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 #include "llvm/CodeGen/AsmPrinter.h"
15 #include "DwarfDebug.h"
16 #include "DwarfException.h"
17 #include "Win64Exception.h"
18 #include "WinCodeViewLineTables.h"
19 #include "llvm/ADT/SmallString.h"
20 #include "llvm/ADT/Statistic.h"
21 #include "llvm/Analysis/ConstantFolding.h"
22 #include "llvm/Analysis/JumpInstrTableInfo.h"
23 #include "llvm/CodeGen/Analysis.h"
24 #include "llvm/CodeGen/GCMetadataPrinter.h"
25 #include "llvm/CodeGen/MachineConstantPool.h"
26 #include "llvm/CodeGen/MachineFrameInfo.h"
27 #include "llvm/CodeGen/MachineFunction.h"
28 #include "llvm/CodeGen/MachineInstrBundle.h"
29 #include "llvm/CodeGen/MachineJumpTableInfo.h"
30 #include "llvm/CodeGen/MachineLoopInfo.h"
31 #include "llvm/CodeGen/MachineModuleInfo.h"
32 #include "llvm/IR/DataLayout.h"
33 #include "llvm/IR/DebugInfo.h"
34 #include "llvm/IR/Mangler.h"
35 #include "llvm/IR/Module.h"
36 #include "llvm/IR/Operator.h"
37 #include "llvm/MC/MCAsmInfo.h"
38 #include "llvm/MC/MCContext.h"
39 #include "llvm/MC/MCExpr.h"
40 #include "llvm/MC/MCInst.h"
41 #include "llvm/MC/MCSection.h"
42 #include "llvm/MC/MCStreamer.h"
43 #include "llvm/MC/MCSymbol.h"
44 #include "llvm/MC/MCValue.h"
45 #include "llvm/Support/ErrorHandling.h"
46 #include "llvm/Support/Format.h"
47 #include "llvm/Support/MathExtras.h"
48 #include "llvm/Support/TargetRegistry.h"
49 #include "llvm/Support/Timer.h"
50 #include "llvm/Target/TargetFrameLowering.h"
51 #include "llvm/Target/TargetInstrInfo.h"
52 #include "llvm/Target/TargetLowering.h"
53 #include "llvm/Target/TargetLoweringObjectFile.h"
54 #include "llvm/Target/TargetRegisterInfo.h"
55 #include "llvm/Target/TargetSubtargetInfo.h"
58 #define DEBUG_TYPE "asm-printer"
60 static const char *const DWARFGroupName = "DWARF Emission";
61 static const char *const DbgTimerName = "Debug Info Emission";
62 static const char *const EHTimerName = "DWARF Exception Writer";
63 static const char *const CodeViewLineTablesGroupName = "CodeView Line Tables";
65 STATISTIC(EmittedInsts, "Number of machine instrs printed");
67 char AsmPrinter::ID = 0;
69 typedef DenseMap<GCStrategy*, std::unique_ptr<GCMetadataPrinter>> gcp_map_type;
70 static gcp_map_type &getGCMap(void *&P) {
72 P = new gcp_map_type();
73 return *(gcp_map_type*)P;
77 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
78 /// value in log2 form. This rounds up to the preferred alignment if possible
80 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD,
81 unsigned InBits = 0) {
83 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
84 NumBits = TD.getPreferredAlignmentLog(GVar);
86 // If InBits is specified, round it to it.
90 // If the GV has a specified alignment, take it into account.
91 if (GV->getAlignment() == 0)
94 unsigned GVAlign = Log2_32(GV->getAlignment());
96 // If the GVAlign is larger than NumBits, or if we are required to obey
97 // NumBits because the GV has an assigned section, obey it.
98 if (GVAlign > NumBits || GV->hasSection())
103 AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
104 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
105 OutContext(Streamer->getContext()), OutStreamer(*Streamer.release()),
106 LastMI(nullptr), LastFn(0), Counter(~0U), SetCounter(0) {
111 CurrentFnSym = CurrentFnSymForSize = nullptr;
112 CurrentFnBegin = nullptr;
113 CurrentFnEnd = nullptr;
114 GCMetadataPrinters = nullptr;
115 VerboseAsm = OutStreamer.isVerboseAsm();
118 AsmPrinter::~AsmPrinter() {
119 assert(!DD && Handlers.empty() && "Debug/EH info didn't get finalized");
121 if (GCMetadataPrinters) {
122 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
125 GCMetadataPrinters = nullptr;
131 /// getFunctionNumber - Return a unique ID for the current function.
133 unsigned AsmPrinter::getFunctionNumber() const {
134 return MF->getFunctionNumber();
137 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
138 return *TM.getObjFileLowering();
141 /// getDataLayout - Return information about data layout.
142 const DataLayout &AsmPrinter::getDataLayout() const {
143 return *TM.getDataLayout();
146 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
147 assert(MF && "getSubtargetInfo requires a valid MachineFunction!");
148 return MF->getSubtarget<MCSubtargetInfo>();
151 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
152 S.EmitInstruction(Inst, getSubtargetInfo());
155 StringRef AsmPrinter::getTargetTriple() const {
156 return TM.getTargetTriple();
159 /// getCurrentSection() - Return the current section we are emitting to.
160 const MCSection *AsmPrinter::getCurrentSection() const {
161 return OutStreamer.getCurrentSection().first;
166 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
167 AU.setPreservesAll();
168 MachineFunctionPass::getAnalysisUsage(AU);
169 AU.addRequired<MachineModuleInfo>();
170 AU.addRequired<GCModuleInfo>();
172 AU.addRequired<MachineLoopInfo>();
175 bool AsmPrinter::doInitialization(Module &M) {
176 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
177 MMI->AnalyzeModule(M);
179 // Initialize TargetLoweringObjectFile.
180 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
181 .Initialize(OutContext, TM);
183 OutStreamer.InitSections(false);
185 Mang = new Mangler(TM.getDataLayout());
187 // Emit the version-min deplyment target directive if needed.
189 // FIXME: If we end up with a collection of these sorts of Darwin-specific
190 // or ELF-specific things, it may make sense to have a platform helper class
191 // that will work with the target helper class. For now keep it here, as the
192 // alternative is duplicated code in each of the target asm printers that
193 // use the directive, where it would need the same conditionalization
195 Triple TT(getTargetTriple());
196 if (TT.isOSDarwin()) {
197 unsigned Major, Minor, Update;
198 TT.getOSVersion(Major, Minor, Update);
199 // If there is a version specified, Major will be non-zero.
201 OutStreamer.EmitVersionMin((TT.isMacOSX() ?
202 MCVM_OSXVersionMin : MCVM_IOSVersionMin),
203 Major, Minor, Update);
206 // Allow the target to emit any magic that it wants at the start of the file.
207 EmitStartOfAsmFile(M);
209 // Very minimal debug info. It is ignored if we emit actual debug info. If we
210 // don't, this at least helps the user find where a global came from.
211 if (MAI->hasSingleParameterDotFile()) {
213 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
216 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
217 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
219 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
220 MP->beginAssembly(M, *MI, *this);
222 // Emit module-level inline asm if it exists.
223 if (!M.getModuleInlineAsm().empty()) {
224 OutStreamer.AddComment("Start of file scope inline assembly");
225 OutStreamer.AddBlankLine();
226 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
227 OutStreamer.AddComment("End of file scope inline assembly");
228 OutStreamer.AddBlankLine();
231 if (MAI->doesSupportDebugInformation()) {
232 bool skip_dwarf = false;
233 if (Triple(TM.getTargetTriple()).isKnownWindowsMSVCEnvironment()) {
234 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this),
236 CodeViewLineTablesGroupName));
237 // FIXME: Don't emit DWARF debug info if there's at least one function
238 // with AddressSanitizer instrumentation.
239 // This is a band-aid fix for PR22032.
240 for (auto &F : M.functions()) {
241 if (F.hasFnAttribute(Attribute::SanitizeAddress)) {
248 DD = new DwarfDebug(this, &M);
249 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
253 EHStreamer *ES = nullptr;
254 switch (MAI->getExceptionHandlingType()) {
255 case ExceptionHandling::None:
257 case ExceptionHandling::SjLj:
258 case ExceptionHandling::DwarfCFI:
259 ES = new DwarfCFIException(this);
261 case ExceptionHandling::ARM:
262 ES = new ARMException(this);
264 case ExceptionHandling::WinEH:
265 switch (MAI->getWinEHEncodingType()) {
266 default: llvm_unreachable("unsupported unwinding information encoding");
267 case WinEH::EncodingType::Itanium:
268 ES = new Win64Exception(this);
274 Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
278 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
279 if (!MAI.hasWeakDefCanBeHiddenDirective())
282 return canBeOmittedFromSymbolTable(GV);
285 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
286 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
288 case GlobalValue::CommonLinkage:
289 case GlobalValue::LinkOnceAnyLinkage:
290 case GlobalValue::LinkOnceODRLinkage:
291 case GlobalValue::WeakAnyLinkage:
292 case GlobalValue::WeakODRLinkage:
293 if (MAI->hasWeakDefDirective()) {
295 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
297 if (!canBeHidden(GV, *MAI))
298 // .weak_definition _foo
299 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
301 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
302 } else if (MAI->hasLinkOnceDirective()) {
304 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
305 //NOTE: linkonce is handled by the section the symbol was assigned to.
308 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
311 case GlobalValue::AppendingLinkage:
312 // FIXME: appending linkage variables should go into a section of
313 // their name or something. For now, just emit them as external.
314 case GlobalValue::ExternalLinkage:
315 // If external or appending, declare as a global symbol.
317 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
319 case GlobalValue::PrivateLinkage:
320 case GlobalValue::InternalLinkage:
322 case GlobalValue::AvailableExternallyLinkage:
323 llvm_unreachable("Should never emit this");
324 case GlobalValue::ExternalWeakLinkage:
325 llvm_unreachable("Don't know how to emit these");
327 llvm_unreachable("Unknown linkage type!");
330 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
331 const GlobalValue *GV) const {
332 TM.getNameWithPrefix(Name, GV, *Mang);
335 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
336 return TM.getSymbol(GV, *Mang);
339 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
340 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
341 if (GV->hasInitializer()) {
342 // Check to see if this is a special global used by LLVM, if so, emit it.
343 if (EmitSpecialLLVMGlobal(GV))
346 // Skip the emission of global equivalents. The symbol can be emitted later
347 // on by emitGlobalGOTEquivs in case it turns out to be needed.
348 if (GlobalGOTEquivs.count(getSymbol(GV)))
352 GV->printAsOperand(OutStreamer.GetCommentOS(),
353 /*PrintType=*/false, GV->getParent());
354 OutStreamer.GetCommentOS() << '\n';
358 MCSymbol *GVSym = getSymbol(GV);
359 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
361 if (!GV->hasInitializer()) // External globals require no extra code.
364 GVSym->redefineIfPossible();
365 if (GVSym->isDefined() || GVSym->isVariable())
366 report_fatal_error("symbol '" + Twine(GVSym->getName()) +
367 "' is already defined");
369 if (MAI->hasDotTypeDotSizeDirective())
370 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
372 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
374 const DataLayout *DL = TM.getDataLayout();
375 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
377 // If the alignment is specified, we *must* obey it. Overaligning a global
378 // with a specified alignment is a prompt way to break globals emitted to
379 // sections and expected to be contiguous (e.g. ObjC metadata).
380 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
382 for (const HandlerInfo &HI : Handlers) {
383 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
384 HI.Handler->setSymbolSize(GVSym, Size);
387 // Handle common and BSS local symbols (.lcomm).
388 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
389 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
390 unsigned Align = 1 << AlignLog;
392 // Handle common symbols.
393 if (GVKind.isCommon()) {
394 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
398 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
402 // Handle local BSS symbols.
403 if (MAI->hasMachoZeroFillDirective()) {
404 const MCSection *TheSection =
405 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
406 // .zerofill __DATA, __bss, _foo, 400, 5
407 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
411 // Use .lcomm only if it supports user-specified alignment.
412 // Otherwise, while it would still be correct to use .lcomm in some
413 // cases (e.g. when Align == 1), the external assembler might enfore
414 // some -unknown- default alignment behavior, which could cause
415 // spurious differences between external and integrated assembler.
416 // Prefer to simply fall back to .local / .comm in this case.
417 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
419 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
423 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
427 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
429 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
433 const MCSection *TheSection =
434 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
436 // Handle the zerofill directive on darwin, which is a special form of BSS
438 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
439 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
442 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
443 // .zerofill __DATA, __common, _foo, 400, 5
444 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
448 // Handle thread local data for mach-o which requires us to output an
449 // additional structure of data and mangle the original symbol so that we
450 // can reference it later.
452 // TODO: This should become an "emit thread local global" method on TLOF.
453 // All of this macho specific stuff should be sunk down into TLOFMachO and
454 // stuff like "TLSExtraDataSection" should no longer be part of the parent
455 // TLOF class. This will also make it more obvious that stuff like
456 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
458 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
459 // Emit the .tbss symbol
461 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
463 if (GVKind.isThreadBSS()) {
464 TheSection = getObjFileLowering().getTLSBSSSection();
465 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
466 } else if (GVKind.isThreadData()) {
467 OutStreamer.SwitchSection(TheSection);
469 EmitAlignment(AlignLog, GV);
470 OutStreamer.EmitLabel(MangSym);
472 EmitGlobalConstant(GV->getInitializer());
475 OutStreamer.AddBlankLine();
477 // Emit the variable struct for the runtime.
478 const MCSection *TLVSect
479 = getObjFileLowering().getTLSExtraDataSection();
481 OutStreamer.SwitchSection(TLVSect);
482 // Emit the linkage here.
483 EmitLinkage(GV, GVSym);
484 OutStreamer.EmitLabel(GVSym);
486 // Three pointers in size:
487 // - __tlv_bootstrap - used to make sure support exists
488 // - spare pointer, used when mapped by the runtime
489 // - pointer to mangled symbol above with initializer
490 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
491 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
493 OutStreamer.EmitIntValue(0, PtrSize);
494 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
496 OutStreamer.AddBlankLine();
500 OutStreamer.SwitchSection(TheSection);
502 EmitLinkage(GV, GVSym);
503 EmitAlignment(AlignLog, GV);
505 OutStreamer.EmitLabel(GVSym);
507 EmitGlobalConstant(GV->getInitializer());
509 if (MAI->hasDotTypeDotSizeDirective())
511 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
513 OutStreamer.AddBlankLine();
516 /// EmitFunctionHeader - This method emits the header for the current
518 void AsmPrinter::EmitFunctionHeader() {
519 // Print out constants referenced by the function
522 // Print the 'header' of function.
523 const Function *F = MF->getFunction();
525 OutStreamer.SwitchSection(
526 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
527 EmitVisibility(CurrentFnSym, F->getVisibility());
529 EmitLinkage(F, CurrentFnSym);
530 EmitAlignment(MF->getAlignment(), F);
532 if (MAI->hasDotTypeDotSizeDirective())
533 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
536 F->printAsOperand(OutStreamer.GetCommentOS(),
537 /*PrintType=*/false, F->getParent());
538 OutStreamer.GetCommentOS() << '\n';
541 // Emit the prefix data.
542 if (F->hasPrefixData())
543 EmitGlobalConstant(F->getPrefixData());
545 // Emit the CurrentFnSym. This is a virtual function to allow targets to
546 // do their wild and crazy things as required.
547 EmitFunctionEntryLabel();
549 // If the function had address-taken blocks that got deleted, then we have
550 // references to the dangling symbols. Emit them at the start of the function
551 // so that we don't get references to undefined symbols.
552 std::vector<MCSymbol*> DeadBlockSyms;
553 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
554 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
555 OutStreamer.AddComment("Address taken block that was later removed");
556 OutStreamer.EmitLabel(DeadBlockSyms[i]);
559 if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo()) {
560 CurrentFnBegin = createTempSymbol("func_begin", getFunctionNumber());
562 if (MAI->useAssignmentForEHBegin()) {
563 MCSymbol *CurPos = OutContext.CreateTempSymbol();
564 OutStreamer.EmitLabel(CurPos);
565 OutStreamer.EmitAssignment(CurrentFnBegin,
566 MCSymbolRefExpr::Create(CurPos, OutContext));
568 OutStreamer.EmitLabel(CurrentFnBegin);
572 // Emit pre-function debug and/or EH information.
573 for (const HandlerInfo &HI : Handlers) {
574 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
575 HI.Handler->beginFunction(MF);
578 // Emit the prologue data.
579 if (F->hasPrologueData())
580 EmitGlobalConstant(F->getPrologueData());
583 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
584 /// function. This can be overridden by targets as required to do custom stuff.
585 void AsmPrinter::EmitFunctionEntryLabel() {
586 CurrentFnSym->redefineIfPossible();
588 // The function label could have already been emitted if two symbols end up
589 // conflicting due to asm renaming. Detect this and emit an error.
590 if (CurrentFnSym->isVariable())
591 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
592 "' is a protected alias");
593 if (CurrentFnSym->isDefined())
594 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
595 "' label emitted multiple times to assembly file");
597 return OutStreamer.EmitLabel(CurrentFnSym);
600 /// emitComments - Pretty-print comments for instructions.
601 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
602 const MachineFunction *MF = MI.getParent()->getParent();
603 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
605 // Check for spills and reloads
608 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
610 // We assume a single instruction only has a spill or reload, not
612 const MachineMemOperand *MMO;
613 if (TII->isLoadFromStackSlotPostFE(&MI, FI)) {
614 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
615 MMO = *MI.memoperands_begin();
616 CommentOS << MMO->getSize() << "-byte Reload\n";
618 } else if (TII->hasLoadFromStackSlot(&MI, MMO, FI)) {
619 if (FrameInfo->isSpillSlotObjectIndex(FI))
620 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
621 } else if (TII->isStoreToStackSlotPostFE(&MI, FI)) {
622 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
623 MMO = *MI.memoperands_begin();
624 CommentOS << MMO->getSize() << "-byte Spill\n";
626 } else if (TII->hasStoreToStackSlot(&MI, MMO, FI)) {
627 if (FrameInfo->isSpillSlotObjectIndex(FI))
628 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
631 // Check for spill-induced copies
632 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
633 CommentOS << " Reload Reuse\n";
636 /// emitImplicitDef - This method emits the specified machine instruction
637 /// that is an implicit def.
638 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
639 unsigned RegNo = MI->getOperand(0).getReg();
640 OutStreamer.AddComment(Twine("implicit-def: ") +
641 MMI->getContext().getRegisterInfo()->getName(RegNo));
642 OutStreamer.AddBlankLine();
645 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
646 std::string Str = "kill:";
647 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
648 const MachineOperand &Op = MI->getOperand(i);
649 assert(Op.isReg() && "KILL instruction must have only register operands");
651 Str += AP.MMI->getContext().getRegisterInfo()->getName(Op.getReg());
652 Str += (Op.isDef() ? "<def>" : "<kill>");
654 AP.OutStreamer.AddComment(Str);
655 AP.OutStreamer.AddBlankLine();
658 /// emitDebugValueComment - This method handles the target-independent form
659 /// of DBG_VALUE, returning true if it was able to do so. A false return
660 /// means the target will need to handle MI in EmitInstruction.
661 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
662 // This code handles only the 4-operand target-independent form.
663 if (MI->getNumOperands() != 4)
666 SmallString<128> Str;
667 raw_svector_ostream OS(Str);
668 OS << "DEBUG_VALUE: ";
670 DIVariable V = MI->getDebugVariable();
671 if (V.getContext().isSubprogram()) {
672 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
678 DIExpression Expr = MI->getDebugExpression();
679 if (Expr.isBitPiece())
680 OS << " [bit_piece offset=" << Expr.getBitPieceOffset()
681 << " size=" << Expr.getBitPieceSize() << "]";
684 // The second operand is only an offset if it's an immediate.
685 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
686 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
688 // Register or immediate value. Register 0 means undef.
689 if (MI->getOperand(0).isFPImm()) {
690 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
691 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
692 OS << (double)APF.convertToFloat();
693 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
694 OS << APF.convertToDouble();
696 // There is no good way to print long double. Convert a copy to
697 // double. Ah well, it's only a comment.
699 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
701 OS << "(long double) " << APF.convertToDouble();
703 } else if (MI->getOperand(0).isImm()) {
704 OS << MI->getOperand(0).getImm();
705 } else if (MI->getOperand(0).isCImm()) {
706 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
709 if (MI->getOperand(0).isReg()) {
710 Reg = MI->getOperand(0).getReg();
712 assert(MI->getOperand(0).isFI() && "Unknown operand type");
713 const TargetFrameLowering *TFI = AP.MF->getSubtarget().getFrameLowering();
714 Offset += TFI->getFrameIndexReference(*AP.MF,
715 MI->getOperand(0).getIndex(), Reg);
719 // Suppress offset, it is not meaningful here.
721 // NOTE: Want this comment at start of line, don't emit with AddComment.
722 AP.OutStreamer.emitRawComment(OS.str());
727 OS << AP.MMI->getContext().getRegisterInfo()->getName(Reg);
731 OS << '+' << Offset << ']';
733 // NOTE: Want this comment at start of line, don't emit with AddComment.
734 AP.OutStreamer.emitRawComment(OS.str());
738 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
739 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
740 MF->getFunction()->needsUnwindTableEntry())
743 if (MMI->hasDebugInfo())
749 bool AsmPrinter::needsSEHMoves() {
750 return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
753 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
754 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
755 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
756 ExceptionHandlingType != ExceptionHandling::ARM)
759 if (needsCFIMoves() == CFI_M_None)
762 const MachineModuleInfo &MMI = MF->getMMI();
763 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
764 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
765 const MCCFIInstruction &CFI = Instrs[CFIIndex];
766 emitCFIInstruction(CFI);
769 void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
770 // The operands are the MCSymbol and the frame offset of the allocation.
771 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
772 int FrameOffset = MI.getOperand(1).getImm();
774 // Emit a symbol assignment.
775 OutStreamer.EmitAssignment(FrameAllocSym,
776 MCConstantExpr::Create(FrameOffset, OutContext));
779 /// EmitFunctionBody - This method emits the body and trailer for a
781 void AsmPrinter::EmitFunctionBody() {
782 // Emit target-specific gunk before the function body.
783 EmitFunctionBodyStart();
785 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
787 // Print out code for the function.
788 bool HasAnyRealCode = false;
789 for (auto &MBB : *MF) {
790 // Print a label for the basic block.
791 EmitBasicBlockStart(MBB);
792 for (auto &MI : MBB) {
794 // Print the assembly for the instruction.
795 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
796 !MI.isDebugValue()) {
797 HasAnyRealCode = true;
801 if (ShouldPrintDebugScopes) {
802 for (const HandlerInfo &HI : Handlers) {
803 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
804 TimePassesIsEnabled);
805 HI.Handler->beginInstruction(&MI);
810 emitComments(MI, OutStreamer.GetCommentOS());
812 switch (MI.getOpcode()) {
813 case TargetOpcode::CFI_INSTRUCTION:
814 emitCFIInstruction(MI);
817 case TargetOpcode::FRAME_ALLOC:
821 case TargetOpcode::EH_LABEL:
822 case TargetOpcode::GC_LABEL:
823 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
825 case TargetOpcode::INLINEASM:
828 case TargetOpcode::DBG_VALUE:
830 if (!emitDebugValueComment(&MI, *this))
831 EmitInstruction(&MI);
834 case TargetOpcode::IMPLICIT_DEF:
835 if (isVerbose()) emitImplicitDef(&MI);
837 case TargetOpcode::KILL:
838 if (isVerbose()) emitKill(&MI, *this);
841 EmitInstruction(&MI);
845 if (ShouldPrintDebugScopes) {
846 for (const HandlerInfo &HI : Handlers) {
847 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
848 TimePassesIsEnabled);
849 HI.Handler->endInstruction();
854 EmitBasicBlockEnd(MBB);
857 // If the function is empty and the object file uses .subsections_via_symbols,
858 // then we need to emit *something* to the function body to prevent the
859 // labels from collapsing together. Just emit a noop.
860 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
862 MF->getSubtarget().getInstrInfo()->getNoopForMachoTarget(Noop);
863 OutStreamer.AddComment("avoids zero-length function");
865 // Targets can opt-out of emitting the noop here by leaving the opcode
867 if (Noop.getOpcode())
868 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
871 const Function *F = MF->getFunction();
872 for (const auto &BB : *F) {
873 if (!BB.hasAddressTaken())
875 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
876 if (Sym->isDefined())
878 OutStreamer.AddComment("Address of block that was removed by CodeGen");
879 OutStreamer.EmitLabel(Sym);
882 // Emit target-specific gunk after the function body.
883 EmitFunctionBodyEnd();
885 if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
886 MAI->hasDotTypeDotSizeDirective()) {
887 // Create a symbol for the end of function.
888 CurrentFnEnd = createTempSymbol("func_end", getFunctionNumber());
889 OutStreamer.EmitLabel(CurrentFnEnd);
892 // If the target wants a .size directive for the size of the function, emit
894 if (MAI->hasDotTypeDotSizeDirective()) {
895 // We can get the size as difference between the function label and the
897 const MCExpr *SizeExp =
898 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(CurrentFnEnd, OutContext),
899 MCSymbolRefExpr::Create(CurrentFnSymForSize,
902 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
905 // Emit post-function debug and/or EH information.
906 for (const HandlerInfo &HI : Handlers) {
907 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
908 HI.Handler->endFunction(MF);
912 // Print out jump tables referenced by the function.
915 OutStreamer.AddBlankLine();
918 /// \brief Compute the number of Global Variables that uses a Constant.
919 static unsigned getNumGlobalVariableUses(const Constant *C) {
923 if (isa<GlobalVariable>(C))
926 unsigned NumUses = 0;
927 for (auto *CU : C->users())
928 NumUses += getNumGlobalVariableUses(dyn_cast<Constant>(CU));
933 /// \brief Only consider global GOT equivalents if at least one user is a
934 /// cstexpr inside an initializer of another global variables. Also, don't
935 /// handle cstexpr inside instructions. During global variable emission,
936 /// candidates are skipped and are emitted later in case at least one cstexpr
937 /// isn't replaced by a PC relative GOT entry access.
938 static bool isGOTEquivalentCandidate(const GlobalVariable *GV,
939 unsigned &NumGOTEquivUsers) {
940 // Global GOT equivalents are unnamed private globals with a constant
941 // pointer initializer to another global symbol. They must point to a
942 // GlobalVariable or Function, i.e., as GlobalValue.
943 if (!GV->hasUnnamedAddr() || !GV->hasInitializer() || !GV->isConstant() ||
944 !GV->isDiscardableIfUnused() || !dyn_cast<GlobalValue>(GV->getOperand(0)))
947 // To be a got equivalent, at least one of its users need to be a constant
948 // expression used by another global variable.
949 for (auto *U : GV->users())
950 NumGOTEquivUsers += getNumGlobalVariableUses(cast<Constant>(U));
952 return NumGOTEquivUsers > 0;
955 /// \brief Unnamed constant global variables solely contaning a pointer to
956 /// another globals variable is equivalent to a GOT table entry; it contains the
957 /// the address of another symbol. Optimize it and replace accesses to these
958 /// "GOT equivalents" by using the GOT entry for the final global instead.
959 /// Compute GOT equivalent candidates among all global variables to avoid
960 /// emitting them if possible later on, after it use is replaced by a GOT entry
962 void AsmPrinter::computeGlobalGOTEquivs(Module &M) {
963 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
966 for (const auto &G : M.globals()) {
967 unsigned NumGOTEquivUsers = 0;
968 if (!isGOTEquivalentCandidate(&G, NumGOTEquivUsers))
971 const MCSymbol *GOTEquivSym = getSymbol(&G);
972 GlobalGOTEquivs[GOTEquivSym] = std::make_pair(&G, NumGOTEquivUsers);
976 /// \brief Constant expressions using GOT equivalent globals may not be eligible
977 /// for PC relative GOT entry conversion, in such cases we need to emit such
978 /// globals we previously omitted in EmitGlobalVariable.
979 void AsmPrinter::emitGlobalGOTEquivs() {
980 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
983 while (!GlobalGOTEquivs.empty()) {
984 DenseMap<const MCSymbol *, GOTEquivUsePair>::iterator I =
985 GlobalGOTEquivs.begin();
986 const MCSymbol *S = I->first;
987 const GlobalVariable *GV = I->second.first;
988 GlobalGOTEquivs.erase(S);
989 EmitGlobalVariable(GV);
993 bool AsmPrinter::doFinalization(Module &M) {
994 // Gather all GOT equivalent globals in the module. We really need two
995 // passes over the globals: one to compute and another to avoid its emission
996 // in EmitGlobalVariable, otherwise we would not be able to handle cases
997 // where the got equivalent shows up before its use.
998 computeGlobalGOTEquivs(M);
1000 // Emit global variables.
1001 for (const auto &G : M.globals())
1002 EmitGlobalVariable(&G);
1004 // Emit remaining GOT equivalent globals.
1005 emitGlobalGOTEquivs();
1007 // Emit visibility info for declarations
1008 for (const Function &F : M) {
1009 if (!F.isDeclaration())
1011 GlobalValue::VisibilityTypes V = F.getVisibility();
1012 if (V == GlobalValue::DefaultVisibility)
1015 MCSymbol *Name = getSymbol(&F);
1016 EmitVisibility(Name, V, false);
1019 // Emit module flags.
1020 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
1021 M.getModuleFlagsMetadata(ModuleFlags);
1022 if (!ModuleFlags.empty())
1023 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
1025 // Make sure we wrote out everything we need.
1026 OutStreamer.Flush();
1028 // Finalize debug and EH information.
1029 for (const HandlerInfo &HI : Handlers) {
1030 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
1031 TimePassesIsEnabled);
1032 HI.Handler->endModule();
1038 // If the target wants to know about weak references, print them all.
1039 if (MAI->getWeakRefDirective()) {
1040 // FIXME: This is not lazy, it would be nice to only print weak references
1041 // to stuff that is actually used. Note that doing so would require targets
1042 // to notice uses in operands (due to constant exprs etc). This should
1043 // happen with the MC stuff eventually.
1045 // Print out module-level global variables here.
1046 for (const auto &G : M.globals()) {
1047 if (!G.hasExternalWeakLinkage())
1049 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
1052 for (const auto &F : M) {
1053 if (!F.hasExternalWeakLinkage())
1055 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
1059 OutStreamer.AddBlankLine();
1060 for (const auto &Alias : M.aliases()) {
1061 MCSymbol *Name = getSymbol(&Alias);
1063 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
1064 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
1065 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
1066 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
1068 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
1070 EmitVisibility(Name, Alias.getVisibility());
1072 // Emit the directives as assignments aka .set:
1073 OutStreamer.EmitAssignment(Name, lowerConstant(Alias.getAliasee()));
1076 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1077 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1078 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1079 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1080 MP->finishAssembly(M, *MI, *this);
1082 // Emit llvm.ident metadata in an '.ident' directive.
1083 EmitModuleIdents(M);
1085 // Emit __morestack address if needed for indirect calls.
1086 if (MMI->usesMorestackAddr()) {
1087 const MCSection *ReadOnlySection =
1088 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
1090 OutStreamer.SwitchSection(ReadOnlySection);
1092 MCSymbol *AddrSymbol =
1093 OutContext.GetOrCreateSymbol(StringRef("__morestack_addr"));
1094 OutStreamer.EmitLabel(AddrSymbol);
1096 unsigned PtrSize = TM.getDataLayout()->getPointerSize(0);
1097 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("__morestack"),
1101 // If we don't have any trampolines, then we don't require stack memory
1102 // to be executable. Some targets have a directive to declare this.
1103 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1104 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1105 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1106 OutStreamer.SwitchSection(S);
1108 // Allow the target to emit any magic that it wants at the end of the file,
1109 // after everything else has gone out.
1110 EmitEndOfAsmFile(M);
1112 delete Mang; Mang = nullptr;
1115 OutStreamer.Finish();
1116 OutStreamer.reset();
1121 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1123 // Get the function symbol.
1124 CurrentFnSym = getSymbol(MF.getFunction());
1125 CurrentFnSymForSize = CurrentFnSym;
1128 LI = &getAnalysis<MachineLoopInfo>();
1132 // SectionCPs - Keep track the alignment, constpool entries per Section.
1136 SmallVector<unsigned, 4> CPEs;
1137 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1141 /// EmitConstantPool - Print to the current output stream assembly
1142 /// representations of the constants in the constant pool MCP. This is
1143 /// used to print out constants which have been "spilled to memory" by
1144 /// the code generator.
1146 void AsmPrinter::EmitConstantPool() {
1147 const MachineConstantPool *MCP = MF->getConstantPool();
1148 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1149 if (CP.empty()) return;
1151 // Calculate sections for constant pool entries. We collect entries to go into
1152 // the same section together to reduce amount of section switch statements.
1153 SmallVector<SectionCPs, 4> CPSections;
1154 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1155 const MachineConstantPoolEntry &CPE = CP[i];
1156 unsigned Align = CPE.getAlignment();
1159 CPE.getSectionKind(TM.getDataLayout());
1161 const Constant *C = nullptr;
1162 if (!CPE.isMachineConstantPoolEntry())
1163 C = CPE.Val.ConstVal;
1165 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind, C);
1167 // The number of sections are small, just do a linear search from the
1168 // last section to the first.
1170 unsigned SecIdx = CPSections.size();
1171 while (SecIdx != 0) {
1172 if (CPSections[--SecIdx].S == S) {
1178 SecIdx = CPSections.size();
1179 CPSections.push_back(SectionCPs(S, Align));
1182 if (Align > CPSections[SecIdx].Alignment)
1183 CPSections[SecIdx].Alignment = Align;
1184 CPSections[SecIdx].CPEs.push_back(i);
1187 // Now print stuff into the calculated sections.
1188 const MCSection *CurSection = nullptr;
1189 unsigned Offset = 0;
1190 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1191 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1192 unsigned CPI = CPSections[i].CPEs[j];
1193 MCSymbol *Sym = GetCPISymbol(CPI);
1194 if (!Sym->isUndefined())
1197 if (CurSection != CPSections[i].S) {
1198 OutStreamer.SwitchSection(CPSections[i].S);
1199 EmitAlignment(Log2_32(CPSections[i].Alignment));
1200 CurSection = CPSections[i].S;
1204 MachineConstantPoolEntry CPE = CP[CPI];
1206 // Emit inter-object padding for alignment.
1207 unsigned AlignMask = CPE.getAlignment() - 1;
1208 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1209 OutStreamer.EmitZeros(NewOffset - Offset);
1211 Type *Ty = CPE.getType();
1212 Offset = NewOffset +
1213 TM.getDataLayout()->getTypeAllocSize(Ty);
1215 OutStreamer.EmitLabel(Sym);
1216 if (CPE.isMachineConstantPoolEntry())
1217 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1219 EmitGlobalConstant(CPE.Val.ConstVal);
1224 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1225 /// by the current function to the current output stream.
1227 void AsmPrinter::EmitJumpTableInfo() {
1228 const DataLayout *DL = MF->getTarget().getDataLayout();
1229 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1231 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1232 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1233 if (JT.empty()) return;
1235 // Pick the directive to use to print the jump table entries, and switch to
1236 // the appropriate section.
1237 const Function *F = MF->getFunction();
1238 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1239 bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
1240 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
1242 if (!JTInDiffSection) {
1243 OutStreamer.SwitchSection(TLOF.SectionForGlobal(F, *Mang, TM));
1245 // Otherwise, drop it in the readonly section.
1246 const MCSection *ReadOnlySection =
1247 TLOF.getSectionForJumpTable(*F, *Mang, TM);
1248 OutStreamer.SwitchSection(ReadOnlySection);
1251 EmitAlignment(Log2_32(
1252 MJTI->getEntryAlignment(*TM.getDataLayout())));
1254 // Jump tables in code sections are marked with a data_region directive
1255 // where that's supported.
1256 if (!JTInDiffSection)
1257 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1259 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1260 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1262 // If this jump table was deleted, ignore it.
1263 if (JTBBs.empty()) continue;
1265 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1266 /// emit a .set directive for each unique entry.
1267 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1268 MAI->doesSetDirectiveSuppressesReloc()) {
1269 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1270 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1271 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1272 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1273 const MachineBasicBlock *MBB = JTBBs[ii];
1274 if (!EmittedSets.insert(MBB).second)
1277 // .set LJTSet, LBB32-base
1279 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1280 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1281 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1285 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1286 // before each jump table. The first label is never referenced, but tells
1287 // the assembler and linker the extents of the jump table object. The
1288 // second label is actually referenced by the code.
1289 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1290 // FIXME: This doesn't have to have any specific name, just any randomly
1291 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1292 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1294 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1296 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1297 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1299 if (!JTInDiffSection)
1300 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1303 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1305 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1306 const MachineBasicBlock *MBB,
1307 unsigned UID) const {
1308 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1309 const MCExpr *Value = nullptr;
1310 switch (MJTI->getEntryKind()) {
1311 case MachineJumpTableInfo::EK_Inline:
1312 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1313 case MachineJumpTableInfo::EK_Custom32:
1314 Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
1315 MJTI, MBB, UID, OutContext);
1317 case MachineJumpTableInfo::EK_BlockAddress:
1318 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1320 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1322 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1323 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1324 // with a relocation as gp-relative, e.g.:
1326 MCSymbol *MBBSym = MBB->getSymbol();
1327 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1331 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1332 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1333 // with a relocation as gp-relative, e.g.:
1335 MCSymbol *MBBSym = MBB->getSymbol();
1336 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1340 case MachineJumpTableInfo::EK_LabelDifference32: {
1341 // Each entry is the address of the block minus the address of the jump
1342 // table. This is used for PIC jump tables where gprel32 is not supported.
1344 // .word LBB123 - LJTI1_2
1345 // If the .set directive avoids relocations, this is emitted as:
1346 // .set L4_5_set_123, LBB123 - LJTI1_2
1347 // .word L4_5_set_123
1348 if (MAI->doesSetDirectiveSuppressesReloc()) {
1349 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1353 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1354 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1355 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1356 Value = MCBinaryExpr::CreateSub(Value, Base, OutContext);
1361 assert(Value && "Unknown entry kind!");
1363 unsigned EntrySize =
1364 MJTI->getEntrySize(*TM.getDataLayout());
1365 OutStreamer.EmitValue(Value, EntrySize);
1369 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1370 /// special global used by LLVM. If so, emit it and return true, otherwise
1371 /// do nothing and return false.
1372 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1373 if (GV->getName() == "llvm.used") {
1374 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1375 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1379 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1380 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1381 GV->hasAvailableExternallyLinkage())
1384 if (!GV->hasAppendingLinkage()) return false;
1386 assert(GV->hasInitializer() && "Not a special LLVM global!");
1388 if (GV->getName() == "llvm.global_ctors") {
1389 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1391 if (TM.getRelocationModel() == Reloc::Static &&
1392 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1393 StringRef Sym(".constructors_used");
1394 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1400 if (GV->getName() == "llvm.global_dtors") {
1401 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1403 if (TM.getRelocationModel() == Reloc::Static &&
1404 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1405 StringRef Sym(".destructors_used");
1406 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1415 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1416 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1417 /// is true, as being used with this directive.
1418 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1419 // Should be an array of 'i8*'.
1420 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1421 const GlobalValue *GV =
1422 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1424 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1430 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1432 llvm::Constant *Func;
1433 llvm::GlobalValue *ComdatKey;
1437 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1439 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1440 // Should be an array of '{ int, void ()* }' structs. The first value is the
1442 if (!isa<ConstantArray>(List)) return;
1444 // Sanity check the structors list.
1445 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1446 if (!InitList) return; // Not an array!
1447 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1448 // FIXME: Only allow the 3-field form in LLVM 4.0.
1449 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1450 return; // Not an array of two or three elements!
1451 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1452 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1453 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1454 return; // Not (int, ptr, ptr).
1456 // Gather the structors in a form that's convenient for sorting by priority.
1457 SmallVector<Structor, 8> Structors;
1458 for (Value *O : InitList->operands()) {
1459 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1460 if (!CS) continue; // Malformed.
1461 if (CS->getOperand(1)->isNullValue())
1462 break; // Found a null terminator, skip the rest.
1463 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1464 if (!Priority) continue; // Malformed.
1465 Structors.push_back(Structor());
1466 Structor &S = Structors.back();
1467 S.Priority = Priority->getLimitedValue(65535);
1468 S.Func = CS->getOperand(1);
1469 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1470 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1473 // Emit the function pointers in the target-specific order
1474 const DataLayout *DL = TM.getDataLayout();
1475 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1476 std::stable_sort(Structors.begin(), Structors.end(),
1477 [](const Structor &L,
1478 const Structor &R) { return L.Priority < R.Priority; });
1479 for (Structor &S : Structors) {
1480 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1481 const MCSymbol *KeySym = nullptr;
1482 if (GlobalValue *GV = S.ComdatKey) {
1483 if (GV->hasAvailableExternallyLinkage())
1484 // If the associated variable is available_externally, some other TU
1485 // will provide its dynamic initializer.
1488 KeySym = getSymbol(GV);
1490 const MCSection *OutputSection =
1491 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1492 : Obj.getStaticDtorSection(S.Priority, KeySym));
1493 OutStreamer.SwitchSection(OutputSection);
1494 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1495 EmitAlignment(Align);
1496 EmitXXStructor(S.Func);
1500 void AsmPrinter::EmitModuleIdents(Module &M) {
1501 if (!MAI->hasIdentDirective())
1504 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1505 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1506 const MDNode *N = NMD->getOperand(i);
1507 assert(N->getNumOperands() == 1 &&
1508 "llvm.ident metadata entry can have only one operand");
1509 const MDString *S = cast<MDString>(N->getOperand(0));
1510 OutStreamer.EmitIdent(S->getString());
1515 //===--------------------------------------------------------------------===//
1516 // Emission and print routines
1519 /// EmitInt8 - Emit a byte directive and value.
1521 void AsmPrinter::EmitInt8(int Value) const {
1522 OutStreamer.EmitIntValue(Value, 1);
1525 /// EmitInt16 - Emit a short directive and value.
1527 void AsmPrinter::EmitInt16(int Value) const {
1528 OutStreamer.EmitIntValue(Value, 2);
1531 /// EmitInt32 - Emit a long directive and value.
1533 void AsmPrinter::EmitInt32(int Value) const {
1534 OutStreamer.EmitIntValue(Value, 4);
1537 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1538 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1539 /// .set if it avoids relocations.
1540 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1541 unsigned Size) const {
1542 // Get the Hi-Lo expression.
1543 const MCExpr *Diff =
1544 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1545 MCSymbolRefExpr::Create(Lo, OutContext),
1548 if (!MAI->doesSetDirectiveSuppressesReloc()) {
1549 OutStreamer.EmitValue(Diff, Size);
1553 // Otherwise, emit with .set (aka assignment).
1554 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1555 OutStreamer.EmitAssignment(SetLabel, Diff);
1556 OutStreamer.EmitSymbolValue(SetLabel, Size);
1559 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1560 /// where the size in bytes of the directive is specified by Size and Label
1561 /// specifies the label. This implicitly uses .set if it is available.
1562 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1564 bool IsSectionRelative) const {
1565 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1566 OutStreamer.EmitCOFFSecRel32(Label);
1570 // Emit Label+Offset (or just Label if Offset is zero)
1571 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1573 Expr = MCBinaryExpr::CreateAdd(
1574 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1576 OutStreamer.EmitValue(Expr, Size);
1579 //===----------------------------------------------------------------------===//
1581 // EmitAlignment - Emit an alignment directive to the specified power of
1582 // two boundary. For example, if you pass in 3 here, you will get an 8
1583 // byte alignment. If a global value is specified, and if that global has
1584 // an explicit alignment requested, it will override the alignment request
1585 // if required for correctness.
1587 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1589 NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(),
1592 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1595 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
1596 "undefined behavior");
1597 if (getCurrentSection()->getKind().isText())
1598 OutStreamer.EmitCodeAlignment(1u << NumBits);
1600 OutStreamer.EmitValueToAlignment(1u << NumBits);
1603 //===----------------------------------------------------------------------===//
1604 // Constant emission.
1605 //===----------------------------------------------------------------------===//
1607 const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1608 MCContext &Ctx = OutContext;
1610 if (CV->isNullValue() || isa<UndefValue>(CV))
1611 return MCConstantExpr::Create(0, Ctx);
1613 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1614 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1616 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1617 return MCSymbolRefExpr::Create(getSymbol(GV), Ctx);
1619 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1620 return MCSymbolRefExpr::Create(GetBlockAddressSymbol(BA), Ctx);
1622 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1624 llvm_unreachable("Unknown constant value to lower!");
1627 if (const MCExpr *RelocExpr
1628 = getObjFileLowering().getExecutableRelativeSymbol(CE, *Mang, TM))
1631 switch (CE->getOpcode()) {
1633 // If the code isn't optimized, there may be outstanding folding
1634 // opportunities. Attempt to fold the expression using DataLayout as a
1635 // last resort before giving up.
1636 if (Constant *C = ConstantFoldConstantExpression(
1637 CE, TM.getDataLayout()))
1639 return lowerConstant(C);
1641 // Otherwise report the problem to the user.
1644 raw_string_ostream OS(S);
1645 OS << "Unsupported expression in static initializer: ";
1646 CE->printAsOperand(OS, /*PrintType=*/false,
1647 !MF ? nullptr : MF->getFunction()->getParent());
1648 report_fatal_error(OS.str());
1650 case Instruction::GetElementPtr: {
1651 const DataLayout &DL = *TM.getDataLayout();
1653 // Generate a symbolic expression for the byte address
1654 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1655 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1657 const MCExpr *Base = lowerConstant(CE->getOperand(0));
1661 int64_t Offset = OffsetAI.getSExtValue();
1662 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1666 case Instruction::Trunc:
1667 // We emit the value and depend on the assembler to truncate the generated
1668 // expression properly. This is important for differences between
1669 // blockaddress labels. Since the two labels are in the same function, it
1670 // is reasonable to treat their delta as a 32-bit value.
1672 case Instruction::BitCast:
1673 return lowerConstant(CE->getOperand(0));
1675 case Instruction::IntToPtr: {
1676 const DataLayout &DL = *TM.getDataLayout();
1678 // Handle casts to pointers by changing them into casts to the appropriate
1679 // integer type. This promotes constant folding and simplifies this code.
1680 Constant *Op = CE->getOperand(0);
1681 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1683 return lowerConstant(Op);
1686 case Instruction::PtrToInt: {
1687 const DataLayout &DL = *TM.getDataLayout();
1689 // Support only foldable casts to/from pointers that can be eliminated by
1690 // changing the pointer to the appropriately sized integer type.
1691 Constant *Op = CE->getOperand(0);
1692 Type *Ty = CE->getType();
1694 const MCExpr *OpExpr = lowerConstant(Op);
1696 // We can emit the pointer value into this slot if the slot is an
1697 // integer slot equal to the size of the pointer.
1698 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1701 // Otherwise the pointer is smaller than the resultant integer, mask off
1702 // the high bits so we are sure to get a proper truncation if the input is
1704 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1705 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1706 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1709 // The MC library also has a right-shift operator, but it isn't consistently
1710 // signed or unsigned between different targets.
1711 case Instruction::Add:
1712 case Instruction::Sub:
1713 case Instruction::Mul:
1714 case Instruction::SDiv:
1715 case Instruction::SRem:
1716 case Instruction::Shl:
1717 case Instruction::And:
1718 case Instruction::Or:
1719 case Instruction::Xor: {
1720 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
1721 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
1722 switch (CE->getOpcode()) {
1723 default: llvm_unreachable("Unknown binary operator constant cast expr");
1724 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1725 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1726 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1727 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1728 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1729 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1730 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1731 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1732 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1738 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP,
1739 const Constant *BaseCV = nullptr,
1740 uint64_t Offset = 0);
1742 /// isRepeatedByteSequence - Determine whether the given value is
1743 /// composed of a repeated sequence of identical bytes and return the
1744 /// byte value. If it is not a repeated sequence, return -1.
1745 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1746 StringRef Data = V->getRawDataValues();
1747 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1749 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1750 if (Data[i] != C) return -1;
1751 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1755 /// isRepeatedByteSequence - Determine whether the given value is
1756 /// composed of a repeated sequence of identical bytes and return the
1757 /// byte value. If it is not a repeated sequence, return -1.
1758 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1760 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1761 if (CI->getBitWidth() > 64) return -1;
1764 TM.getDataLayout()->getTypeAllocSize(V->getType());
1765 uint64_t Value = CI->getZExtValue();
1767 // Make sure the constant is at least 8 bits long and has a power
1768 // of 2 bit width. This guarantees the constant bit width is
1769 // always a multiple of 8 bits, avoiding issues with padding out
1770 // to Size and other such corner cases.
1771 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1773 uint8_t Byte = static_cast<uint8_t>(Value);
1775 for (unsigned i = 1; i < Size; ++i) {
1777 if (static_cast<uint8_t>(Value) != Byte) return -1;
1781 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1782 // Make sure all array elements are sequences of the same repeated
1784 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1785 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1786 if (Byte == -1) return -1;
1788 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1789 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1790 if (ThisByte == -1) return -1;
1791 if (Byte != ThisByte) return -1;
1796 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1797 return isRepeatedByteSequence(CDS);
1802 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1805 // See if we can aggregate this into a .fill, if so, emit it as such.
1806 int Value = isRepeatedByteSequence(CDS, AP.TM);
1809 AP.TM.getDataLayout()->getTypeAllocSize(
1811 // Don't emit a 1-byte object as a .fill.
1813 return AP.OutStreamer.EmitFill(Bytes, Value);
1816 // If this can be emitted with .ascii/.asciz, emit it as such.
1817 if (CDS->isString())
1818 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1820 // Otherwise, emit the values in successive locations.
1821 unsigned ElementByteSize = CDS->getElementByteSize();
1822 if (isa<IntegerType>(CDS->getElementType())) {
1823 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1825 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1826 CDS->getElementAsInteger(i));
1827 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1830 } else if (ElementByteSize == 4) {
1831 // FP Constants are printed as integer constants to avoid losing
1833 assert(CDS->getElementType()->isFloatTy());
1834 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1840 F = CDS->getElementAsFloat(i);
1842 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1843 AP.OutStreamer.EmitIntValue(I, 4);
1846 assert(CDS->getElementType()->isDoubleTy());
1847 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1853 F = CDS->getElementAsDouble(i);
1855 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1856 AP.OutStreamer.EmitIntValue(I, 8);
1860 const DataLayout &DL = *AP.TM.getDataLayout();
1861 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1862 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1863 CDS->getNumElements();
1864 if (unsigned Padding = Size - EmittedSize)
1865 AP.OutStreamer.EmitZeros(Padding);
1869 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP,
1870 const Constant *BaseCV, uint64_t Offset) {
1871 // See if we can aggregate some values. Make sure it can be
1872 // represented as a series of bytes of the constant value.
1873 int Value = isRepeatedByteSequence(CA, AP.TM);
1874 const DataLayout &DL = *AP.TM.getDataLayout();
1877 uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
1878 AP.OutStreamer.EmitFill(Bytes, Value);
1881 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
1882 emitGlobalConstantImpl(CA->getOperand(i), AP, BaseCV, Offset);
1883 Offset += DL.getTypeAllocSize(CA->getOperand(i)->getType());
1888 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1889 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1890 emitGlobalConstantImpl(CV->getOperand(i), AP);
1892 const DataLayout &DL = *AP.TM.getDataLayout();
1893 unsigned Size = DL.getTypeAllocSize(CV->getType());
1894 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1895 CV->getType()->getNumElements();
1896 if (unsigned Padding = Size - EmittedSize)
1897 AP.OutStreamer.EmitZeros(Padding);
1900 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP,
1901 const Constant *BaseCV, uint64_t Offset) {
1902 // Print the fields in successive locations. Pad to align if needed!
1903 const DataLayout *DL = AP.TM.getDataLayout();
1904 unsigned Size = DL->getTypeAllocSize(CS->getType());
1905 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1906 uint64_t SizeSoFar = 0;
1907 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1908 const Constant *Field = CS->getOperand(i);
1910 // Print the actual field value.
1911 emitGlobalConstantImpl(Field, AP, BaseCV, Offset+SizeSoFar);
1913 // Check if padding is needed and insert one or more 0s.
1914 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1915 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1916 - Layout->getElementOffset(i)) - FieldSize;
1917 SizeSoFar += FieldSize + PadSize;
1919 // Insert padding - this may include padding to increase the size of the
1920 // current field up to the ABI size (if the struct is not packed) as well
1921 // as padding to ensure that the next field starts at the right offset.
1922 AP.OutStreamer.EmitZeros(PadSize);
1924 assert(SizeSoFar == Layout->getSizeInBytes() &&
1925 "Layout of constant struct may be incorrect!");
1928 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1929 APInt API = CFP->getValueAPF().bitcastToAPInt();
1931 // First print a comment with what we think the original floating-point value
1932 // should have been.
1933 if (AP.isVerbose()) {
1934 SmallString<8> StrVal;
1935 CFP->getValueAPF().toString(StrVal);
1938 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1940 AP.OutStreamer.GetCommentOS() << "Printing <null> Type";
1941 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1944 // Now iterate through the APInt chunks, emitting them in endian-correct
1945 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1947 unsigned NumBytes = API.getBitWidth() / 8;
1948 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1949 const uint64_t *p = API.getRawData();
1951 // PPC's long double has odd notions of endianness compared to how LLVM
1952 // handles it: p[0] goes first for *big* endian on PPC.
1953 if (AP.TM.getDataLayout()->isBigEndian() &&
1954 !CFP->getType()->isPPC_FP128Ty()) {
1955 int Chunk = API.getNumWords() - 1;
1958 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1960 for (; Chunk >= 0; --Chunk)
1961 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1964 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1965 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1968 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1971 // Emit the tail padding for the long double.
1972 const DataLayout &DL = *AP.TM.getDataLayout();
1973 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1974 DL.getTypeStoreSize(CFP->getType()));
1977 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1978 const DataLayout *DL = AP.TM.getDataLayout();
1979 unsigned BitWidth = CI->getBitWidth();
1981 // Copy the value as we may massage the layout for constants whose bit width
1982 // is not a multiple of 64-bits.
1983 APInt Realigned(CI->getValue());
1984 uint64_t ExtraBits = 0;
1985 unsigned ExtraBitsSize = BitWidth & 63;
1987 if (ExtraBitsSize) {
1988 // The bit width of the data is not a multiple of 64-bits.
1989 // The extra bits are expected to be at the end of the chunk of the memory.
1991 // * Nothing to be done, just record the extra bits to emit.
1993 // * Record the extra bits to emit.
1994 // * Realign the raw data to emit the chunks of 64-bits.
1995 if (DL->isBigEndian()) {
1996 // Basically the structure of the raw data is a chunk of 64-bits cells:
1997 // 0 1 BitWidth / 64
1998 // [chunk1][chunk2] ... [chunkN].
1999 // The most significant chunk is chunkN and it should be emitted first.
2000 // However, due to the alignment issue chunkN contains useless bits.
2001 // Realign the chunks so that they contain only useless information:
2002 // ExtraBits 0 1 (BitWidth / 64) - 1
2003 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
2004 ExtraBits = Realigned.getRawData()[0] &
2005 (((uint64_t)-1) >> (64 - ExtraBitsSize));
2006 Realigned = Realigned.lshr(ExtraBitsSize);
2008 ExtraBits = Realigned.getRawData()[BitWidth / 64];
2011 // We don't expect assemblers to support integer data directives
2012 // for more than 64 bits, so we emit the data in at most 64-bit
2013 // quantities at a time.
2014 const uint64_t *RawData = Realigned.getRawData();
2015 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
2016 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
2017 AP.OutStreamer.EmitIntValue(Val, 8);
2020 if (ExtraBitsSize) {
2021 // Emit the extra bits after the 64-bits chunks.
2023 // Emit a directive that fills the expected size.
2024 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(
2026 Size -= (BitWidth / 64) * 8;
2027 assert(Size && Size * 8 >= ExtraBitsSize &&
2028 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
2029 == ExtraBits && "Directive too small for extra bits.");
2030 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
2034 /// \brief Transform a not absolute MCExpr containing a reference to a GOT
2035 /// equivalent global, by a target specific GOT pc relative access to the
2037 static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
2038 const Constant *BaseCst,
2040 // The global @foo below illustrates a global that uses a got equivalent.
2042 // @bar = global i32 42
2043 // @gotequiv = private unnamed_addr constant i32* @bar
2044 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
2045 // i64 ptrtoint (i32* @foo to i64))
2048 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
2049 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
2052 // foo = cstexpr, where
2053 // cstexpr := <gotequiv> - "." + <cst>
2054 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
2056 // After canonicalization by EvaluateAsRelocatable `ME` turns into:
2058 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
2059 // gotpcrelcst := <offset from @foo base> + <cst>
2062 if (!(*ME)->EvaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
2065 const MCSymbol *GOTEquivSym = &MV.getSymA()->getSymbol();
2066 if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
2069 const GlobalValue *BaseGV = dyn_cast<GlobalValue>(BaseCst);
2073 const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
2074 if (BaseSym != &MV.getSymB()->getSymbol())
2077 // Make sure to match:
2079 // gotpcrelcst := <offset from @foo base> + <cst>
2081 int64_t GOTPCRelCst = Offset + MV.getConstant();
2082 if (GOTPCRelCst < 0)
2085 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
2092 // .long gotequiv - "." + <cst>
2094 // is replaced by the target specific equivalent to:
2099 // .long bar@GOTPCREL+<gotpcrelcst>
2101 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
2102 const GlobalVariable *GV = Result.first;
2103 unsigned NumUses = Result.second;
2104 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
2105 const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
2106 *ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(FinalSym,
2109 // Update GOT equivalent usage information
2112 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
2114 AP.GlobalGOTEquivs.erase(GOTEquivSym);
2117 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP,
2118 const Constant *BaseCV, uint64_t Offset) {
2119 const DataLayout *DL = AP.TM.getDataLayout();
2120 uint64_t Size = DL->getTypeAllocSize(CV->getType());
2122 // Globals with sub-elements such as combinations of arrays and structs
2123 // are handled recursively by emitGlobalConstantImpl. Keep track of the
2124 // constant symbol base and the current position with BaseCV and Offset.
2125 if (!BaseCV && CV->hasOneUse())
2126 BaseCV = dyn_cast<Constant>(CV->user_back());
2128 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
2129 return AP.OutStreamer.EmitZeros(Size);
2131 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
2138 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
2139 CI->getZExtValue());
2140 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
2143 emitGlobalConstantLargeInt(CI, AP);
2148 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
2149 return emitGlobalConstantFP(CFP, AP);
2151 if (isa<ConstantPointerNull>(CV)) {
2152 AP.OutStreamer.EmitIntValue(0, Size);
2156 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
2157 return emitGlobalConstantDataSequential(CDS, AP);
2159 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2160 return emitGlobalConstantArray(CVA, AP, BaseCV, Offset);
2162 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2163 return emitGlobalConstantStruct(CVS, AP, BaseCV, Offset);
2165 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2166 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2168 if (CE->getOpcode() == Instruction::BitCast)
2169 return emitGlobalConstantImpl(CE->getOperand(0), AP);
2172 // If the constant expression's size is greater than 64-bits, then we have
2173 // to emit the value in chunks. Try to constant fold the value and emit it
2175 Constant *New = ConstantFoldConstantExpression(CE, DL);
2176 if (New && New != CE)
2177 return emitGlobalConstantImpl(New, AP);
2181 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2182 return emitGlobalConstantVector(V, AP);
2184 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2185 // thread the streamer with EmitValue.
2186 const MCExpr *ME = AP.lowerConstant(CV);
2188 // Since lowerConstant already folded and got rid of all IR pointer and
2189 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
2191 if (AP.getObjFileLowering().supportIndirectSymViaGOTPCRel())
2192 handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
2194 AP.OutStreamer.EmitValue(ME, Size);
2197 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2198 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2200 TM.getDataLayout()->getTypeAllocSize(CV->getType());
2202 emitGlobalConstantImpl(CV, *this);
2203 else if (MAI->hasSubsectionsViaSymbols()) {
2204 // If the global has zero size, emit a single byte so that two labels don't
2205 // look like they are at the same location.
2206 OutStreamer.EmitIntValue(0, 1);
2210 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2211 // Target doesn't support this yet!
2212 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2215 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2217 OS << '+' << Offset;
2218 else if (Offset < 0)
2222 //===----------------------------------------------------------------------===//
2223 // Symbol Lowering Routines.
2224 //===----------------------------------------------------------------------===//
2226 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2227 /// temporary label with the specified stem and unique ID.
2228 MCSymbol *AsmPrinter::GetTempSymbol(const Twine &Name, unsigned ID) const {
2229 const DataLayout *DL = TM.getDataLayout();
2230 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2234 /// GetTempSymbol - Return an assembler temporary label with the specified
2236 MCSymbol *AsmPrinter::GetTempSymbol(const Twine &Name) const {
2237 const DataLayout *DL = TM.getDataLayout();
2238 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2242 MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name, unsigned ID) const {
2243 return OutContext.createTempSymbol(Name + Twine(ID));
2246 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2247 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2250 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2251 return MMI->getAddrLabelSymbol(BB);
2254 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2255 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2256 const DataLayout *DL = TM.getDataLayout();
2257 return OutContext.GetOrCreateSymbol
2258 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2259 + "_" + Twine(CPID));
2262 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2263 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2264 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2267 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2268 /// FIXME: privatize to AsmPrinter.
2269 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2270 const DataLayout *DL = TM.getDataLayout();
2271 return OutContext.GetOrCreateSymbol
2272 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2273 Twine(UID) + "_set_" + Twine(MBBID));
2276 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2277 StringRef Suffix) const {
2278 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2282 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2284 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2285 SmallString<60> NameStr;
2286 Mang->getNameWithPrefix(NameStr, Sym);
2287 return OutContext.GetOrCreateSymbol(NameStr.str());
2292 /// PrintParentLoopComment - Print comments about parent loops of this one.
2293 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2294 unsigned FunctionNumber) {
2296 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2297 OS.indent(Loop->getLoopDepth()*2)
2298 << "Parent Loop BB" << FunctionNumber << "_"
2299 << Loop->getHeader()->getNumber()
2300 << " Depth=" << Loop->getLoopDepth() << '\n';
2304 /// PrintChildLoopComment - Print comments about child loops within
2305 /// the loop for this basic block, with nesting.
2306 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2307 unsigned FunctionNumber) {
2308 // Add child loop information
2309 for (const MachineLoop *CL : *Loop) {
2310 OS.indent(CL->getLoopDepth()*2)
2311 << "Child Loop BB" << FunctionNumber << "_"
2312 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2314 PrintChildLoopComment(OS, CL, FunctionNumber);
2318 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2319 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2320 const MachineLoopInfo *LI,
2321 const AsmPrinter &AP) {
2322 // Add loop depth information
2323 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2326 MachineBasicBlock *Header = Loop->getHeader();
2327 assert(Header && "No header for loop");
2329 // If this block is not a loop header, just print out what is the loop header
2331 if (Header != &MBB) {
2332 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2333 Twine(AP.getFunctionNumber())+"_" +
2334 Twine(Loop->getHeader()->getNumber())+
2335 " Depth="+Twine(Loop->getLoopDepth()));
2339 // Otherwise, it is a loop header. Print out information about child and
2341 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2343 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2346 OS.indent(Loop->getLoopDepth()*2-2);
2351 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2353 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2357 /// EmitBasicBlockStart - This method prints the label for the specified
2358 /// MachineBasicBlock, an alignment (if present) and a comment describing
2359 /// it if appropriate.
2360 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2361 // Emit an alignment directive for this block, if needed.
2362 if (unsigned Align = MBB.getAlignment())
2363 EmitAlignment(Align);
2365 // If the block has its address taken, emit any labels that were used to
2366 // reference the block. It is possible that there is more than one label
2367 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2368 // the references were generated.
2369 if (MBB.hasAddressTaken()) {
2370 const BasicBlock *BB = MBB.getBasicBlock();
2372 OutStreamer.AddComment("Block address taken");
2374 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2375 for (auto *Sym : Symbols)
2376 OutStreamer.EmitLabel(Sym);
2379 // Print some verbose block comments.
2381 if (const BasicBlock *BB = MBB.getBasicBlock())
2383 OutStreamer.AddComment("%" + BB->getName());
2384 emitBasicBlockLoopComments(MBB, LI, *this);
2387 // Print the main label for the block.
2388 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2390 // NOTE: Want this comment at start of line, don't emit with AddComment.
2391 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2394 OutStreamer.EmitLabel(MBB.getSymbol());
2398 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2399 bool IsDefinition) const {
2400 MCSymbolAttr Attr = MCSA_Invalid;
2402 switch (Visibility) {
2404 case GlobalValue::HiddenVisibility:
2406 Attr = MAI->getHiddenVisibilityAttr();
2408 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2410 case GlobalValue::ProtectedVisibility:
2411 Attr = MAI->getProtectedVisibilityAttr();
2415 if (Attr != MCSA_Invalid)
2416 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2419 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2420 /// exactly one predecessor and the control transfer mechanism between
2421 /// the predecessor and this block is a fall-through.
2423 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2424 // If this is a landing pad, it isn't a fall through. If it has no preds,
2425 // then nothing falls through to it.
2426 if (MBB->isLandingPad() || MBB->pred_empty())
2429 // If there isn't exactly one predecessor, it can't be a fall through.
2430 if (MBB->pred_size() > 1)
2433 // The predecessor has to be immediately before this block.
2434 MachineBasicBlock *Pred = *MBB->pred_begin();
2435 if (!Pred->isLayoutSuccessor(MBB))
2438 // If the block is completely empty, then it definitely does fall through.
2442 // Check the terminators in the previous blocks
2443 for (const auto &MI : Pred->terminators()) {
2444 // If it is not a simple branch, we are in a table somewhere.
2445 if (!MI.isBranch() || MI.isIndirectBranch())
2448 // If we are the operands of one of the branches, this is not a fall
2449 // through. Note that targets with delay slots will usually bundle
2450 // terminators with the delay slot instruction.
2451 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2454 if (OP->isMBB() && OP->getMBB() == MBB)
2464 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2465 if (!S.usesMetadata())
2468 assert(!S.useStatepoints() && "statepoints do not currently support custom"
2469 " stackmap formats, please see the documentation for a description of"
2470 " the default format. If you really need a custom serialized format,"
2471 " please file a bug");
2473 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2474 gcp_map_type::iterator GCPI = GCMap.find(&S);
2475 if (GCPI != GCMap.end())
2476 return GCPI->second.get();
2478 const char *Name = S.getName().c_str();
2480 for (GCMetadataPrinterRegistry::iterator
2481 I = GCMetadataPrinterRegistry::begin(),
2482 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2483 if (strcmp(Name, I->getName()) == 0) {
2484 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2486 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2487 return IterBool.first->second.get();
2490 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2493 /// Pin vtable to this file.
2494 AsmPrinterHandler::~AsmPrinterHandler() {}