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 "WinException.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/CodeGen/Analysis.h"
23 #include "llvm/CodeGen/GCMetadataPrinter.h"
24 #include "llvm/CodeGen/MachineConstantPool.h"
25 #include "llvm/CodeGen/MachineFrameInfo.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/CodeGen/MachineInstrBundle.h"
28 #include "llvm/CodeGen/MachineJumpTableInfo.h"
29 #include "llvm/CodeGen/MachineLoopInfo.h"
30 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
31 #include "llvm/IR/DataLayout.h"
32 #include "llvm/IR/DebugInfo.h"
33 #include "llvm/IR/Mangler.h"
34 #include "llvm/IR/Module.h"
35 #include "llvm/IR/Operator.h"
36 #include "llvm/MC/MCAsmInfo.h"
37 #include "llvm/MC/MCContext.h"
38 #include "llvm/MC/MCExpr.h"
39 #include "llvm/MC/MCInst.h"
40 #include "llvm/MC/MCSection.h"
41 #include "llvm/MC/MCStreamer.h"
42 #include "llvm/MC/MCSymbolELF.h"
43 #include "llvm/MC/MCValue.h"
44 #include "llvm/Support/ErrorHandling.h"
45 #include "llvm/Support/Format.h"
46 #include "llvm/Support/MathExtras.h"
47 #include "llvm/Support/TargetRegistry.h"
48 #include "llvm/Support/Timer.h"
49 #include "llvm/Target/TargetFrameLowering.h"
50 #include "llvm/Target/TargetInstrInfo.h"
51 #include "llvm/Target/TargetLowering.h"
52 #include "llvm/Target/TargetLoweringObjectFile.h"
53 #include "llvm/Target/TargetRegisterInfo.h"
54 #include "llvm/Target/TargetSubtargetInfo.h"
57 #define DEBUG_TYPE "asm-printer"
59 static const char *const DWARFGroupName = "DWARF Emission";
60 static const char *const DbgTimerName = "Debug Info Emission";
61 static const char *const EHTimerName = "DWARF Exception Writer";
62 static const char *const CodeViewLineTablesGroupName = "CodeView Line Tables";
64 STATISTIC(EmittedInsts, "Number of machine instrs printed");
66 char AsmPrinter::ID = 0;
68 typedef DenseMap<GCStrategy*, std::unique_ptr<GCMetadataPrinter>> gcp_map_type;
69 static gcp_map_type &getGCMap(void *&P) {
71 P = new gcp_map_type();
72 return *(gcp_map_type*)P;
76 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
77 /// value in log2 form. This rounds up to the preferred alignment if possible
79 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &DL,
80 unsigned InBits = 0) {
82 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
83 NumBits = DL.getPreferredAlignmentLog(GVar);
85 // If InBits is specified, round it to it.
89 // If the GV has a specified alignment, take it into account.
90 if (GV->getAlignment() == 0)
93 unsigned GVAlign = Log2_32(GV->getAlignment());
95 // If the GVAlign is larger than NumBits, or if we are required to obey
96 // NumBits because the GV has an assigned section, obey it.
97 if (GVAlign > NumBits || GV->hasSection())
102 AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
103 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
104 OutContext(Streamer->getContext()), OutStreamer(std::move(Streamer)),
105 LastMI(nullptr), LastFn(0), Counter(~0U) {
110 CurExceptionSym = CurrentFnSym = CurrentFnSymForSize = nullptr;
111 CurrentFnBegin = nullptr;
112 CurrentFnEnd = nullptr;
113 GCMetadataPrinters = nullptr;
114 VerboseAsm = OutStreamer->isVerboseAsm();
117 AsmPrinter::~AsmPrinter() {
118 assert(!DD && Handlers.empty() && "Debug/EH info didn't get finalized");
120 if (GCMetadataPrinters) {
121 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
124 GCMetadataPrinters = nullptr;
128 /// getFunctionNumber - Return a unique ID for the current function.
130 unsigned AsmPrinter::getFunctionNumber() const {
131 return MF->getFunctionNumber();
134 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
135 return *TM.getObjFileLowering();
138 /// getDataLayout - Return information about data layout.
139 const DataLayout &AsmPrinter::getDataLayout() const {
140 return MMI->getModule()->getDataLayout();
143 unsigned AsmPrinter::getPointerSize() const { return TM.getDataLayout()->getPointerSize(); }
145 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
146 assert(MF && "getSubtargetInfo requires a valid MachineFunction!");
147 return MF->getSubtarget<MCSubtargetInfo>();
150 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
151 S.EmitInstruction(Inst, getSubtargetInfo());
154 StringRef AsmPrinter::getTargetTriple() const {
155 return TM.getTargetTriple().str();
158 /// getCurrentSection() - Return the current section we are emitting to.
159 const MCSection *AsmPrinter::getCurrentSection() const {
160 return OutStreamer->getCurrentSection().first;
165 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
166 AU.setPreservesAll();
167 MachineFunctionPass::getAnalysisUsage(AU);
168 AU.addRequired<MachineModuleInfo>();
169 AU.addRequired<GCModuleInfo>();
171 AU.addRequired<MachineLoopInfo>();
174 bool AsmPrinter::doInitialization(Module &M) {
175 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
177 // Initialize TargetLoweringObjectFile.
178 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
179 .Initialize(OutContext, TM);
181 OutStreamer->InitSections(false);
183 Mang = new Mangler();
185 // Emit the version-min deplyment target directive if needed.
187 // FIXME: If we end up with a collection of these sorts of Darwin-specific
188 // or ELF-specific things, it may make sense to have a platform helper class
189 // that will work with the target helper class. For now keep it here, as the
190 // alternative is duplicated code in each of the target asm printers that
191 // use the directive, where it would need the same conditionalization
193 Triple TT(getTargetTriple());
194 if (TT.isOSDarwin()) {
195 unsigned Major, Minor, Update;
196 TT.getOSVersion(Major, Minor, Update);
197 // If there is a version specified, Major will be non-zero.
199 OutStreamer->EmitVersionMin((TT.isMacOSX() ?
200 MCVM_OSXVersionMin : MCVM_IOSVersionMin),
201 Major, Minor, Update);
204 // Allow the target to emit any magic that it wants at the start of the file.
205 EmitStartOfAsmFile(M);
207 // Very minimal debug info. It is ignored if we emit actual debug info. If we
208 // don't, this at least helps the user find where a global came from.
209 if (MAI->hasSingleParameterDotFile()) {
211 OutStreamer->EmitFileDirective(M.getModuleIdentifier());
214 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
215 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
217 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
218 MP->beginAssembly(M, *MI, *this);
220 // Emit module-level inline asm if it exists.
221 if (!M.getModuleInlineAsm().empty()) {
222 // We're at the module level. Construct MCSubtarget from the default CPU
223 // and target triple.
224 std::unique_ptr<MCSubtargetInfo> STI(TM.getTarget().createMCSubtargetInfo(
225 TM.getTargetTriple().str(), TM.getTargetCPU(),
226 TM.getTargetFeatureString()));
227 OutStreamer->AddComment("Start of file scope inline assembly");
228 OutStreamer->AddBlankLine();
229 EmitInlineAsm(M.getModuleInlineAsm()+"\n", *STI, TM.Options.MCOptions);
230 OutStreamer->AddComment("End of file scope inline assembly");
231 OutStreamer->AddBlankLine();
234 if (MAI->doesSupportDebugInformation()) {
235 bool skip_dwarf = false;
236 if (TM.getTargetTriple().isKnownWindowsMSVCEnvironment()) {
237 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this),
239 CodeViewLineTablesGroupName));
240 // FIXME: Don't emit DWARF debug info if there's at least one function
241 // with AddressSanitizer instrumentation.
242 // This is a band-aid fix for PR22032.
243 for (auto &F : M.functions()) {
244 if (F.hasFnAttribute(Attribute::SanitizeAddress)) {
251 DD = new DwarfDebug(this, &M);
252 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
256 EHStreamer *ES = nullptr;
257 switch (MAI->getExceptionHandlingType()) {
258 case ExceptionHandling::None:
260 case ExceptionHandling::SjLj:
261 case ExceptionHandling::DwarfCFI:
262 ES = new DwarfCFIException(this);
264 case ExceptionHandling::ARM:
265 ES = new ARMException(this);
267 case ExceptionHandling::WinEH:
268 switch (MAI->getWinEHEncodingType()) {
269 default: llvm_unreachable("unsupported unwinding information encoding");
270 case WinEH::EncodingType::Invalid:
272 case WinEH::EncodingType::X86:
273 case WinEH::EncodingType::Itanium:
274 ES = new WinException(this);
280 Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
284 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
285 if (!MAI.hasWeakDefCanBeHiddenDirective())
288 return canBeOmittedFromSymbolTable(GV);
291 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
292 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
294 case GlobalValue::CommonLinkage:
295 case GlobalValue::LinkOnceAnyLinkage:
296 case GlobalValue::LinkOnceODRLinkage:
297 case GlobalValue::WeakAnyLinkage:
298 case GlobalValue::WeakODRLinkage:
299 if (MAI->hasWeakDefDirective()) {
301 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
303 if (!canBeHidden(GV, *MAI))
304 // .weak_definition _foo
305 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
307 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
308 } else if (MAI->hasLinkOnceDirective()) {
310 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
311 //NOTE: linkonce is handled by the section the symbol was assigned to.
314 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Weak);
317 case GlobalValue::AppendingLinkage:
318 // FIXME: appending linkage variables should go into a section of
319 // their name or something. For now, just emit them as external.
320 case GlobalValue::ExternalLinkage:
321 // If external or appending, declare as a global symbol.
323 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
325 case GlobalValue::PrivateLinkage:
326 case GlobalValue::InternalLinkage:
328 case GlobalValue::AvailableExternallyLinkage:
329 llvm_unreachable("Should never emit this");
330 case GlobalValue::ExternalWeakLinkage:
331 llvm_unreachable("Don't know how to emit these");
333 llvm_unreachable("Unknown linkage type!");
336 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
337 const GlobalValue *GV) const {
338 TM.getNameWithPrefix(Name, GV, *Mang);
341 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
342 return TM.getSymbol(GV, *Mang);
345 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
346 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
347 if (GV->hasInitializer()) {
348 // Check to see if this is a special global used by LLVM, if so, emit it.
349 if (EmitSpecialLLVMGlobal(GV))
352 // Skip the emission of global equivalents. The symbol can be emitted later
353 // on by emitGlobalGOTEquivs in case it turns out to be needed.
354 if (GlobalGOTEquivs.count(getSymbol(GV)))
358 GV->printAsOperand(OutStreamer->GetCommentOS(),
359 /*PrintType=*/false, GV->getParent());
360 OutStreamer->GetCommentOS() << '\n';
364 MCSymbol *GVSym = getSymbol(GV);
365 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
367 if (!GV->hasInitializer()) // External globals require no extra code.
370 GVSym->redefineIfPossible();
371 if (GVSym->isDefined() || GVSym->isVariable())
372 report_fatal_error("symbol '" + Twine(GVSym->getName()) +
373 "' is already defined");
375 if (MAI->hasDotTypeDotSizeDirective())
376 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
378 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
380 const DataLayout &DL = GV->getParent()->getDataLayout();
381 uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
383 // If the alignment is specified, we *must* obey it. Overaligning a global
384 // with a specified alignment is a prompt way to break globals emitted to
385 // sections and expected to be contiguous (e.g. ObjC metadata).
386 unsigned AlignLog = getGVAlignmentLog2(GV, DL);
388 for (const HandlerInfo &HI : Handlers) {
389 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
390 HI.Handler->setSymbolSize(GVSym, Size);
393 // Handle common and BSS local symbols (.lcomm).
394 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
395 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
396 unsigned Align = 1 << AlignLog;
398 // Handle common symbols.
399 if (GVKind.isCommon()) {
400 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
404 OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
408 // Handle local BSS symbols.
409 if (MAI->hasMachoZeroFillDirective()) {
410 MCSection *TheSection =
411 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
412 // .zerofill __DATA, __bss, _foo, 400, 5
413 OutStreamer->EmitZerofill(TheSection, GVSym, Size, Align);
417 // Use .lcomm only if it supports user-specified alignment.
418 // Otherwise, while it would still be correct to use .lcomm in some
419 // cases (e.g. when Align == 1), the external assembler might enfore
420 // some -unknown- default alignment behavior, which could cause
421 // spurious differences between external and integrated assembler.
422 // Prefer to simply fall back to .local / .comm in this case.
423 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
425 OutStreamer->EmitLocalCommonSymbol(GVSym, Size, Align);
429 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
433 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Local);
435 OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
439 MCSection *TheSection =
440 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
442 // Handle the zerofill directive on darwin, which is a special form of BSS
444 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
445 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
448 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
449 // .zerofill __DATA, __common, _foo, 400, 5
450 OutStreamer->EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
454 // Handle thread local data for mach-o which requires us to output an
455 // additional structure of data and mangle the original symbol so that we
456 // can reference it later.
458 // TODO: This should become an "emit thread local global" method on TLOF.
459 // All of this macho specific stuff should be sunk down into TLOFMachO and
460 // stuff like "TLSExtraDataSection" should no longer be part of the parent
461 // TLOF class. This will also make it more obvious that stuff like
462 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
464 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
465 // Emit the .tbss symbol
467 OutContext.getOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
469 if (GVKind.isThreadBSS()) {
470 TheSection = getObjFileLowering().getTLSBSSSection();
471 OutStreamer->EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
472 } else if (GVKind.isThreadData()) {
473 OutStreamer->SwitchSection(TheSection);
475 EmitAlignment(AlignLog, GV);
476 OutStreamer->EmitLabel(MangSym);
478 EmitGlobalConstant(GV->getInitializer());
481 OutStreamer->AddBlankLine();
483 // Emit the variable struct for the runtime.
484 MCSection *TLVSect = getObjFileLowering().getTLSExtraDataSection();
486 OutStreamer->SwitchSection(TLVSect);
487 // Emit the linkage here.
488 EmitLinkage(GV, GVSym);
489 OutStreamer->EmitLabel(GVSym);
491 // Three pointers in size:
492 // - __tlv_bootstrap - used to make sure support exists
493 // - spare pointer, used when mapped by the runtime
494 // - pointer to mangled symbol above with initializer
495 unsigned PtrSize = DL.getPointerTypeSize(GV->getType());
496 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
498 OutStreamer->EmitIntValue(0, PtrSize);
499 OutStreamer->EmitSymbolValue(MangSym, PtrSize);
501 OutStreamer->AddBlankLine();
505 OutStreamer->SwitchSection(TheSection);
507 EmitLinkage(GV, GVSym);
508 EmitAlignment(AlignLog, GV);
510 OutStreamer->EmitLabel(GVSym);
512 EmitGlobalConstant(GV->getInitializer());
514 if (MAI->hasDotTypeDotSizeDirective())
516 OutStreamer->emitELFSize(cast<MCSymbolELF>(GVSym),
517 MCConstantExpr::create(Size, OutContext));
519 OutStreamer->AddBlankLine();
522 /// EmitFunctionHeader - This method emits the header for the current
524 void AsmPrinter::EmitFunctionHeader() {
525 // Print out constants referenced by the function
528 // Print the 'header' of function.
529 const Function *F = MF->getFunction();
531 OutStreamer->SwitchSection(
532 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
533 EmitVisibility(CurrentFnSym, F->getVisibility());
535 EmitLinkage(F, CurrentFnSym);
536 if (MAI->hasFunctionAlignment())
537 EmitAlignment(MF->getAlignment(), F);
539 if (MAI->hasDotTypeDotSizeDirective())
540 OutStreamer->EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
543 F->printAsOperand(OutStreamer->GetCommentOS(),
544 /*PrintType=*/false, F->getParent());
545 OutStreamer->GetCommentOS() << '\n';
548 // Emit the prefix data.
549 if (F->hasPrefixData())
550 EmitGlobalConstant(F->getPrefixData());
552 // Emit the CurrentFnSym. This is a virtual function to allow targets to
553 // do their wild and crazy things as required.
554 EmitFunctionEntryLabel();
556 // If the function had address-taken blocks that got deleted, then we have
557 // references to the dangling symbols. Emit them at the start of the function
558 // so that we don't get references to undefined symbols.
559 std::vector<MCSymbol*> DeadBlockSyms;
560 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
561 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
562 OutStreamer->AddComment("Address taken block that was later removed");
563 OutStreamer->EmitLabel(DeadBlockSyms[i]);
566 if (CurrentFnBegin) {
567 if (MAI->useAssignmentForEHBegin()) {
568 MCSymbol *CurPos = OutContext.createTempSymbol();
569 OutStreamer->EmitLabel(CurPos);
570 OutStreamer->EmitAssignment(CurrentFnBegin,
571 MCSymbolRefExpr::create(CurPos, OutContext));
573 OutStreamer->EmitLabel(CurrentFnBegin);
577 // Emit pre-function debug and/or EH information.
578 for (const HandlerInfo &HI : Handlers) {
579 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
580 HI.Handler->beginFunction(MF);
583 // Emit the prologue data.
584 if (F->hasPrologueData())
585 EmitGlobalConstant(F->getPrologueData());
588 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
589 /// function. This can be overridden by targets as required to do custom stuff.
590 void AsmPrinter::EmitFunctionEntryLabel() {
591 CurrentFnSym->redefineIfPossible();
593 // The function label could have already been emitted if two symbols end up
594 // conflicting due to asm renaming. Detect this and emit an error.
595 if (CurrentFnSym->isVariable())
596 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
597 "' is a protected alias");
598 if (CurrentFnSym->isDefined())
599 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
600 "' label emitted multiple times to assembly file");
602 return OutStreamer->EmitLabel(CurrentFnSym);
605 /// emitComments - Pretty-print comments for instructions.
606 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
607 const MachineFunction *MF = MI.getParent()->getParent();
608 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
610 // Check for spills and reloads
613 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
615 // We assume a single instruction only has a spill or reload, not
617 const MachineMemOperand *MMO;
618 if (TII->isLoadFromStackSlotPostFE(&MI, FI)) {
619 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
620 MMO = *MI.memoperands_begin();
621 CommentOS << MMO->getSize() << "-byte Reload\n";
623 } else if (TII->hasLoadFromStackSlot(&MI, MMO, FI)) {
624 if (FrameInfo->isSpillSlotObjectIndex(FI))
625 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
626 } else if (TII->isStoreToStackSlotPostFE(&MI, FI)) {
627 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
628 MMO = *MI.memoperands_begin();
629 CommentOS << MMO->getSize() << "-byte Spill\n";
631 } else if (TII->hasStoreToStackSlot(&MI, MMO, FI)) {
632 if (FrameInfo->isSpillSlotObjectIndex(FI))
633 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
636 // Check for spill-induced copies
637 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
638 CommentOS << " Reload Reuse\n";
641 /// emitImplicitDef - This method emits the specified machine instruction
642 /// that is an implicit def.
643 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
644 unsigned RegNo = MI->getOperand(0).getReg();
645 OutStreamer->AddComment(Twine("implicit-def: ") +
646 MMI->getContext().getRegisterInfo()->getName(RegNo));
647 OutStreamer->AddBlankLine();
650 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
651 std::string Str = "kill:";
652 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
653 const MachineOperand &Op = MI->getOperand(i);
654 assert(Op.isReg() && "KILL instruction must have only register operands");
656 Str += AP.MMI->getContext().getRegisterInfo()->getName(Op.getReg());
657 Str += (Op.isDef() ? "<def>" : "<kill>");
659 AP.OutStreamer->AddComment(Str);
660 AP.OutStreamer->AddBlankLine();
663 /// emitDebugValueComment - This method handles the target-independent form
664 /// of DBG_VALUE, returning true if it was able to do so. A false return
665 /// means the target will need to handle MI in EmitInstruction.
666 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
667 // This code handles only the 4-operand target-independent form.
668 if (MI->getNumOperands() != 4)
671 SmallString<128> Str;
672 raw_svector_ostream OS(Str);
673 OS << "DEBUG_VALUE: ";
675 const DILocalVariable *V = MI->getDebugVariable();
676 if (auto *SP = dyn_cast<DISubprogram>(V->getScope())) {
677 StringRef Name = SP->getDisplayName();
683 const DIExpression *Expr = MI->getDebugExpression();
684 if (Expr->isBitPiece())
685 OS << " [bit_piece offset=" << Expr->getBitPieceOffset()
686 << " size=" << Expr->getBitPieceSize() << "]";
689 // The second operand is only an offset if it's an immediate.
690 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
691 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
693 // Register or immediate value. Register 0 means undef.
694 if (MI->getOperand(0).isFPImm()) {
695 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
696 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
697 OS << (double)APF.convertToFloat();
698 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
699 OS << APF.convertToDouble();
701 // There is no good way to print long double. Convert a copy to
702 // double. Ah well, it's only a comment.
704 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
706 OS << "(long double) " << APF.convertToDouble();
708 } else if (MI->getOperand(0).isImm()) {
709 OS << MI->getOperand(0).getImm();
710 } else if (MI->getOperand(0).isCImm()) {
711 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
714 if (MI->getOperand(0).isReg()) {
715 Reg = MI->getOperand(0).getReg();
717 assert(MI->getOperand(0).isFI() && "Unknown operand type");
718 const TargetFrameLowering *TFI = AP.MF->getSubtarget().getFrameLowering();
719 Offset += TFI->getFrameIndexReference(*AP.MF,
720 MI->getOperand(0).getIndex(), Reg);
724 // Suppress offset, it is not meaningful here.
726 // NOTE: Want this comment at start of line, don't emit with AddComment.
727 AP.OutStreamer->emitRawComment(OS.str());
732 OS << AP.MMI->getContext().getRegisterInfo()->getName(Reg);
736 OS << '+' << Offset << ']';
738 // NOTE: Want this comment at start of line, don't emit with AddComment.
739 AP.OutStreamer->emitRawComment(OS.str());
743 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
744 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
745 MF->getFunction()->needsUnwindTableEntry())
748 if (MMI->hasDebugInfo())
754 bool AsmPrinter::needsSEHMoves() {
755 return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
758 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
759 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
760 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
761 ExceptionHandlingType != ExceptionHandling::ARM)
764 if (needsCFIMoves() == CFI_M_None)
767 const MachineModuleInfo &MMI = MF->getMMI();
768 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
769 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
770 const MCCFIInstruction &CFI = Instrs[CFIIndex];
771 emitCFIInstruction(CFI);
774 void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
775 // The operands are the MCSymbol and the frame offset of the allocation.
776 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
777 int FrameOffset = MI.getOperand(1).getImm();
779 // Emit a symbol assignment.
780 OutStreamer->EmitAssignment(FrameAllocSym,
781 MCConstantExpr::create(FrameOffset, OutContext));
784 /// EmitFunctionBody - This method emits the body and trailer for a
786 void AsmPrinter::EmitFunctionBody() {
787 EmitFunctionHeader();
789 // Emit target-specific gunk before the function body.
790 EmitFunctionBodyStart();
792 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
794 // Print out code for the function.
795 bool HasAnyRealCode = false;
796 for (auto &MBB : *MF) {
797 // Print a label for the basic block.
798 EmitBasicBlockStart(MBB);
799 for (auto &MI : MBB) {
801 // Print the assembly for the instruction.
802 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
803 !MI.isDebugValue()) {
804 HasAnyRealCode = true;
808 if (ShouldPrintDebugScopes) {
809 for (const HandlerInfo &HI : Handlers) {
810 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
811 TimePassesIsEnabled);
812 HI.Handler->beginInstruction(&MI);
817 emitComments(MI, OutStreamer->GetCommentOS());
819 switch (MI.getOpcode()) {
820 case TargetOpcode::CFI_INSTRUCTION:
821 emitCFIInstruction(MI);
824 case TargetOpcode::LOCAL_ESCAPE:
828 case TargetOpcode::EH_LABEL:
829 case TargetOpcode::GC_LABEL:
830 OutStreamer->EmitLabel(MI.getOperand(0).getMCSymbol());
832 case TargetOpcode::INLINEASM:
835 case TargetOpcode::DBG_VALUE:
837 if (!emitDebugValueComment(&MI, *this))
838 EmitInstruction(&MI);
841 case TargetOpcode::IMPLICIT_DEF:
842 if (isVerbose()) emitImplicitDef(&MI);
844 case TargetOpcode::KILL:
845 if (isVerbose()) emitKill(&MI, *this);
848 EmitInstruction(&MI);
852 if (ShouldPrintDebugScopes) {
853 for (const HandlerInfo &HI : Handlers) {
854 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
855 TimePassesIsEnabled);
856 HI.Handler->endInstruction();
861 EmitBasicBlockEnd(MBB);
864 // If the function is empty and the object file uses .subsections_via_symbols,
865 // then we need to emit *something* to the function body to prevent the
866 // labels from collapsing together. Just emit a noop.
867 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
869 MF->getSubtarget().getInstrInfo()->getNoopForMachoTarget(Noop);
870 OutStreamer->AddComment("avoids zero-length function");
872 // Targets can opt-out of emitting the noop here by leaving the opcode
874 if (Noop.getOpcode())
875 OutStreamer->EmitInstruction(Noop, getSubtargetInfo());
878 const Function *F = MF->getFunction();
879 for (const auto &BB : *F) {
880 if (!BB.hasAddressTaken())
882 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
883 if (Sym->isDefined())
885 OutStreamer->AddComment("Address of block that was removed by CodeGen");
886 OutStreamer->EmitLabel(Sym);
889 // Emit target-specific gunk after the function body.
890 EmitFunctionBodyEnd();
892 if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
893 MAI->hasDotTypeDotSizeDirective()) {
894 // Create a symbol for the end of function.
895 CurrentFnEnd = createTempSymbol("func_end");
896 OutStreamer->EmitLabel(CurrentFnEnd);
899 // If the target wants a .size directive for the size of the function, emit
901 if (MAI->hasDotTypeDotSizeDirective()) {
902 // We can get the size as difference between the function label and the
904 const MCExpr *SizeExp = MCBinaryExpr::createSub(
905 MCSymbolRefExpr::create(CurrentFnEnd, OutContext),
906 MCSymbolRefExpr::create(CurrentFnSymForSize, OutContext), OutContext);
907 if (auto Sym = dyn_cast<MCSymbolELF>(CurrentFnSym))
908 OutStreamer->emitELFSize(Sym, SizeExp);
911 for (const HandlerInfo &HI : Handlers) {
912 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
913 HI.Handler->markFunctionEnd();
916 // Print out jump tables referenced by the function.
919 // Emit post-function debug and/or EH information.
920 for (const HandlerInfo &HI : Handlers) {
921 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
922 HI.Handler->endFunction(MF);
926 OutStreamer->AddBlankLine();
929 /// \brief Compute the number of Global Variables that uses a Constant.
930 static unsigned getNumGlobalVariableUses(const Constant *C) {
934 if (isa<GlobalVariable>(C))
937 unsigned NumUses = 0;
938 for (auto *CU : C->users())
939 NumUses += getNumGlobalVariableUses(dyn_cast<Constant>(CU));
944 /// \brief Only consider global GOT equivalents if at least one user is a
945 /// cstexpr inside an initializer of another global variables. Also, don't
946 /// handle cstexpr inside instructions. During global variable emission,
947 /// candidates are skipped and are emitted later in case at least one cstexpr
948 /// isn't replaced by a PC relative GOT entry access.
949 static bool isGOTEquivalentCandidate(const GlobalVariable *GV,
950 unsigned &NumGOTEquivUsers) {
951 // Global GOT equivalents are unnamed private globals with a constant
952 // pointer initializer to another global symbol. They must point to a
953 // GlobalVariable or Function, i.e., as GlobalValue.
954 if (!GV->hasUnnamedAddr() || !GV->hasInitializer() || !GV->isConstant() ||
955 !GV->isDiscardableIfUnused() || !dyn_cast<GlobalValue>(GV->getOperand(0)))
958 // To be a got equivalent, at least one of its users need to be a constant
959 // expression used by another global variable.
960 for (auto *U : GV->users())
961 NumGOTEquivUsers += getNumGlobalVariableUses(dyn_cast<Constant>(U));
963 return NumGOTEquivUsers > 0;
966 /// \brief Unnamed constant global variables solely contaning a pointer to
967 /// another globals variable is equivalent to a GOT table entry; it contains the
968 /// the address of another symbol. Optimize it and replace accesses to these
969 /// "GOT equivalents" by using the GOT entry for the final global instead.
970 /// Compute GOT equivalent candidates among all global variables to avoid
971 /// emitting them if possible later on, after it use is replaced by a GOT entry
973 void AsmPrinter::computeGlobalGOTEquivs(Module &M) {
974 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
977 for (const auto &G : M.globals()) {
978 unsigned NumGOTEquivUsers = 0;
979 if (!isGOTEquivalentCandidate(&G, NumGOTEquivUsers))
982 const MCSymbol *GOTEquivSym = getSymbol(&G);
983 GlobalGOTEquivs[GOTEquivSym] = std::make_pair(&G, NumGOTEquivUsers);
987 /// \brief Constant expressions using GOT equivalent globals may not be eligible
988 /// for PC relative GOT entry conversion, in such cases we need to emit such
989 /// globals we previously omitted in EmitGlobalVariable.
990 void AsmPrinter::emitGlobalGOTEquivs() {
991 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
994 SmallVector<const GlobalVariable *, 8> FailedCandidates;
995 for (auto &I : GlobalGOTEquivs) {
996 const GlobalVariable *GV = I.second.first;
997 unsigned Cnt = I.second.second;
999 FailedCandidates.push_back(GV);
1001 GlobalGOTEquivs.clear();
1003 for (auto *GV : FailedCandidates)
1004 EmitGlobalVariable(GV);
1007 bool AsmPrinter::doFinalization(Module &M) {
1008 // Set the MachineFunction to nullptr so that we can catch attempted
1009 // accesses to MF specific features at the module level and so that
1010 // we can conditionalize accesses based on whether or not it is nullptr.
1013 // Gather all GOT equivalent globals in the module. We really need two
1014 // passes over the globals: one to compute and another to avoid its emission
1015 // in EmitGlobalVariable, otherwise we would not be able to handle cases
1016 // where the got equivalent shows up before its use.
1017 computeGlobalGOTEquivs(M);
1019 // Emit global variables.
1020 for (const auto &G : M.globals())
1021 EmitGlobalVariable(&G);
1023 // Emit remaining GOT equivalent globals.
1024 emitGlobalGOTEquivs();
1026 // Emit visibility info for declarations
1027 for (const Function &F : M) {
1028 if (!F.isDeclarationForLinker())
1030 GlobalValue::VisibilityTypes V = F.getVisibility();
1031 if (V == GlobalValue::DefaultVisibility)
1034 MCSymbol *Name = getSymbol(&F);
1035 EmitVisibility(Name, V, false);
1038 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1040 // Emit module flags.
1041 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
1042 M.getModuleFlagsMetadata(ModuleFlags);
1043 if (!ModuleFlags.empty())
1044 TLOF.emitModuleFlags(*OutStreamer, ModuleFlags, *Mang, TM);
1046 if (TM.getTargetTriple().isOSBinFormatELF()) {
1047 MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
1049 // Output stubs for external and common global variables.
1050 MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
1051 if (!Stubs.empty()) {
1052 OutStreamer->SwitchSection(TLOF.getDataRelSection());
1053 const DataLayout *DL = TM.getDataLayout();
1055 for (const auto &Stub : Stubs) {
1056 OutStreamer->EmitLabel(Stub.first);
1057 OutStreamer->EmitSymbolValue(Stub.second.getPointer(),
1058 DL->getPointerSize());
1063 // Make sure we wrote out everything we need.
1064 OutStreamer->Flush();
1066 // Finalize debug and EH information.
1067 for (const HandlerInfo &HI : Handlers) {
1068 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
1069 TimePassesIsEnabled);
1070 HI.Handler->endModule();
1076 // If the target wants to know about weak references, print them all.
1077 if (MAI->getWeakRefDirective()) {
1078 // FIXME: This is not lazy, it would be nice to only print weak references
1079 // to stuff that is actually used. Note that doing so would require targets
1080 // to notice uses in operands (due to constant exprs etc). This should
1081 // happen with the MC stuff eventually.
1083 // Print out module-level global variables here.
1084 for (const auto &G : M.globals()) {
1085 if (!G.hasExternalWeakLinkage())
1087 OutStreamer->EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
1090 for (const auto &F : M) {
1091 if (!F.hasExternalWeakLinkage())
1093 OutStreamer->EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
1097 OutStreamer->AddBlankLine();
1098 for (const auto &Alias : M.aliases()) {
1099 MCSymbol *Name = getSymbol(&Alias);
1101 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
1102 OutStreamer->EmitSymbolAttribute(Name, MCSA_Global);
1103 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
1104 OutStreamer->EmitSymbolAttribute(Name, MCSA_WeakReference);
1106 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
1108 EmitVisibility(Name, Alias.getVisibility());
1110 // Emit the directives as assignments aka .set:
1111 OutStreamer->EmitAssignment(Name, lowerConstant(Alias.getAliasee()));
1114 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1115 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1116 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1117 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1118 MP->finishAssembly(M, *MI, *this);
1120 // Emit llvm.ident metadata in an '.ident' directive.
1121 EmitModuleIdents(M);
1123 // Emit __morestack address if needed for indirect calls.
1124 if (MMI->usesMorestackAddr()) {
1125 MCSection *ReadOnlySection = getObjFileLowering().getSectionForConstant(
1126 getDataLayout(), SectionKind::getReadOnly(), /*C=*/nullptr);
1127 OutStreamer->SwitchSection(ReadOnlySection);
1129 MCSymbol *AddrSymbol =
1130 OutContext.getOrCreateSymbol(StringRef("__morestack_addr"));
1131 OutStreamer->EmitLabel(AddrSymbol);
1133 unsigned PtrSize = TM.getDataLayout()->getPointerSize(0);
1134 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("__morestack"),
1138 // If we don't have any trampolines, then we don't require stack memory
1139 // to be executable. Some targets have a directive to declare this.
1140 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1141 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1142 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1143 OutStreamer->SwitchSection(S);
1145 // Allow the target to emit any magic that it wants at the end of the file,
1146 // after everything else has gone out.
1147 EmitEndOfAsmFile(M);
1149 delete Mang; Mang = nullptr;
1152 OutStreamer->Finish();
1153 OutStreamer->reset();
1158 MCSymbol *AsmPrinter::getCurExceptionSym() {
1159 if (!CurExceptionSym)
1160 CurExceptionSym = createTempSymbol("exception");
1161 return CurExceptionSym;
1164 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1166 // Get the function symbol.
1167 CurrentFnSym = getSymbol(MF.getFunction());
1168 CurrentFnSymForSize = CurrentFnSym;
1169 CurrentFnBegin = nullptr;
1170 CurExceptionSym = nullptr;
1171 bool NeedsLocalForSize = MAI->needsLocalForSize();
1172 if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
1173 NeedsLocalForSize) {
1174 CurrentFnBegin = createTempSymbol("func_begin");
1175 if (NeedsLocalForSize)
1176 CurrentFnSymForSize = CurrentFnBegin;
1180 LI = &getAnalysis<MachineLoopInfo>();
1184 // Keep track the alignment, constpool entries per Section.
1188 SmallVector<unsigned, 4> CPEs;
1189 SectionCPs(MCSection *s, unsigned a) : S(s), Alignment(a) {}
1193 /// EmitConstantPool - Print to the current output stream assembly
1194 /// representations of the constants in the constant pool MCP. This is
1195 /// used to print out constants which have been "spilled to memory" by
1196 /// the code generator.
1198 void AsmPrinter::EmitConstantPool() {
1199 const MachineConstantPool *MCP = MF->getConstantPool();
1200 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1201 if (CP.empty()) return;
1203 // Calculate sections for constant pool entries. We collect entries to go into
1204 // the same section together to reduce amount of section switch statements.
1205 SmallVector<SectionCPs, 4> CPSections;
1206 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1207 const MachineConstantPoolEntry &CPE = CP[i];
1208 unsigned Align = CPE.getAlignment();
1211 CPE.getSectionKind(TM.getDataLayout());
1213 const Constant *C = nullptr;
1214 if (!CPE.isMachineConstantPoolEntry())
1215 C = CPE.Val.ConstVal;
1218 getObjFileLowering().getSectionForConstant(getDataLayout(), Kind, C);
1220 // The number of sections are small, just do a linear search from the
1221 // last section to the first.
1223 unsigned SecIdx = CPSections.size();
1224 while (SecIdx != 0) {
1225 if (CPSections[--SecIdx].S == S) {
1231 SecIdx = CPSections.size();
1232 CPSections.push_back(SectionCPs(S, Align));
1235 if (Align > CPSections[SecIdx].Alignment)
1236 CPSections[SecIdx].Alignment = Align;
1237 CPSections[SecIdx].CPEs.push_back(i);
1240 // Now print stuff into the calculated sections.
1241 const MCSection *CurSection = nullptr;
1242 unsigned Offset = 0;
1243 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1244 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1245 unsigned CPI = CPSections[i].CPEs[j];
1246 MCSymbol *Sym = GetCPISymbol(CPI);
1247 if (!Sym->isUndefined())
1250 if (CurSection != CPSections[i].S) {
1251 OutStreamer->SwitchSection(CPSections[i].S);
1252 EmitAlignment(Log2_32(CPSections[i].Alignment));
1253 CurSection = CPSections[i].S;
1257 MachineConstantPoolEntry CPE = CP[CPI];
1259 // Emit inter-object padding for alignment.
1260 unsigned AlignMask = CPE.getAlignment() - 1;
1261 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1262 OutStreamer->EmitZeros(NewOffset - Offset);
1264 Type *Ty = CPE.getType();
1265 Offset = NewOffset +
1266 TM.getDataLayout()->getTypeAllocSize(Ty);
1268 OutStreamer->EmitLabel(Sym);
1269 if (CPE.isMachineConstantPoolEntry())
1270 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1272 EmitGlobalConstant(CPE.Val.ConstVal);
1277 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1278 /// by the current function to the current output stream.
1280 void AsmPrinter::EmitJumpTableInfo() {
1281 const DataLayout *DL = MF->getTarget().getDataLayout();
1282 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1284 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1285 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1286 if (JT.empty()) return;
1288 // Pick the directive to use to print the jump table entries, and switch to
1289 // the appropriate section.
1290 const Function *F = MF->getFunction();
1291 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1292 bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
1293 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
1295 if (JTInDiffSection) {
1296 // Drop it in the readonly section.
1297 MCSection *ReadOnlySection = TLOF.getSectionForJumpTable(*F, *Mang, TM);
1298 OutStreamer->SwitchSection(ReadOnlySection);
1301 EmitAlignment(Log2_32(
1302 MJTI->getEntryAlignment(*TM.getDataLayout())));
1304 // Jump tables in code sections are marked with a data_region directive
1305 // where that's supported.
1306 if (!JTInDiffSection)
1307 OutStreamer->EmitDataRegion(MCDR_DataRegionJT32);
1309 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1310 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1312 // If this jump table was deleted, ignore it.
1313 if (JTBBs.empty()) continue;
1315 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1316 /// emit a .set directive for each unique entry.
1317 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1318 MAI->doesSetDirectiveSuppressesReloc()) {
1319 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1320 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1321 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1322 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1323 const MachineBasicBlock *MBB = JTBBs[ii];
1324 if (!EmittedSets.insert(MBB).second)
1327 // .set LJTSet, LBB32-base
1329 MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1330 OutStreamer->EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1331 MCBinaryExpr::createSub(LHS, Base,
1336 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1337 // before each jump table. The first label is never referenced, but tells
1338 // the assembler and linker the extents of the jump table object. The
1339 // second label is actually referenced by the code.
1340 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1341 // FIXME: This doesn't have to have any specific name, just any randomly
1342 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1343 OutStreamer->EmitLabel(GetJTISymbol(JTI, true));
1345 OutStreamer->EmitLabel(GetJTISymbol(JTI));
1347 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1348 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1350 if (!JTInDiffSection)
1351 OutStreamer->EmitDataRegion(MCDR_DataRegionEnd);
1354 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1356 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1357 const MachineBasicBlock *MBB,
1358 unsigned UID) const {
1359 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1360 const MCExpr *Value = nullptr;
1361 switch (MJTI->getEntryKind()) {
1362 case MachineJumpTableInfo::EK_Inline:
1363 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1364 case MachineJumpTableInfo::EK_Custom32:
1365 Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
1366 MJTI, MBB, UID, OutContext);
1368 case MachineJumpTableInfo::EK_BlockAddress:
1369 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1371 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1373 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1374 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1375 // with a relocation as gp-relative, e.g.:
1377 MCSymbol *MBBSym = MBB->getSymbol();
1378 OutStreamer->EmitGPRel32Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1382 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1383 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1384 // with a relocation as gp-relative, e.g.:
1386 MCSymbol *MBBSym = MBB->getSymbol();
1387 OutStreamer->EmitGPRel64Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1391 case MachineJumpTableInfo::EK_LabelDifference32: {
1392 // Each entry is the address of the block minus the address of the jump
1393 // table. This is used for PIC jump tables where gprel32 is not supported.
1395 // .word LBB123 - LJTI1_2
1396 // If the .set directive avoids relocations, this is emitted as:
1397 // .set L4_5_set_123, LBB123 - LJTI1_2
1398 // .word L4_5_set_123
1399 if (MAI->doesSetDirectiveSuppressesReloc()) {
1400 Value = MCSymbolRefExpr::create(GetJTSetSymbol(UID, MBB->getNumber()),
1404 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1405 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1406 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1407 Value = MCBinaryExpr::createSub(Value, Base, OutContext);
1412 assert(Value && "Unknown entry kind!");
1414 unsigned EntrySize =
1415 MJTI->getEntrySize(*TM.getDataLayout());
1416 OutStreamer->EmitValue(Value, EntrySize);
1420 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1421 /// special global used by LLVM. If so, emit it and return true, otherwise
1422 /// do nothing and return false.
1423 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1424 if (GV->getName() == "llvm.used") {
1425 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1426 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1430 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1431 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1432 GV->hasAvailableExternallyLinkage())
1435 if (!GV->hasAppendingLinkage()) return false;
1437 assert(GV->hasInitializer() && "Not a special LLVM global!");
1439 if (GV->getName() == "llvm.global_ctors") {
1440 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1442 if (TM.getRelocationModel() == Reloc::Static &&
1443 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1444 StringRef Sym(".constructors_used");
1445 OutStreamer->EmitSymbolAttribute(OutContext.getOrCreateSymbol(Sym),
1451 if (GV->getName() == "llvm.global_dtors") {
1452 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1454 if (TM.getRelocationModel() == Reloc::Static &&
1455 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1456 StringRef Sym(".destructors_used");
1457 OutStreamer->EmitSymbolAttribute(OutContext.getOrCreateSymbol(Sym),
1466 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1467 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1468 /// is true, as being used with this directive.
1469 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1470 // Should be an array of 'i8*'.
1471 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1472 const GlobalValue *GV =
1473 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1475 OutStreamer->EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1481 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1483 llvm::Constant *Func;
1484 llvm::GlobalValue *ComdatKey;
1488 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1490 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1491 // Should be an array of '{ int, void ()* }' structs. The first value is the
1493 if (!isa<ConstantArray>(List)) return;
1495 // Sanity check the structors list.
1496 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1497 if (!InitList) return; // Not an array!
1498 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1499 // FIXME: Only allow the 3-field form in LLVM 4.0.
1500 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1501 return; // Not an array of two or three elements!
1502 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1503 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1504 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1505 return; // Not (int, ptr, ptr).
1507 // Gather the structors in a form that's convenient for sorting by priority.
1508 SmallVector<Structor, 8> Structors;
1509 for (Value *O : InitList->operands()) {
1510 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1511 if (!CS) continue; // Malformed.
1512 if (CS->getOperand(1)->isNullValue())
1513 break; // Found a null terminator, skip the rest.
1514 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1515 if (!Priority) continue; // Malformed.
1516 Structors.push_back(Structor());
1517 Structor &S = Structors.back();
1518 S.Priority = Priority->getLimitedValue(65535);
1519 S.Func = CS->getOperand(1);
1520 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1521 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1524 // Emit the function pointers in the target-specific order
1525 const DataLayout *DL = TM.getDataLayout();
1526 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1527 std::stable_sort(Structors.begin(), Structors.end(),
1528 [](const Structor &L,
1529 const Structor &R) { return L.Priority < R.Priority; });
1530 for (Structor &S : Structors) {
1531 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1532 const MCSymbol *KeySym = nullptr;
1533 if (GlobalValue *GV = S.ComdatKey) {
1534 if (GV->hasAvailableExternallyLinkage())
1535 // If the associated variable is available_externally, some other TU
1536 // will provide its dynamic initializer.
1539 KeySym = getSymbol(GV);
1541 MCSection *OutputSection =
1542 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1543 : Obj.getStaticDtorSection(S.Priority, KeySym));
1544 OutStreamer->SwitchSection(OutputSection);
1545 if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
1546 EmitAlignment(Align);
1547 EmitXXStructor(S.Func);
1551 void AsmPrinter::EmitModuleIdents(Module &M) {
1552 if (!MAI->hasIdentDirective())
1555 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1556 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1557 const MDNode *N = NMD->getOperand(i);
1558 assert(N->getNumOperands() == 1 &&
1559 "llvm.ident metadata entry can have only one operand");
1560 const MDString *S = cast<MDString>(N->getOperand(0));
1561 OutStreamer->EmitIdent(S->getString());
1566 //===--------------------------------------------------------------------===//
1567 // Emission and print routines
1570 /// EmitInt8 - Emit a byte directive and value.
1572 void AsmPrinter::EmitInt8(int Value) const {
1573 OutStreamer->EmitIntValue(Value, 1);
1576 /// EmitInt16 - Emit a short directive and value.
1578 void AsmPrinter::EmitInt16(int Value) const {
1579 OutStreamer->EmitIntValue(Value, 2);
1582 /// EmitInt32 - Emit a long directive and value.
1584 void AsmPrinter::EmitInt32(int Value) const {
1585 OutStreamer->EmitIntValue(Value, 4);
1588 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1589 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1590 /// .set if it avoids relocations.
1591 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1592 unsigned Size) const {
1593 OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
1596 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1597 /// where the size in bytes of the directive is specified by Size and Label
1598 /// specifies the label. This implicitly uses .set if it is available.
1599 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1601 bool IsSectionRelative) const {
1602 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1603 OutStreamer->EmitCOFFSecRel32(Label);
1607 // Emit Label+Offset (or just Label if Offset is zero)
1608 const MCExpr *Expr = MCSymbolRefExpr::create(Label, OutContext);
1610 Expr = MCBinaryExpr::createAdd(
1611 Expr, MCConstantExpr::create(Offset, OutContext), OutContext);
1613 OutStreamer->EmitValue(Expr, Size);
1616 //===----------------------------------------------------------------------===//
1618 // EmitAlignment - Emit an alignment directive to the specified power of
1619 // two boundary. For example, if you pass in 3 here, you will get an 8
1620 // byte alignment. If a global value is specified, and if that global has
1621 // an explicit alignment requested, it will override the alignment request
1622 // if required for correctness.
1624 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1626 NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(),
1629 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1632 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
1633 "undefined behavior");
1634 if (getCurrentSection()->getKind().isText())
1635 OutStreamer->EmitCodeAlignment(1u << NumBits);
1637 OutStreamer->EmitValueToAlignment(1u << NumBits);
1640 //===----------------------------------------------------------------------===//
1641 // Constant emission.
1642 //===----------------------------------------------------------------------===//
1644 const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1645 MCContext &Ctx = OutContext;
1647 if (CV->isNullValue() || isa<UndefValue>(CV))
1648 return MCConstantExpr::create(0, Ctx);
1650 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1651 return MCConstantExpr::create(CI->getZExtValue(), Ctx);
1653 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1654 return MCSymbolRefExpr::create(getSymbol(GV), Ctx);
1656 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1657 return MCSymbolRefExpr::create(GetBlockAddressSymbol(BA), Ctx);
1659 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1661 llvm_unreachable("Unknown constant value to lower!");
1664 if (const MCExpr *RelocExpr
1665 = getObjFileLowering().getExecutableRelativeSymbol(CE, *Mang, TM))
1668 switch (CE->getOpcode()) {
1670 // If the code isn't optimized, there may be outstanding folding
1671 // opportunities. Attempt to fold the expression using DataLayout as a
1672 // last resort before giving up.
1673 if (Constant *C = ConstantFoldConstantExpression(CE, *TM.getDataLayout()))
1675 return lowerConstant(C);
1677 // Otherwise report the problem to the user.
1680 raw_string_ostream OS(S);
1681 OS << "Unsupported expression in static initializer: ";
1682 CE->printAsOperand(OS, /*PrintType=*/false,
1683 !MF ? nullptr : MF->getFunction()->getParent());
1684 report_fatal_error(OS.str());
1686 case Instruction::GetElementPtr: {
1687 const DataLayout &DL = *TM.getDataLayout();
1689 // Generate a symbolic expression for the byte address
1690 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1691 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1693 const MCExpr *Base = lowerConstant(CE->getOperand(0));
1697 int64_t Offset = OffsetAI.getSExtValue();
1698 return MCBinaryExpr::createAdd(Base, MCConstantExpr::create(Offset, Ctx),
1702 case Instruction::Trunc:
1703 // We emit the value and depend on the assembler to truncate the generated
1704 // expression properly. This is important for differences between
1705 // blockaddress labels. Since the two labels are in the same function, it
1706 // is reasonable to treat their delta as a 32-bit value.
1708 case Instruction::BitCast:
1709 return lowerConstant(CE->getOperand(0));
1711 case Instruction::IntToPtr: {
1712 const DataLayout &DL = *TM.getDataLayout();
1714 // Handle casts to pointers by changing them into casts to the appropriate
1715 // integer type. This promotes constant folding and simplifies this code.
1716 Constant *Op = CE->getOperand(0);
1717 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1719 return lowerConstant(Op);
1722 case Instruction::PtrToInt: {
1723 const DataLayout &DL = *TM.getDataLayout();
1725 // Support only foldable casts to/from pointers that can be eliminated by
1726 // changing the pointer to the appropriately sized integer type.
1727 Constant *Op = CE->getOperand(0);
1728 Type *Ty = CE->getType();
1730 const MCExpr *OpExpr = lowerConstant(Op);
1732 // We can emit the pointer value into this slot if the slot is an
1733 // integer slot equal to the size of the pointer.
1734 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1737 // Otherwise the pointer is smaller than the resultant integer, mask off
1738 // the high bits so we are sure to get a proper truncation if the input is
1740 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1741 const MCExpr *MaskExpr = MCConstantExpr::create(~0ULL >> (64-InBits), Ctx);
1742 return MCBinaryExpr::createAnd(OpExpr, MaskExpr, Ctx);
1745 // The MC library also has a right-shift operator, but it isn't consistently
1746 // signed or unsigned between different targets.
1747 case Instruction::Add:
1748 case Instruction::Sub:
1749 case Instruction::Mul:
1750 case Instruction::SDiv:
1751 case Instruction::SRem:
1752 case Instruction::Shl:
1753 case Instruction::And:
1754 case Instruction::Or:
1755 case Instruction::Xor: {
1756 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
1757 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
1758 switch (CE->getOpcode()) {
1759 default: llvm_unreachable("Unknown binary operator constant cast expr");
1760 case Instruction::Add: return MCBinaryExpr::createAdd(LHS, RHS, Ctx);
1761 case Instruction::Sub: return MCBinaryExpr::createSub(LHS, RHS, Ctx);
1762 case Instruction::Mul: return MCBinaryExpr::createMul(LHS, RHS, Ctx);
1763 case Instruction::SDiv: return MCBinaryExpr::createDiv(LHS, RHS, Ctx);
1764 case Instruction::SRem: return MCBinaryExpr::createMod(LHS, RHS, Ctx);
1765 case Instruction::Shl: return MCBinaryExpr::createShl(LHS, RHS, Ctx);
1766 case Instruction::And: return MCBinaryExpr::createAnd(LHS, RHS, Ctx);
1767 case Instruction::Or: return MCBinaryExpr::createOr (LHS, RHS, Ctx);
1768 case Instruction::Xor: return MCBinaryExpr::createXor(LHS, RHS, Ctx);
1774 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP,
1775 const Constant *BaseCV = nullptr,
1776 uint64_t Offset = 0);
1778 /// isRepeatedByteSequence - Determine whether the given value is
1779 /// composed of a repeated sequence of identical bytes and return the
1780 /// byte value. If it is not a repeated sequence, return -1.
1781 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1782 StringRef Data = V->getRawDataValues();
1783 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1785 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1786 if (Data[i] != C) return -1;
1787 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1791 /// isRepeatedByteSequence - Determine whether the given value is
1792 /// composed of a repeated sequence of identical bytes and return the
1793 /// byte value. If it is not a repeated sequence, return -1.
1794 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1795 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1796 uint64_t Size = TM.getDataLayout()->getTypeAllocSizeInBits(V->getType());
1797 assert(Size % 8 == 0);
1799 // Extend the element to take zero padding into account.
1800 APInt Value = CI->getValue().zextOrSelf(Size);
1801 if (!Value.isSplat(8))
1804 return Value.zextOrTrunc(8).getZExtValue();
1806 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1807 // Make sure all array elements are sequences of the same repeated
1809 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1810 Constant *Op0 = CA->getOperand(0);
1811 int Byte = isRepeatedByteSequence(Op0, TM);
1815 // All array elements must be equal.
1816 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i)
1817 if (CA->getOperand(i) != Op0)
1822 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1823 return isRepeatedByteSequence(CDS);
1828 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1831 // See if we can aggregate this into a .fill, if so, emit it as such.
1832 int Value = isRepeatedByteSequence(CDS, AP.TM);
1835 AP.TM.getDataLayout()->getTypeAllocSize(
1837 // Don't emit a 1-byte object as a .fill.
1839 return AP.OutStreamer->EmitFill(Bytes, Value);
1842 // If this can be emitted with .ascii/.asciz, emit it as such.
1843 if (CDS->isString())
1844 return AP.OutStreamer->EmitBytes(CDS->getAsString());
1846 // Otherwise, emit the values in successive locations.
1847 unsigned ElementByteSize = CDS->getElementByteSize();
1848 if (isa<IntegerType>(CDS->getElementType())) {
1849 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1851 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
1852 CDS->getElementAsInteger(i));
1853 AP.OutStreamer->EmitIntValue(CDS->getElementAsInteger(i),
1856 } else if (ElementByteSize == 4) {
1857 // FP Constants are printed as integer constants to avoid losing
1859 assert(CDS->getElementType()->isFloatTy());
1860 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1866 F = CDS->getElementAsFloat(i);
1868 AP.OutStreamer->GetCommentOS() << "float " << F << '\n';
1869 AP.OutStreamer->EmitIntValue(I, 4);
1872 assert(CDS->getElementType()->isDoubleTy());
1873 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1879 F = CDS->getElementAsDouble(i);
1881 AP.OutStreamer->GetCommentOS() << "double " << F << '\n';
1882 AP.OutStreamer->EmitIntValue(I, 8);
1886 const DataLayout &DL = *AP.TM.getDataLayout();
1887 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1888 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1889 CDS->getNumElements();
1890 if (unsigned Padding = Size - EmittedSize)
1891 AP.OutStreamer->EmitZeros(Padding);
1895 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP,
1896 const Constant *BaseCV, uint64_t Offset) {
1897 // See if we can aggregate some values. Make sure it can be
1898 // represented as a series of bytes of the constant value.
1899 int Value = isRepeatedByteSequence(CA, AP.TM);
1900 const DataLayout &DL = *AP.TM.getDataLayout();
1903 uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
1904 AP.OutStreamer->EmitFill(Bytes, Value);
1907 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
1908 emitGlobalConstantImpl(CA->getOperand(i), AP, BaseCV, Offset);
1909 Offset += DL.getTypeAllocSize(CA->getOperand(i)->getType());
1914 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1915 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1916 emitGlobalConstantImpl(CV->getOperand(i), AP);
1918 const DataLayout &DL = *AP.TM.getDataLayout();
1919 unsigned Size = DL.getTypeAllocSize(CV->getType());
1920 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1921 CV->getType()->getNumElements();
1922 if (unsigned Padding = Size - EmittedSize)
1923 AP.OutStreamer->EmitZeros(Padding);
1926 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP,
1927 const Constant *BaseCV, uint64_t Offset) {
1928 // Print the fields in successive locations. Pad to align if needed!
1929 const DataLayout *DL = AP.TM.getDataLayout();
1930 unsigned Size = DL->getTypeAllocSize(CS->getType());
1931 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1932 uint64_t SizeSoFar = 0;
1933 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1934 const Constant *Field = CS->getOperand(i);
1936 // Print the actual field value.
1937 emitGlobalConstantImpl(Field, AP, BaseCV, Offset+SizeSoFar);
1939 // Check if padding is needed and insert one or more 0s.
1940 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1941 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1942 - Layout->getElementOffset(i)) - FieldSize;
1943 SizeSoFar += FieldSize + PadSize;
1945 // Insert padding - this may include padding to increase the size of the
1946 // current field up to the ABI size (if the struct is not packed) as well
1947 // as padding to ensure that the next field starts at the right offset.
1948 AP.OutStreamer->EmitZeros(PadSize);
1950 assert(SizeSoFar == Layout->getSizeInBytes() &&
1951 "Layout of constant struct may be incorrect!");
1954 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1955 APInt API = CFP->getValueAPF().bitcastToAPInt();
1957 // First print a comment with what we think the original floating-point value
1958 // should have been.
1959 if (AP.isVerbose()) {
1960 SmallString<8> StrVal;
1961 CFP->getValueAPF().toString(StrVal);
1964 CFP->getType()->print(AP.OutStreamer->GetCommentOS());
1966 AP.OutStreamer->GetCommentOS() << "Printing <null> Type";
1967 AP.OutStreamer->GetCommentOS() << ' ' << StrVal << '\n';
1970 // Now iterate through the APInt chunks, emitting them in endian-correct
1971 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1973 unsigned NumBytes = API.getBitWidth() / 8;
1974 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1975 const uint64_t *p = API.getRawData();
1977 // PPC's long double has odd notions of endianness compared to how LLVM
1978 // handles it: p[0] goes first for *big* endian on PPC.
1979 if (AP.TM.getDataLayout()->isBigEndian() &&
1980 !CFP->getType()->isPPC_FP128Ty()) {
1981 int Chunk = API.getNumWords() - 1;
1984 AP.OutStreamer->EmitIntValue(p[Chunk--], TrailingBytes);
1986 for (; Chunk >= 0; --Chunk)
1987 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
1990 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1991 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
1994 AP.OutStreamer->EmitIntValue(p[Chunk], TrailingBytes);
1997 // Emit the tail padding for the long double.
1998 const DataLayout &DL = *AP.TM.getDataLayout();
1999 AP.OutStreamer->EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
2000 DL.getTypeStoreSize(CFP->getType()));
2003 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
2004 const DataLayout *DL = AP.TM.getDataLayout();
2005 unsigned BitWidth = CI->getBitWidth();
2007 // Copy the value as we may massage the layout for constants whose bit width
2008 // is not a multiple of 64-bits.
2009 APInt Realigned(CI->getValue());
2010 uint64_t ExtraBits = 0;
2011 unsigned ExtraBitsSize = BitWidth & 63;
2013 if (ExtraBitsSize) {
2014 // The bit width of the data is not a multiple of 64-bits.
2015 // The extra bits are expected to be at the end of the chunk of the memory.
2017 // * Nothing to be done, just record the extra bits to emit.
2019 // * Record the extra bits to emit.
2020 // * Realign the raw data to emit the chunks of 64-bits.
2021 if (DL->isBigEndian()) {
2022 // Basically the structure of the raw data is a chunk of 64-bits cells:
2023 // 0 1 BitWidth / 64
2024 // [chunk1][chunk2] ... [chunkN].
2025 // The most significant chunk is chunkN and it should be emitted first.
2026 // However, due to the alignment issue chunkN contains useless bits.
2027 // Realign the chunks so that they contain only useless information:
2028 // ExtraBits 0 1 (BitWidth / 64) - 1
2029 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
2030 ExtraBits = Realigned.getRawData()[0] &
2031 (((uint64_t)-1) >> (64 - ExtraBitsSize));
2032 Realigned = Realigned.lshr(ExtraBitsSize);
2034 ExtraBits = Realigned.getRawData()[BitWidth / 64];
2037 // We don't expect assemblers to support integer data directives
2038 // for more than 64 bits, so we emit the data in at most 64-bit
2039 // quantities at a time.
2040 const uint64_t *RawData = Realigned.getRawData();
2041 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
2042 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
2043 AP.OutStreamer->EmitIntValue(Val, 8);
2046 if (ExtraBitsSize) {
2047 // Emit the extra bits after the 64-bits chunks.
2049 // Emit a directive that fills the expected size.
2050 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(
2052 Size -= (BitWidth / 64) * 8;
2053 assert(Size && Size * 8 >= ExtraBitsSize &&
2054 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
2055 == ExtraBits && "Directive too small for extra bits.");
2056 AP.OutStreamer->EmitIntValue(ExtraBits, Size);
2060 /// \brief Transform a not absolute MCExpr containing a reference to a GOT
2061 /// equivalent global, by a target specific GOT pc relative access to the
2063 static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
2064 const Constant *BaseCst,
2066 // The global @foo below illustrates a global that uses a got equivalent.
2068 // @bar = global i32 42
2069 // @gotequiv = private unnamed_addr constant i32* @bar
2070 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
2071 // i64 ptrtoint (i32* @foo to i64))
2074 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
2075 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
2078 // foo = cstexpr, where
2079 // cstexpr := <gotequiv> - "." + <cst>
2080 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
2082 // After canonicalization by evaluateAsRelocatable `ME` turns into:
2084 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
2085 // gotpcrelcst := <offset from @foo base> + <cst>
2088 if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
2090 const MCSymbolRefExpr *SymA = MV.getSymA();
2094 // Check that GOT equivalent symbol is cached.
2095 const MCSymbol *GOTEquivSym = &SymA->getSymbol();
2096 if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
2099 const GlobalValue *BaseGV = dyn_cast<GlobalValue>(BaseCst);
2103 // Check for a valid base symbol
2104 const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
2105 const MCSymbolRefExpr *SymB = MV.getSymB();
2107 if (!SymB || BaseSym != &SymB->getSymbol())
2110 // Make sure to match:
2112 // gotpcrelcst := <offset from @foo base> + <cst>
2114 // If gotpcrelcst is positive it means that we can safely fold the pc rel
2115 // displacement into the GOTPCREL. We can also can have an extra offset <cst>
2116 // if the target knows how to encode it.
2118 int64_t GOTPCRelCst = Offset + MV.getConstant();
2119 if (GOTPCRelCst < 0)
2121 if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
2124 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
2131 // .long gotequiv - "." + <cst>
2133 // is replaced by the target specific equivalent to:
2138 // .long bar@GOTPCREL+<gotpcrelcst>
2140 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
2141 const GlobalVariable *GV = Result.first;
2142 int NumUses = (int)Result.second;
2143 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
2144 const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
2145 *ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(
2146 FinalSym, MV, Offset, AP.MMI, *AP.OutStreamer);
2148 // Update GOT equivalent usage information
2151 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
2154 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP,
2155 const Constant *BaseCV, uint64_t Offset) {
2156 const DataLayout *DL = AP.TM.getDataLayout();
2157 uint64_t Size = DL->getTypeAllocSize(CV->getType());
2159 // Globals with sub-elements such as combinations of arrays and structs
2160 // are handled recursively by emitGlobalConstantImpl. Keep track of the
2161 // constant symbol base and the current position with BaseCV and Offset.
2162 if (!BaseCV && CV->hasOneUse())
2163 BaseCV = dyn_cast<Constant>(CV->user_back());
2165 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
2166 return AP.OutStreamer->EmitZeros(Size);
2168 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
2175 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
2176 CI->getZExtValue());
2177 AP.OutStreamer->EmitIntValue(CI->getZExtValue(), Size);
2180 emitGlobalConstantLargeInt(CI, AP);
2185 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
2186 return emitGlobalConstantFP(CFP, AP);
2188 if (isa<ConstantPointerNull>(CV)) {
2189 AP.OutStreamer->EmitIntValue(0, Size);
2193 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
2194 return emitGlobalConstantDataSequential(CDS, AP);
2196 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2197 return emitGlobalConstantArray(CVA, AP, BaseCV, Offset);
2199 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2200 return emitGlobalConstantStruct(CVS, AP, BaseCV, Offset);
2202 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2203 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2205 if (CE->getOpcode() == Instruction::BitCast)
2206 return emitGlobalConstantImpl(CE->getOperand(0), AP);
2209 // If the constant expression's size is greater than 64-bits, then we have
2210 // to emit the value in chunks. Try to constant fold the value and emit it
2212 Constant *New = ConstantFoldConstantExpression(CE, *DL);
2213 if (New && New != CE)
2214 return emitGlobalConstantImpl(New, AP);
2218 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2219 return emitGlobalConstantVector(V, AP);
2221 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2222 // thread the streamer with EmitValue.
2223 const MCExpr *ME = AP.lowerConstant(CV);
2225 // Since lowerConstant already folded and got rid of all IR pointer and
2226 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
2228 if (AP.getObjFileLowering().supportIndirectSymViaGOTPCRel())
2229 handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
2231 AP.OutStreamer->EmitValue(ME, Size);
2234 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2235 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2237 TM.getDataLayout()->getTypeAllocSize(CV->getType());
2239 emitGlobalConstantImpl(CV, *this);
2240 else if (MAI->hasSubsectionsViaSymbols()) {
2241 // If the global has zero size, emit a single byte so that two labels don't
2242 // look like they are at the same location.
2243 OutStreamer->EmitIntValue(0, 1);
2247 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2248 // Target doesn't support this yet!
2249 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2252 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2254 OS << '+' << Offset;
2255 else if (Offset < 0)
2259 //===----------------------------------------------------------------------===//
2260 // Symbol Lowering Routines.
2261 //===----------------------------------------------------------------------===//
2263 MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name) const {
2264 return OutContext.createTempSymbol(Name, true);
2267 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2268 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2271 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2272 return MMI->getAddrLabelSymbol(BB);
2275 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2276 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2277 const DataLayout *DL = TM.getDataLayout();
2278 return OutContext.getOrCreateSymbol
2279 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2280 + "_" + Twine(CPID));
2283 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2284 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2285 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2288 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2289 /// FIXME: privatize to AsmPrinter.
2290 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2291 const DataLayout *DL = TM.getDataLayout();
2292 return OutContext.getOrCreateSymbol
2293 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2294 Twine(UID) + "_set_" + Twine(MBBID));
2297 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2298 StringRef Suffix) const {
2299 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2303 /// Return the MCSymbol for the specified ExternalSymbol.
2304 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2305 SmallString<60> NameStr;
2306 Mangler::getNameWithPrefix(NameStr, Sym, *TM.getDataLayout());
2307 return OutContext.getOrCreateSymbol(NameStr);
2312 /// PrintParentLoopComment - Print comments about parent loops of this one.
2313 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2314 unsigned FunctionNumber) {
2316 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2317 OS.indent(Loop->getLoopDepth()*2)
2318 << "Parent Loop BB" << FunctionNumber << "_"
2319 << Loop->getHeader()->getNumber()
2320 << " Depth=" << Loop->getLoopDepth() << '\n';
2324 /// PrintChildLoopComment - Print comments about child loops within
2325 /// the loop for this basic block, with nesting.
2326 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2327 unsigned FunctionNumber) {
2328 // Add child loop information
2329 for (const MachineLoop *CL : *Loop) {
2330 OS.indent(CL->getLoopDepth()*2)
2331 << "Child Loop BB" << FunctionNumber << "_"
2332 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2334 PrintChildLoopComment(OS, CL, FunctionNumber);
2338 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2339 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2340 const MachineLoopInfo *LI,
2341 const AsmPrinter &AP) {
2342 // Add loop depth information
2343 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2346 MachineBasicBlock *Header = Loop->getHeader();
2347 assert(Header && "No header for loop");
2349 // If this block is not a loop header, just print out what is the loop header
2351 if (Header != &MBB) {
2352 AP.OutStreamer->AddComment(" in Loop: Header=BB" +
2353 Twine(AP.getFunctionNumber())+"_" +
2354 Twine(Loop->getHeader()->getNumber())+
2355 " Depth="+Twine(Loop->getLoopDepth()));
2359 // Otherwise, it is a loop header. Print out information about child and
2361 raw_ostream &OS = AP.OutStreamer->GetCommentOS();
2363 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2366 OS.indent(Loop->getLoopDepth()*2-2);
2371 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2373 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2377 /// EmitBasicBlockStart - This method prints the label for the specified
2378 /// MachineBasicBlock, an alignment (if present) and a comment describing
2379 /// it if appropriate.
2380 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2381 // Emit an alignment directive for this block, if needed.
2382 if (unsigned Align = MBB.getAlignment())
2383 EmitAlignment(Align);
2385 // If the block has its address taken, emit any labels that were used to
2386 // reference the block. It is possible that there is more than one label
2387 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2388 // the references were generated.
2389 if (MBB.hasAddressTaken()) {
2390 const BasicBlock *BB = MBB.getBasicBlock();
2392 OutStreamer->AddComment("Block address taken");
2394 for (MCSymbol *Sym : MMI->getAddrLabelSymbolToEmit(BB))
2395 OutStreamer->EmitLabel(Sym);
2398 // Print some verbose block comments.
2400 if (const BasicBlock *BB = MBB.getBasicBlock())
2402 OutStreamer->AddComment("%" + BB->getName());
2403 emitBasicBlockLoopComments(MBB, LI, *this);
2406 // Print the main label for the block.
2407 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2409 // NOTE: Want this comment at start of line, don't emit with AddComment.
2410 OutStreamer->emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2413 OutStreamer->EmitLabel(MBB.getSymbol());
2417 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2418 bool IsDefinition) const {
2419 MCSymbolAttr Attr = MCSA_Invalid;
2421 switch (Visibility) {
2423 case GlobalValue::HiddenVisibility:
2425 Attr = MAI->getHiddenVisibilityAttr();
2427 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2429 case GlobalValue::ProtectedVisibility:
2430 Attr = MAI->getProtectedVisibilityAttr();
2434 if (Attr != MCSA_Invalid)
2435 OutStreamer->EmitSymbolAttribute(Sym, Attr);
2438 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2439 /// exactly one predecessor and the control transfer mechanism between
2440 /// the predecessor and this block is a fall-through.
2442 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2443 // If this is a landing pad, it isn't a fall through. If it has no preds,
2444 // then nothing falls through to it.
2445 if (MBB->isLandingPad() || MBB->pred_empty())
2448 // If there isn't exactly one predecessor, it can't be a fall through.
2449 if (MBB->pred_size() > 1)
2452 // The predecessor has to be immediately before this block.
2453 MachineBasicBlock *Pred = *MBB->pred_begin();
2454 if (!Pred->isLayoutSuccessor(MBB))
2457 // If the block is completely empty, then it definitely does fall through.
2461 // Check the terminators in the previous blocks
2462 for (const auto &MI : Pred->terminators()) {
2463 // If it is not a simple branch, we are in a table somewhere.
2464 if (!MI.isBranch() || MI.isIndirectBranch())
2467 // If we are the operands of one of the branches, this is not a fall
2468 // through. Note that targets with delay slots will usually bundle
2469 // terminators with the delay slot instruction.
2470 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2473 if (OP->isMBB() && OP->getMBB() == MBB)
2483 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2484 if (!S.usesMetadata())
2487 assert(!S.useStatepoints() && "statepoints do not currently support custom"
2488 " stackmap formats, please see the documentation for a description of"
2489 " the default format. If you really need a custom serialized format,"
2490 " please file a bug");
2492 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2493 gcp_map_type::iterator GCPI = GCMap.find(&S);
2494 if (GCPI != GCMap.end())
2495 return GCPI->second.get();
2497 const char *Name = S.getName().c_str();
2499 for (GCMetadataPrinterRegistry::iterator
2500 I = GCMetadataPrinterRegistry::begin(),
2501 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2502 if (strcmp(Name, I->getName()) == 0) {
2503 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2505 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2506 return IterBool.first->second.get();
2509 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2512 /// Pin vtable to this file.
2513 AsmPrinterHandler::~AsmPrinterHandler() {}
2515 void AsmPrinterHandler::markFunctionEnd() {}