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(), 0/*no loc cookie*/);
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::LinkerPrivateLinkage:
203 if (MAI->getWeakDefDirective() != 0) {
205 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
206 // .weak_definition _foo
207 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
208 } else if (MAI->getLinkOnceDirective() != 0) {
210 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
211 //NOTE: linkonce is handled by the section the symbol was assigned to.
214 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
217 case GlobalValue::DLLExportLinkage:
218 case GlobalValue::AppendingLinkage:
219 // FIXME: appending linkage variables should go into a section of
220 // their name or something. For now, just emit them as external.
221 case GlobalValue::ExternalLinkage:
222 // If external or appending, declare as a global symbol.
224 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
226 case GlobalValue::PrivateLinkage:
227 case GlobalValue::InternalLinkage:
230 llvm_unreachable("Unknown linkage type!");
235 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
236 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
237 if (!GV->hasInitializer()) // External globals require no code.
240 // Check to see if this is a special global used by LLVM, if so, emit it.
241 if (EmitSpecialLLVMGlobal(GV))
245 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
246 /*PrintType=*/false, GV->getParent());
247 OutStreamer.GetCommentOS() << '\n';
250 MCSymbol *GVSym = Mang->getSymbol(GV);
251 EmitVisibility(GVSym, GV->getVisibility());
253 if (MAI->hasDotTypeDotSizeDirective())
254 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
256 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
258 const TargetData *TD = TM.getTargetData();
259 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType());
261 // If the alignment is specified, we *must* obey it. Overaligning a global
262 // with a specified alignment is a prompt way to break globals emitted to
263 // sections and expected to be contiguous (e.g. ObjC metadata).
264 unsigned AlignLog = getGVAlignmentLog2(GV, *TD);
266 // Handle common and BSS local symbols (.lcomm).
267 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
268 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
271 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
272 /*PrintType=*/false, GV->getParent());
273 OutStreamer.GetCommentOS() << '\n';
276 // Handle common symbols.
277 if (GVKind.isCommon()) {
279 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
283 // Handle local BSS symbols.
284 if (MAI->hasMachoZeroFillDirective()) {
285 const MCSection *TheSection =
286 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
287 // .zerofill __DATA, __bss, _foo, 400, 5
288 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
292 if (MAI->hasLCOMMDirective()) {
294 OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
299 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
301 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
305 const MCSection *TheSection =
306 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
308 // Handle the zerofill directive on darwin, which is a special form of BSS
310 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
311 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
314 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
315 // .zerofill __DATA, __common, _foo, 400, 5
316 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
320 // Handle thread local data for mach-o which requires us to output an
321 // additional structure of data and mangle the original symbol so that we
322 // can reference it later.
323 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
324 // Emit the .tbss symbol
326 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
328 if (GVKind.isThreadBSS())
329 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
330 else if (GVKind.isThreadData()) {
331 OutStreamer.SwitchSection(TheSection);
333 EmitAlignment(AlignLog, GV);
334 OutStreamer.EmitLabel(MangSym);
336 EmitGlobalConstant(GV->getInitializer());
339 OutStreamer.AddBlankLine();
341 // Emit the variable struct for the runtime.
342 const MCSection *TLVSect
343 = getObjFileLowering().getTLSExtraDataSection();
345 OutStreamer.SwitchSection(TLVSect);
346 // Emit the linkage here.
347 EmitLinkage(GV->getLinkage(), GVSym);
348 OutStreamer.EmitLabel(GVSym);
350 // Three pointers in size:
351 // - __tlv_bootstrap - used to make sure support exists
352 // - spare pointer, used when mapped by the runtime
353 // - pointer to mangled symbol above with initializer
354 unsigned PtrSize = TD->getPointerSizeInBits()/8;
355 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
357 OutStreamer.EmitIntValue(0, PtrSize, 0);
358 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0);
360 OutStreamer.AddBlankLine();
364 OutStreamer.SwitchSection(TheSection);
366 EmitLinkage(GV->getLinkage(), GVSym);
367 EmitAlignment(AlignLog, GV);
369 OutStreamer.EmitLabel(GVSym);
371 EmitGlobalConstant(GV->getInitializer());
373 if (MAI->hasDotTypeDotSizeDirective())
375 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
377 OutStreamer.AddBlankLine();
380 /// EmitFunctionHeader - This method emits the header for the current
382 void AsmPrinter::EmitFunctionHeader() {
383 // Print out constants referenced by the function
386 // Print the 'header' of function.
387 const Function *F = MF->getFunction();
389 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
390 EmitVisibility(CurrentFnSym, F->getVisibility());
392 EmitLinkage(F->getLinkage(), CurrentFnSym);
393 EmitAlignment(MF->getAlignment(), F);
395 if (MAI->hasDotTypeDotSizeDirective())
396 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
399 WriteAsOperand(OutStreamer.GetCommentOS(), F,
400 /*PrintType=*/false, F->getParent());
401 OutStreamer.GetCommentOS() << '\n';
404 // Emit the CurrentFnSym. This is a virtual function to allow targets to
405 // do their wild and crazy things as required.
406 EmitFunctionEntryLabel();
408 // If the function had address-taken blocks that got deleted, then we have
409 // references to the dangling symbols. Emit them at the start of the function
410 // so that we don't get references to undefined symbols.
411 std::vector<MCSymbol*> DeadBlockSyms;
412 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
413 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
414 OutStreamer.AddComment("Address taken block that was later removed");
415 OutStreamer.EmitLabel(DeadBlockSyms[i]);
418 // Add some workaround for linkonce linkage on Cygwin\MinGW.
419 if (MAI->getLinkOnceDirective() != 0 &&
420 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
421 // FIXME: What is this?
423 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
424 CurrentFnSym->getName());
425 OutStreamer.EmitLabel(FakeStub);
428 // Emit pre-function debug and/or EH information.
430 if (TimePassesIsEnabled) {
431 NamedRegionTimer T(EHTimerName, DWARFGroupName);
432 DE->BeginFunction(MF);
434 DE->BeginFunction(MF);
438 if (TimePassesIsEnabled) {
439 NamedRegionTimer T(DbgTimerName, DWARFGroupName);
440 DD->beginFunction(MF);
442 DD->beginFunction(MF);
447 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
448 /// function. This can be overridden by targets as required to do custom stuff.
449 void AsmPrinter::EmitFunctionEntryLabel() {
450 // The function label could have already been emitted if two symbols end up
451 // conflicting due to asm renaming. Detect this and emit an error.
452 if (CurrentFnSym->isUndefined())
453 return OutStreamer.EmitLabel(CurrentFnSym);
455 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
456 "' label emitted multiple times to assembly file");
460 /// EmitComments - Pretty-print comments for instructions.
461 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
462 const MachineFunction *MF = MI.getParent()->getParent();
463 const TargetMachine &TM = MF->getTarget();
465 DebugLoc DL = MI.getDebugLoc();
466 if (!DL.isUnknown()) { // Print source line info.
467 DIScope Scope(DL.getScope(MF->getFunction()->getContext()));
468 // Omit the directory, because it's likely to be long and uninteresting.
470 CommentOS << Scope.getFilename();
472 CommentOS << "<unknown>";
473 CommentOS << ':' << DL.getLine();
474 if (DL.getCol() != 0)
475 CommentOS << ':' << DL.getCol();
479 // Check for spills and reloads
482 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
484 // We assume a single instruction only has a spill or reload, not
486 const MachineMemOperand *MMO;
487 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
488 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
489 MMO = *MI.memoperands_begin();
490 CommentOS << MMO->getSize() << "-byte Reload\n";
492 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
493 if (FrameInfo->isSpillSlotObjectIndex(FI))
494 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
495 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
496 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
497 MMO = *MI.memoperands_begin();
498 CommentOS << MMO->getSize() << "-byte Spill\n";
500 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
501 if (FrameInfo->isSpillSlotObjectIndex(FI))
502 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
505 // Check for spill-induced copies
506 unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
507 if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
508 SrcSubIdx, DstSubIdx)) {
509 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
510 CommentOS << " Reload Reuse\n";
514 /// EmitImplicitDef - This method emits the specified machine instruction
515 /// that is an implicit def.
516 static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
517 unsigned RegNo = MI->getOperand(0).getReg();
518 AP.OutStreamer.AddComment(Twine("implicit-def: ") +
519 AP.TM.getRegisterInfo()->getName(RegNo));
520 AP.OutStreamer.AddBlankLine();
523 static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) {
524 std::string Str = "kill:";
525 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
526 const MachineOperand &Op = MI->getOperand(i);
527 assert(Op.isReg() && "KILL instruction must have only register operands");
529 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
530 Str += (Op.isDef() ? "<def>" : "<kill>");
532 AP.OutStreamer.AddComment(Str);
533 AP.OutStreamer.AddBlankLine();
536 /// EmitDebugValueComment - This method handles the target-independent form
537 /// of DBG_VALUE, returning true if it was able to do so. A false return
538 /// means the target will need to handle MI in EmitInstruction.
539 static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
540 // This code handles only the 3-operand target-independent form.
541 if (MI->getNumOperands() != 3)
544 SmallString<128> Str;
545 raw_svector_ostream OS(Str);
546 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
548 // cast away const; DIetc do not take const operands for some reason.
549 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
550 if (V.getContext().isSubprogram())
551 OS << DISubprogram(V.getContext()).getDisplayName() << ":";
552 OS << V.getName() << " <- ";
554 // Register or immediate value. Register 0 means undef.
555 if (MI->getOperand(0).isFPImm()) {
556 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
557 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
558 OS << (double)APF.convertToFloat();
559 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
560 OS << APF.convertToDouble();
562 // There is no good way to print long double. Convert a copy to
563 // double. Ah well, it's only a comment.
565 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
567 OS << "(long double) " << APF.convertToDouble();
569 } else if (MI->getOperand(0).isImm()) {
570 OS << MI->getOperand(0).getImm();
572 assert(MI->getOperand(0).isReg() && "Unknown operand type");
573 if (MI->getOperand(0).getReg() == 0) {
574 // Suppress offset, it is not meaningful here.
576 // NOTE: Want this comment at start of line, don't emit with AddComment.
577 AP.OutStreamer.EmitRawText(OS.str());
580 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg());
583 OS << '+' << MI->getOperand(1).getImm();
584 // NOTE: Want this comment at start of line, don't emit with AddComment.
585 AP.OutStreamer.EmitRawText(OS.str());
589 /// EmitFunctionBody - This method emits the body and trailer for a
591 void AsmPrinter::EmitFunctionBody() {
592 // Emit target-specific gunk before the function body.
593 EmitFunctionBodyStart();
595 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
597 // Print out code for the function.
598 bool HasAnyRealCode = false;
599 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
601 // Print a label for the basic block.
602 EmitBasicBlockStart(I);
603 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
605 // Print the assembly for the instruction.
606 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
607 !II->isDebugValue()) {
608 HasAnyRealCode = true;
612 if (ShouldPrintDebugScopes) {
613 if (TimePassesIsEnabled) {
614 NamedRegionTimer T(DbgTimerName, DWARFGroupName);
622 EmitComments(*II, OutStreamer.GetCommentOS());
624 switch (II->getOpcode()) {
625 case TargetOpcode::DBG_LABEL:
626 case TargetOpcode::EH_LABEL:
627 case TargetOpcode::GC_LABEL:
628 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
630 case TargetOpcode::INLINEASM:
633 case TargetOpcode::DBG_VALUE:
635 if (!EmitDebugValueComment(II, *this))
639 case TargetOpcode::IMPLICIT_DEF:
640 if (isVerbose()) EmitImplicitDef(II, *this);
642 case TargetOpcode::KILL:
643 if (isVerbose()) EmitKill(II, *this);
650 if (ShouldPrintDebugScopes) {
651 if (TimePassesIsEnabled) {
652 NamedRegionTimer T(DbgTimerName, DWARFGroupName);
661 // If the function is empty and the object file uses .subsections_via_symbols,
662 // then we need to emit *something* to the function body to prevent the
663 // labels from collapsing together. Just emit a noop.
664 if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) {
666 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
667 if (Noop.getOpcode()) {
668 OutStreamer.AddComment("avoids zero-length function");
669 OutStreamer.EmitInstruction(Noop);
670 } else // Target not mc-ized yet.
671 OutStreamer.EmitRawText(StringRef("\tnop\n"));
674 // Emit target-specific gunk after the function body.
675 EmitFunctionBodyEnd();
677 // If the target wants a .size directive for the size of the function, emit
679 if (MAI->hasDotTypeDotSizeDirective()) {
680 // Create a symbol for the end of function, so we can get the size as
681 // difference between the function label and the temp label.
682 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
683 OutStreamer.EmitLabel(FnEndLabel);
685 const MCExpr *SizeExp =
686 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
687 MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
689 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
692 // Emit post-function debug information.
694 if (TimePassesIsEnabled) {
695 NamedRegionTimer T(DbgTimerName, DWARFGroupName);
702 if (TimePassesIsEnabled) {
703 NamedRegionTimer T(EHTimerName, DWARFGroupName);
711 // Print out jump tables referenced by the function.
714 OutStreamer.AddBlankLine();
717 /// getDebugValueLocation - Get location information encoded by DBG_VALUE
719 MachineLocation AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const {
720 // Target specific DBG_VALUE instructions are handled by each target.
721 return MachineLocation();
724 bool AsmPrinter::doFinalization(Module &M) {
725 // Emit global variables.
726 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
728 EmitGlobalVariable(I);
730 // Finalize debug and EH information.
732 if (TimePassesIsEnabled) {
733 NamedRegionTimer T(EHTimerName, DWARFGroupName);
741 if (TimePassesIsEnabled) {
742 NamedRegionTimer T(DbgTimerName, DWARFGroupName);
750 // If the target wants to know about weak references, print them all.
751 if (MAI->getWeakRefDirective()) {
752 // FIXME: This is not lazy, it would be nice to only print weak references
753 // to stuff that is actually used. Note that doing so would require targets
754 // to notice uses in operands (due to constant exprs etc). This should
755 // happen with the MC stuff eventually.
757 // Print out module-level global variables here.
758 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
760 if (!I->hasExternalWeakLinkage()) continue;
761 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
764 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
765 if (!I->hasExternalWeakLinkage()) continue;
766 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
770 if (MAI->hasSetDirective()) {
771 OutStreamer.AddBlankLine();
772 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
774 MCSymbol *Name = Mang->getSymbol(I);
776 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
777 MCSymbol *Target = Mang->getSymbol(GV);
779 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
780 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
781 else if (I->hasWeakLinkage())
782 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
784 assert(I->hasLocalLinkage() && "Invalid alias linkage");
786 EmitVisibility(Name, I->getVisibility());
788 // Emit the directives as assignments aka .set:
789 OutStreamer.EmitAssignment(Name,
790 MCSymbolRefExpr::Create(Target, OutContext));
794 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
795 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
796 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
797 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
798 MP->finishAssembly(*this);
800 // If we don't have any trampolines, then we don't require stack memory
801 // to be executable. Some targets have a directive to declare this.
802 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
803 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
804 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
805 OutStreamer.SwitchSection(S);
807 // Allow the target to emit any magic that it wants at the end of the file,
808 // after everything else has gone out.
811 delete Mang; Mang = 0;
814 OutStreamer.Finish();
818 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
820 // Get the function symbol.
821 CurrentFnSym = Mang->getSymbol(MF.getFunction());
824 LI = &getAnalysis<MachineLoopInfo>();
828 // SectionCPs - Keep track the alignment, constpool entries per Section.
832 SmallVector<unsigned, 4> CPEs;
833 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
837 /// EmitConstantPool - Print to the current output stream assembly
838 /// representations of the constants in the constant pool MCP. This is
839 /// used to print out constants which have been "spilled to memory" by
840 /// the code generator.
842 void AsmPrinter::EmitConstantPool() {
843 const MachineConstantPool *MCP = MF->getConstantPool();
844 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
845 if (CP.empty()) return;
847 // Calculate sections for constant pool entries. We collect entries to go into
848 // the same section together to reduce amount of section switch statements.
849 SmallVector<SectionCPs, 4> CPSections;
850 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
851 const MachineConstantPoolEntry &CPE = CP[i];
852 unsigned Align = CPE.getAlignment();
855 switch (CPE.getRelocationInfo()) {
856 default: llvm_unreachable("Unknown section kind");
857 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
859 Kind = SectionKind::getReadOnlyWithRelLocal();
862 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
863 case 4: Kind = SectionKind::getMergeableConst4(); break;
864 case 8: Kind = SectionKind::getMergeableConst8(); break;
865 case 16: Kind = SectionKind::getMergeableConst16();break;
866 default: Kind = SectionKind::getMergeableConst(); break;
870 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
872 // The number of sections are small, just do a linear search from the
873 // last section to the first.
875 unsigned SecIdx = CPSections.size();
876 while (SecIdx != 0) {
877 if (CPSections[--SecIdx].S == S) {
883 SecIdx = CPSections.size();
884 CPSections.push_back(SectionCPs(S, Align));
887 if (Align > CPSections[SecIdx].Alignment)
888 CPSections[SecIdx].Alignment = Align;
889 CPSections[SecIdx].CPEs.push_back(i);
892 // Now print stuff into the calculated sections.
893 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
894 OutStreamer.SwitchSection(CPSections[i].S);
895 EmitAlignment(Log2_32(CPSections[i].Alignment));
898 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
899 unsigned CPI = CPSections[i].CPEs[j];
900 MachineConstantPoolEntry CPE = CP[CPI];
902 // Emit inter-object padding for alignment.
903 unsigned AlignMask = CPE.getAlignment() - 1;
904 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
905 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
907 const Type *Ty = CPE.getType();
908 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
910 // Emit the label with a comment on it.
912 OutStreamer.GetCommentOS() << "constant pool ";
913 WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
914 MF->getFunction()->getParent());
915 OutStreamer.GetCommentOS() << '\n';
917 OutStreamer.EmitLabel(GetCPISymbol(CPI));
919 if (CPE.isMachineConstantPoolEntry())
920 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
922 EmitGlobalConstant(CPE.Val.ConstVal);
927 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
928 /// by the current function to the current output stream.
930 void AsmPrinter::EmitJumpTableInfo() {
931 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
932 if (MJTI == 0) return;
933 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
934 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
935 if (JT.empty()) return;
937 // Pick the directive to use to print the jump table entries, and switch to
938 // the appropriate section.
939 const Function *F = MF->getFunction();
940 bool JTInDiffSection = false;
941 if (// In PIC mode, we need to emit the jump table to the same section as the
942 // function body itself, otherwise the label differences won't make sense.
943 // FIXME: Need a better predicate for this: what about custom entries?
944 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
945 // We should also do if the section name is NULL or function is declared
946 // in discardable section
947 // FIXME: this isn't the right predicate, should be based on the MCSection
949 F->isWeakForLinker()) {
950 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
952 // Otherwise, drop it in the readonly section.
953 const MCSection *ReadOnlySection =
954 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
955 OutStreamer.SwitchSection(ReadOnlySection);
956 JTInDiffSection = true;
959 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
961 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
962 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
964 // If this jump table was deleted, ignore it.
965 if (JTBBs.empty()) continue;
967 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
968 // .set directive for each unique entry. This reduces the number of
969 // relocations the assembler will generate for the jump table.
970 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
971 MAI->hasSetDirective()) {
972 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
973 const TargetLowering *TLI = TM.getTargetLowering();
974 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
975 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
976 const MachineBasicBlock *MBB = JTBBs[ii];
977 if (!EmittedSets.insert(MBB)) continue;
979 // .set LJTSet, LBB32-base
981 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
982 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
983 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
987 // On some targets (e.g. Darwin) we want to emit two consequtive labels
988 // before each jump table. The first label is never referenced, but tells
989 // the assembler and linker the extents of the jump table object. The
990 // second label is actually referenced by the code.
991 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
992 // FIXME: This doesn't have to have any specific name, just any randomly
993 // named and numbered 'l' label would work. Simplify GetJTISymbol.
994 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
996 OutStreamer.EmitLabel(GetJTISymbol(JTI));
998 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
999 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1003 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1005 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1006 const MachineBasicBlock *MBB,
1007 unsigned UID) const {
1008 const MCExpr *Value = 0;
1009 switch (MJTI->getEntryKind()) {
1010 case MachineJumpTableInfo::EK_Inline:
1011 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
1012 case MachineJumpTableInfo::EK_Custom32:
1013 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1016 case MachineJumpTableInfo::EK_BlockAddress:
1017 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1019 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1021 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1022 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1023 // with a relocation as gp-relative, e.g.:
1025 MCSymbol *MBBSym = MBB->getSymbol();
1026 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1030 case MachineJumpTableInfo::EK_LabelDifference32: {
1031 // EK_LabelDifference32 - Each entry is the address of the block minus
1032 // the address of the jump table. This is used for PIC jump tables where
1033 // gprel32 is not supported. e.g.:
1034 // .word LBB123 - LJTI1_2
1035 // If the .set directive is supported, this is emitted as:
1036 // .set L4_5_set_123, LBB123 - LJTI1_2
1037 // .word L4_5_set_123
1039 // If we have emitted set directives for the jump table entries, print
1040 // them rather than the entries themselves. If we're emitting PIC, then
1041 // emit the table entries as differences between two text section labels.
1042 if (MAI->hasSetDirective()) {
1043 // If we used .set, reference the .set's symbol.
1044 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1048 // Otherwise, use the difference as the jump table entry.
1049 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1050 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1051 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1056 assert(Value && "Unknown entry kind!");
1058 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
1059 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
1063 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1064 /// special global used by LLVM. If so, emit it and return true, otherwise
1065 /// do nothing and return false.
1066 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1067 if (GV->getName() == "llvm.used") {
1068 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1069 EmitLLVMUsedList(GV->getInitializer());
1073 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1074 if (GV->getSection() == "llvm.metadata" ||
1075 GV->hasAvailableExternallyLinkage())
1078 if (!GV->hasAppendingLinkage()) return false;
1080 assert(GV->hasInitializer() && "Not a special LLVM global!");
1082 const TargetData *TD = TM.getTargetData();
1083 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1084 if (GV->getName() == "llvm.global_ctors") {
1085 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
1086 EmitAlignment(Align);
1087 EmitXXStructorList(GV->getInitializer());
1089 if (TM.getRelocationModel() == Reloc::Static &&
1090 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1091 StringRef Sym(".constructors_used");
1092 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1098 if (GV->getName() == "llvm.global_dtors") {
1099 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
1100 EmitAlignment(Align);
1101 EmitXXStructorList(GV->getInitializer());
1103 if (TM.getRelocationModel() == Reloc::Static &&
1104 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1105 StringRef Sym(".destructors_used");
1106 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1115 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1116 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1117 /// is true, as being used with this directive.
1118 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
1119 // Should be an array of 'i8*'.
1120 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1121 if (InitList == 0) return;
1123 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1124 const GlobalValue *GV =
1125 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1126 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1127 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1131 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
1132 /// function pointers, ignoring the init priority.
1133 void AsmPrinter::EmitXXStructorList(Constant *List) {
1134 // Should be an array of '{ int, void ()* }' structs. The first value is the
1135 // init priority, which we ignore.
1136 if (!isa<ConstantArray>(List)) return;
1137 ConstantArray *InitList = cast<ConstantArray>(List);
1138 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
1139 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
1140 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
1142 if (CS->getOperand(1)->isNullValue())
1143 return; // Found a null terminator, exit printing.
1144 // Emit the function pointer.
1145 EmitGlobalConstant(CS->getOperand(1));
1149 //===--------------------------------------------------------------------===//
1150 // Emission and print routines
1153 /// EmitInt8 - Emit a byte directive and value.
1155 void AsmPrinter::EmitInt8(int Value) const {
1156 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
1159 /// EmitInt16 - Emit a short directive and value.
1161 void AsmPrinter::EmitInt16(int Value) const {
1162 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
1165 /// EmitInt32 - Emit a long directive and value.
1167 void AsmPrinter::EmitInt32(int Value) const {
1168 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
1171 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1172 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1173 /// labels. This implicitly uses .set if it is available.
1174 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1175 unsigned Size) const {
1176 // Get the Hi-Lo expression.
1177 const MCExpr *Diff =
1178 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1179 MCSymbolRefExpr::Create(Lo, OutContext),
1182 if (!MAI->hasSetDirective()) {
1183 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
1187 // Otherwise, emit with .set (aka assignment).
1188 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1189 OutStreamer.EmitAssignment(SetLabel, Diff);
1190 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
1193 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1194 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1195 /// specify the labels. This implicitly uses .set if it is available.
1196 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1197 const MCSymbol *Lo, unsigned Size)
1200 // Emit Hi+Offset - Lo
1201 // Get the Hi+Offset expression.
1202 const MCExpr *Plus =
1203 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1204 MCConstantExpr::Create(Offset, OutContext),
1207 // Get the Hi+Offset-Lo expression.
1208 const MCExpr *Diff =
1209 MCBinaryExpr::CreateSub(Plus,
1210 MCSymbolRefExpr::Create(Lo, OutContext),
1213 if (!MAI->hasSetDirective())
1214 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/);
1216 // Otherwise, emit with .set (aka assignment).
1217 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1218 OutStreamer.EmitAssignment(SetLabel, Diff);
1219 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/);
1224 //===----------------------------------------------------------------------===//
1226 // EmitAlignment - Emit an alignment directive to the specified power of
1227 // two boundary. For example, if you pass in 3 here, you will get an 8
1228 // byte alignment. If a global value is specified, and if that global has
1229 // an explicit alignment requested, it will override the alignment request
1230 // if required for correctness.
1232 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1233 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits);
1235 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1237 if (getCurrentSection()->getKind().isText())
1238 OutStreamer.EmitCodeAlignment(1 << NumBits);
1240 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1243 //===----------------------------------------------------------------------===//
1244 // Constant emission.
1245 //===----------------------------------------------------------------------===//
1247 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1249 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1250 MCContext &Ctx = AP.OutContext;
1252 if (CV->isNullValue() || isa<UndefValue>(CV))
1253 return MCConstantExpr::Create(0, Ctx);
1255 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1256 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1258 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1259 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1260 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1261 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1263 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1265 llvm_unreachable("Unknown constant value to lower!");
1266 return MCConstantExpr::Create(0, Ctx);
1269 switch (CE->getOpcode()) {
1271 // If the code isn't optimized, there may be outstanding folding
1272 // opportunities. Attempt to fold the expression using TargetData as a
1273 // last resort before giving up.
1275 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1277 return LowerConstant(C, AP);
1281 llvm_unreachable("FIXME: Don't support this constant expr");
1282 case Instruction::GetElementPtr: {
1283 const TargetData &TD = *AP.TM.getTargetData();
1284 // Generate a symbolic expression for the byte address
1285 const Constant *PtrVal = CE->getOperand(0);
1286 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1287 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1290 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1294 // Truncate/sext the offset to the pointer size.
1295 if (TD.getPointerSizeInBits() != 64) {
1296 int SExtAmount = 64-TD.getPointerSizeInBits();
1297 Offset = (Offset << SExtAmount) >> SExtAmount;
1300 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1304 case Instruction::Trunc:
1305 // We emit the value and depend on the assembler to truncate the generated
1306 // expression properly. This is important for differences between
1307 // blockaddress labels. Since the two labels are in the same function, it
1308 // is reasonable to treat their delta as a 32-bit value.
1310 case Instruction::BitCast:
1311 return LowerConstant(CE->getOperand(0), AP);
1313 case Instruction::IntToPtr: {
1314 const TargetData &TD = *AP.TM.getTargetData();
1315 // Handle casts to pointers by changing them into casts to the appropriate
1316 // integer type. This promotes constant folding and simplifies this code.
1317 Constant *Op = CE->getOperand(0);
1318 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1320 return LowerConstant(Op, AP);
1323 case Instruction::PtrToInt: {
1324 const TargetData &TD = *AP.TM.getTargetData();
1325 // Support only foldable casts to/from pointers that can be eliminated by
1326 // changing the pointer to the appropriately sized integer type.
1327 Constant *Op = CE->getOperand(0);
1328 const Type *Ty = CE->getType();
1330 const MCExpr *OpExpr = LowerConstant(Op, AP);
1332 // We can emit the pointer value into this slot if the slot is an
1333 // integer slot equal to the size of the pointer.
1334 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1337 // Otherwise the pointer is smaller than the resultant integer, mask off
1338 // the high bits so we are sure to get a proper truncation if the input is
1340 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1341 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1342 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1345 // The MC library also has a right-shift operator, but it isn't consistently
1346 // signed or unsigned between different targets.
1347 case Instruction::Add:
1348 case Instruction::Sub:
1349 case Instruction::Mul:
1350 case Instruction::SDiv:
1351 case Instruction::SRem:
1352 case Instruction::Shl:
1353 case Instruction::And:
1354 case Instruction::Or:
1355 case Instruction::Xor: {
1356 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1357 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1358 switch (CE->getOpcode()) {
1359 default: llvm_unreachable("Unknown binary operator constant cast expr");
1360 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1361 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1362 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1363 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1364 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1365 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1366 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1367 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1368 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1374 static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace,
1377 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1379 if (AddrSpace != 0 || !CA->isString()) {
1380 // Not a string. Print the values in successive locations
1381 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1382 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP);
1386 // Otherwise, it can be emitted as .ascii.
1387 SmallVector<char, 128> TmpVec;
1388 TmpVec.reserve(CA->getNumOperands());
1389 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1390 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1392 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1395 static void EmitGlobalConstantVector(const ConstantVector *CV,
1396 unsigned AddrSpace, AsmPrinter &AP) {
1397 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1398 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP);
1401 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1402 unsigned AddrSpace, AsmPrinter &AP) {
1403 // Print the fields in successive locations. Pad to align if needed!
1404 const TargetData *TD = AP.TM.getTargetData();
1405 unsigned Size = TD->getTypeAllocSize(CS->getType());
1406 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1407 uint64_t SizeSoFar = 0;
1408 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1409 const Constant *Field = CS->getOperand(i);
1411 // Check if padding is needed and insert one or more 0s.
1412 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1413 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1414 - Layout->getElementOffset(i)) - FieldSize;
1415 SizeSoFar += FieldSize + PadSize;
1417 // Now print the actual field value.
1418 EmitGlobalConstantImpl(Field, AddrSpace, AP);
1420 // Insert padding - this may include padding to increase the size of the
1421 // current field up to the ABI size (if the struct is not packed) as well
1422 // as padding to ensure that the next field starts at the right offset.
1423 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1425 assert(SizeSoFar == Layout->getSizeInBytes() &&
1426 "Layout of constant struct may be incorrect!");
1429 static void EmitGlobalConstantUnion(const ConstantUnion *CU,
1430 unsigned AddrSpace, AsmPrinter &AP) {
1431 const TargetData *TD = AP.TM.getTargetData();
1432 unsigned Size = TD->getTypeAllocSize(CU->getType());
1434 const Constant *Contents = CU->getOperand(0);
1435 unsigned FilledSize = TD->getTypeAllocSize(Contents->getType());
1437 // Print the actually filled part
1438 EmitGlobalConstantImpl(Contents, AddrSpace, AP);
1440 // And pad with enough zeroes
1441 AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace);
1444 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1446 // FP Constants are printed as integer constants to avoid losing
1448 if (CFP->getType()->isDoubleTy()) {
1449 if (AP.isVerbose()) {
1450 double Val = CFP->getValueAPF().convertToDouble();
1451 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1454 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1455 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1459 if (CFP->getType()->isFloatTy()) {
1460 if (AP.isVerbose()) {
1461 float Val = CFP->getValueAPF().convertToFloat();
1462 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1464 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1465 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1469 if (CFP->getType()->isX86_FP80Ty()) {
1470 // all long double variants are printed as hex
1471 // API needed to prevent premature destruction
1472 APInt API = CFP->getValueAPF().bitcastToAPInt();
1473 const uint64_t *p = API.getRawData();
1474 if (AP.isVerbose()) {
1475 // Convert to double so we can print the approximate val as a comment.
1476 APFloat DoubleVal = CFP->getValueAPF();
1478 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1480 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1481 << DoubleVal.convertToDouble() << '\n';
1484 if (AP.TM.getTargetData()->isBigEndian()) {
1485 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1486 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1488 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1489 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1492 // Emit the tail padding for the long double.
1493 const TargetData &TD = *AP.TM.getTargetData();
1494 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1495 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1499 assert(CFP->getType()->isPPC_FP128Ty() &&
1500 "Floating point constant type not handled");
1501 // All long double variants are printed as hex
1502 // API needed to prevent premature destruction.
1503 APInt API = CFP->getValueAPF().bitcastToAPInt();
1504 const uint64_t *p = API.getRawData();
1505 if (AP.TM.getTargetData()->isBigEndian()) {
1506 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1507 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1509 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1510 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1514 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1515 unsigned AddrSpace, AsmPrinter &AP) {
1516 const TargetData *TD = AP.TM.getTargetData();
1517 unsigned BitWidth = CI->getBitWidth();
1518 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1520 // We don't expect assemblers to support integer data directives
1521 // for more than 64 bits, so we emit the data in at most 64-bit
1522 // quantities at a time.
1523 const uint64_t *RawData = CI->getValue().getRawData();
1524 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1525 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1526 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1530 static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
1532 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1533 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1534 return AP.OutStreamer.EmitZeros(Size, AddrSpace);
1537 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1538 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1545 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1546 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1549 EmitGlobalConstantLargeInt(CI, AddrSpace, AP);
1554 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1555 return EmitGlobalConstantArray(CVA, AddrSpace, AP);
1557 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1558 return EmitGlobalConstantStruct(CVS, AddrSpace, AP);
1560 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1561 return EmitGlobalConstantFP(CFP, AddrSpace, AP);
1563 if (isa<ConstantPointerNull>(CV)) {
1564 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1565 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace);
1569 if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV))
1570 return EmitGlobalConstantUnion(CVU, AddrSpace, AP);
1572 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1573 return EmitGlobalConstantVector(V, AddrSpace, AP);
1575 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1576 // thread the streamer with EmitValue.
1577 AP.OutStreamer.EmitValue(LowerConstant(CV, AP),
1578 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()),
1582 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1583 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1584 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1586 EmitGlobalConstantImpl(CV, AddrSpace, *this);
1587 else if (MAI->hasSubsectionsViaSymbols()) {
1588 // If the global has zero size, emit a single byte so that two labels don't
1589 // look like they are at the same location.
1590 OutStreamer.EmitIntValue(0, 1, AddrSpace);
1594 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1595 // Target doesn't support this yet!
1596 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1599 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1601 OS << '+' << Offset;
1602 else if (Offset < 0)
1606 //===----------------------------------------------------------------------===//
1607 // Symbol Lowering Routines.
1608 //===----------------------------------------------------------------------===//
1610 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1611 /// temporary label with the specified stem and unique ID.
1612 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1613 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1617 /// GetTempSymbol - Return an assembler temporary label with the specified
1619 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1620 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1625 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1626 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1629 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1630 return MMI->getAddrLabelSymbol(BB);
1633 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1634 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1635 return OutContext.GetOrCreateSymbol
1636 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1637 + "_" + Twine(CPID));
1640 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1641 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1642 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1645 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1646 /// FIXME: privatize to AsmPrinter.
1647 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1648 return OutContext.GetOrCreateSymbol
1649 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1650 Twine(UID) + "_set_" + Twine(MBBID));
1653 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1654 /// global value name as its base, with the specified suffix, and where the
1655 /// symbol is forced to have private linkage if ForcePrivate is true.
1656 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1658 bool ForcePrivate) const {
1659 SmallString<60> NameStr;
1660 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1661 NameStr.append(Suffix.begin(), Suffix.end());
1662 return OutContext.GetOrCreateSymbol(NameStr.str());
1665 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1667 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1668 SmallString<60> NameStr;
1669 Mang->getNameWithPrefix(NameStr, Sym);
1670 return OutContext.GetOrCreateSymbol(NameStr.str());
1675 /// PrintParentLoopComment - Print comments about parent loops of this one.
1676 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1677 unsigned FunctionNumber) {
1678 if (Loop == 0) return;
1679 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1680 OS.indent(Loop->getLoopDepth()*2)
1681 << "Parent Loop BB" << FunctionNumber << "_"
1682 << Loop->getHeader()->getNumber()
1683 << " Depth=" << Loop->getLoopDepth() << '\n';
1687 /// PrintChildLoopComment - Print comments about child loops within
1688 /// the loop for this basic block, with nesting.
1689 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1690 unsigned FunctionNumber) {
1691 // Add child loop information
1692 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1693 OS.indent((*CL)->getLoopDepth()*2)
1694 << "Child Loop BB" << FunctionNumber << "_"
1695 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1697 PrintChildLoopComment(OS, *CL, FunctionNumber);
1701 /// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks.
1702 static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB,
1703 const MachineLoopInfo *LI,
1704 const AsmPrinter &AP) {
1705 // Add loop depth information
1706 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1707 if (Loop == 0) return;
1709 MachineBasicBlock *Header = Loop->getHeader();
1710 assert(Header && "No header for loop");
1712 // If this block is not a loop header, just print out what is the loop header
1714 if (Header != &MBB) {
1715 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1716 Twine(AP.getFunctionNumber())+"_" +
1717 Twine(Loop->getHeader()->getNumber())+
1718 " Depth="+Twine(Loop->getLoopDepth()));
1722 // Otherwise, it is a loop header. Print out information about child and
1724 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1726 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1729 OS.indent(Loop->getLoopDepth()*2-2);
1734 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1736 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1740 /// EmitBasicBlockStart - This method prints the label for the specified
1741 /// MachineBasicBlock, an alignment (if present) and a comment describing
1742 /// it if appropriate.
1743 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1744 // Emit an alignment directive for this block, if needed.
1745 if (unsigned Align = MBB->getAlignment())
1746 EmitAlignment(Log2_32(Align));
1748 // If the block has its address taken, emit any labels that were used to
1749 // reference the block. It is possible that there is more than one label
1750 // here, because multiple LLVM BB's may have been RAUW'd to this block after
1751 // the references were generated.
1752 if (MBB->hasAddressTaken()) {
1753 const BasicBlock *BB = MBB->getBasicBlock();
1755 OutStreamer.AddComment("Block address taken");
1757 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1759 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1760 OutStreamer.EmitLabel(Syms[i]);
1763 // Print the main label for the block.
1764 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1765 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
1766 if (const BasicBlock *BB = MBB->getBasicBlock())
1768 OutStreamer.AddComment("%" + BB->getName());
1770 EmitBasicBlockLoopComments(*MBB, LI, *this);
1772 // NOTE: Want this comment at start of line, don't emit with AddComment.
1773 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1774 Twine(MBB->getNumber()) + ":");
1778 if (const BasicBlock *BB = MBB->getBasicBlock())
1780 OutStreamer.AddComment("%" + BB->getName());
1781 EmitBasicBlockLoopComments(*MBB, LI, *this);
1784 OutStreamer.EmitLabel(MBB->getSymbol());
1788 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1789 MCSymbolAttr Attr = MCSA_Invalid;
1791 switch (Visibility) {
1793 case GlobalValue::HiddenVisibility:
1794 Attr = MAI->getHiddenVisibilityAttr();
1796 case GlobalValue::ProtectedVisibility:
1797 Attr = MAI->getProtectedVisibilityAttr();
1801 if (Attr != MCSA_Invalid)
1802 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1805 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1806 /// exactly one predecessor and the control transfer mechanism between
1807 /// the predecessor and this block is a fall-through.
1809 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1810 // If this is a landing pad, it isn't a fall through. If it has no preds,
1811 // then nothing falls through to it.
1812 if (MBB->isLandingPad() || MBB->pred_empty())
1815 // If there isn't exactly one predecessor, it can't be a fall through.
1816 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1818 if (PI2 != MBB->pred_end())
1821 // The predecessor has to be immediately before this block.
1822 const MachineBasicBlock *Pred = *PI;
1824 if (!Pred->isLayoutSuccessor(MBB))
1827 // If the block is completely empty, then it definitely does fall through.
1831 // Otherwise, check the last instruction.
1832 const MachineInstr &LastInst = Pred->back();
1833 return !LastInst.getDesc().isBarrier();
1838 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1839 if (!S->usesMetadata())
1842 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1843 gcp_map_type::iterator GCPI = GCMap.find(S);
1844 if (GCPI != GCMap.end())
1845 return GCPI->second;
1847 const char *Name = S->getName().c_str();
1849 for (GCMetadataPrinterRegistry::iterator
1850 I = GCMetadataPrinterRegistry::begin(),
1851 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1852 if (strcmp(Name, I->getName()) == 0) {
1853 GCMetadataPrinter *GMP = I->instantiate();
1855 GCMap.insert(std::make_pair(S, GMP));
1859 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));