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/Support/ErrorHandling.h"
45 #include "llvm/Support/Format.h"
46 #include "llvm/Support/MathExtras.h"
47 #include "llvm/Support/Timer.h"
48 #include "llvm/Target/TargetFrameLowering.h"
49 #include "llvm/Target/TargetInstrInfo.h"
50 #include "llvm/Target/TargetLowering.h"
51 #include "llvm/Target/TargetLoweringObjectFile.h"
52 #include "llvm/Target/TargetRegisterInfo.h"
53 #include "llvm/Target/TargetSubtargetInfo.h"
56 #define DEBUG_TYPE "asm-printer"
58 static const char *const DWARFGroupName = "DWARF Emission";
59 static const char *const DbgTimerName = "Debug Info Emission";
60 static const char *const EHTimerName = "DWARF Exception Writer";
61 static const char *const CodeViewLineTablesGroupName = "CodeView Line Tables";
63 STATISTIC(EmittedInsts, "Number of machine instrs printed");
65 char AsmPrinter::ID = 0;
67 typedef DenseMap<GCStrategy*, std::unique_ptr<GCMetadataPrinter>> gcp_map_type;
68 static gcp_map_type &getGCMap(void *&P) {
70 P = new gcp_map_type();
71 return *(gcp_map_type*)P;
75 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
76 /// value in log2 form. This rounds up to the preferred alignment if possible
78 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD,
79 unsigned InBits = 0) {
81 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
82 NumBits = TD.getPreferredAlignmentLog(GVar);
84 // If InBits is specified, round it to it.
88 // If the GV has a specified alignment, take it into account.
89 if (GV->getAlignment() == 0)
92 unsigned GVAlign = Log2_32(GV->getAlignment());
94 // If the GVAlign is larger than NumBits, or if we are required to obey
95 // NumBits because the GV has an assigned section, obey it.
96 if (GVAlign > NumBits || GV->hasSection())
101 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
102 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
103 MII(tm.getSubtargetImpl()->getInstrInfo()),
104 OutContext(Streamer.getContext()), OutStreamer(Streamer), LastMI(nullptr),
105 LastFn(0), Counter(~0U), SetCounter(0) {
106 DD = nullptr; MMI = nullptr; LI = nullptr; MF = nullptr;
107 CurrentFnSym = CurrentFnSymForSize = nullptr;
108 GCMetadataPrinters = nullptr;
109 VerboseAsm = Streamer.isVerboseAsm();
112 AsmPrinter::~AsmPrinter() {
113 assert(!DD && Handlers.empty() && "Debug/EH info didn't get finalized");
115 if (GCMetadataPrinters) {
116 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
119 GCMetadataPrinters = nullptr;
125 /// getFunctionNumber - Return a unique ID for the current function.
127 unsigned AsmPrinter::getFunctionNumber() const {
128 return MF->getFunctionNumber();
131 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
132 return TM.getSubtargetImpl()->getTargetLowering()->getObjFileLowering();
135 /// getDataLayout - Return information about data layout.
136 const DataLayout &AsmPrinter::getDataLayout() const {
137 return *TM.getSubtargetImpl()->getDataLayout();
140 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
141 return TM.getSubtarget<MCSubtargetInfo>();
144 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
145 S.EmitInstruction(Inst, getSubtargetInfo());
148 StringRef AsmPrinter::getTargetTriple() const {
149 return TM.getTargetTriple();
152 /// getCurrentSection() - Return the current section we are emitting to.
153 const MCSection *AsmPrinter::getCurrentSection() const {
154 return OutStreamer.getCurrentSection().first;
159 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
160 AU.setPreservesAll();
161 MachineFunctionPass::getAnalysisUsage(AU);
162 AU.addRequired<MachineModuleInfo>();
163 AU.addRequired<GCModuleInfo>();
165 AU.addRequired<MachineLoopInfo>();
168 bool AsmPrinter::doInitialization(Module &M) {
169 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
170 MMI->AnalyzeModule(M);
172 // Initialize TargetLoweringObjectFile.
173 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
174 .Initialize(OutContext, TM);
176 OutStreamer.InitSections();
178 Mang = new Mangler(TM.getSubtargetImpl()->getDataLayout());
180 // Emit the version-min deplyment target directive if needed.
182 // FIXME: If we end up with a collection of these sorts of Darwin-specific
183 // or ELF-specific things, it may make sense to have a platform helper class
184 // that will work with the target helper class. For now keep it here, as the
185 // alternative is duplicated code in each of the target asm printers that
186 // use the directive, where it would need the same conditionalization
188 Triple TT(getTargetTriple());
189 if (TT.isOSDarwin()) {
190 unsigned Major, Minor, Update;
191 TT.getOSVersion(Major, Minor, Update);
192 // If there is a version specified, Major will be non-zero.
194 OutStreamer.EmitVersionMin((TT.isMacOSX() ?
195 MCVM_OSXVersionMin : MCVM_IOSVersionMin),
196 Major, Minor, Update);
199 // Allow the target to emit any magic that it wants at the start of the file.
200 EmitStartOfAsmFile(M);
202 // Very minimal debug info. It is ignored if we emit actual debug info. If we
203 // don't, this at least helps the user find where a global came from.
204 if (MAI->hasSingleParameterDotFile()) {
206 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
209 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
210 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
212 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
213 MP->beginAssembly(*this);
215 // Emit module-level inline asm if it exists.
216 if (!M.getModuleInlineAsm().empty()) {
217 OutStreamer.AddComment("Start of file scope inline assembly");
218 OutStreamer.AddBlankLine();
219 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
220 OutStreamer.AddComment("End of file scope inline assembly");
221 OutStreamer.AddBlankLine();
224 if (MAI->doesSupportDebugInformation()) {
225 if (Triple(TM.getTargetTriple()).isKnownWindowsMSVCEnvironment()) {
226 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this),
228 CodeViewLineTablesGroupName));
230 DD = new DwarfDebug(this, &M);
231 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
235 EHStreamer *ES = nullptr;
236 switch (MAI->getExceptionHandlingType()) {
237 case ExceptionHandling::None:
239 case ExceptionHandling::SjLj:
240 case ExceptionHandling::DwarfCFI:
241 ES = new DwarfCFIException(this);
243 case ExceptionHandling::ARM:
244 ES = new ARMException(this);
246 case ExceptionHandling::WinEH:
247 switch (MAI->getWinEHEncodingType()) {
248 default: llvm_unreachable("unsupported unwinding information encoding");
249 case WinEH::EncodingType::Itanium:
250 ES = new Win64Exception(this);
256 Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
260 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
261 if (!MAI.hasWeakDefCanBeHiddenDirective())
264 return canBeOmittedFromSymbolTable(GV);
267 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
268 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
270 case GlobalValue::CommonLinkage:
271 case GlobalValue::LinkOnceAnyLinkage:
272 case GlobalValue::LinkOnceODRLinkage:
273 case GlobalValue::WeakAnyLinkage:
274 case GlobalValue::WeakODRLinkage:
275 if (MAI->hasWeakDefDirective()) {
277 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
279 if (!canBeHidden(GV, *MAI))
280 // .weak_definition _foo
281 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
283 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
284 } else if (MAI->hasLinkOnceDirective()) {
286 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
287 //NOTE: linkonce is handled by the section the symbol was assigned to.
290 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
293 case GlobalValue::AppendingLinkage:
294 // FIXME: appending linkage variables should go into a section of
295 // their name or something. For now, just emit them as external.
296 case GlobalValue::ExternalLinkage:
297 // If external or appending, declare as a global symbol.
299 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
301 case GlobalValue::PrivateLinkage:
302 case GlobalValue::InternalLinkage:
304 case GlobalValue::AvailableExternallyLinkage:
305 llvm_unreachable("Should never emit this");
306 case GlobalValue::ExternalWeakLinkage:
307 llvm_unreachable("Don't know how to emit these");
309 llvm_unreachable("Unknown linkage type!");
312 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
313 const GlobalValue *GV) const {
314 TM.getNameWithPrefix(Name, GV, *Mang);
317 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
318 return TM.getSymbol(GV, *Mang);
321 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
322 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
323 if (GV->hasInitializer()) {
324 // Check to see if this is a special global used by LLVM, if so, emit it.
325 if (EmitSpecialLLVMGlobal(GV))
329 GV->printAsOperand(OutStreamer.GetCommentOS(),
330 /*PrintType=*/false, GV->getParent());
331 OutStreamer.GetCommentOS() << '\n';
335 MCSymbol *GVSym = getSymbol(GV);
336 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
338 if (!GV->hasInitializer()) // External globals require no extra code.
341 if (MAI->hasDotTypeDotSizeDirective())
342 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
344 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
346 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
347 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
349 // If the alignment is specified, we *must* obey it. Overaligning a global
350 // with a specified alignment is a prompt way to break globals emitted to
351 // sections and expected to be contiguous (e.g. ObjC metadata).
352 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
354 for (const HandlerInfo &HI : Handlers) {
355 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
356 HI.Handler->setSymbolSize(GVSym, Size);
359 // Handle common and BSS local symbols (.lcomm).
360 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
361 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
362 unsigned Align = 1 << AlignLog;
364 // Handle common symbols.
365 if (GVKind.isCommon()) {
366 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
370 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
374 // Handle local BSS symbols.
375 if (MAI->hasMachoZeroFillDirective()) {
376 const MCSection *TheSection =
377 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
378 // .zerofill __DATA, __bss, _foo, 400, 5
379 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
383 // Use .lcomm only if it supports user-specified alignment.
384 // Otherwise, while it would still be correct to use .lcomm in some
385 // cases (e.g. when Align == 1), the external assembler might enfore
386 // some -unknown- default alignment behavior, which could cause
387 // spurious differences between external and integrated assembler.
388 // Prefer to simply fall back to .local / .comm in this case.
389 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
391 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
395 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
399 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
401 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
405 const MCSection *TheSection =
406 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
408 // Handle the zerofill directive on darwin, which is a special form of BSS
410 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
411 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
414 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
415 // .zerofill __DATA, __common, _foo, 400, 5
416 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
420 // Handle thread local data for mach-o which requires us to output an
421 // additional structure of data and mangle the original symbol so that we
422 // can reference it later.
424 // TODO: This should become an "emit thread local global" method on TLOF.
425 // All of this macho specific stuff should be sunk down into TLOFMachO and
426 // stuff like "TLSExtraDataSection" should no longer be part of the parent
427 // TLOF class. This will also make it more obvious that stuff like
428 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
430 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
431 // Emit the .tbss symbol
433 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
435 if (GVKind.isThreadBSS()) {
436 TheSection = getObjFileLowering().getTLSBSSSection();
437 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
438 } else if (GVKind.isThreadData()) {
439 OutStreamer.SwitchSection(TheSection);
441 EmitAlignment(AlignLog, GV);
442 OutStreamer.EmitLabel(MangSym);
444 EmitGlobalConstant(GV->getInitializer());
447 OutStreamer.AddBlankLine();
449 // Emit the variable struct for the runtime.
450 const MCSection *TLVSect
451 = getObjFileLowering().getTLSExtraDataSection();
453 OutStreamer.SwitchSection(TLVSect);
454 // Emit the linkage here.
455 EmitLinkage(GV, GVSym);
456 OutStreamer.EmitLabel(GVSym);
458 // Three pointers in size:
459 // - __tlv_bootstrap - used to make sure support exists
460 // - spare pointer, used when mapped by the runtime
461 // - pointer to mangled symbol above with initializer
462 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
463 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
465 OutStreamer.EmitIntValue(0, PtrSize);
466 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
468 OutStreamer.AddBlankLine();
472 OutStreamer.SwitchSection(TheSection);
474 EmitLinkage(GV, GVSym);
475 EmitAlignment(AlignLog, GV);
477 OutStreamer.EmitLabel(GVSym);
479 EmitGlobalConstant(GV->getInitializer());
481 if (MAI->hasDotTypeDotSizeDirective())
483 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
485 OutStreamer.AddBlankLine();
488 /// EmitFunctionHeader - This method emits the header for the current
490 void AsmPrinter::EmitFunctionHeader() {
491 // Print out constants referenced by the function
494 // Print the 'header' of function.
495 const Function *F = MF->getFunction();
497 OutStreamer.SwitchSection(
498 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
499 EmitVisibility(CurrentFnSym, F->getVisibility());
501 EmitLinkage(F, CurrentFnSym);
502 EmitAlignment(MF->getAlignment(), F);
504 if (MAI->hasDotTypeDotSizeDirective())
505 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
508 F->printAsOperand(OutStreamer.GetCommentOS(),
509 /*PrintType=*/false, F->getParent());
510 OutStreamer.GetCommentOS() << '\n';
513 // Emit the CurrentFnSym. This is a virtual function to allow targets to
514 // do their wild and crazy things as required.
515 EmitFunctionEntryLabel();
517 // If the function had address-taken blocks that got deleted, then we have
518 // references to the dangling symbols. Emit them at the start of the function
519 // so that we don't get references to undefined symbols.
520 std::vector<MCSymbol*> DeadBlockSyms;
521 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
522 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
523 OutStreamer.AddComment("Address taken block that was later removed");
524 OutStreamer.EmitLabel(DeadBlockSyms[i]);
527 // Emit pre-function debug and/or EH information.
528 for (const HandlerInfo &HI : Handlers) {
529 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
530 HI.Handler->beginFunction(MF);
533 // Emit the prefix data.
534 if (F->hasPrefixData())
535 EmitGlobalConstant(F->getPrefixData());
538 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
539 /// function. This can be overridden by targets as required to do custom stuff.
540 void AsmPrinter::EmitFunctionEntryLabel() {
541 // The function label could have already been emitted if two symbols end up
542 // conflicting due to asm renaming. Detect this and emit an error.
543 if (CurrentFnSym->isUndefined())
544 return OutStreamer.EmitLabel(CurrentFnSym);
546 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
547 "' label emitted multiple times to assembly file");
550 /// emitComments - Pretty-print comments for instructions.
551 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
552 const MachineFunction *MF = MI.getParent()->getParent();
553 const TargetMachine &TM = MF->getTarget();
555 // Check for spills and reloads
558 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
560 // We assume a single instruction only has a spill or reload, not
562 const MachineMemOperand *MMO;
563 if (TM.getSubtargetImpl()->getInstrInfo()->isLoadFromStackSlotPostFE(&MI,
565 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
566 MMO = *MI.memoperands_begin();
567 CommentOS << MMO->getSize() << "-byte Reload\n";
569 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasLoadFromStackSlot(
571 if (FrameInfo->isSpillSlotObjectIndex(FI))
572 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
573 } else if (TM.getSubtargetImpl()->getInstrInfo()->isStoreToStackSlotPostFE(
575 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
576 MMO = *MI.memoperands_begin();
577 CommentOS << MMO->getSize() << "-byte Spill\n";
579 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasStoreToStackSlot(
581 if (FrameInfo->isSpillSlotObjectIndex(FI))
582 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
585 // Check for spill-induced copies
586 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
587 CommentOS << " Reload Reuse\n";
590 /// emitImplicitDef - This method emits the specified machine instruction
591 /// that is an implicit def.
592 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
593 unsigned RegNo = MI->getOperand(0).getReg();
594 OutStreamer.AddComment(
595 Twine("implicit-def: ") +
596 TM.getSubtargetImpl()->getRegisterInfo()->getName(RegNo));
597 OutStreamer.AddBlankLine();
600 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
601 std::string Str = "kill:";
602 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
603 const MachineOperand &Op = MI->getOperand(i);
604 assert(Op.isReg() && "KILL instruction must have only register operands");
606 Str += AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Op.getReg());
607 Str += (Op.isDef() ? "<def>" : "<kill>");
609 AP.OutStreamer.AddComment(Str);
610 AP.OutStreamer.AddBlankLine();
613 /// emitDebugValueComment - This method handles the target-independent form
614 /// of DBG_VALUE, returning true if it was able to do so. A false return
615 /// means the target will need to handle MI in EmitInstruction.
616 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
617 // This code handles only the 3-operand target-independent form.
618 if (MI->getNumOperands() != 3)
621 SmallString<128> Str;
622 raw_svector_ostream OS(Str);
623 OS << "DEBUG_VALUE: ";
625 DIVariable V = MI->getDebugVariable();
626 if (V.getContext().isSubprogram()) {
627 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
632 if (V.isVariablePiece())
633 OS << " [piece offset=" << V.getPieceOffset()
634 << " size="<<V.getPieceSize()<<"]";
637 // The second operand is only an offset if it's an immediate.
638 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
639 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
641 // Register or immediate value. Register 0 means undef.
642 if (MI->getOperand(0).isFPImm()) {
643 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
644 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
645 OS << (double)APF.convertToFloat();
646 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
647 OS << APF.convertToDouble();
649 // There is no good way to print long double. Convert a copy to
650 // double. Ah well, it's only a comment.
652 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
654 OS << "(long double) " << APF.convertToDouble();
656 } else if (MI->getOperand(0).isImm()) {
657 OS << MI->getOperand(0).getImm();
658 } else if (MI->getOperand(0).isCImm()) {
659 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
662 if (MI->getOperand(0).isReg()) {
663 Reg = MI->getOperand(0).getReg();
665 assert(MI->getOperand(0).isFI() && "Unknown operand type");
666 const TargetFrameLowering *TFI =
667 AP.TM.getSubtargetImpl()->getFrameLowering();
668 Offset += TFI->getFrameIndexReference(*AP.MF,
669 MI->getOperand(0).getIndex(), Reg);
673 // Suppress offset, it is not meaningful here.
675 // NOTE: Want this comment at start of line, don't emit with AddComment.
676 AP.OutStreamer.emitRawComment(OS.str());
681 OS << AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Reg);
685 OS << '+' << Offset << ']';
687 // NOTE: Want this comment at start of line, don't emit with AddComment.
688 AP.OutStreamer.emitRawComment(OS.str());
692 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
693 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
694 MF->getFunction()->needsUnwindTableEntry())
697 if (MMI->hasDebugInfo())
703 bool AsmPrinter::needsSEHMoves() {
704 return MAI->getExceptionHandlingType() == ExceptionHandling::WinEH &&
705 MF->getFunction()->needsUnwindTableEntry();
708 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
709 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
710 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
711 ExceptionHandlingType != ExceptionHandling::ARM)
714 if (needsCFIMoves() == CFI_M_None)
717 const MachineModuleInfo &MMI = MF->getMMI();
718 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
719 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
720 const MCCFIInstruction &CFI = Instrs[CFIIndex];
721 emitCFIInstruction(CFI);
724 /// EmitFunctionBody - This method emits the body and trailer for a
726 void AsmPrinter::EmitFunctionBody() {
727 // Emit target-specific gunk before the function body.
728 EmitFunctionBodyStart();
730 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
732 // Print out code for the function.
733 bool HasAnyRealCode = false;
734 for (auto &MBB : *MF) {
735 // Print a label for the basic block.
736 EmitBasicBlockStart(MBB);
737 for (auto &MI : MBB) {
739 // Print the assembly for the instruction.
740 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
741 !MI.isDebugValue()) {
742 HasAnyRealCode = true;
746 if (ShouldPrintDebugScopes) {
747 for (const HandlerInfo &HI : Handlers) {
748 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
749 TimePassesIsEnabled);
750 HI.Handler->beginInstruction(&MI);
755 emitComments(MI, OutStreamer.GetCommentOS());
757 switch (MI.getOpcode()) {
758 case TargetOpcode::CFI_INSTRUCTION:
759 emitCFIInstruction(MI);
762 case TargetOpcode::EH_LABEL:
763 case TargetOpcode::GC_LABEL:
764 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
766 case TargetOpcode::INLINEASM:
769 case TargetOpcode::DBG_VALUE:
771 if (!emitDebugValueComment(&MI, *this))
772 EmitInstruction(&MI);
775 case TargetOpcode::IMPLICIT_DEF:
776 if (isVerbose()) emitImplicitDef(&MI);
778 case TargetOpcode::KILL:
779 if (isVerbose()) emitKill(&MI, *this);
782 EmitInstruction(&MI);
786 if (ShouldPrintDebugScopes) {
787 for (const HandlerInfo &HI : Handlers) {
788 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
789 TimePassesIsEnabled);
790 HI.Handler->endInstruction();
795 EmitBasicBlockEnd(MBB);
798 // If the function is empty and the object file uses .subsections_via_symbols,
799 // then we need to emit *something* to the function body to prevent the
800 // labels from collapsing together. Just emit a noop.
801 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
803 TM.getSubtargetImpl()->getInstrInfo()->getNoopForMachoTarget(Noop);
804 OutStreamer.AddComment("avoids zero-length function");
806 // Targets can opt-out of emitting the noop here by leaving the opcode
808 if (Noop.getOpcode())
809 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
812 const Function *F = MF->getFunction();
813 for (const auto &BB : *F) {
814 if (!BB.hasAddressTaken())
816 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
817 if (Sym->isDefined())
819 OutStreamer.AddComment("Address of block that was removed by CodeGen");
820 OutStreamer.EmitLabel(Sym);
823 // Emit target-specific gunk after the function body.
824 EmitFunctionBodyEnd();
826 // If the target wants a .size directive for the size of the function, emit
828 if (MAI->hasDotTypeDotSizeDirective()) {
829 // Create a symbol for the end of function, so we can get the size as
830 // difference between the function label and the temp label.
831 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
832 OutStreamer.EmitLabel(FnEndLabel);
834 const MCExpr *SizeExp =
835 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
836 MCSymbolRefExpr::Create(CurrentFnSymForSize,
839 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
842 // Emit post-function debug and/or EH information.
843 for (const HandlerInfo &HI : Handlers) {
844 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
845 HI.Handler->endFunction(MF);
849 // Print out jump tables referenced by the function.
852 OutStreamer.AddBlankLine();
855 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP);
857 bool AsmPrinter::doFinalization(Module &M) {
858 // Emit global variables.
859 for (const auto &G : M.globals())
860 EmitGlobalVariable(&G);
862 // Emit visibility info for declarations
863 for (const Function &F : M) {
864 if (!F.isDeclaration())
866 GlobalValue::VisibilityTypes V = F.getVisibility();
867 if (V == GlobalValue::DefaultVisibility)
870 MCSymbol *Name = getSymbol(&F);
871 EmitVisibility(Name, V, false);
874 // Get information about jump-instruction tables to print.
875 JumpInstrTableInfo *JITI = getAnalysisIfAvailable<JumpInstrTableInfo>();
877 if (JITI && !JITI->getTables().empty()) {
878 unsigned Arch = Triple(getTargetTriple()).getArch();
879 bool IsThumb = (Arch == Triple::thumb || Arch == Triple::thumbeb);
881 TM.getSubtargetImpl()->getInstrInfo()->getTrap(TrapInst);
882 for (const auto &KV : JITI->getTables()) {
884 for (const auto &FunPair : KV.second) {
885 // Emit the function labels to make this be a function entry point.
887 OutContext.GetOrCreateSymbol(FunPair.second->getName());
888 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_Global);
889 // FIXME: JumpTableInstrInfo should store information about the required
890 // alignment of table entries and the size of the padding instruction.
893 OutStreamer.EmitThumbFunc(FunSym);
894 if (MAI->hasDotTypeDotSizeDirective())
895 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_ELF_TypeFunction);
896 OutStreamer.EmitLabel(FunSym);
898 // Emit the jump instruction to transfer control to the original
901 MCSymbol *TargetSymbol =
902 OutContext.GetOrCreateSymbol(FunPair.first->getName());
903 const MCSymbolRefExpr *TargetSymRef =
904 MCSymbolRefExpr::Create(TargetSymbol, MCSymbolRefExpr::VK_PLT,
906 TM.getSubtargetImpl()->getInstrInfo()->getUnconditionalBranch(
907 JumpToFun, TargetSymRef);
908 OutStreamer.EmitInstruction(JumpToFun, getSubtargetInfo());
912 // Emit enough padding instructions to fill up to the next power of two.
913 // This assumes that the trap instruction takes 8 bytes or fewer.
914 uint64_t Remaining = NextPowerOf2(Count) - Count;
915 for (uint64_t C = 0; C < Remaining; ++C) {
917 OutStreamer.EmitInstruction(TrapInst, getSubtargetInfo());
923 // Emit module flags.
924 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
925 M.getModuleFlagsMetadata(ModuleFlags);
926 if (!ModuleFlags.empty())
927 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
929 // Make sure we wrote out everything we need.
932 // Finalize debug and EH information.
933 for (const HandlerInfo &HI : Handlers) {
934 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
935 TimePassesIsEnabled);
936 HI.Handler->endModule();
942 // If the target wants to know about weak references, print them all.
943 if (MAI->getWeakRefDirective()) {
944 // FIXME: This is not lazy, it would be nice to only print weak references
945 // to stuff that is actually used. Note that doing so would require targets
946 // to notice uses in operands (due to constant exprs etc). This should
947 // happen with the MC stuff eventually.
949 // Print out module-level global variables here.
950 for (const auto &G : M.globals()) {
951 if (!G.hasExternalWeakLinkage())
953 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
956 for (const auto &F : M) {
957 if (!F.hasExternalWeakLinkage())
959 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
963 if (MAI->hasSetDirective()) {
964 OutStreamer.AddBlankLine();
965 for (const auto &Alias : M.aliases()) {
966 MCSymbol *Name = getSymbol(&Alias);
968 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
969 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
970 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
971 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
973 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
975 EmitVisibility(Name, Alias.getVisibility());
977 // Emit the directives as assignments aka .set:
978 OutStreamer.EmitAssignment(Name,
979 lowerConstant(Alias.getAliasee(), *this));
983 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
984 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
985 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
986 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
987 MP->finishAssembly(*this);
989 // Emit llvm.ident metadata in an '.ident' directive.
992 // If we don't have any trampolines, then we don't require stack memory
993 // to be executable. Some targets have a directive to declare this.
994 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
995 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
996 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
997 OutStreamer.SwitchSection(S);
999 // Allow the target to emit any magic that it wants at the end of the file,
1000 // after everything else has gone out.
1001 EmitEndOfAsmFile(M);
1003 delete Mang; Mang = nullptr;
1006 OutStreamer.Finish();
1007 OutStreamer.reset();
1012 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1014 // Get the function symbol.
1015 CurrentFnSym = getSymbol(MF.getFunction());
1016 CurrentFnSymForSize = CurrentFnSym;
1019 LI = &getAnalysis<MachineLoopInfo>();
1023 // SectionCPs - Keep track the alignment, constpool entries per Section.
1027 SmallVector<unsigned, 4> CPEs;
1028 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1032 /// EmitConstantPool - Print to the current output stream assembly
1033 /// representations of the constants in the constant pool MCP. This is
1034 /// used to print out constants which have been "spilled to memory" by
1035 /// the code generator.
1037 void AsmPrinter::EmitConstantPool() {
1038 const MachineConstantPool *MCP = MF->getConstantPool();
1039 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1040 if (CP.empty()) return;
1042 // Calculate sections for constant pool entries. We collect entries to go into
1043 // the same section together to reduce amount of section switch statements.
1044 SmallVector<SectionCPs, 4> CPSections;
1045 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1046 const MachineConstantPoolEntry &CPE = CP[i];
1047 unsigned Align = CPE.getAlignment();
1050 CPE.getSectionKind(TM.getSubtargetImpl()->getDataLayout());
1052 const Constant *C = nullptr;
1053 if (!CPE.isMachineConstantPoolEntry())
1054 C = CPE.Val.ConstVal;
1056 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind, C);
1058 // The number of sections are small, just do a linear search from the
1059 // last section to the first.
1061 unsigned SecIdx = CPSections.size();
1062 while (SecIdx != 0) {
1063 if (CPSections[--SecIdx].S == S) {
1069 SecIdx = CPSections.size();
1070 CPSections.push_back(SectionCPs(S, Align));
1073 if (Align > CPSections[SecIdx].Alignment)
1074 CPSections[SecIdx].Alignment = Align;
1075 CPSections[SecIdx].CPEs.push_back(i);
1078 // Now print stuff into the calculated sections.
1079 const MCSection *CurSection = nullptr;
1080 unsigned Offset = 0;
1081 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1082 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1083 unsigned CPI = CPSections[i].CPEs[j];
1084 MCSymbol *Sym = GetCPISymbol(CPI);
1085 if (!Sym->isUndefined())
1088 if (CurSection != CPSections[i].S) {
1089 OutStreamer.SwitchSection(CPSections[i].S);
1090 EmitAlignment(Log2_32(CPSections[i].Alignment));
1091 CurSection = CPSections[i].S;
1095 MachineConstantPoolEntry CPE = CP[CPI];
1097 // Emit inter-object padding for alignment.
1098 unsigned AlignMask = CPE.getAlignment() - 1;
1099 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1100 OutStreamer.EmitZeros(NewOffset - Offset);
1102 Type *Ty = CPE.getType();
1103 Offset = NewOffset +
1104 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(Ty);
1106 OutStreamer.EmitLabel(Sym);
1107 if (CPE.isMachineConstantPoolEntry())
1108 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1110 EmitGlobalConstant(CPE.Val.ConstVal);
1115 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1116 /// by the current function to the current output stream.
1118 void AsmPrinter::EmitJumpTableInfo() {
1119 const DataLayout *DL = MF->getSubtarget().getDataLayout();
1120 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1122 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1123 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1124 if (JT.empty()) return;
1126 // Pick the directive to use to print the jump table entries, and switch to
1127 // the appropriate section.
1128 const Function *F = MF->getFunction();
1129 bool JTInDiffSection = false;
1130 if (// In PIC mode, we need to emit the jump table to the same section as the
1131 // function body itself, otherwise the label differences won't make sense.
1132 // FIXME: Need a better predicate for this: what about custom entries?
1133 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1134 // We should also do if the section name is NULL or function is declared
1135 // in discardable section
1136 // FIXME: this isn't the right predicate, should be based on the MCSection
1137 // for the function.
1138 F->isWeakForLinker()) {
1139 OutStreamer.SwitchSection(
1140 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1142 // Otherwise, drop it in the readonly section.
1143 const MCSection *ReadOnlySection =
1144 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
1146 OutStreamer.SwitchSection(ReadOnlySection);
1147 JTInDiffSection = true;
1150 EmitAlignment(Log2_32(
1151 MJTI->getEntryAlignment(*TM.getSubtargetImpl()->getDataLayout())));
1153 // Jump tables in code sections are marked with a data_region directive
1154 // where that's supported.
1155 if (!JTInDiffSection)
1156 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1158 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1159 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1161 // If this jump table was deleted, ignore it.
1162 if (JTBBs.empty()) continue;
1164 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1165 // .set directive for each unique entry. This reduces the number of
1166 // relocations the assembler will generate for the jump table.
1167 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1168 MAI->hasSetDirective()) {
1169 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1170 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1171 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1172 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1173 const MachineBasicBlock *MBB = JTBBs[ii];
1174 if (!EmittedSets.insert(MBB)) continue;
1176 // .set LJTSet, LBB32-base
1178 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1179 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1180 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1184 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1185 // before each jump table. The first label is never referenced, but tells
1186 // the assembler and linker the extents of the jump table object. The
1187 // second label is actually referenced by the code.
1188 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1189 // FIXME: This doesn't have to have any specific name, just any randomly
1190 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1191 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1193 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1195 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1196 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1198 if (!JTInDiffSection)
1199 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1202 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1204 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1205 const MachineBasicBlock *MBB,
1206 unsigned UID) const {
1207 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1208 const MCExpr *Value = nullptr;
1209 switch (MJTI->getEntryKind()) {
1210 case MachineJumpTableInfo::EK_Inline:
1211 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1212 case MachineJumpTableInfo::EK_Custom32:
1214 TM.getSubtargetImpl()->getTargetLowering()->LowerCustomJumpTableEntry(
1215 MJTI, MBB, UID, OutContext);
1217 case MachineJumpTableInfo::EK_BlockAddress:
1218 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1220 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1222 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1223 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1224 // with a relocation as gp-relative, e.g.:
1226 MCSymbol *MBBSym = MBB->getSymbol();
1227 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1231 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1232 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1233 // with a relocation as gp-relative, e.g.:
1235 MCSymbol *MBBSym = MBB->getSymbol();
1236 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1240 case MachineJumpTableInfo::EK_LabelDifference32: {
1241 // EK_LabelDifference32 - Each entry is the address of the block minus
1242 // the address of the jump table. This is used for PIC jump tables where
1243 // gprel32 is not supported. e.g.:
1244 // .word LBB123 - LJTI1_2
1245 // If the .set directive is supported, this is emitted as:
1246 // .set L4_5_set_123, LBB123 - LJTI1_2
1247 // .word L4_5_set_123
1249 // If we have emitted set directives for the jump table entries, print
1250 // them rather than the entries themselves. If we're emitting PIC, then
1251 // emit the table entries as differences between two text section labels.
1252 if (MAI->hasSetDirective()) {
1253 // If we used .set, reference the .set's symbol.
1254 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1258 // Otherwise, use the difference as the jump table entry.
1259 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1260 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1261 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1266 assert(Value && "Unknown entry kind!");
1268 unsigned EntrySize =
1269 MJTI->getEntrySize(*TM.getSubtargetImpl()->getDataLayout());
1270 OutStreamer.EmitValue(Value, EntrySize);
1274 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1275 /// special global used by LLVM. If so, emit it and return true, otherwise
1276 /// do nothing and return false.
1277 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1278 if (GV->getName() == "llvm.used") {
1279 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1280 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1284 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1285 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1286 GV->hasAvailableExternallyLinkage())
1289 if (!GV->hasAppendingLinkage()) return false;
1291 assert(GV->hasInitializer() && "Not a special LLVM global!");
1293 if (GV->getName() == "llvm.global_ctors") {
1294 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1296 if (TM.getRelocationModel() == Reloc::Static &&
1297 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1298 StringRef Sym(".constructors_used");
1299 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1305 if (GV->getName() == "llvm.global_dtors") {
1306 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1308 if (TM.getRelocationModel() == Reloc::Static &&
1309 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1310 StringRef Sym(".destructors_used");
1311 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1320 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1321 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1322 /// is true, as being used with this directive.
1323 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1324 // Should be an array of 'i8*'.
1325 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1326 const GlobalValue *GV =
1327 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1329 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1335 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1337 llvm::Constant *Func;
1338 llvm::GlobalValue *ComdatKey;
1342 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1344 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1345 // Should be an array of '{ int, void ()* }' structs. The first value is the
1347 if (!isa<ConstantArray>(List)) return;
1349 // Sanity check the structors list.
1350 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1351 if (!InitList) return; // Not an array!
1352 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1353 // FIXME: Only allow the 3-field form in LLVM 4.0.
1354 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1355 return; // Not an array of two or three elements!
1356 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1357 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1358 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1359 return; // Not (int, ptr, ptr).
1361 // Gather the structors in a form that's convenient for sorting by priority.
1362 SmallVector<Structor, 8> Structors;
1363 for (Value *O : InitList->operands()) {
1364 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1365 if (!CS) continue; // Malformed.
1366 if (CS->getOperand(1)->isNullValue())
1367 break; // Found a null terminator, skip the rest.
1368 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1369 if (!Priority) continue; // Malformed.
1370 Structors.push_back(Structor());
1371 Structor &S = Structors.back();
1372 S.Priority = Priority->getLimitedValue(65535);
1373 S.Func = CS->getOperand(1);
1374 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1375 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1378 // Emit the function pointers in the target-specific order
1379 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
1380 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1381 std::stable_sort(Structors.begin(), Structors.end(),
1382 [](const Structor &L,
1383 const Structor &R) { return L.Priority < R.Priority; });
1384 for (Structor &S : Structors) {
1385 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1386 const MCSymbol *KeySym = nullptr;
1387 if (GlobalValue *GV = S.ComdatKey) {
1388 if (GV->hasAvailableExternallyLinkage())
1389 // If the associated variable is available_externally, some other TU
1390 // will provide its dynamic initializer.
1393 KeySym = getSymbol(GV);
1395 const MCSection *OutputSection =
1396 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1397 : Obj.getStaticDtorSection(S.Priority, KeySym));
1398 OutStreamer.SwitchSection(OutputSection);
1399 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1400 EmitAlignment(Align);
1401 EmitXXStructor(S.Func);
1405 void AsmPrinter::EmitModuleIdents(Module &M) {
1406 if (!MAI->hasIdentDirective())
1409 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1410 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1411 const MDNode *N = NMD->getOperand(i);
1412 assert(N->getNumOperands() == 1 &&
1413 "llvm.ident metadata entry can have only one operand");
1414 const MDString *S = cast<MDString>(N->getOperand(0));
1415 OutStreamer.EmitIdent(S->getString());
1420 //===--------------------------------------------------------------------===//
1421 // Emission and print routines
1424 /// EmitInt8 - Emit a byte directive and value.
1426 void AsmPrinter::EmitInt8(int Value) const {
1427 OutStreamer.EmitIntValue(Value, 1);
1430 /// EmitInt16 - Emit a short directive and value.
1432 void AsmPrinter::EmitInt16(int Value) const {
1433 OutStreamer.EmitIntValue(Value, 2);
1436 /// EmitInt32 - Emit a long directive and value.
1438 void AsmPrinter::EmitInt32(int Value) const {
1439 OutStreamer.EmitIntValue(Value, 4);
1442 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1443 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1444 /// labels. This implicitly uses .set if it is available.
1445 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1446 unsigned Size) const {
1447 // Get the Hi-Lo expression.
1448 const MCExpr *Diff =
1449 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1450 MCSymbolRefExpr::Create(Lo, OutContext),
1453 if (!MAI->hasSetDirective()) {
1454 OutStreamer.EmitValue(Diff, Size);
1458 // Otherwise, emit with .set (aka assignment).
1459 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1460 OutStreamer.EmitAssignment(SetLabel, Diff);
1461 OutStreamer.EmitSymbolValue(SetLabel, Size);
1464 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1465 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1466 /// specify the labels. This implicitly uses .set if it is available.
1467 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1469 unsigned Size) const {
1471 // Emit Hi+Offset - Lo
1472 // Get the Hi+Offset expression.
1473 const MCExpr *Plus =
1474 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1475 MCConstantExpr::Create(Offset, OutContext),
1478 // Get the Hi+Offset-Lo expression.
1479 const MCExpr *Diff =
1480 MCBinaryExpr::CreateSub(Plus,
1481 MCSymbolRefExpr::Create(Lo, OutContext),
1484 if (!MAI->hasSetDirective())
1485 OutStreamer.EmitValue(Diff, Size);
1487 // Otherwise, emit with .set (aka assignment).
1488 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1489 OutStreamer.EmitAssignment(SetLabel, Diff);
1490 OutStreamer.EmitSymbolValue(SetLabel, Size);
1494 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1495 /// where the size in bytes of the directive is specified by Size and Label
1496 /// specifies the label. This implicitly uses .set if it is available.
1497 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1499 bool IsSectionRelative) const {
1500 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1501 OutStreamer.EmitCOFFSecRel32(Label);
1505 // Emit Label+Offset (or just Label if Offset is zero)
1506 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1508 Expr = MCBinaryExpr::CreateAdd(
1509 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1511 OutStreamer.EmitValue(Expr, Size);
1514 //===----------------------------------------------------------------------===//
1516 // EmitAlignment - Emit an alignment directive to the specified power of
1517 // two boundary. For example, if you pass in 3 here, you will get an 8
1518 // byte alignment. If a global value is specified, and if that global has
1519 // an explicit alignment requested, it will override the alignment request
1520 // if required for correctness.
1522 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1524 NumBits = getGVAlignmentLog2(GV, *TM.getSubtargetImpl()->getDataLayout(),
1527 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1529 if (getCurrentSection()->getKind().isText())
1530 OutStreamer.EmitCodeAlignment(1 << NumBits);
1532 OutStreamer.EmitValueToAlignment(1 << NumBits);
1535 //===----------------------------------------------------------------------===//
1536 // Constant emission.
1537 //===----------------------------------------------------------------------===//
1539 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1541 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1542 MCContext &Ctx = AP.OutContext;
1544 if (CV->isNullValue() || isa<UndefValue>(CV))
1545 return MCConstantExpr::Create(0, Ctx);
1547 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1548 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1550 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1551 return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx);
1553 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1554 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1556 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1558 llvm_unreachable("Unknown constant value to lower!");
1561 if (const MCExpr *RelocExpr =
1562 AP.getObjFileLowering().getExecutableRelativeSymbol(CE, *AP.Mang,
1566 switch (CE->getOpcode()) {
1568 // If the code isn't optimized, there may be outstanding folding
1569 // opportunities. Attempt to fold the expression using DataLayout as a
1570 // last resort before giving up.
1571 if (Constant *C = ConstantFoldConstantExpression(
1572 CE, AP.TM.getSubtargetImpl()->getDataLayout()))
1574 return lowerConstant(C, AP);
1576 // Otherwise report the problem to the user.
1579 raw_string_ostream OS(S);
1580 OS << "Unsupported expression in static initializer: ";
1581 CE->printAsOperand(OS, /*PrintType=*/false,
1582 !AP.MF ? nullptr : AP.MF->getFunction()->getParent());
1583 report_fatal_error(OS.str());
1585 case Instruction::GetElementPtr: {
1586 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1587 // Generate a symbolic expression for the byte address
1588 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1589 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1591 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1595 int64_t Offset = OffsetAI.getSExtValue();
1596 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1600 case Instruction::Trunc:
1601 // We emit the value and depend on the assembler to truncate the generated
1602 // expression properly. This is important for differences between
1603 // blockaddress labels. Since the two labels are in the same function, it
1604 // is reasonable to treat their delta as a 32-bit value.
1606 case Instruction::BitCast:
1607 return lowerConstant(CE->getOperand(0), AP);
1609 case Instruction::IntToPtr: {
1610 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1611 // Handle casts to pointers by changing them into casts to the appropriate
1612 // integer type. This promotes constant folding and simplifies this code.
1613 Constant *Op = CE->getOperand(0);
1614 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1616 return lowerConstant(Op, AP);
1619 case Instruction::PtrToInt: {
1620 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1621 // Support only foldable casts to/from pointers that can be eliminated by
1622 // changing the pointer to the appropriately sized integer type.
1623 Constant *Op = CE->getOperand(0);
1624 Type *Ty = CE->getType();
1626 const MCExpr *OpExpr = lowerConstant(Op, AP);
1628 // We can emit the pointer value into this slot if the slot is an
1629 // integer slot equal to the size of the pointer.
1630 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1633 // Otherwise the pointer is smaller than the resultant integer, mask off
1634 // the high bits so we are sure to get a proper truncation if the input is
1636 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1637 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1638 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1641 // The MC library also has a right-shift operator, but it isn't consistently
1642 // signed or unsigned between different targets.
1643 case Instruction::Add:
1644 case Instruction::Sub:
1645 case Instruction::Mul:
1646 case Instruction::SDiv:
1647 case Instruction::SRem:
1648 case Instruction::Shl:
1649 case Instruction::And:
1650 case Instruction::Or:
1651 case Instruction::Xor: {
1652 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1653 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1654 switch (CE->getOpcode()) {
1655 default: llvm_unreachable("Unknown binary operator constant cast expr");
1656 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1657 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1658 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1659 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1660 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1661 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1662 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1663 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1664 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1670 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1672 /// isRepeatedByteSequence - Determine whether the given value is
1673 /// composed of a repeated sequence of identical bytes and return the
1674 /// byte value. If it is not a repeated sequence, return -1.
1675 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1676 StringRef Data = V->getRawDataValues();
1677 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1679 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1680 if (Data[i] != C) return -1;
1681 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1685 /// isRepeatedByteSequence - Determine whether the given value is
1686 /// composed of a repeated sequence of identical bytes and return the
1687 /// byte value. If it is not a repeated sequence, return -1.
1688 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1690 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1691 if (CI->getBitWidth() > 64) return -1;
1694 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(V->getType());
1695 uint64_t Value = CI->getZExtValue();
1697 // Make sure the constant is at least 8 bits long and has a power
1698 // of 2 bit width. This guarantees the constant bit width is
1699 // always a multiple of 8 bits, avoiding issues with padding out
1700 // to Size and other such corner cases.
1701 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1703 uint8_t Byte = static_cast<uint8_t>(Value);
1705 for (unsigned i = 1; i < Size; ++i) {
1707 if (static_cast<uint8_t>(Value) != Byte) return -1;
1711 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1712 // Make sure all array elements are sequences of the same repeated
1714 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1715 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1716 if (Byte == -1) return -1;
1718 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1719 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1720 if (ThisByte == -1) return -1;
1721 if (Byte != ThisByte) return -1;
1726 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1727 return isRepeatedByteSequence(CDS);
1732 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1735 // See if we can aggregate this into a .fill, if so, emit it as such.
1736 int Value = isRepeatedByteSequence(CDS, AP.TM);
1739 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1741 // Don't emit a 1-byte object as a .fill.
1743 return AP.OutStreamer.EmitFill(Bytes, Value);
1746 // If this can be emitted with .ascii/.asciz, emit it as such.
1747 if (CDS->isString())
1748 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1750 // Otherwise, emit the values in successive locations.
1751 unsigned ElementByteSize = CDS->getElementByteSize();
1752 if (isa<IntegerType>(CDS->getElementType())) {
1753 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1755 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1756 CDS->getElementAsInteger(i));
1757 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1760 } else if (ElementByteSize == 4) {
1761 // FP Constants are printed as integer constants to avoid losing
1763 assert(CDS->getElementType()->isFloatTy());
1764 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1770 F = CDS->getElementAsFloat(i);
1772 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1773 AP.OutStreamer.EmitIntValue(I, 4);
1776 assert(CDS->getElementType()->isDoubleTy());
1777 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1783 F = CDS->getElementAsDouble(i);
1785 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1786 AP.OutStreamer.EmitIntValue(I, 8);
1790 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1791 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1792 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1793 CDS->getNumElements();
1794 if (unsigned Padding = Size - EmittedSize)
1795 AP.OutStreamer.EmitZeros(Padding);
1799 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1800 // See if we can aggregate some values. Make sure it can be
1801 // represented as a series of bytes of the constant value.
1802 int Value = isRepeatedByteSequence(CA, AP.TM);
1806 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1808 AP.OutStreamer.EmitFill(Bytes, Value);
1811 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1812 emitGlobalConstantImpl(CA->getOperand(i), AP);
1816 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1817 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1818 emitGlobalConstantImpl(CV->getOperand(i), AP);
1820 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1821 unsigned Size = DL.getTypeAllocSize(CV->getType());
1822 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1823 CV->getType()->getNumElements();
1824 if (unsigned Padding = Size - EmittedSize)
1825 AP.OutStreamer.EmitZeros(Padding);
1828 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1829 // Print the fields in successive locations. Pad to align if needed!
1830 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1831 unsigned Size = DL->getTypeAllocSize(CS->getType());
1832 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1833 uint64_t SizeSoFar = 0;
1834 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1835 const Constant *Field = CS->getOperand(i);
1837 // Check if padding is needed and insert one or more 0s.
1838 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1839 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1840 - Layout->getElementOffset(i)) - FieldSize;
1841 SizeSoFar += FieldSize + PadSize;
1843 // Now print the actual field value.
1844 emitGlobalConstantImpl(Field, AP);
1846 // Insert padding - this may include padding to increase the size of the
1847 // current field up to the ABI size (if the struct is not packed) as well
1848 // as padding to ensure that the next field starts at the right offset.
1849 AP.OutStreamer.EmitZeros(PadSize);
1851 assert(SizeSoFar == Layout->getSizeInBytes() &&
1852 "Layout of constant struct may be incorrect!");
1855 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1856 APInt API = CFP->getValueAPF().bitcastToAPInt();
1858 // First print a comment with what we think the original floating-point value
1859 // should have been.
1860 if (AP.isVerbose()) {
1861 SmallString<8> StrVal;
1862 CFP->getValueAPF().toString(StrVal);
1865 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1867 AP.OutStreamer.GetCommentOS() << "Printing <null> Type";
1868 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1871 // Now iterate through the APInt chunks, emitting them in endian-correct
1872 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1874 unsigned NumBytes = API.getBitWidth() / 8;
1875 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1876 const uint64_t *p = API.getRawData();
1878 // PPC's long double has odd notions of endianness compared to how LLVM
1879 // handles it: p[0] goes first for *big* endian on PPC.
1880 if (AP.TM.getSubtargetImpl()->getDataLayout()->isBigEndian() &&
1881 !CFP->getType()->isPPC_FP128Ty()) {
1882 int Chunk = API.getNumWords() - 1;
1885 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1887 for (; Chunk >= 0; --Chunk)
1888 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1891 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1892 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1895 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1898 // Emit the tail padding for the long double.
1899 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1900 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1901 DL.getTypeStoreSize(CFP->getType()));
1904 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1905 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1906 unsigned BitWidth = CI->getBitWidth();
1908 // Copy the value as we may massage the layout for constants whose bit width
1909 // is not a multiple of 64-bits.
1910 APInt Realigned(CI->getValue());
1911 uint64_t ExtraBits = 0;
1912 unsigned ExtraBitsSize = BitWidth & 63;
1914 if (ExtraBitsSize) {
1915 // The bit width of the data is not a multiple of 64-bits.
1916 // The extra bits are expected to be at the end of the chunk of the memory.
1918 // * Nothing to be done, just record the extra bits to emit.
1920 // * Record the extra bits to emit.
1921 // * Realign the raw data to emit the chunks of 64-bits.
1922 if (DL->isBigEndian()) {
1923 // Basically the structure of the raw data is a chunk of 64-bits cells:
1924 // 0 1 BitWidth / 64
1925 // [chunk1][chunk2] ... [chunkN].
1926 // The most significant chunk is chunkN and it should be emitted first.
1927 // However, due to the alignment issue chunkN contains useless bits.
1928 // Realign the chunks so that they contain only useless information:
1929 // ExtraBits 0 1 (BitWidth / 64) - 1
1930 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1931 ExtraBits = Realigned.getRawData()[0] &
1932 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1933 Realigned = Realigned.lshr(ExtraBitsSize);
1935 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1938 // We don't expect assemblers to support integer data directives
1939 // for more than 64 bits, so we emit the data in at most 64-bit
1940 // quantities at a time.
1941 const uint64_t *RawData = Realigned.getRawData();
1942 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1943 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1944 AP.OutStreamer.EmitIntValue(Val, 8);
1947 if (ExtraBitsSize) {
1948 // Emit the extra bits after the 64-bits chunks.
1950 // Emit a directive that fills the expected size.
1951 uint64_t Size = AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1953 Size -= (BitWidth / 64) * 8;
1954 assert(Size && Size * 8 >= ExtraBitsSize &&
1955 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1956 == ExtraBits && "Directive too small for extra bits.");
1957 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1961 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1962 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1963 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1964 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1965 return AP.OutStreamer.EmitZeros(Size);
1967 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1974 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1975 CI->getZExtValue());
1976 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1979 emitGlobalConstantLargeInt(CI, AP);
1984 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1985 return emitGlobalConstantFP(CFP, AP);
1987 if (isa<ConstantPointerNull>(CV)) {
1988 AP.OutStreamer.EmitIntValue(0, Size);
1992 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1993 return emitGlobalConstantDataSequential(CDS, AP);
1995 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1996 return emitGlobalConstantArray(CVA, AP);
1998 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1999 return emitGlobalConstantStruct(CVS, AP);
2001 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2002 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2004 if (CE->getOpcode() == Instruction::BitCast)
2005 return emitGlobalConstantImpl(CE->getOperand(0), AP);
2008 // If the constant expression's size is greater than 64-bits, then we have
2009 // to emit the value in chunks. Try to constant fold the value and emit it
2011 Constant *New = ConstantFoldConstantExpression(CE, DL);
2012 if (New && New != CE)
2013 return emitGlobalConstantImpl(New, AP);
2017 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2018 return emitGlobalConstantVector(V, AP);
2020 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2021 // thread the streamer with EmitValue.
2022 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
2025 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2026 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2028 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(CV->getType());
2030 emitGlobalConstantImpl(CV, *this);
2031 else if (MAI->hasSubsectionsViaSymbols()) {
2032 // If the global has zero size, emit a single byte so that two labels don't
2033 // look like they are at the same location.
2034 OutStreamer.EmitIntValue(0, 1);
2038 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2039 // Target doesn't support this yet!
2040 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2043 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2045 OS << '+' << Offset;
2046 else if (Offset < 0)
2050 //===----------------------------------------------------------------------===//
2051 // Symbol Lowering Routines.
2052 //===----------------------------------------------------------------------===//
2054 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2055 /// temporary label with the specified stem and unique ID.
2056 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const {
2057 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2058 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2062 /// GetTempSymbol - Return an assembler temporary label with the specified
2064 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const {
2065 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2066 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2071 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2072 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2075 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2076 return MMI->getAddrLabelSymbol(BB);
2079 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2080 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2081 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2082 return OutContext.GetOrCreateSymbol
2083 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2084 + "_" + Twine(CPID));
2087 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2088 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2089 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2092 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2093 /// FIXME: privatize to AsmPrinter.
2094 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2095 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2096 return OutContext.GetOrCreateSymbol
2097 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2098 Twine(UID) + "_set_" + Twine(MBBID));
2101 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2102 StringRef Suffix) const {
2103 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2107 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2109 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2110 SmallString<60> NameStr;
2111 Mang->getNameWithPrefix(NameStr, Sym);
2112 return OutContext.GetOrCreateSymbol(NameStr.str());
2117 /// PrintParentLoopComment - Print comments about parent loops of this one.
2118 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2119 unsigned FunctionNumber) {
2121 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2122 OS.indent(Loop->getLoopDepth()*2)
2123 << "Parent Loop BB" << FunctionNumber << "_"
2124 << Loop->getHeader()->getNumber()
2125 << " Depth=" << Loop->getLoopDepth() << '\n';
2129 /// PrintChildLoopComment - Print comments about child loops within
2130 /// the loop for this basic block, with nesting.
2131 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2132 unsigned FunctionNumber) {
2133 // Add child loop information
2134 for (const MachineLoop *CL : *Loop) {
2135 OS.indent(CL->getLoopDepth()*2)
2136 << "Child Loop BB" << FunctionNumber << "_"
2137 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2139 PrintChildLoopComment(OS, CL, FunctionNumber);
2143 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2144 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2145 const MachineLoopInfo *LI,
2146 const AsmPrinter &AP) {
2147 // Add loop depth information
2148 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2151 MachineBasicBlock *Header = Loop->getHeader();
2152 assert(Header && "No header for loop");
2154 // If this block is not a loop header, just print out what is the loop header
2156 if (Header != &MBB) {
2157 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2158 Twine(AP.getFunctionNumber())+"_" +
2159 Twine(Loop->getHeader()->getNumber())+
2160 " Depth="+Twine(Loop->getLoopDepth()));
2164 // Otherwise, it is a loop header. Print out information about child and
2166 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2168 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2171 OS.indent(Loop->getLoopDepth()*2-2);
2176 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2178 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2182 /// EmitBasicBlockStart - This method prints the label for the specified
2183 /// MachineBasicBlock, an alignment (if present) and a comment describing
2184 /// it if appropriate.
2185 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2186 // Emit an alignment directive for this block, if needed.
2187 if (unsigned Align = MBB.getAlignment())
2188 EmitAlignment(Align);
2190 // If the block has its address taken, emit any labels that were used to
2191 // reference the block. It is possible that there is more than one label
2192 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2193 // the references were generated.
2194 if (MBB.hasAddressTaken()) {
2195 const BasicBlock *BB = MBB.getBasicBlock();
2197 OutStreamer.AddComment("Block address taken");
2199 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2200 for (auto *Sym : Symbols)
2201 OutStreamer.EmitLabel(Sym);
2204 // Print some verbose block comments.
2206 if (const BasicBlock *BB = MBB.getBasicBlock())
2208 OutStreamer.AddComment("%" + BB->getName());
2209 emitBasicBlockLoopComments(MBB, LI, *this);
2212 // Print the main label for the block.
2213 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2215 // NOTE: Want this comment at start of line, don't emit with AddComment.
2216 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2219 OutStreamer.EmitLabel(MBB.getSymbol());
2223 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2224 bool IsDefinition) const {
2225 MCSymbolAttr Attr = MCSA_Invalid;
2227 switch (Visibility) {
2229 case GlobalValue::HiddenVisibility:
2231 Attr = MAI->getHiddenVisibilityAttr();
2233 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2235 case GlobalValue::ProtectedVisibility:
2236 Attr = MAI->getProtectedVisibilityAttr();
2240 if (Attr != MCSA_Invalid)
2241 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2244 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2245 /// exactly one predecessor and the control transfer mechanism between
2246 /// the predecessor and this block is a fall-through.
2248 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2249 // If this is a landing pad, it isn't a fall through. If it has no preds,
2250 // then nothing falls through to it.
2251 if (MBB->isLandingPad() || MBB->pred_empty())
2254 // If there isn't exactly one predecessor, it can't be a fall through.
2255 if (MBB->pred_size() > 1)
2258 // The predecessor has to be immediately before this block.
2259 MachineBasicBlock *Pred = *MBB->pred_begin();
2260 if (!Pred->isLayoutSuccessor(MBB))
2263 // If the block is completely empty, then it definitely does fall through.
2267 // Check the terminators in the previous blocks
2268 for (const auto &MI : Pred->terminators()) {
2269 // If it is not a simple branch, we are in a table somewhere.
2270 if (!MI.isBranch() || MI.isIndirectBranch())
2273 // If we are the operands of one of the branches, this is not a fall
2274 // through. Note that targets with delay slots will usually bundle
2275 // terminators with the delay slot instruction.
2276 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2279 if (OP->isMBB() && OP->getMBB() == MBB)
2289 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2290 if (!S.usesMetadata())
2293 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2294 gcp_map_type::iterator GCPI = GCMap.find(&S);
2295 if (GCPI != GCMap.end())
2296 return GCPI->second.get();
2298 const char *Name = S.getName().c_str();
2300 for (GCMetadataPrinterRegistry::iterator
2301 I = GCMetadataPrinterRegistry::begin(),
2302 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2303 if (strcmp(Name, I->getName()) == 0) {
2304 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2306 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2307 return IterBool.first->second.get();
2310 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2313 /// Pin vtable to this file.
2314 AsmPrinterHandler::~AsmPrinterHandler() {}