:
666 if (isVerbose()) EmitKill(II, *this);
673 if (ShouldPrintDebugScopes) {
674 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
675 DD->endInstruction(II);
680 // If the last instruction was a prolog label, then we have a situation where
681 // we emitted a prolog but no function body. This results in the ending prolog
682 // label equaling the end of function label and an invalid "row" in the
683 // FDE. We need to emit a noop in this situation so that the FDE's rows are
685 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
687 // If the function is empty and the object file uses .subsections_via_symbols,
688 // then we need to emit *something* to the function body to prevent the
689 // labels from collapsing together. Just emit a noop.
690 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
692 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
693 if (Noop.getOpcode()) {
694 OutStreamer.AddComment("avoids zero-length function");
695 OutStreamer.EmitInstruction(Noop);
696 } else // Target not mc-ized yet.
697 OutStreamer.EmitRawText(StringRef("\tnop\n"));
700 // Emit target-specific gunk after the function body.
701 EmitFunctionBodyEnd();
703 // If the target wants a .size directive for the size of the function, emit
705 if (MAI->hasDotTypeDotSizeDirective()) {
706 // Create a symbol for the end of function, so we can get the size as
707 // difference between the function label and the temp label.
708 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
709 OutStreamer.EmitLabel(FnEndLabel);
711 const MCExpr *SizeExp =
712 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
713 MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
715 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
718 // Emit post-function debug information.
720 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
724 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
729 // Print out jump tables referenced by the function.
732 OutStreamer.AddBlankLine();
735 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
737 MachineLocation AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const {
738 // Target specific DBG_VALUE instructions are handled by each target.
739 return MachineLocation();
742 bool AsmPrinter::doFinalization(Module &M) {
743 // Emit global variables.
744 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
746 EmitGlobalVariable(I);
748 // Finalize debug and EH information.
751 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
758 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
764 // If the target wants to know about weak references, print them all.
765 if (MAI->getWeakRefDirective()) {
766 // FIXME: This is not lazy, it would be nice to only print weak references
767 // to stuff that is actually used. Note that doing so would require targets
768 // to notice uses in operands (due to constant exprs etc). This should
769 // happen with the MC stuff eventually.
771 // Print out module-level global variables here.
772 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
774 if (!I->hasExternalWeakLinkage()) continue;
775 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
778 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
779 if (!I->hasExternalWeakLinkage()) continue;
780 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
784 if (MAI->hasSetDirective()) {
785 OutStreamer.AddBlankLine();
786 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
788 MCSymbol *Name = Mang->getSymbol(I);
790 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
791 MCSymbol *Target = Mang->getSymbol(GV);
793 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
794 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
795 else if (I->hasWeakLinkage())
796 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
798 assert(I->hasLocalLinkage() && "Invalid alias linkage");
800 EmitVisibility(Name, I->getVisibility());
802 // Emit the directives as assignments aka .set:
803 OutStreamer.EmitAssignment(Name,
804 MCSymbolRefExpr::Create(Target, OutContext));
808 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
809 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
810 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
811 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
812 MP->finishAssembly(*this);
814 // If we don't have any trampolines, then we don't require stack memory
815 // to be executable. Some targets have a directive to declare this.
816 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
817 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
818 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
819 OutStreamer.SwitchSection(S);
821 // Allow the target to emit any magic that it wants at the end of the file,
822 // after everything else has gone out.
825 delete Mang; Mang = 0;
828 OutStreamer.Finish();
832 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
834 // Get the function symbol.
835 CurrentFnSym = Mang->getSymbol(MF.getFunction());
838 LI = &getAnalysis<MachineLoopInfo>();
842 // SectionCPs - Keep track the alignment, constpool entries per Section.
846 SmallVector<unsigned, 4> CPEs;
847 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
851 /// EmitConstantPool - Print to the current output stream assembly
852 /// representations of the constants in the constant pool MCP. This is
853 /// used to print out constants which have been "spilled to memory" by
854 /// the code generator.
856 void AsmPrinter::EmitConstantPool() {
857 const MachineConstantPool *MCP = MF->getConstantPool();
858 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
859 if (CP.empty()) return;
861 // Calculate sections for constant pool entries. We collect entries to go into
862 // the same section together to reduce amount of section switch statements.
863 SmallVector<SectionCPs, 4> CPSections;
864 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
865 const MachineConstantPoolEntry &CPE = CP[i];
866 unsigned Align = CPE.getAlignment();
869 switch (CPE.getRelocationInfo()) {
870 default: llvm_unreachable("Unknown section kind");
871 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
873 Kind = SectionKind::getReadOnlyWithRelLocal();
876 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
877 case 4: Kind = SectionKind::getMergeableConst4(); break;
878 case 8: Kind = SectionKind::getMergeableConst8(); break;
879 case 16: Kind = SectionKind::getMergeableConst16();break;
880 default: Kind = SectionKind::getMergeableConst(); break;
884 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
886 // The number of sections are small, just do a linear search from the
887 // last section to the first.
889 unsigned SecIdx = CPSections.size();
890 while (SecIdx != 0) {
891 if (CPSections[--SecIdx].S == S) {
897 SecIdx = CPSections.size();
898 CPSections.push_back(SectionCPs(S, Align));
901 if (Align > CPSections[SecIdx].Alignment)
902 CPSections[SecIdx].Alignment = Align;
903 CPSections[SecIdx].CPEs.push_back(i);
906 // Now print stuff into the calculated sections.
907 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
908 OutStreamer.SwitchSection(CPSections[i].S);
909 EmitAlignment(Log2_32(CPSections[i].Alignment));
912 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
913 unsigned CPI = CPSections[i].CPEs[j];
914 MachineConstantPoolEntry CPE = CP[CPI];
916 // Emit inter-object padding for alignment.
917 unsigned AlignMask = CPE.getAlignment() - 1;
918 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
919 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
921 const Type *Ty = CPE.getType();
922 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
924 // Emit the label with a comment on it.
926 OutStreamer.GetCommentOS() << "constant pool ";
927 WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
928 MF->getFunction()->getParent());
929 OutStreamer.GetCommentOS() << '\n';
931 OutStreamer.EmitLabel(GetCPISymbol(CPI));
933 if (CPE.isMachineConstantPoolEntry())
934 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
936 EmitGlobalConstant(CPE.Val.ConstVal);
941 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
942 /// by the current function to the current output stream.
944 void AsmPrinter::EmitJumpTableInfo() {
945 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
946 if (MJTI == 0) return;
947 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
948 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
949 if (JT.empty()) return;
951 // Pick the directive to use to print the jump table entries, and switch to
952 // the appropriate section.
953 const Function *F = MF->getFunction();
954 bool JTInDiffSection = false;
955 if (// In PIC mode, we need to emit the jump table to the same section as the
956 // function body itself, otherwise the label differences won't make sense.
957 // FIXME: Need a better predicate for this: what about custom entries?
958 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
959 // We should also do if the section name is NULL or function is declared
960 // in discardable section
961 // FIXME: this isn't the right predicate, should be based on the MCSection
963 F->isWeakForLinker()) {
964 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
966 // Otherwise, drop it in the readonly section.
967 const MCSection *ReadOnlySection =
968 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
969 OutStreamer.SwitchSection(ReadOnlySection);
970 JTInDiffSection = true;
973 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
975 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
976 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
978 // If this jump table was deleted, ignore it.
979 if (JTBBs.empty()) continue;
981 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
982 // .set directive for each unique entry. This reduces the number of
983 // relocations the assembler will generate for the jump table.
984 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
985 MAI->hasSetDirective()) {
986 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
987 const TargetLowering *TLI = TM.getTargetLowering();
988 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
989 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
990 const MachineBasicBlock *MBB = JTBBs[ii];
991 if (!EmittedSets.insert(MBB)) continue;
993 // .set LJTSet, LBB32-base
995 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
996 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
997 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1001 // On some targets (e.g. Darwin) we want to emit two consequtive labels
1002 // before each jump table. The first label is never referenced, but tells
1003 // the assembler and linker the extents of the jump table object. The
1004 // second label is actually referenced by the code.
1005 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1006 // FIXME: This doesn't have to have any specific name, just any randomly
1007 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1008 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1010 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1012 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1013 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1017 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1019 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1020 const MachineBasicBlock *MBB,
1021 unsigned UID) const {
1022 const MCExpr *Value = 0;
1023 switch (MJTI->getEntryKind()) {
1024 case MachineJumpTableInfo::EK_Inline:
1025 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
1026 case MachineJumpTableInfo::EK_Custom32:
1027 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1030 case MachineJumpTableInfo::EK_BlockAddress:
1031 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1033 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1035 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1036 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1037 // with a relocation as gp-relative, e.g.:
1039 MCSymbol *MBBSym = MBB->getSymbol();
1040 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1044 case MachineJumpTableInfo::EK_LabelDifference32: {
1045 // EK_LabelDifference32 - Each entry is the address of the block minus
1046 // the address of the jump table. This is used for PIC jump tables where
1047 // gprel32 is not supported. e.g.:
1048 // .word LBB123 - LJTI1_2
1049 // If the .set directive is supported, this is emitted as:
1050 // .set L4_5_set_123, LBB123 - LJTI1_2
1051 // .word L4_5_set_123
1053 // If we have emitted set directives for the jump table entries, print
1054 // them rather than the entries themselves. If we're emitting PIC, then
1055 // emit the table entries as differences between two text section labels.
1056 if (MAI->hasSetDirective()) {
1057 // If we used .set, reference the .set's symbol.
1058 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1062 // Otherwise, use the difference as the jump table entry.
1063 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1064 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1065 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1070 assert(Value && "Unknown entry kind!");
1072 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
1073 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
1077 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1078 /// special global used by LLVM. If so, emit it and return true, otherwise
1079 /// do nothing and return false.
1080 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1081 if (GV->getName() == "llvm.used") {
1082 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1083 EmitLLVMUsedList(GV->getInitializer());
1087 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1088 if (GV->getSection() == "llvm.metadata" ||
1089 GV->hasAvailableExternallyLinkage())
1092 if (!GV->hasAppendingLinkage()) return false;
1094 assert(GV->hasInitializer() && "Not a special LLVM global!");
1096 const TargetData *TD = TM.getTargetData();
1097 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1098 if (GV->getName() == "llvm.global_ctors") {
1099 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
1100 EmitAlignment(Align);
1101 EmitXXStructorList(GV->getInitializer());
1103 if (TM.getRelocationModel() == Reloc::Static &&
1104 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1105 StringRef Sym(".constructors_used");
1106 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1112 if (GV->getName() == "llvm.global_dtors") {
1113 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
1114 EmitAlignment(Align);
1115 EmitXXStructorList(GV->getInitializer());
1117 if (TM.getRelocationModel() == Reloc::Static &&
1118 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1119 StringRef Sym(".destructors_used");
1120 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1129 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1130 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1131 /// is true, as being used with this directive.
1132 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
1133 // Should be an array of 'i8*'.
1134 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1135 if (InitList == 0) return;
1137 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1138 const GlobalValue *GV =
1139 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1140 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1141 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1145 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
1146 /// function pointers, ignoring the init priority.
1147 void AsmPrinter::EmitXXStructorList(Constant *List) {
1148 // Should be an array of '{ int, void ()* }' structs. The first value is the
1149 // init priority, which we ignore.
1150 if (!isa<ConstantArray>(List)) return;
1151 ConstantArray *InitList = cast<ConstantArray>(List);
1152 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
1153 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
1154 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
1156 if (CS->getOperand(1)->isNullValue())
1157 return; // Found a null terminator, exit printing.
1158 // Emit the function pointer.
1159 EmitGlobalConstant(CS->getOperand(1));
1163 //===--------------------------------------------------------------------===//
1164 // Emission and print routines
1167 /// EmitInt8 - Emit a byte directive and value.
1169 void AsmPrinter::EmitInt8(int Value) const {
1170 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
1173 /// EmitInt16 - Emit a short directive and value.
1175 void AsmPrinter::EmitInt16(int Value) const {
1176 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
1179 /// EmitInt32 - Emit a long directive and value.
1181 void AsmPrinter::EmitInt32(int Value) const {
1182 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
1185 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1186 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1187 /// labels. This implicitly uses .set if it is available.
1188 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1189 unsigned Size) const {
1190 // Get the Hi-Lo expression.
1191 const MCExpr *Diff =
1192 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1193 MCSymbolRefExpr::Create(Lo, OutContext),
1196 if (!MAI->hasSetDirective()) {
1197 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
1201 // Otherwise, emit with .set (aka assignment).
1202 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1203 OutStreamer.EmitAssignment(SetLabel, Diff);
1204 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
1207 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1208 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1209 /// specify the labels. This implicitly uses .set if it is available.
1210 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1211 const MCSymbol *Lo, unsigned Size)
1214 // Emit Hi+Offset - Lo
1215 // Get the Hi+Offset expression.
1216 const MCExpr *Plus =
1217 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1218 MCConstantExpr::Create(Offset, OutContext),
1221 // Get the Hi+Offset-Lo expression.
1222 const MCExpr *Diff =
1223 MCBinaryExpr::CreateSub(Plus,
1224 MCSymbolRefExpr::Create(Lo, OutContext),
1227 if (!MAI->hasSetDirective())
1228 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/);
1230 // Otherwise, emit with .set (aka assignment).
1231 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1232 OutStreamer.EmitAssignment(SetLabel, Diff);
1233 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/);
1237 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1238 /// where the size in bytes of the directive is specified by Size and Label
1239 /// specifies the label. This implicitly uses .set if it is available.
1240 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1244 // Emit Label+Offset
1245 const MCExpr *Plus =
1246 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext),
1247 MCConstantExpr::Create(Offset, OutContext),
1250 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/);
1254 //===----------------------------------------------------------------------===//
1256 // EmitAlignment - Emit an alignment directive to the specified power of
1257 // two boundary. For example, if you pass in 3 here, you will get an 8
1258 // byte alignment. If a global value is specified, and if that global has
1259 // an explicit alignment requested, it will override the alignment request
1260 // if required for correctness.
1262 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1263 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits);
1265 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1267 if (getCurrentSection()->getKind().isText())
1268 OutStreamer.EmitCodeAlignment(1 << NumBits);
1270 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1273 //===----------------------------------------------------------------------===//
1274 // Constant emission.
1275 //===----------------------------------------------------------------------===//
1277 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1279 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1280 MCContext &Ctx = AP.OutContext;
1282 if (CV->isNullValue() || isa<UndefValue>(CV))
1283 return MCConstantExpr::Create(0, Ctx);
1285 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1286 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1288 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1289 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1291 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1292 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1294 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1296 llvm_unreachable("Unknown constant value to lower!");
1297 return MCConstantExpr::Create(0, Ctx);
1300 switch (CE->getOpcode()) {
1302 // If the code isn't optimized, there may be outstanding folding
1303 // opportunities. Attempt to fold the expression using TargetData as a
1304 // last resort before giving up.
1306 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1308 return LowerConstant(C, AP);
1310 // Otherwise report the problem to the user.
1313 raw_string_ostream OS(S);
1314 OS << "Unsupported expression in static initializer: ";
1315 WriteAsOperand(OS, CE, /*PrintType=*/false,
1316 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1317 report_fatal_error(OS.str());
1319 return MCConstantExpr::Create(0, Ctx);
1320 case Instruction::GetElementPtr: {
1321 const TargetData &TD = *AP.TM.getTargetData();
1322 // Generate a symbolic expression for the byte address
1323 const Constant *PtrVal = CE->getOperand(0);
1324 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1325 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1328 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1332 // Truncate/sext the offset to the pointer size.
1333 if (TD.getPointerSizeInBits() != 64) {
1334 int SExtAmount = 64-TD.getPointerSizeInBits();
1335 Offset = (Offset << SExtAmount) >> SExtAmount;
1338 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1342 case Instruction::Trunc:
1343 // We emit the value and depend on the assembler to truncate the generated
1344 // expression properly. This is important for differences between
1345 // blockaddress labels. Since the two labels are in the same function, it
1346 // is reasonable to treat their delta as a 32-bit value.
1348 case Instruction::BitCast:
1349 return LowerConstant(CE->getOperand(0), AP);
1351 case Instruction::IntToPtr: {
1352 const TargetData &TD = *AP.TM.getTargetData();
1353 // Handle casts to pointers by changing them into casts to the appropriate
1354 // integer type. This promotes constant folding and simplifies this code.
1355 Constant *Op = CE->getOperand(0);
1356 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1358 return LowerConstant(Op, AP);
1361 case Instruction::PtrToInt: {
1362 const TargetData &TD = *AP.TM.getTargetData();
1363 // Support only foldable casts to/from pointers that can be eliminated by
1364 // changing the pointer to the appropriately sized integer type.
1365 Constant *Op = CE->getOperand(0);
1366 const Type *Ty = CE->getType();
1368 const MCExpr *OpExpr = LowerConstant(Op, AP);
1370 // We can emit the pointer value into this slot if the slot is an
1371 // integer slot equal to the size of the pointer.
1372 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1375 // Otherwise the pointer is smaller than the resultant integer, mask off
1376 // the high bits so we are sure to get a proper truncation if the input is
1378 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1379 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1380 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1383 // The MC library also has a right-shift operator, but it isn't consistently
1384 // signed or unsigned between different targets.
1385 case Instruction::Add:
1386 case Instruction::Sub:
1387 case Instruction::Mul:
1388 case Instruction::SDiv:
1389 case Instruction::SRem:
1390 case Instruction::Shl:
1391 case Instruction::And:
1392 case Instruction::Or:
1393 case Instruction::Xor: {
1394 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1395 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1396 switch (CE->getOpcode()) {
1397 default: llvm_unreachable("Unknown binary operator constant cast expr");
1398 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1399 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1400 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1401 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1402 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1403 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1404 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1405 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1406 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1412 static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace,
1415 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1417 if (AddrSpace != 0 || !CA->isString()) {
1418 // Not a string. Print the values in successive locations
1419 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1420 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP);
1424 // Otherwise, it can be emitted as .ascii.
1425 SmallVector<char, 128> TmpVec;
1426 TmpVec.reserve(CA->getNumOperands());
1427 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1428 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1430 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1433 static void EmitGlobalConstantVector(const ConstantVector *CV,
1434 unsigned AddrSpace, AsmPrinter &AP) {
1435 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1436 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP);
1439 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1440 unsigned AddrSpace, AsmPrinter &AP) {
1441 // Print the fields in successive locations. Pad to align if needed!
1442 const TargetData *TD = AP.TM.getTargetData();
1443 unsigned Size = TD->getTypeAllocSize(CS->getType());
1444 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1445 uint64_t SizeSoFar = 0;
1446 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1447 const Constant *Field = CS->getOperand(i);
1449 // Check if padding is needed and insert one or more 0s.
1450 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1451 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1452 - Layout->getElementOffset(i)) - FieldSize;
1453 SizeSoFar += FieldSize + PadSize;
1455 // Now print the actual field value.
1456 EmitGlobalConstantImpl(Field, AddrSpace, AP);
1458 // Insert padding - this may include padding to increase the size of the
1459 // current field up to the ABI size (if the struct is not packed) as well
1460 // as padding to ensure that the next field starts at the right offset.
1461 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1463 assert(SizeSoFar == Layout->getSizeInBytes() &&
1464 "Layout of constant struct may be incorrect!");
1467 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1469 // FP Constants are printed as integer constants to avoid losing
1471 if (CFP->getType()->isDoubleTy()) {
1472 if (AP.isVerbose()) {
1473 double Val = CFP->getValueAPF().convertToDouble();
1474 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1477 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1478 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1482 if (CFP->getType()->isFloatTy()) {
1483 if (AP.isVerbose()) {
1484 float Val = CFP->getValueAPF().convertToFloat();
1485 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1487 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1488 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1492 if (CFP->getType()->isX86_FP80Ty()) {
1493 // all long double variants are printed as hex
1494 // API needed to prevent premature destruction
1495 APInt API = CFP->getValueAPF().bitcastToAPInt();
1496 const uint64_t *p = API.getRawData();
1497 if (AP.isVerbose()) {
1498 // Convert to double so we can print the approximate val as a comment.
1499 APFloat DoubleVal = CFP->getValueAPF();
1501 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1503 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1504 << DoubleVal.convertToDouble() << '\n';
1507 if (AP.TM.getTargetData()->isBigEndian()) {
1508 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1509 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1511 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1512 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1515 // Emit the tail padding for the long double.
1516 const TargetData &TD = *AP.TM.getTargetData();
1517 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1518 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1522 assert(CFP->getType()->isPPC_FP128Ty() &&
1523 "Floating point constant type not handled");
1524 // All long double variants are printed as hex
1525 // API needed to prevent premature destruction.
1526 APInt API = CFP->getValueAPF().bitcastToAPInt();
1527 const uint64_t *p = API.getRawData();
1528 if (AP.TM.getTargetData()->isBigEndian()) {
1529 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1530 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1532 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1533 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1537 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1538 unsigned AddrSpace, AsmPrinter &AP) {
1539 const TargetData *TD = AP.TM.getTargetData();
1540 unsigned BitWidth = CI->getBitWidth();
1541 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1543 // We don't expect assemblers to support integer data directives
1544 // for more than 64 bits, so we emit the data in at most 64-bit
1545 // quantities at a time.
1546 const uint64_t *RawData = CI->getValue().getRawData();
1547 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1548 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1549 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1553 static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
1555 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1556 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1557 return AP.OutStreamer.EmitZeros(Size, AddrSpace);
1560 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1561 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1568 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1569 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1572 EmitGlobalConstantLargeInt(CI, AddrSpace, AP);
1577 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1578 return EmitGlobalConstantArray(CVA, AddrSpace, AP);
1580 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1581 return EmitGlobalConstantStruct(CVS, AddrSpace, AP);
1583 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1584 return EmitGlobalConstantFP(CFP, AddrSpace, AP);
1586 if (isa<ConstantPointerNull>(CV)) {
1587 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1588 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace);
1592 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1593 return EmitGlobalConstantVector(V, AddrSpace, AP);
1595 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1596 // thread the streamer with EmitValue.
1597 AP.OutStreamer.EmitValue(LowerConstant(CV, AP),
1598 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()),
1602 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1603 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1604 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1606 EmitGlobalConstantImpl(CV, AddrSpace, *this);
1607 else if (MAI->hasSubsectionsViaSymbols()) {
1608 // If the global has zero size, emit a single byte so that two labels don't
1609 // look like they are at the same location.
1610 OutStreamer.EmitIntValue(0, 1, AddrSpace);
1614 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1615 // Target doesn't support this yet!
1616 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1619 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1621 OS << '+' << Offset;
1622 else if (Offset < 0)
1626 //===----------------------------------------------------------------------===//
1627 // Symbol Lowering Routines.
1628 //===----------------------------------------------------------------------===//
1630 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1631 /// temporary label with the specified stem and unique ID.
1632 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1633 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1637 /// GetTempSymbol - Return an assembler temporary label with the specified
1639 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1640 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1645 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1646 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1649 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1650 return MMI->getAddrLabelSymbol(BB);
1653 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1654 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1655 return OutContext.GetOrCreateSymbol
1656 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1657 + "_" + Twine(CPID));
1660 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1661 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1662 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1665 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1666 /// FIXME: privatize to AsmPrinter.
1667 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1668 return OutContext.GetOrCreateSymbol
1669 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1670 Twine(UID) + "_set_" + Twine(MBBID));
1673 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1674 /// global value name as its base, with the specified suffix, and where the
1675 /// symbol is forced to have private linkage if ForcePrivate is true.
1676 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1678 bool ForcePrivate) const {
1679 SmallString<60> NameStr;
1680 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1681 NameStr.append(Suffix.begin(), Suffix.end());
1682 return OutContext.GetOrCreateSymbol(NameStr.str());
1685 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1687 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1688 SmallString<60> NameStr;
1689 Mang->getNameWithPrefix(NameStr, Sym);
1690 return OutContext.GetOrCreateSymbol(NameStr.str());
1695 /// PrintParentLoopComment - Print comments about parent loops of this one.
1696 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1697 unsigned FunctionNumber) {
1698 if (Loop == 0) return;
1699 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1700 OS.indent(Loop->getLoopDepth()*2)
1701 << "Parent Loop BB" << FunctionNumber << "_"
1702 << Loop->getHeader()->getNumber()
1703 << " Depth=" << Loop->getLoopDepth() << '\n';
1707 /// PrintChildLoopComment - Print comments about child loops within
1708 /// the loop for this basic block, with nesting.
1709 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1710 unsigned FunctionNumber) {
1711 // Add child loop information
1712 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1713 OS.indent((*CL)->getLoopDepth()*2)
1714 << "Child Loop BB" << FunctionNumber << "_"
1715 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1717 PrintChildLoopComment(OS, *CL, FunctionNumber);
1721 /// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks.
1722 static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB,
1723 const MachineLoopInfo *LI,
1724 const AsmPrinter &AP) {
1725 // Add loop depth information
1726 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1727 if (Loop == 0) return;
1729 MachineBasicBlock *Header = Loop->getHeader();
1730 assert(Header && "No header for loop");
1732 // If this block is not a loop header, just print out what is the loop header
1734 if (Header != &MBB) {
1735 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1736 Twine(AP.getFunctionNumber())+"_" +
1737 Twine(Loop->getHeader()->getNumber())+
1738 " Depth="+Twine(Loop->getLoopDepth()));
1742 // Otherwise, it is a loop header. Print out information about child and
1744 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1746 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1749 OS.indent(Loop->getLoopDepth()*2-2);
1754 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1756 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1760 /// EmitBasicBlockStart - This method prints the label for the specified
1761 /// MachineBasicBlock, an alignment (if present) and a comment describing
1762 /// it if appropriate.
1763 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1764 // Emit an alignment directive for this block, if needed.
1765 if (unsigned Align = MBB->getAlignment())
1766 EmitAlignment(Log2_32(Align));
1768 // If the block has its address taken, emit any labels that were used to
1769 // reference the block. It is possible that there is more than one label
1770 // here, because multiple LLVM BB's may have been RAUW'd to this block after
1771 // the references were generated.
1772 if (MBB->hasAddressTaken()) {
1773 const BasicBlock *BB = MBB->getBasicBlock();
1775 OutStreamer.AddComment("Block address taken");
1777 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1779 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1780 OutStreamer.EmitLabel(Syms[i]);
1783 // Print the main label for the block.
1784 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1785 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
1786 if (const BasicBlock *BB = MBB->getBasicBlock())
1788 OutStreamer.AddComment("%" + BB->getName());
1790 EmitBasicBlockLoopComments(*MBB, LI, *this);
1792 // NOTE: Want this comment at start of line, don't emit with AddComment.
1793 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1794 Twine(MBB->getNumber()) + ":");
1798 if (const BasicBlock *BB = MBB->getBasicBlock())
1800 OutStreamer.AddComment("%" + BB->getName());
1801 EmitBasicBlockLoopComments(*MBB, LI, *this);
1804 OutStreamer.EmitLabel(MBB->getSymbol());
1808 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1809 MCSymbolAttr Attr = MCSA_Invalid;
1811 switch (Visibility) {
1813 case GlobalValue::HiddenVisibility:
1814 Attr = MAI->getHiddenVisibilityAttr();
1816 case GlobalValue::ProtectedVisibility:
1817 Attr = MAI->getProtectedVisibilityAttr();
1821 if (Attr != MCSA_Invalid)
1822 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1825 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1826 /// exactly one predecessor and the control transfer mechanism between
1827 /// the predecessor and this block is a fall-through.
1829 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1830 // If this is a landing pad, it isn't a fall through. If it has no preds,
1831 // then nothing falls through to it.
1832 if (MBB->isLandingPad() || MBB->pred_empty())
1835 // If there isn't exactly one predecessor, it can't be a fall through.
1836 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1838 if (PI2 != MBB->pred_end())
1841 // The predecessor has to be immediately before this block.
1842 const MachineBasicBlock *Pred = *PI;
1844 if (!Pred->isLayoutSuccessor(MBB))
1847 // If the block is completely empty, then it definitely does fall through.
1851 // Otherwise, check the last instruction.
1852 const MachineInstr &LastInst = Pred->back();
1853 return !LastInst.getDesc().isBarrier();
1858 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1859 if (!S->usesMetadata())
1862 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1863 gcp_map_type::iterator GCPI = GCMap.find(S);
1864 if (GCPI != GCMap.end())
1865 return GCPI->second;
1867 const char *Name = S->getName().c_str();
1869 for (GCMetadataPrinterRegistry::iterator
1870 I = GCMetadataPrinterRegistry::begin(),
1871 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1872 if (strcmp(Name, I->getName()) == 0) {
1873 GCMetadataPrinter *GMP = I->instantiate();
1875 GCMap.insert(std::make_pair(S, GMP));
1879 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));