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 &DL,
81 unsigned InBits = 0) {
83 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
84 NumBits = DL.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 if (MAI->hasFunctionAlignment())
531 EmitAlignment(MF->getAlignment(), F);
533 if (MAI->hasDotTypeDotSizeDirective())
534 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
537 F->printAsOperand(OutStreamer.GetCommentOS(),
538 /*PrintType=*/false, F->getParent());
539 OutStreamer.GetCommentOS() << '\n';
542 // Emit the prefix data.
543 if (F->hasPrefixData())
544 EmitGlobalConstant(F->getPrefixData());
546 // Emit the CurrentFnSym. This is a virtual function to allow targets to
547 // do their wild and crazy things as required.
548 EmitFunctionEntryLabel();
550 // If the function had address-taken blocks that got deleted, then we have
551 // references to the dangling symbols. Emit them at the start of the function
552 // so that we don't get references to undefined symbols.
553 std::vector<MCSymbol*> DeadBlockSyms;
554 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
555 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
556 OutStreamer.AddComment("Address taken block that was later removed");
557 OutStreamer.EmitLabel(DeadBlockSyms[i]);
560 if (CurrentFnBegin) {
561 if (MAI->useAssignmentForEHBegin()) {
562 MCSymbol *CurPos = OutContext.CreateTempSymbol();
563 OutStreamer.EmitLabel(CurPos);
564 OutStreamer.EmitAssignment(CurrentFnBegin,
565 MCSymbolRefExpr::Create(CurPos, OutContext));
567 OutStreamer.EmitLabel(CurrentFnBegin);
571 // Emit pre-function debug and/or EH information.
572 for (const HandlerInfo &HI : Handlers) {
573 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
574 HI.Handler->beginFunction(MF);
577 // Emit the prologue data.
578 if (F->hasPrologueData())
579 EmitGlobalConstant(F->getPrologueData());
582 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
583 /// function. This can be overridden by targets as required to do custom stuff.
584 void AsmPrinter::EmitFunctionEntryLabel() {
585 CurrentFnSym->redefineIfPossible();
587 // The function label could have already been emitted if two symbols end up
588 // conflicting due to asm renaming. Detect this and emit an error.
589 if (CurrentFnSym->isVariable())
590 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
591 "' is a protected alias");
592 if (CurrentFnSym->isDefined())
593 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
594 "' label emitted multiple times to assembly file");
596 return OutStreamer.EmitLabel(CurrentFnSym);
599 /// emitComments - Pretty-print comments for instructions.
600 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
601 const MachineFunction *MF = MI.getParent()->getParent();
602 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
604 // Check for spills and reloads
607 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
609 // We assume a single instruction only has a spill or reload, not
611 const MachineMemOperand *MMO;
612 if (TII->isLoadFromStackSlotPostFE(&MI, FI)) {
613 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
614 MMO = *MI.memoperands_begin();
615 CommentOS << MMO->getSize() << "-byte Reload\n";
617 } else if (TII->hasLoadFromStackSlot(&MI, MMO, FI)) {
618 if (FrameInfo->isSpillSlotObjectIndex(FI))
619 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
620 } else if (TII->isStoreToStackSlotPostFE(&MI, FI)) {
621 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
622 MMO = *MI.memoperands_begin();
623 CommentOS << MMO->getSize() << "-byte Spill\n";
625 } else if (TII->hasStoreToStackSlot(&MI, MMO, FI)) {
626 if (FrameInfo->isSpillSlotObjectIndex(FI))
627 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
630 // Check for spill-induced copies
631 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
632 CommentOS << " Reload Reuse\n";
635 /// emitImplicitDef - This method emits the specified machine instruction
636 /// that is an implicit def.
637 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
638 unsigned RegNo = MI->getOperand(0).getReg();
639 OutStreamer.AddComment(Twine("implicit-def: ") +
640 MMI->getContext().getRegisterInfo()->getName(RegNo));
641 OutStreamer.AddBlankLine();
644 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
645 std::string Str = "kill:";
646 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
647 const MachineOperand &Op = MI->getOperand(i);
648 assert(Op.isReg() && "KILL instruction must have only register operands");
650 Str += AP.MMI->getContext().getRegisterInfo()->getName(Op.getReg());
651 Str += (Op.isDef() ? "<def>" : "<kill>");
653 AP.OutStreamer.AddComment(Str);
654 AP.OutStreamer.AddBlankLine();
657 /// emitDebugValueComment - This method handles the target-independent form
658 /// of DBG_VALUE, returning true if it was able to do so. A false return
659 /// means the target will need to handle MI in EmitInstruction.
660 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
661 // This code handles only the 4-operand target-independent form.
662 if (MI->getNumOperands() != 4)
665 SmallString<128> Str;
666 raw_svector_ostream OS(Str);
667 OS << "DEBUG_VALUE: ";
669 DIVariable V = MI->getDebugVariable();
670 if (V.getContext().isSubprogram()) {
671 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
677 DIExpression Expr = MI->getDebugExpression();
678 if (Expr.isBitPiece())
679 OS << " [bit_piece offset=" << Expr.getBitPieceOffset()
680 << " size=" << Expr.getBitPieceSize() << "]";
683 // The second operand is only an offset if it's an immediate.
684 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
685 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
687 // Register or immediate value. Register 0 means undef.
688 if (MI->getOperand(0).isFPImm()) {
689 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
690 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
691 OS << (double)APF.convertToFloat();
692 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
693 OS << APF.convertToDouble();
695 // There is no good way to print long double. Convert a copy to
696 // double. Ah well, it's only a comment.
698 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
700 OS << "(long double) " << APF.convertToDouble();
702 } else if (MI->getOperand(0).isImm()) {
703 OS << MI->getOperand(0).getImm();
704 } else if (MI->getOperand(0).isCImm()) {
705 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
708 if (MI->getOperand(0).isReg()) {
709 Reg = MI->getOperand(0).getReg();
711 assert(MI->getOperand(0).isFI() && "Unknown operand type");
712 const TargetFrameLowering *TFI = AP.MF->getSubtarget().getFrameLowering();
713 Offset += TFI->getFrameIndexReference(*AP.MF,
714 MI->getOperand(0).getIndex(), Reg);
718 // Suppress offset, it is not meaningful here.
720 // NOTE: Want this comment at start of line, don't emit with AddComment.
721 AP.OutStreamer.emitRawComment(OS.str());
726 OS << AP.MMI->getContext().getRegisterInfo()->getName(Reg);
730 OS << '+' << Offset << ']';
732 // NOTE: Want this comment at start of line, don't emit with AddComment.
733 AP.OutStreamer.emitRawComment(OS.str());
737 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
738 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
739 MF->getFunction()->needsUnwindTableEntry())
742 if (MMI->hasDebugInfo())
748 bool AsmPrinter::needsSEHMoves() {
749 return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
752 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
753 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
754 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
755 ExceptionHandlingType != ExceptionHandling::ARM)
758 if (needsCFIMoves() == CFI_M_None)
761 const MachineModuleInfo &MMI = MF->getMMI();
762 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
763 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
764 const MCCFIInstruction &CFI = Instrs[CFIIndex];
765 emitCFIInstruction(CFI);
768 void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
769 // The operands are the MCSymbol and the frame offset of the allocation.
770 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
771 int FrameOffset = MI.getOperand(1).getImm();
773 // Emit a symbol assignment.
774 OutStreamer.EmitAssignment(FrameAllocSym,
775 MCConstantExpr::Create(FrameOffset, OutContext));
778 /// EmitFunctionBody - This method emits the body and trailer for a
780 void AsmPrinter::EmitFunctionBody() {
781 // Emit target-specific gunk before the function body.
782 EmitFunctionBodyStart();
784 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
786 // Print out code for the function.
787 bool HasAnyRealCode = false;
788 for (auto &MBB : *MF) {
789 // Print a label for the basic block.
790 EmitBasicBlockStart(MBB);
791 for (auto &MI : MBB) {
793 // Print the assembly for the instruction.
794 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
795 !MI.isDebugValue()) {
796 HasAnyRealCode = true;
800 if (ShouldPrintDebugScopes) {
801 for (const HandlerInfo &HI : Handlers) {
802 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
803 TimePassesIsEnabled);
804 HI.Handler->beginInstruction(&MI);
809 emitComments(MI, OutStreamer.GetCommentOS());
811 switch (MI.getOpcode()) {
812 case TargetOpcode::CFI_INSTRUCTION:
813 emitCFIInstruction(MI);
816 case TargetOpcode::FRAME_ALLOC:
820 case TargetOpcode::EH_LABEL:
821 case TargetOpcode::GC_LABEL:
822 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
824 case TargetOpcode::INLINEASM:
827 case TargetOpcode::DBG_VALUE:
829 if (!emitDebugValueComment(&MI, *this))
830 EmitInstruction(&MI);
833 case TargetOpcode::IMPLICIT_DEF:
834 if (isVerbose()) emitImplicitDef(&MI);
836 case TargetOpcode::KILL:
837 if (isVerbose()) emitKill(&MI, *this);
840 EmitInstruction(&MI);
844 if (ShouldPrintDebugScopes) {
845 for (const HandlerInfo &HI : Handlers) {
846 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
847 TimePassesIsEnabled);
848 HI.Handler->endInstruction();
853 EmitBasicBlockEnd(MBB);
856 // If the function is empty and the object file uses .subsections_via_symbols,
857 // then we need to emit *something* to the function body to prevent the
858 // labels from collapsing together. Just emit a noop.
859 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
861 MF->getSubtarget().getInstrInfo()->getNoopForMachoTarget(Noop);
862 OutStreamer.AddComment("avoids zero-length function");
864 // Targets can opt-out of emitting the noop here by leaving the opcode
866 if (Noop.getOpcode())
867 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
870 const Function *F = MF->getFunction();
871 for (const auto &BB : *F) {
872 if (!BB.hasAddressTaken())
874 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
875 if (Sym->isDefined())
877 OutStreamer.AddComment("Address of block that was removed by CodeGen");
878 OutStreamer.EmitLabel(Sym);
881 // Emit target-specific gunk after the function body.
882 EmitFunctionBodyEnd();
884 if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
885 MAI->hasDotTypeDotSizeDirective()) {
886 // Create a symbol for the end of function.
887 CurrentFnEnd = createTempSymbol("func_end", getFunctionNumber());
888 OutStreamer.EmitLabel(CurrentFnEnd);
891 // If the target wants a .size directive for the size of the function, emit
893 if (MAI->hasDotTypeDotSizeDirective()) {
894 // We can get the size as difference between the function label and the
896 const MCExpr *SizeExp =
897 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(CurrentFnEnd, OutContext),
898 MCSymbolRefExpr::Create(CurrentFnSymForSize,
901 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
904 for (const HandlerInfo &HI : Handlers) {
905 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
906 HI.Handler->markFunctionEnd();
909 // Print out jump tables referenced by the function.
912 // Emit post-function debug and/or EH information.
913 for (const HandlerInfo &HI : Handlers) {
914 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
915 HI.Handler->endFunction(MF);
919 OutStreamer.AddBlankLine();
922 /// \brief Compute the number of Global Variables that uses a Constant.
923 static unsigned getNumGlobalVariableUses(const Constant *C) {
927 if (isa<GlobalVariable>(C))
930 unsigned NumUses = 0;
931 for (auto *CU : C->users())
932 NumUses += getNumGlobalVariableUses(dyn_cast<Constant>(CU));
937 /// \brief Only consider global GOT equivalents if at least one user is a
938 /// cstexpr inside an initializer of another global variables. Also, don't
939 /// handle cstexpr inside instructions. During global variable emission,
940 /// candidates are skipped and are emitted later in case at least one cstexpr
941 /// isn't replaced by a PC relative GOT entry access.
942 static bool isGOTEquivalentCandidate(const GlobalVariable *GV,
943 unsigned &NumGOTEquivUsers) {
944 // Global GOT equivalents are unnamed private globals with a constant
945 // pointer initializer to another global symbol. They must point to a
946 // GlobalVariable or Function, i.e., as GlobalValue.
947 if (!GV->hasUnnamedAddr() || !GV->hasInitializer() || !GV->isConstant() ||
948 !GV->isDiscardableIfUnused() || !dyn_cast<GlobalValue>(GV->getOperand(0)))
951 // To be a got equivalent, at least one of its users need to be a constant
952 // expression used by another global variable.
953 for (auto *U : GV->users())
954 NumGOTEquivUsers += getNumGlobalVariableUses(cast<Constant>(U));
956 return NumGOTEquivUsers > 0;
959 /// \brief Unnamed constant global variables solely contaning a pointer to
960 /// another globals variable is equivalent to a GOT table entry; it contains the
961 /// the address of another symbol. Optimize it and replace accesses to these
962 /// "GOT equivalents" by using the GOT entry for the final global instead.
963 /// Compute GOT equivalent candidates among all global variables to avoid
964 /// emitting them if possible later on, after it use is replaced by a GOT entry
966 void AsmPrinter::computeGlobalGOTEquivs(Module &M) {
967 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
970 for (const auto &G : M.globals()) {
971 unsigned NumGOTEquivUsers = 0;
972 if (!isGOTEquivalentCandidate(&G, NumGOTEquivUsers))
975 const MCSymbol *GOTEquivSym = getSymbol(&G);
976 GlobalGOTEquivs[GOTEquivSym] = std::make_pair(&G, NumGOTEquivUsers);
980 /// \brief Constant expressions using GOT equivalent globals may not be eligible
981 /// for PC relative GOT entry conversion, in such cases we need to emit such
982 /// globals we previously omitted in EmitGlobalVariable.
983 void AsmPrinter::emitGlobalGOTEquivs() {
984 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
987 SmallVector<const GlobalVariable *, 8> FailedCandidates;
988 for (auto &I : GlobalGOTEquivs) {
989 const GlobalVariable *GV = I.second.first;
990 unsigned Cnt = I.second.second;
992 FailedCandidates.push_back(GV);
994 GlobalGOTEquivs.clear();
996 for (auto *GV : FailedCandidates)
997 EmitGlobalVariable(GV);
1000 bool AsmPrinter::doFinalization(Module &M) {
1001 // Gather all GOT equivalent globals in the module. We really need two
1002 // passes over the globals: one to compute and another to avoid its emission
1003 // in EmitGlobalVariable, otherwise we would not be able to handle cases
1004 // where the got equivalent shows up before its use.
1005 computeGlobalGOTEquivs(M);
1007 // Emit global variables.
1008 for (const auto &G : M.globals())
1009 EmitGlobalVariable(&G);
1011 // Emit remaining GOT equivalent globals.
1012 emitGlobalGOTEquivs();
1014 // Emit visibility info for declarations
1015 for (const Function &F : M) {
1016 if (!F.isDeclaration())
1018 GlobalValue::VisibilityTypes V = F.getVisibility();
1019 if (V == GlobalValue::DefaultVisibility)
1022 MCSymbol *Name = getSymbol(&F);
1023 EmitVisibility(Name, V, false);
1026 // Emit module flags.
1027 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
1028 M.getModuleFlagsMetadata(ModuleFlags);
1029 if (!ModuleFlags.empty())
1030 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
1032 // Make sure we wrote out everything we need.
1033 OutStreamer.Flush();
1035 // Finalize debug and EH information.
1036 for (const HandlerInfo &HI : Handlers) {
1037 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
1038 TimePassesIsEnabled);
1039 HI.Handler->endModule();
1045 // If the target wants to know about weak references, print them all.
1046 if (MAI->getWeakRefDirective()) {
1047 // FIXME: This is not lazy, it would be nice to only print weak references
1048 // to stuff that is actually used. Note that doing so would require targets
1049 // to notice uses in operands (due to constant exprs etc). This should
1050 // happen with the MC stuff eventually.
1052 // Print out module-level global variables here.
1053 for (const auto &G : M.globals()) {
1054 if (!G.hasExternalWeakLinkage())
1056 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
1059 for (const auto &F : M) {
1060 if (!F.hasExternalWeakLinkage())
1062 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
1066 OutStreamer.AddBlankLine();
1067 for (const auto &Alias : M.aliases()) {
1068 MCSymbol *Name = getSymbol(&Alias);
1070 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
1071 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
1072 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
1073 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
1075 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
1077 EmitVisibility(Name, Alias.getVisibility());
1079 // Emit the directives as assignments aka .set:
1080 OutStreamer.EmitAssignment(Name, lowerConstant(Alias.getAliasee()));
1083 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1084 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1085 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1086 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1087 MP->finishAssembly(M, *MI, *this);
1089 // Emit llvm.ident metadata in an '.ident' directive.
1090 EmitModuleIdents(M);
1092 // Emit __morestack address if needed for indirect calls.
1093 if (MMI->usesMorestackAddr()) {
1094 const MCSection *ReadOnlySection =
1095 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
1097 OutStreamer.SwitchSection(ReadOnlySection);
1099 MCSymbol *AddrSymbol =
1100 OutContext.GetOrCreateSymbol(StringRef("__morestack_addr"));
1101 OutStreamer.EmitLabel(AddrSymbol);
1103 unsigned PtrSize = TM.getDataLayout()->getPointerSize(0);
1104 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("__morestack"),
1108 // If we don't have any trampolines, then we don't require stack memory
1109 // to be executable. Some targets have a directive to declare this.
1110 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1111 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1112 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1113 OutStreamer.SwitchSection(S);
1115 // Allow the target to emit any magic that it wants at the end of the file,
1116 // after everything else has gone out.
1117 EmitEndOfAsmFile(M);
1119 delete Mang; Mang = nullptr;
1122 OutStreamer.Finish();
1123 OutStreamer.reset();
1128 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1130 // Get the function symbol.
1131 CurrentFnSym = getSymbol(MF.getFunction());
1132 CurrentFnSymForSize = CurrentFnSym;
1133 CurrentFnBegin = nullptr;
1134 bool NeedsLocalForSize = MAI->needsLocalForSize();
1135 if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
1136 NeedsLocalForSize) {
1137 CurrentFnBegin = createTempSymbol("func_begin", getFunctionNumber());
1138 if (NeedsLocalForSize)
1139 CurrentFnSymForSize = CurrentFnBegin;
1143 LI = &getAnalysis<MachineLoopInfo>();
1147 // SectionCPs - Keep track the alignment, constpool entries per Section.
1151 SmallVector<unsigned, 4> CPEs;
1152 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1156 /// EmitConstantPool - Print to the current output stream assembly
1157 /// representations of the constants in the constant pool MCP. This is
1158 /// used to print out constants which have been "spilled to memory" by
1159 /// the code generator.
1161 void AsmPrinter::EmitConstantPool() {
1162 const MachineConstantPool *MCP = MF->getConstantPool();
1163 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1164 if (CP.empty()) return;
1166 // Calculate sections for constant pool entries. We collect entries to go into
1167 // the same section together to reduce amount of section switch statements.
1168 SmallVector<SectionCPs, 4> CPSections;
1169 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1170 const MachineConstantPoolEntry &CPE = CP[i];
1171 unsigned Align = CPE.getAlignment();
1174 CPE.getSectionKind(TM.getDataLayout());
1176 const Constant *C = nullptr;
1177 if (!CPE.isMachineConstantPoolEntry())
1178 C = CPE.Val.ConstVal;
1180 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind, C);
1182 // The number of sections are small, just do a linear search from the
1183 // last section to the first.
1185 unsigned SecIdx = CPSections.size();
1186 while (SecIdx != 0) {
1187 if (CPSections[--SecIdx].S == S) {
1193 SecIdx = CPSections.size();
1194 CPSections.push_back(SectionCPs(S, Align));
1197 if (Align > CPSections[SecIdx].Alignment)
1198 CPSections[SecIdx].Alignment = Align;
1199 CPSections[SecIdx].CPEs.push_back(i);
1202 // Now print stuff into the calculated sections.
1203 const MCSection *CurSection = nullptr;
1204 unsigned Offset = 0;
1205 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1206 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1207 unsigned CPI = CPSections[i].CPEs[j];
1208 MCSymbol *Sym = GetCPISymbol(CPI);
1209 if (!Sym->isUndefined())
1212 if (CurSection != CPSections[i].S) {
1213 OutStreamer.SwitchSection(CPSections[i].S);
1214 EmitAlignment(Log2_32(CPSections[i].Alignment));
1215 CurSection = CPSections[i].S;
1219 MachineConstantPoolEntry CPE = CP[CPI];
1221 // Emit inter-object padding for alignment.
1222 unsigned AlignMask = CPE.getAlignment() - 1;
1223 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1224 OutStreamer.EmitZeros(NewOffset - Offset);
1226 Type *Ty = CPE.getType();
1227 Offset = NewOffset +
1228 TM.getDataLayout()->getTypeAllocSize(Ty);
1230 OutStreamer.EmitLabel(Sym);
1231 if (CPE.isMachineConstantPoolEntry())
1232 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1234 EmitGlobalConstant(CPE.Val.ConstVal);
1239 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1240 /// by the current function to the current output stream.
1242 void AsmPrinter::EmitJumpTableInfo() {
1243 const DataLayout *DL = MF->getTarget().getDataLayout();
1244 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1246 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1247 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1248 if (JT.empty()) return;
1250 // Pick the directive to use to print the jump table entries, and switch to
1251 // the appropriate section.
1252 const Function *F = MF->getFunction();
1253 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1254 bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
1255 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
1257 if (JTInDiffSection) {
1258 // Drop it in the readonly section.
1259 const MCSection *ReadOnlySection =
1260 TLOF.getSectionForJumpTable(*F, *Mang, TM);
1261 OutStreamer.SwitchSection(ReadOnlySection);
1264 EmitAlignment(Log2_32(
1265 MJTI->getEntryAlignment(*TM.getDataLayout())));
1267 // Jump tables in code sections are marked with a data_region directive
1268 // where that's supported.
1269 if (!JTInDiffSection)
1270 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1272 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1273 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1275 // If this jump table was deleted, ignore it.
1276 if (JTBBs.empty()) continue;
1278 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1279 /// emit a .set directive for each unique entry.
1280 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1281 MAI->doesSetDirectiveSuppressesReloc()) {
1282 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1283 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1284 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1285 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1286 const MachineBasicBlock *MBB = JTBBs[ii];
1287 if (!EmittedSets.insert(MBB).second)
1290 // .set LJTSet, LBB32-base
1292 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1293 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1294 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1298 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1299 // before each jump table. The first label is never referenced, but tells
1300 // the assembler and linker the extents of the jump table object. The
1301 // second label is actually referenced by the code.
1302 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1303 // FIXME: This doesn't have to have any specific name, just any randomly
1304 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1305 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1307 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1309 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1310 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1312 if (!JTInDiffSection)
1313 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1316 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1318 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1319 const MachineBasicBlock *MBB,
1320 unsigned UID) const {
1321 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1322 const MCExpr *Value = nullptr;
1323 switch (MJTI->getEntryKind()) {
1324 case MachineJumpTableInfo::EK_Inline:
1325 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1326 case MachineJumpTableInfo::EK_Custom32:
1327 Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
1328 MJTI, MBB, UID, OutContext);
1330 case MachineJumpTableInfo::EK_BlockAddress:
1331 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1333 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1335 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1336 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1337 // with a relocation as gp-relative, e.g.:
1339 MCSymbol *MBBSym = MBB->getSymbol();
1340 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1344 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1345 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1346 // with a relocation as gp-relative, e.g.:
1348 MCSymbol *MBBSym = MBB->getSymbol();
1349 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1353 case MachineJumpTableInfo::EK_LabelDifference32: {
1354 // Each entry is the address of the block minus the address of the jump
1355 // table. This is used for PIC jump tables where gprel32 is not supported.
1357 // .word LBB123 - LJTI1_2
1358 // If the .set directive avoids relocations, this is emitted as:
1359 // .set L4_5_set_123, LBB123 - LJTI1_2
1360 // .word L4_5_set_123
1361 if (MAI->doesSetDirectiveSuppressesReloc()) {
1362 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1366 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1367 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1368 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1369 Value = MCBinaryExpr::CreateSub(Value, Base, OutContext);
1374 assert(Value && "Unknown entry kind!");
1376 unsigned EntrySize =
1377 MJTI->getEntrySize(*TM.getDataLayout());
1378 OutStreamer.EmitValue(Value, EntrySize);
1382 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1383 /// special global used by LLVM. If so, emit it and return true, otherwise
1384 /// do nothing and return false.
1385 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1386 if (GV->getName() == "llvm.used") {
1387 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1388 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1392 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1393 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1394 GV->hasAvailableExternallyLinkage())
1397 if (!GV->hasAppendingLinkage()) return false;
1399 assert(GV->hasInitializer() && "Not a special LLVM global!");
1401 if (GV->getName() == "llvm.global_ctors") {
1402 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1404 if (TM.getRelocationModel() == Reloc::Static &&
1405 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1406 StringRef Sym(".constructors_used");
1407 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1413 if (GV->getName() == "llvm.global_dtors") {
1414 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1416 if (TM.getRelocationModel() == Reloc::Static &&
1417 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1418 StringRef Sym(".destructors_used");
1419 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1428 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1429 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1430 /// is true, as being used with this directive.
1431 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1432 // Should be an array of 'i8*'.
1433 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1434 const GlobalValue *GV =
1435 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1437 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1443 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1445 llvm::Constant *Func;
1446 llvm::GlobalValue *ComdatKey;
1450 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1452 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1453 // Should be an array of '{ int, void ()* }' structs. The first value is the
1455 if (!isa<ConstantArray>(List)) return;
1457 // Sanity check the structors list.
1458 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1459 if (!InitList) return; // Not an array!
1460 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1461 // FIXME: Only allow the 3-field form in LLVM 4.0.
1462 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1463 return; // Not an array of two or three elements!
1464 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1465 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1466 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1467 return; // Not (int, ptr, ptr).
1469 // Gather the structors in a form that's convenient for sorting by priority.
1470 SmallVector<Structor, 8> Structors;
1471 for (Value *O : InitList->operands()) {
1472 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1473 if (!CS) continue; // Malformed.
1474 if (CS->getOperand(1)->isNullValue())
1475 break; // Found a null terminator, skip the rest.
1476 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1477 if (!Priority) continue; // Malformed.
1478 Structors.push_back(Structor());
1479 Structor &S = Structors.back();
1480 S.Priority = Priority->getLimitedValue(65535);
1481 S.Func = CS->getOperand(1);
1482 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1483 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1486 // Emit the function pointers in the target-specific order
1487 const DataLayout *DL = TM.getDataLayout();
1488 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1489 std::stable_sort(Structors.begin(), Structors.end(),
1490 [](const Structor &L,
1491 const Structor &R) { return L.Priority < R.Priority; });
1492 for (Structor &S : Structors) {
1493 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1494 const MCSymbol *KeySym = nullptr;
1495 if (GlobalValue *GV = S.ComdatKey) {
1496 if (GV->hasAvailableExternallyLinkage())
1497 // If the associated variable is available_externally, some other TU
1498 // will provide its dynamic initializer.
1501 KeySym = getSymbol(GV);
1503 const MCSection *OutputSection =
1504 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1505 : Obj.getStaticDtorSection(S.Priority, KeySym));
1506 OutStreamer.SwitchSection(OutputSection);
1507 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1508 EmitAlignment(Align);
1509 EmitXXStructor(S.Func);
1513 void AsmPrinter::EmitModuleIdents(Module &M) {
1514 if (!MAI->hasIdentDirective())
1517 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1518 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1519 const MDNode *N = NMD->getOperand(i);
1520 assert(N->getNumOperands() == 1 &&
1521 "llvm.ident metadata entry can have only one operand");
1522 const MDString *S = cast<MDString>(N->getOperand(0));
1523 OutStreamer.EmitIdent(S->getString());
1528 //===--------------------------------------------------------------------===//
1529 // Emission and print routines
1532 /// EmitInt8 - Emit a byte directive and value.
1534 void AsmPrinter::EmitInt8(int Value) const {
1535 OutStreamer.EmitIntValue(Value, 1);
1538 /// EmitInt16 - Emit a short directive and value.
1540 void AsmPrinter::EmitInt16(int Value) const {
1541 OutStreamer.EmitIntValue(Value, 2);
1544 /// EmitInt32 - Emit a long directive and value.
1546 void AsmPrinter::EmitInt32(int Value) const {
1547 OutStreamer.EmitIntValue(Value, 4);
1550 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1551 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1552 /// .set if it avoids relocations.
1553 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1554 unsigned Size) const {
1555 // Get the Hi-Lo expression.
1556 const MCExpr *Diff =
1557 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1558 MCSymbolRefExpr::Create(Lo, OutContext),
1561 if (!MAI->doesSetDirectiveSuppressesReloc()) {
1562 OutStreamer.EmitValue(Diff, Size);
1566 // Otherwise, emit with .set (aka assignment).
1567 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1568 OutStreamer.EmitAssignment(SetLabel, Diff);
1569 OutStreamer.EmitSymbolValue(SetLabel, Size);
1572 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1573 /// where the size in bytes of the directive is specified by Size and Label
1574 /// specifies the label. This implicitly uses .set if it is available.
1575 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1577 bool IsSectionRelative) const {
1578 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1579 OutStreamer.EmitCOFFSecRel32(Label);
1583 // Emit Label+Offset (or just Label if Offset is zero)
1584 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1586 Expr = MCBinaryExpr::CreateAdd(
1587 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1589 OutStreamer.EmitValue(Expr, Size);
1592 //===----------------------------------------------------------------------===//
1594 // EmitAlignment - Emit an alignment directive to the specified power of
1595 // two boundary. For example, if you pass in 3 here, you will get an 8
1596 // byte alignment. If a global value is specified, and if that global has
1597 // an explicit alignment requested, it will override the alignment request
1598 // if required for correctness.
1600 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1602 NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(),
1605 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1608 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
1609 "undefined behavior");
1610 if (getCurrentSection()->getKind().isText())
1611 OutStreamer.EmitCodeAlignment(1u << NumBits);
1613 OutStreamer.EmitValueToAlignment(1u << NumBits);
1616 //===----------------------------------------------------------------------===//
1617 // Constant emission.
1618 //===----------------------------------------------------------------------===//
1620 const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1621 MCContext &Ctx = OutContext;
1623 if (CV->isNullValue() || isa<UndefValue>(CV))
1624 return MCConstantExpr::Create(0, Ctx);
1626 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1627 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1629 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1630 return MCSymbolRefExpr::Create(getSymbol(GV), Ctx);
1632 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1633 return MCSymbolRefExpr::Create(GetBlockAddressSymbol(BA), Ctx);
1635 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1637 llvm_unreachable("Unknown constant value to lower!");
1640 if (const MCExpr *RelocExpr
1641 = getObjFileLowering().getExecutableRelativeSymbol(CE, *Mang, TM))
1644 switch (CE->getOpcode()) {
1646 // If the code isn't optimized, there may be outstanding folding
1647 // opportunities. Attempt to fold the expression using DataLayout as a
1648 // last resort before giving up.
1649 if (Constant *C = ConstantFoldConstantExpression(CE, *TM.getDataLayout()))
1651 return lowerConstant(C);
1653 // Otherwise report the problem to the user.
1656 raw_string_ostream OS(S);
1657 OS << "Unsupported expression in static initializer: ";
1658 CE->printAsOperand(OS, /*PrintType=*/false,
1659 !MF ? nullptr : MF->getFunction()->getParent());
1660 report_fatal_error(OS.str());
1662 case Instruction::GetElementPtr: {
1663 const DataLayout &DL = *TM.getDataLayout();
1665 // Generate a symbolic expression for the byte address
1666 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1667 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1669 const MCExpr *Base = lowerConstant(CE->getOperand(0));
1673 int64_t Offset = OffsetAI.getSExtValue();
1674 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1678 case Instruction::Trunc:
1679 // We emit the value and depend on the assembler to truncate the generated
1680 // expression properly. This is important for differences between
1681 // blockaddress labels. Since the two labels are in the same function, it
1682 // is reasonable to treat their delta as a 32-bit value.
1684 case Instruction::BitCast:
1685 return lowerConstant(CE->getOperand(0));
1687 case Instruction::IntToPtr: {
1688 const DataLayout &DL = *TM.getDataLayout();
1690 // Handle casts to pointers by changing them into casts to the appropriate
1691 // integer type. This promotes constant folding and simplifies this code.
1692 Constant *Op = CE->getOperand(0);
1693 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1695 return lowerConstant(Op);
1698 case Instruction::PtrToInt: {
1699 const DataLayout &DL = *TM.getDataLayout();
1701 // Support only foldable casts to/from pointers that can be eliminated by
1702 // changing the pointer to the appropriately sized integer type.
1703 Constant *Op = CE->getOperand(0);
1704 Type *Ty = CE->getType();
1706 const MCExpr *OpExpr = lowerConstant(Op);
1708 // We can emit the pointer value into this slot if the slot is an
1709 // integer slot equal to the size of the pointer.
1710 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1713 // Otherwise the pointer is smaller than the resultant integer, mask off
1714 // the high bits so we are sure to get a proper truncation if the input is
1716 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1717 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1718 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1721 // The MC library also has a right-shift operator, but it isn't consistently
1722 // signed or unsigned between different targets.
1723 case Instruction::Add:
1724 case Instruction::Sub:
1725 case Instruction::Mul:
1726 case Instruction::SDiv:
1727 case Instruction::SRem:
1728 case Instruction::Shl:
1729 case Instruction::And:
1730 case Instruction::Or:
1731 case Instruction::Xor: {
1732 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
1733 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
1734 switch (CE->getOpcode()) {
1735 default: llvm_unreachable("Unknown binary operator constant cast expr");
1736 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1737 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1738 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1739 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1740 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1741 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1742 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1743 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1744 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1750 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP,
1751 const Constant *BaseCV = nullptr,
1752 uint64_t Offset = 0);
1754 /// isRepeatedByteSequence - Determine whether the given value is
1755 /// composed of a repeated sequence of identical bytes and return the
1756 /// byte value. If it is not a repeated sequence, return -1.
1757 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1758 StringRef Data = V->getRawDataValues();
1759 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1761 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1762 if (Data[i] != C) return -1;
1763 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1767 /// isRepeatedByteSequence - Determine whether the given value is
1768 /// composed of a repeated sequence of identical bytes and return the
1769 /// byte value. If it is not a repeated sequence, return -1.
1770 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1772 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1773 if (CI->getBitWidth() > 64) return -1;
1776 TM.getDataLayout()->getTypeAllocSize(V->getType());
1777 uint64_t Value = CI->getZExtValue();
1779 // Make sure the constant is at least 8 bits long and has a power
1780 // of 2 bit width. This guarantees the constant bit width is
1781 // always a multiple of 8 bits, avoiding issues with padding out
1782 // to Size and other such corner cases.
1783 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1785 uint8_t Byte = static_cast<uint8_t>(Value);
1787 for (unsigned i = 1; i < Size; ++i) {
1789 if (static_cast<uint8_t>(Value) != Byte) return -1;
1793 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1794 // Make sure all array elements are sequences of the same repeated
1796 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1797 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1798 if (Byte == -1) return -1;
1800 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1801 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1802 if (ThisByte == -1) return -1;
1803 if (Byte != ThisByte) return -1;
1808 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1809 return isRepeatedByteSequence(CDS);
1814 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1817 // See if we can aggregate this into a .fill, if so, emit it as such.
1818 int Value = isRepeatedByteSequence(CDS, AP.TM);
1821 AP.TM.getDataLayout()->getTypeAllocSize(
1823 // Don't emit a 1-byte object as a .fill.
1825 return AP.OutStreamer.EmitFill(Bytes, Value);
1828 // If this can be emitted with .ascii/.asciz, emit it as such.
1829 if (CDS->isString())
1830 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1832 // Otherwise, emit the values in successive locations.
1833 unsigned ElementByteSize = CDS->getElementByteSize();
1834 if (isa<IntegerType>(CDS->getElementType())) {
1835 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1837 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1838 CDS->getElementAsInteger(i));
1839 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1842 } else if (ElementByteSize == 4) {
1843 // FP Constants are printed as integer constants to avoid losing
1845 assert(CDS->getElementType()->isFloatTy());
1846 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1852 F = CDS->getElementAsFloat(i);
1854 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1855 AP.OutStreamer.EmitIntValue(I, 4);
1858 assert(CDS->getElementType()->isDoubleTy());
1859 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1865 F = CDS->getElementAsDouble(i);
1867 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1868 AP.OutStreamer.EmitIntValue(I, 8);
1872 const DataLayout &DL = *AP.TM.getDataLayout();
1873 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1874 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1875 CDS->getNumElements();
1876 if (unsigned Padding = Size - EmittedSize)
1877 AP.OutStreamer.EmitZeros(Padding);
1881 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP,
1882 const Constant *BaseCV, uint64_t Offset) {
1883 // See if we can aggregate some values. Make sure it can be
1884 // represented as a series of bytes of the constant value.
1885 int Value = isRepeatedByteSequence(CA, AP.TM);
1886 const DataLayout &DL = *AP.TM.getDataLayout();
1889 uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
1890 AP.OutStreamer.EmitFill(Bytes, Value);
1893 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
1894 emitGlobalConstantImpl(CA->getOperand(i), AP, BaseCV, Offset);
1895 Offset += DL.getTypeAllocSize(CA->getOperand(i)->getType());
1900 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1901 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1902 emitGlobalConstantImpl(CV->getOperand(i), AP);
1904 const DataLayout &DL = *AP.TM.getDataLayout();
1905 unsigned Size = DL.getTypeAllocSize(CV->getType());
1906 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1907 CV->getType()->getNumElements();
1908 if (unsigned Padding = Size - EmittedSize)
1909 AP.OutStreamer.EmitZeros(Padding);
1912 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP,
1913 const Constant *BaseCV, uint64_t Offset) {
1914 // Print the fields in successive locations. Pad to align if needed!
1915 const DataLayout *DL = AP.TM.getDataLayout();
1916 unsigned Size = DL->getTypeAllocSize(CS->getType());
1917 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1918 uint64_t SizeSoFar = 0;
1919 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1920 const Constant *Field = CS->getOperand(i);
1922 // Print the actual field value.
1923 emitGlobalConstantImpl(Field, AP, BaseCV, Offset+SizeSoFar);
1925 // Check if padding is needed and insert one or more 0s.
1926 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1927 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1928 - Layout->getElementOffset(i)) - FieldSize;
1929 SizeSoFar += FieldSize + PadSize;
1931 // Insert padding - this may include padding to increase the size of the
1932 // current field up to the ABI size (if the struct is not packed) as well
1933 // as padding to ensure that the next field starts at the right offset.
1934 AP.OutStreamer.EmitZeros(PadSize);
1936 assert(SizeSoFar == Layout->getSizeInBytes() &&
1937 "Layout of constant struct may be incorrect!");
1940 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1941 APInt API = CFP->getValueAPF().bitcastToAPInt();
1943 // First print a comment with what we think the original floating-point value
1944 // should have been.
1945 if (AP.isVerbose()) {
1946 SmallString<8> StrVal;
1947 CFP->getValueAPF().toString(StrVal);
1950 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1952 AP.OutStreamer.GetCommentOS() << "Printing <null> Type";
1953 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1956 // Now iterate through the APInt chunks, emitting them in endian-correct
1957 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1959 unsigned NumBytes = API.getBitWidth() / 8;
1960 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1961 const uint64_t *p = API.getRawData();
1963 // PPC's long double has odd notions of endianness compared to how LLVM
1964 // handles it: p[0] goes first for *big* endian on PPC.
1965 if (AP.TM.getDataLayout()->isBigEndian() &&
1966 !CFP->getType()->isPPC_FP128Ty()) {
1967 int Chunk = API.getNumWords() - 1;
1970 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1972 for (; Chunk >= 0; --Chunk)
1973 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1976 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1977 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1980 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1983 // Emit the tail padding for the long double.
1984 const DataLayout &DL = *AP.TM.getDataLayout();
1985 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1986 DL.getTypeStoreSize(CFP->getType()));
1989 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1990 const DataLayout *DL = AP.TM.getDataLayout();
1991 unsigned BitWidth = CI->getBitWidth();
1993 // Copy the value as we may massage the layout for constants whose bit width
1994 // is not a multiple of 64-bits.
1995 APInt Realigned(CI->getValue());
1996 uint64_t ExtraBits = 0;
1997 unsigned ExtraBitsSize = BitWidth & 63;
1999 if (ExtraBitsSize) {
2000 // The bit width of the data is not a multiple of 64-bits.
2001 // The extra bits are expected to be at the end of the chunk of the memory.
2003 // * Nothing to be done, just record the extra bits to emit.
2005 // * Record the extra bits to emit.
2006 // * Realign the raw data to emit the chunks of 64-bits.
2007 if (DL->isBigEndian()) {
2008 // Basically the structure of the raw data is a chunk of 64-bits cells:
2009 // 0 1 BitWidth / 64
2010 // [chunk1][chunk2] ... [chunkN].
2011 // The most significant chunk is chunkN and it should be emitted first.
2012 // However, due to the alignment issue chunkN contains useless bits.
2013 // Realign the chunks so that they contain only useless information:
2014 // ExtraBits 0 1 (BitWidth / 64) - 1
2015 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
2016 ExtraBits = Realigned.getRawData()[0] &
2017 (((uint64_t)-1) >> (64 - ExtraBitsSize));
2018 Realigned = Realigned.lshr(ExtraBitsSize);
2020 ExtraBits = Realigned.getRawData()[BitWidth / 64];
2023 // We don't expect assemblers to support integer data directives
2024 // for more than 64 bits, so we emit the data in at most 64-bit
2025 // quantities at a time.
2026 const uint64_t *RawData = Realigned.getRawData();
2027 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
2028 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
2029 AP.OutStreamer.EmitIntValue(Val, 8);
2032 if (ExtraBitsSize) {
2033 // Emit the extra bits after the 64-bits chunks.
2035 // Emit a directive that fills the expected size.
2036 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(
2038 Size -= (BitWidth / 64) * 8;
2039 assert(Size && Size * 8 >= ExtraBitsSize &&
2040 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
2041 == ExtraBits && "Directive too small for extra bits.");
2042 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
2046 /// \brief Transform a not absolute MCExpr containing a reference to a GOT
2047 /// equivalent global, by a target specific GOT pc relative access to the
2049 static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
2050 const Constant *BaseCst,
2052 // The global @foo below illustrates a global that uses a got equivalent.
2054 // @bar = global i32 42
2055 // @gotequiv = private unnamed_addr constant i32* @bar
2056 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
2057 // i64 ptrtoint (i32* @foo to i64))
2060 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
2061 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
2064 // foo = cstexpr, where
2065 // cstexpr := <gotequiv> - "." + <cst>
2066 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
2068 // After canonicalization by EvaluateAsRelocatable `ME` turns into:
2070 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
2071 // gotpcrelcst := <offset from @foo base> + <cst>
2074 if (!(*ME)->EvaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
2077 const MCSymbol *GOTEquivSym = &MV.getSymA()->getSymbol();
2078 if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
2081 const GlobalValue *BaseGV = dyn_cast<GlobalValue>(BaseCst);
2085 const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
2086 if (BaseSym != &MV.getSymB()->getSymbol())
2089 // Make sure to match:
2091 // gotpcrelcst := <offset from @foo base> + <cst>
2093 // If gotpcrelcst is positive it means that we can safely fold the pc rel
2094 // displacement into the GOTPCREL. We can also can have an extra offset <cst>
2095 // if the target knows how to encode it.
2097 int64_t GOTPCRelCst = Offset + MV.getConstant();
2098 if (GOTPCRelCst < 0)
2100 if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
2103 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
2110 // .long gotequiv - "." + <cst>
2112 // is replaced by the target specific equivalent to:
2117 // .long bar@GOTPCREL+<gotpcrelcst>
2119 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
2120 const GlobalVariable *GV = Result.first;
2121 int NumUses = (int)Result.second;
2122 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
2123 const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
2124 *ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(
2125 FinalSym, MV, Offset, AP.MMI, AP.OutStreamer);
2127 // Update GOT equivalent usage information
2130 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
2133 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP,
2134 const Constant *BaseCV, uint64_t Offset) {
2135 const DataLayout *DL = AP.TM.getDataLayout();
2136 uint64_t Size = DL->getTypeAllocSize(CV->getType());
2138 // Globals with sub-elements such as combinations of arrays and structs
2139 // are handled recursively by emitGlobalConstantImpl. Keep track of the
2140 // constant symbol base and the current position with BaseCV and Offset.
2141 if (!BaseCV && CV->hasOneUse())
2142 BaseCV = dyn_cast<Constant>(CV->user_back());
2144 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
2145 return AP.OutStreamer.EmitZeros(Size);
2147 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
2154 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
2155 CI->getZExtValue());
2156 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
2159 emitGlobalConstantLargeInt(CI, AP);
2164 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
2165 return emitGlobalConstantFP(CFP, AP);
2167 if (isa<ConstantPointerNull>(CV)) {
2168 AP.OutStreamer.EmitIntValue(0, Size);
2172 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
2173 return emitGlobalConstantDataSequential(CDS, AP);
2175 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2176 return emitGlobalConstantArray(CVA, AP, BaseCV, Offset);
2178 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2179 return emitGlobalConstantStruct(CVS, AP, BaseCV, Offset);
2181 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2182 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2184 if (CE->getOpcode() == Instruction::BitCast)
2185 return emitGlobalConstantImpl(CE->getOperand(0), AP);
2188 // If the constant expression's size is greater than 64-bits, then we have
2189 // to emit the value in chunks. Try to constant fold the value and emit it
2191 Constant *New = ConstantFoldConstantExpression(CE, *DL);
2192 if (New && New != CE)
2193 return emitGlobalConstantImpl(New, AP);
2197 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2198 return emitGlobalConstantVector(V, AP);
2200 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2201 // thread the streamer with EmitValue.
2202 const MCExpr *ME = AP.lowerConstant(CV);
2204 // Since lowerConstant already folded and got rid of all IR pointer and
2205 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
2207 if (AP.getObjFileLowering().supportIndirectSymViaGOTPCRel())
2208 handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
2210 AP.OutStreamer.EmitValue(ME, Size);
2213 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2214 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2216 TM.getDataLayout()->getTypeAllocSize(CV->getType());
2218 emitGlobalConstantImpl(CV, *this);
2219 else if (MAI->hasSubsectionsViaSymbols()) {
2220 // If the global has zero size, emit a single byte so that two labels don't
2221 // look like they are at the same location.
2222 OutStreamer.EmitIntValue(0, 1);
2226 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2227 // Target doesn't support this yet!
2228 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2231 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2233 OS << '+' << Offset;
2234 else if (Offset < 0)
2238 //===----------------------------------------------------------------------===//
2239 // Symbol Lowering Routines.
2240 //===----------------------------------------------------------------------===//
2242 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2243 /// temporary label with the specified stem and unique ID.
2244 MCSymbol *AsmPrinter::GetTempSymbol(const Twine &Name, unsigned ID) const {
2245 const DataLayout *DL = TM.getDataLayout();
2246 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2250 /// GetTempSymbol - Return an assembler temporary label with the specified
2252 MCSymbol *AsmPrinter::GetTempSymbol(const Twine &Name) const {
2253 const DataLayout *DL = TM.getDataLayout();
2254 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2258 MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name, unsigned ID) const {
2259 return OutContext.createTempSymbol(Name + Twine(ID));
2262 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2263 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2266 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2267 return MMI->getAddrLabelSymbol(BB);
2270 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2271 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2272 const DataLayout *DL = TM.getDataLayout();
2273 return OutContext.GetOrCreateSymbol
2274 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2275 + "_" + Twine(CPID));
2278 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2279 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2280 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2283 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2284 /// FIXME: privatize to AsmPrinter.
2285 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2286 const DataLayout *DL = TM.getDataLayout();
2287 return OutContext.GetOrCreateSymbol
2288 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2289 Twine(UID) + "_set_" + Twine(MBBID));
2292 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2293 StringRef Suffix) const {
2294 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2298 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2300 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2301 SmallString<60> NameStr;
2302 Mang->getNameWithPrefix(NameStr, Sym);
2303 return OutContext.GetOrCreateSymbol(NameStr.str());
2308 /// PrintParentLoopComment - Print comments about parent loops of this one.
2309 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2310 unsigned FunctionNumber) {
2312 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2313 OS.indent(Loop->getLoopDepth()*2)
2314 << "Parent Loop BB" << FunctionNumber << "_"
2315 << Loop->getHeader()->getNumber()
2316 << " Depth=" << Loop->getLoopDepth() << '\n';
2320 /// PrintChildLoopComment - Print comments about child loops within
2321 /// the loop for this basic block, with nesting.
2322 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2323 unsigned FunctionNumber) {
2324 // Add child loop information
2325 for (const MachineLoop *CL : *Loop) {
2326 OS.indent(CL->getLoopDepth()*2)
2327 << "Child Loop BB" << FunctionNumber << "_"
2328 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2330 PrintChildLoopComment(OS, CL, FunctionNumber);
2334 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2335 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2336 const MachineLoopInfo *LI,
2337 const AsmPrinter &AP) {
2338 // Add loop depth information
2339 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2342 MachineBasicBlock *Header = Loop->getHeader();
2343 assert(Header && "No header for loop");
2345 // If this block is not a loop header, just print out what is the loop header
2347 if (Header != &MBB) {
2348 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2349 Twine(AP.getFunctionNumber())+"_" +
2350 Twine(Loop->getHeader()->getNumber())+
2351 " Depth="+Twine(Loop->getLoopDepth()));
2355 // Otherwise, it is a loop header. Print out information about child and
2357 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2359 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2362 OS.indent(Loop->getLoopDepth()*2-2);
2367 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2369 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2373 /// EmitBasicBlockStart - This method prints the label for the specified
2374 /// MachineBasicBlock, an alignment (if present) and a comment describing
2375 /// it if appropriate.
2376 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2377 // Emit an alignment directive for this block, if needed.
2378 if (unsigned Align = MBB.getAlignment())
2379 EmitAlignment(Align);
2381 // If the block has its address taken, emit any labels that were used to
2382 // reference the block. It is possible that there is more than one label
2383 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2384 // the references were generated.
2385 if (MBB.hasAddressTaken()) {
2386 const BasicBlock *BB = MBB.getBasicBlock();
2388 OutStreamer.AddComment("Block address taken");
2390 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2391 for (auto *Sym : Symbols)
2392 OutStreamer.EmitLabel(Sym);
2395 // Print some verbose block comments.
2397 if (const BasicBlock *BB = MBB.getBasicBlock())
2399 OutStreamer.AddComment("%" + BB->getName());
2400 emitBasicBlockLoopComments(MBB, LI, *this);
2403 // Print the main label for the block.
2404 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2406 // NOTE: Want this comment at start of line, don't emit with AddComment.
2407 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2410 OutStreamer.EmitLabel(MBB.getSymbol());
2414 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2415 bool IsDefinition) const {
2416 MCSymbolAttr Attr = MCSA_Invalid;
2418 switch (Visibility) {
2420 case GlobalValue::HiddenVisibility:
2422 Attr = MAI->getHiddenVisibilityAttr();
2424 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2426 case GlobalValue::ProtectedVisibility:
2427 Attr = MAI->getProtectedVisibilityAttr();
2431 if (Attr != MCSA_Invalid)
2432 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2435 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2436 /// exactly one predecessor and the control transfer mechanism between
2437 /// the predecessor and this block is a fall-through.
2439 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2440 // If this is a landing pad, it isn't a fall through. If it has no preds,
2441 // then nothing falls through to it.
2442 if (MBB->isLandingPad() || MBB->pred_empty())
2445 // If there isn't exactly one predecessor, it can't be a fall through.
2446 if (MBB->pred_size() > 1)
2449 // The predecessor has to be immediately before this block.
2450 MachineBasicBlock *Pred = *MBB->pred_begin();
2451 if (!Pred->isLayoutSuccessor(MBB))
2454 // If the block is completely empty, then it definitely does fall through.
2458 // Check the terminators in the previous blocks
2459 for (const auto &MI : Pred->terminators()) {
2460 // If it is not a simple branch, we are in a table somewhere.
2461 if (!MI.isBranch() || MI.isIndirectBranch())
2464 // If we are the operands of one of the branches, this is not a fall
2465 // through. Note that targets with delay slots will usually bundle
2466 // terminators with the delay slot instruction.
2467 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2470 if (OP->isMBB() && OP->getMBB() == MBB)
2480 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2481 if (!S.usesMetadata())
2484 assert(!S.useStatepoints() && "statepoints do not currently support custom"
2485 " stackmap formats, please see the documentation for a description of"
2486 " the default format. If you really need a custom serialized format,"
2487 " please file a bug");
2489 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2490 gcp_map_type::iterator GCPI = GCMap.find(&S);
2491 if (GCPI != GCMap.end())
2492 return GCPI->second.get();
2494 const char *Name = S.getName().c_str();
2496 for (GCMetadataPrinterRegistry::iterator
2497 I = GCMetadataPrinterRegistry::begin(),
2498 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2499 if (strcmp(Name, I->getName()) == 0) {
2500 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2502 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2503 return IterBool.first->second.get();
2506 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2509 /// Pin vtable to this file.
2510 AsmPrinterHandler::~AsmPrinterHandler() {}
2512 void AsmPrinterHandler::markFunctionEnd() {}