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 "WinCodeViewLineTables.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/Statistic.h"
20 #include "llvm/Analysis/ConstantFolding.h"
21 #include "llvm/Analysis/JumpInstrTableInfo.h"
22 #include "llvm/CodeGen/GCMetadataPrinter.h"
23 #include "llvm/CodeGen/MachineConstantPool.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineInstrBundle.h"
27 #include "llvm/CodeGen/MachineJumpTableInfo.h"
28 #include "llvm/CodeGen/MachineLoopInfo.h"
29 #include "llvm/CodeGen/MachineModuleInfo.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/DebugInfo.h"
32 #include "llvm/IR/Mangler.h"
33 #include "llvm/IR/Module.h"
34 #include "llvm/IR/Operator.h"
35 #include "llvm/MC/MCAsmInfo.h"
36 #include "llvm/MC/MCContext.h"
37 #include "llvm/MC/MCExpr.h"
38 #include "llvm/MC/MCInst.h"
39 #include "llvm/MC/MCSection.h"
40 #include "llvm/MC/MCStreamer.h"
41 #include "llvm/MC/MCSymbol.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include "llvm/Support/Format.h"
44 #include "llvm/Support/MathExtras.h"
45 #include "llvm/Support/Timer.h"
46 #include "llvm/Target/TargetFrameLowering.h"
47 #include "llvm/Target/TargetInstrInfo.h"
48 #include "llvm/Target/TargetLowering.h"
49 #include "llvm/Target/TargetLoweringObjectFile.h"
50 #include "llvm/Target/TargetRegisterInfo.h"
51 #include "llvm/Target/TargetSubtargetInfo.h"
52 #include "llvm/Transforms/Utils/GlobalStatus.h"
55 #define DEBUG_TYPE "asm-printer"
57 static const char *const DWARFGroupName = "DWARF Emission";
58 static const char *const DbgTimerName = "Debug Info Emission";
59 static const char *const EHTimerName = "DWARF Exception Writer";
60 static const char *const CodeViewLineTablesGroupName = "CodeView Line Tables";
62 STATISTIC(EmittedInsts, "Number of machine instrs printed");
64 char AsmPrinter::ID = 0;
66 typedef DenseMap<GCStrategy*, std::unique_ptr<GCMetadataPrinter>> gcp_map_type;
67 static gcp_map_type &getGCMap(void *&P) {
69 P = new gcp_map_type();
70 return *(gcp_map_type*)P;
74 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
75 /// value in log2 form. This rounds up to the preferred alignment if possible
77 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD,
78 unsigned InBits = 0) {
80 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
81 NumBits = TD.getPreferredAlignmentLog(GVar);
83 // If InBits is specified, round it to it.
87 // If the GV has a specified alignment, take it into account.
88 if (GV->getAlignment() == 0)
91 unsigned GVAlign = Log2_32(GV->getAlignment());
93 // If the GVAlign is larger than NumBits, or if we are required to obey
94 // NumBits because the GV has an assigned section, obey it.
95 if (GVAlign > NumBits || GV->hasSection())
100 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
101 : MachineFunctionPass(ID),
102 TM(tm), MAI(tm.getMCAsmInfo()), MII(tm.getInstrInfo()),
103 OutContext(Streamer.getContext()),
104 OutStreamer(Streamer),
105 LastMI(nullptr), 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.getTargetLowering()->getObjFileLowering();
135 /// getDataLayout - Return information about data layout.
136 const DataLayout &AsmPrinter::getDataLayout() const {
137 return *TM.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.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 ES = new Win64Exception(this);
251 Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
255 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
256 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
257 if (Linkage != GlobalValue::LinkOnceODRLinkage)
260 if (!MAI.hasWeakDefCanBeHiddenDirective())
263 if (GV->hasUnnamedAddr())
266 // This is only used for MachO, so right now it doesn't really matter how
267 // we handle alias. Revisit this once the MachO linker implements aliases.
268 if (isa<GlobalAlias>(GV))
271 // If it is a non constant variable, it needs to be uniqued across shared
273 if (const GlobalVariable *Var = dyn_cast<GlobalVariable>(GV)) {
274 if (!Var->isConstant())
279 if (!GlobalStatus::analyzeGlobal(GV, GS) && !GS.IsCompared)
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))
347 GV->printAsOperand(OutStreamer.GetCommentOS(),
348 /*PrintType=*/false, GV->getParent());
349 OutStreamer.GetCommentOS() << '\n';
353 MCSymbol *GVSym = getSymbol(GV);
354 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
356 if (!GV->hasInitializer()) // External globals require no extra code.
359 if (MAI->hasDotTypeDotSizeDirective())
360 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
362 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
364 const DataLayout *DL = TM.getDataLayout();
365 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
367 // If the alignment is specified, we *must* obey it. Overaligning a global
368 // with a specified alignment is a prompt way to break globals emitted to
369 // sections and expected to be contiguous (e.g. ObjC metadata).
370 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
372 for (const HandlerInfo &HI : Handlers) {
373 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
374 HI.Handler->setSymbolSize(GVSym, Size);
377 // Handle common and BSS local symbols (.lcomm).
378 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
379 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
380 unsigned Align = 1 << AlignLog;
382 // Handle common symbols.
383 if (GVKind.isCommon()) {
384 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
388 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
392 // Handle local BSS symbols.
393 if (MAI->hasMachoZeroFillDirective()) {
394 const MCSection *TheSection =
395 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
396 // .zerofill __DATA, __bss, _foo, 400, 5
397 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
401 // Use .lcomm only if it supports user-specified alignment.
402 // Otherwise, while it would still be correct to use .lcomm in some
403 // cases (e.g. when Align == 1), the external assembler might enfore
404 // some -unknown- default alignment behavior, which could cause
405 // spurious differences between external and integrated assembler.
406 // Prefer to simply fall back to .local / .comm in this case.
407 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
409 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
413 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
417 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
419 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
423 const MCSection *TheSection =
424 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
426 // Handle the zerofill directive on darwin, which is a special form of BSS
428 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
429 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
432 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
433 // .zerofill __DATA, __common, _foo, 400, 5
434 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
438 // Handle thread local data for mach-o which requires us to output an
439 // additional structure of data and mangle the original symbol so that we
440 // can reference it later.
442 // TODO: This should become an "emit thread local global" method on TLOF.
443 // All of this macho specific stuff should be sunk down into TLOFMachO and
444 // stuff like "TLSExtraDataSection" should no longer be part of the parent
445 // TLOF class. This will also make it more obvious that stuff like
446 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
448 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
449 // Emit the .tbss symbol
451 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
453 if (GVKind.isThreadBSS()) {
454 TheSection = getObjFileLowering().getTLSBSSSection();
455 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
456 } else if (GVKind.isThreadData()) {
457 OutStreamer.SwitchSection(TheSection);
459 EmitAlignment(AlignLog, GV);
460 OutStreamer.EmitLabel(MangSym);
462 EmitGlobalConstant(GV->getInitializer());
465 OutStreamer.AddBlankLine();
467 // Emit the variable struct for the runtime.
468 const MCSection *TLVSect
469 = getObjFileLowering().getTLSExtraDataSection();
471 OutStreamer.SwitchSection(TLVSect);
472 // Emit the linkage here.
473 EmitLinkage(GV, GVSym);
474 OutStreamer.EmitLabel(GVSym);
476 // Three pointers in size:
477 // - __tlv_bootstrap - used to make sure support exists
478 // - spare pointer, used when mapped by the runtime
479 // - pointer to mangled symbol above with initializer
480 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
481 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
483 OutStreamer.EmitIntValue(0, PtrSize);
484 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
486 OutStreamer.AddBlankLine();
490 OutStreamer.SwitchSection(TheSection);
492 EmitLinkage(GV, GVSym);
493 EmitAlignment(AlignLog, GV);
495 OutStreamer.EmitLabel(GVSym);
497 EmitGlobalConstant(GV->getInitializer());
499 if (MAI->hasDotTypeDotSizeDirective())
501 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
503 OutStreamer.AddBlankLine();
506 /// EmitFunctionHeader - This method emits the header for the current
508 void AsmPrinter::EmitFunctionHeader() {
509 // Print out constants referenced by the function
512 // Print the 'header' of function.
513 const Function *F = MF->getFunction();
515 OutStreamer.SwitchSection(
516 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
517 EmitVisibility(CurrentFnSym, F->getVisibility());
519 EmitLinkage(F, CurrentFnSym);
520 EmitAlignment(MF->getAlignment(), F);
522 if (MAI->hasDotTypeDotSizeDirective())
523 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
526 F->printAsOperand(OutStreamer.GetCommentOS(),
527 /*PrintType=*/false, F->getParent());
528 OutStreamer.GetCommentOS() << '\n';
531 // Emit the CurrentFnSym. This is a virtual function to allow targets to
532 // do their wild and crazy things as required.
533 EmitFunctionEntryLabel();
535 // If the function had address-taken blocks that got deleted, then we have
536 // references to the dangling symbols. Emit them at the start of the function
537 // so that we don't get references to undefined symbols.
538 std::vector<MCSymbol*> DeadBlockSyms;
539 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
540 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
541 OutStreamer.AddComment("Address taken block that was later removed");
542 OutStreamer.EmitLabel(DeadBlockSyms[i]);
545 // Emit pre-function debug and/or EH information.
546 for (const HandlerInfo &HI : Handlers) {
547 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
548 HI.Handler->beginFunction(MF);
551 // Emit the prefix data.
552 if (F->hasPrefixData())
553 EmitGlobalConstant(F->getPrefixData());
556 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
557 /// function. This can be overridden by targets as required to do custom stuff.
558 void AsmPrinter::EmitFunctionEntryLabel() {
559 // The function label could have already been emitted if two symbols end up
560 // conflicting due to asm renaming. Detect this and emit an error.
561 if (CurrentFnSym->isUndefined())
562 return OutStreamer.EmitLabel(CurrentFnSym);
564 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
565 "' label emitted multiple times to assembly file");
568 /// emitComments - Pretty-print comments for instructions.
569 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
570 const MachineFunction *MF = MI.getParent()->getParent();
571 const TargetMachine &TM = MF->getTarget();
573 // Check for spills and reloads
576 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
578 // We assume a single instruction only has a spill or reload, not
580 const MachineMemOperand *MMO;
581 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
582 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
583 MMO = *MI.memoperands_begin();
584 CommentOS << MMO->getSize() << "-byte Reload\n";
586 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
587 if (FrameInfo->isSpillSlotObjectIndex(FI))
588 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
589 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
590 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
591 MMO = *MI.memoperands_begin();
592 CommentOS << MMO->getSize() << "-byte Spill\n";
594 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
595 if (FrameInfo->isSpillSlotObjectIndex(FI))
596 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
599 // Check for spill-induced copies
600 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
601 CommentOS << " Reload Reuse\n";
604 /// emitImplicitDef - This method emits the specified machine instruction
605 /// that is an implicit def.
606 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
607 unsigned RegNo = MI->getOperand(0).getReg();
608 OutStreamer.AddComment(Twine("implicit-def: ") +
609 TM.getRegisterInfo()->getName(RegNo));
610 OutStreamer.AddBlankLine();
613 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
614 std::string Str = "kill:";
615 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
616 const MachineOperand &Op = MI->getOperand(i);
617 assert(Op.isReg() && "KILL instruction must have only register operands");
619 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
620 Str += (Op.isDef() ? "<def>" : "<kill>");
622 AP.OutStreamer.AddComment(Str);
623 AP.OutStreamer.AddBlankLine();
626 /// emitDebugValueComment - This method handles the target-independent form
627 /// of DBG_VALUE, returning true if it was able to do so. A false return
628 /// means the target will need to handle MI in EmitInstruction.
629 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
630 // This code handles only the 3-operand target-independent form.
631 if (MI->getNumOperands() != 3)
634 SmallString<128> Str;
635 raw_svector_ostream OS(Str);
636 OS << "DEBUG_VALUE: ";
638 DIVariable V(MI->getOperand(2).getMetadata());
639 if (V.getContext().isSubprogram()) {
640 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
644 OS << V.getName() << " <- ";
646 // The second operand is only an offset if it's an immediate.
647 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
648 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
650 // Register or immediate value. Register 0 means undef.
651 if (MI->getOperand(0).isFPImm()) {
652 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
653 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
654 OS << (double)APF.convertToFloat();
655 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
656 OS << APF.convertToDouble();
658 // There is no good way to print long double. Convert a copy to
659 // double. Ah well, it's only a comment.
661 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
663 OS << "(long double) " << APF.convertToDouble();
665 } else if (MI->getOperand(0).isImm()) {
666 OS << MI->getOperand(0).getImm();
667 } else if (MI->getOperand(0).isCImm()) {
668 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
671 if (MI->getOperand(0).isReg()) {
672 Reg = MI->getOperand(0).getReg();
674 assert(MI->getOperand(0).isFI() && "Unknown operand type");
675 const TargetFrameLowering *TFI = AP.TM.getFrameLowering();
676 Offset += TFI->getFrameIndexReference(*AP.MF,
677 MI->getOperand(0).getIndex(), Reg);
681 // Suppress offset, it is not meaningful here.
683 // NOTE: Want this comment at start of line, don't emit with AddComment.
684 AP.OutStreamer.emitRawComment(OS.str());
689 OS << AP.TM.getRegisterInfo()->getName(Reg);
693 OS << '+' << Offset << ']';
695 // NOTE: Want this comment at start of line, don't emit with AddComment.
696 AP.OutStreamer.emitRawComment(OS.str());
700 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
701 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
702 MF->getFunction()->needsUnwindTableEntry())
705 if (MMI->hasDebugInfo())
711 bool AsmPrinter::needsSEHMoves() {
712 return MAI->getExceptionHandlingType() == ExceptionHandling::WinEH &&
713 MF->getFunction()->needsUnwindTableEntry();
716 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
717 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
718 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
719 ExceptionHandlingType != ExceptionHandling::ARM)
722 if (needsCFIMoves() == CFI_M_None)
725 if (MMI->getCompactUnwindEncoding() != 0)
726 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding());
728 const MachineModuleInfo &MMI = MF->getMMI();
729 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
730 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
731 const MCCFIInstruction &CFI = Instrs[CFIIndex];
732 emitCFIInstruction(CFI);
735 /// EmitFunctionBody - This method emits the body and trailer for a
737 void AsmPrinter::EmitFunctionBody() {
738 // Emit target-specific gunk before the function body.
739 EmitFunctionBodyStart();
741 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
743 // Print out code for the function.
744 bool HasAnyRealCode = false;
745 const MachineInstr *LastMI = nullptr;
746 for (auto &MBB : *MF) {
747 // Print a label for the basic block.
748 EmitBasicBlockStart(MBB);
749 for (auto &MI : MBB) {
752 // Print the assembly for the instruction.
753 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
754 !MI.isDebugValue()) {
755 HasAnyRealCode = true;
759 if (ShouldPrintDebugScopes) {
760 for (const HandlerInfo &HI : Handlers) {
761 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
762 TimePassesIsEnabled);
763 HI.Handler->beginInstruction(&MI);
768 emitComments(MI, OutStreamer.GetCommentOS());
770 switch (MI.getOpcode()) {
771 case TargetOpcode::CFI_INSTRUCTION:
772 emitCFIInstruction(MI);
775 case TargetOpcode::EH_LABEL:
776 case TargetOpcode::GC_LABEL:
777 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
779 case TargetOpcode::INLINEASM:
782 case TargetOpcode::DBG_VALUE:
784 if (!emitDebugValueComment(&MI, *this))
785 EmitInstruction(&MI);
788 case TargetOpcode::IMPLICIT_DEF:
789 if (isVerbose()) emitImplicitDef(&MI);
791 case TargetOpcode::KILL:
792 if (isVerbose()) emitKill(&MI, *this);
795 EmitInstruction(&MI);
799 if (ShouldPrintDebugScopes) {
800 for (const HandlerInfo &HI : Handlers) {
801 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
802 TimePassesIsEnabled);
803 HI.Handler->endInstruction();
809 // If the last instruction was a prolog label, then we have a situation where
810 // we emitted a prolog but no function body. This results in the ending prolog
811 // label equaling the end of function label and an invalid "row" in the
812 // FDE. We need to emit a noop in this situation so that the FDE's rows are
814 bool RequiresNoop = LastMI && LastMI->isCFIInstruction();
816 // If the function is empty and the object file uses .subsections_via_symbols,
817 // then we need to emit *something* to the function body to prevent the
818 // labels from collapsing together. Just emit a noop.
819 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
821 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
822 if (Noop.getOpcode()) {
823 OutStreamer.AddComment("avoids zero-length function");
824 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
825 } else // Target not mc-ized yet.
826 OutStreamer.EmitRawText(StringRef("\tnop\n"));
829 const Function *F = MF->getFunction();
830 for (const auto &BB : *F) {
831 if (!BB.hasAddressTaken())
833 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
834 if (Sym->isDefined())
836 OutStreamer.AddComment("Address of block that was removed by CodeGen");
837 OutStreamer.EmitLabel(Sym);
840 // Emit target-specific gunk after the function body.
841 EmitFunctionBodyEnd();
843 // If the target wants a .size directive for the size of the function, emit
845 if (MAI->hasDotTypeDotSizeDirective()) {
846 // Create a symbol for the end of function, so we can get the size as
847 // difference between the function label and the temp label.
848 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
849 OutStreamer.EmitLabel(FnEndLabel);
851 const MCExpr *SizeExp =
852 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
853 MCSymbolRefExpr::Create(CurrentFnSymForSize,
856 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
859 // Emit post-function debug and/or EH information.
860 for (const HandlerInfo &HI : Handlers) {
861 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
862 HI.Handler->endFunction(MF);
866 // Print out jump tables referenced by the function.
869 OutStreamer.AddBlankLine();
872 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP);
874 bool AsmPrinter::doFinalization(Module &M) {
875 // Emit global variables.
876 for (const auto &G : M.globals())
877 EmitGlobalVariable(&G);
879 // Emit visibility info for declarations
880 for (const Function &F : M) {
881 if (!F.isDeclaration())
883 GlobalValue::VisibilityTypes V = F.getVisibility();
884 if (V == GlobalValue::DefaultVisibility)
887 MCSymbol *Name = getSymbol(&F);
888 EmitVisibility(Name, V, false);
891 // Get information about jump-instruction tables to print.
892 JumpInstrTableInfo *JITI = getAnalysisIfAvailable<JumpInstrTableInfo>();
894 if (JITI && !JITI->getTables().empty()) {
895 unsigned Arch = Triple(getTargetTriple()).getArch();
896 bool IsThumb = (Arch == Triple::thumb || Arch == Triple::thumbeb);
898 TM.getInstrInfo()->getTrap(TrapInst);
899 for (const auto &KV : JITI->getTables()) {
901 for (const auto &FunPair : KV.second) {
902 // Emit the function labels to make this be a function entry point.
904 OutContext.GetOrCreateSymbol(FunPair.second->getName());
905 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_Global);
906 // FIXME: JumpTableInstrInfo should store information about the required
907 // alignment of table entries and the size of the padding instruction.
910 OutStreamer.EmitThumbFunc(FunSym);
911 if (MAI->hasDotTypeDotSizeDirective())
912 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_ELF_TypeFunction);
913 OutStreamer.EmitLabel(FunSym);
915 // Emit the jump instruction to transfer control to the original
918 MCSymbol *TargetSymbol =
919 OutContext.GetOrCreateSymbol(FunPair.first->getName());
920 const MCSymbolRefExpr *TargetSymRef =
921 MCSymbolRefExpr::Create(TargetSymbol, MCSymbolRefExpr::VK_PLT,
923 TM.getInstrInfo()->getUnconditionalBranch(JumpToFun, TargetSymRef);
924 OutStreamer.EmitInstruction(JumpToFun, getSubtargetInfo());
928 // Emit enough padding instructions to fill up to the next power of two.
929 // This assumes that the trap instruction takes 8 bytes or fewer.
930 uint64_t Remaining = NextPowerOf2(Count) - Count;
931 for (uint64_t C = 0; C < Remaining; ++C) {
933 OutStreamer.EmitInstruction(TrapInst, getSubtargetInfo());
939 // Emit module flags.
940 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
941 M.getModuleFlagsMetadata(ModuleFlags);
942 if (!ModuleFlags.empty())
943 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
945 // Make sure we wrote out everything we need.
948 // Finalize debug and EH information.
949 for (const HandlerInfo &HI : Handlers) {
950 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
951 TimePassesIsEnabled);
952 HI.Handler->endModule();
958 // If the target wants to know about weak references, print them all.
959 if (MAI->getWeakRefDirective()) {
960 // FIXME: This is not lazy, it would be nice to only print weak references
961 // to stuff that is actually used. Note that doing so would require targets
962 // to notice uses in operands (due to constant exprs etc). This should
963 // happen with the MC stuff eventually.
965 // Print out module-level global variables here.
966 for (const auto &G : M.globals()) {
967 if (!G.hasExternalWeakLinkage())
969 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
972 for (const auto &F : M) {
973 if (!F.hasExternalWeakLinkage())
975 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
979 if (MAI->hasSetDirective()) {
980 OutStreamer.AddBlankLine();
981 for (const auto &Alias : M.aliases()) {
982 MCSymbol *Name = getSymbol(&Alias);
984 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
985 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
986 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
987 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
989 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
991 EmitVisibility(Name, Alias.getVisibility());
993 // Emit the directives as assignments aka .set:
994 OutStreamer.EmitAssignment(Name,
995 lowerConstant(Alias.getAliasee(), *this));
999 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1000 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1001 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1002 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1003 MP->finishAssembly(*this);
1005 // Emit llvm.ident metadata in an '.ident' directive.
1006 EmitModuleIdents(M);
1008 // If we don't have any trampolines, then we don't require stack memory
1009 // to be executable. Some targets have a directive to declare this.
1010 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1011 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1012 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1013 OutStreamer.SwitchSection(S);
1015 // Allow the target to emit any magic that it wants at the end of the file,
1016 // after everything else has gone out.
1017 EmitEndOfAsmFile(M);
1019 delete Mang; Mang = nullptr;
1022 OutStreamer.Finish();
1023 OutStreamer.reset();
1028 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1030 // Get the function symbol.
1031 CurrentFnSym = getSymbol(MF.getFunction());
1032 CurrentFnSymForSize = CurrentFnSym;
1035 LI = &getAnalysis<MachineLoopInfo>();
1039 // SectionCPs - Keep track the alignment, constpool entries per Section.
1043 SmallVector<unsigned, 4> CPEs;
1044 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1048 /// EmitConstantPool - Print to the current output stream assembly
1049 /// representations of the constants in the constant pool MCP. This is
1050 /// used to print out constants which have been "spilled to memory" by
1051 /// the code generator.
1053 void AsmPrinter::EmitConstantPool() {
1054 const MachineConstantPool *MCP = MF->getConstantPool();
1055 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1056 if (CP.empty()) return;
1058 // Calculate sections for constant pool entries. We collect entries to go into
1059 // the same section together to reduce amount of section switch statements.
1060 SmallVector<SectionCPs, 4> CPSections;
1061 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1062 const MachineConstantPoolEntry &CPE = CP[i];
1063 unsigned Align = CPE.getAlignment();
1066 switch (CPE.getRelocationInfo()) {
1067 default: llvm_unreachable("Unknown section kind");
1068 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
1070 Kind = SectionKind::getReadOnlyWithRelLocal();
1073 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) {
1074 case 4: Kind = SectionKind::getMergeableConst4(); break;
1075 case 8: Kind = SectionKind::getMergeableConst8(); break;
1076 case 16: Kind = SectionKind::getMergeableConst16();break;
1077 default: Kind = SectionKind::getMergeableConst(); break;
1081 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
1083 // The number of sections are small, just do a linear search from the
1084 // last section to the first.
1086 unsigned SecIdx = CPSections.size();
1087 while (SecIdx != 0) {
1088 if (CPSections[--SecIdx].S == S) {
1094 SecIdx = CPSections.size();
1095 CPSections.push_back(SectionCPs(S, Align));
1098 if (Align > CPSections[SecIdx].Alignment)
1099 CPSections[SecIdx].Alignment = Align;
1100 CPSections[SecIdx].CPEs.push_back(i);
1103 // Now print stuff into the calculated sections.
1104 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1105 OutStreamer.SwitchSection(CPSections[i].S);
1106 EmitAlignment(Log2_32(CPSections[i].Alignment));
1108 unsigned Offset = 0;
1109 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1110 unsigned CPI = CPSections[i].CPEs[j];
1111 MachineConstantPoolEntry CPE = CP[CPI];
1113 // Emit inter-object padding for alignment.
1114 unsigned AlignMask = CPE.getAlignment() - 1;
1115 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1116 OutStreamer.EmitZeros(NewOffset - Offset);
1118 Type *Ty = CPE.getType();
1119 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty);
1120 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1122 if (CPE.isMachineConstantPoolEntry())
1123 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1125 EmitGlobalConstant(CPE.Val.ConstVal);
1130 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1131 /// by the current function to the current output stream.
1133 void AsmPrinter::EmitJumpTableInfo() {
1134 const DataLayout *DL = MF->getTarget().getDataLayout();
1135 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1137 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1138 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1139 if (JT.empty()) return;
1141 // Pick the directive to use to print the jump table entries, and switch to
1142 // the appropriate section.
1143 const Function *F = MF->getFunction();
1144 bool JTInDiffSection = false;
1145 if (// In PIC mode, we need to emit the jump table to the same section as the
1146 // function body itself, otherwise the label differences won't make sense.
1147 // FIXME: Need a better predicate for this: what about custom entries?
1148 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1149 // We should also do if the section name is NULL or function is declared
1150 // in discardable section
1151 // FIXME: this isn't the right predicate, should be based on the MCSection
1152 // for the function.
1153 F->isWeakForLinker()) {
1154 OutStreamer.SwitchSection(
1155 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1157 // Otherwise, drop it in the readonly section.
1158 const MCSection *ReadOnlySection =
1159 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1160 OutStreamer.SwitchSection(ReadOnlySection);
1161 JTInDiffSection = true;
1164 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout())));
1166 // Jump tables in code sections are marked with a data_region directive
1167 // where that's supported.
1168 if (!JTInDiffSection)
1169 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1171 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1172 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1174 // If this jump table was deleted, ignore it.
1175 if (JTBBs.empty()) continue;
1177 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1178 // .set directive for each unique entry. This reduces the number of
1179 // relocations the assembler will generate for the jump table.
1180 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1181 MAI->hasSetDirective()) {
1182 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1183 const TargetLowering *TLI = TM.getTargetLowering();
1184 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1185 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1186 const MachineBasicBlock *MBB = JTBBs[ii];
1187 if (!EmittedSets.insert(MBB)) continue;
1189 // .set LJTSet, LBB32-base
1191 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1192 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1193 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1197 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1198 // before each jump table. The first label is never referenced, but tells
1199 // the assembler and linker the extents of the jump table object. The
1200 // second label is actually referenced by the code.
1201 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1202 // FIXME: This doesn't have to have any specific name, just any randomly
1203 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1204 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1206 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1208 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1209 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1211 if (!JTInDiffSection)
1212 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1215 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1217 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1218 const MachineBasicBlock *MBB,
1219 unsigned UID) const {
1220 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1221 const MCExpr *Value = nullptr;
1222 switch (MJTI->getEntryKind()) {
1223 case MachineJumpTableInfo::EK_Inline:
1224 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1225 case MachineJumpTableInfo::EK_Custom32:
1226 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1229 case MachineJumpTableInfo::EK_BlockAddress:
1230 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1232 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1234 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1235 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1236 // with a relocation as gp-relative, e.g.:
1238 MCSymbol *MBBSym = MBB->getSymbol();
1239 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1243 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1244 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1245 // with a relocation as gp-relative, e.g.:
1247 MCSymbol *MBBSym = MBB->getSymbol();
1248 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1252 case MachineJumpTableInfo::EK_LabelDifference32: {
1253 // EK_LabelDifference32 - Each entry is the address of the block minus
1254 // the address of the jump table. This is used for PIC jump tables where
1255 // gprel32 is not supported. e.g.:
1256 // .word LBB123 - LJTI1_2
1257 // If the .set directive is supported, this is emitted as:
1258 // .set L4_5_set_123, LBB123 - LJTI1_2
1259 // .word L4_5_set_123
1261 // If we have emitted set directives for the jump table entries, print
1262 // them rather than the entries themselves. If we're emitting PIC, then
1263 // emit the table entries as differences between two text section labels.
1264 if (MAI->hasSetDirective()) {
1265 // If we used .set, reference the .set's symbol.
1266 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1270 // Otherwise, use the difference as the jump table entry.
1271 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1272 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1273 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1278 assert(Value && "Unknown entry kind!");
1280 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout());
1281 OutStreamer.EmitValue(Value, EntrySize);
1285 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1286 /// special global used by LLVM. If so, emit it and return true, otherwise
1287 /// do nothing and return false.
1288 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1289 if (GV->getName() == "llvm.used") {
1290 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1291 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1295 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1296 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1297 GV->hasAvailableExternallyLinkage())
1300 if (!GV->hasAppendingLinkage()) return false;
1302 assert(GV->hasInitializer() && "Not a special LLVM global!");
1304 if (GV->getName() == "llvm.global_ctors") {
1305 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1307 if (TM.getRelocationModel() == Reloc::Static &&
1308 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1309 StringRef Sym(".constructors_used");
1310 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1316 if (GV->getName() == "llvm.global_dtors") {
1317 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1319 if (TM.getRelocationModel() == Reloc::Static &&
1320 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1321 StringRef Sym(".destructors_used");
1322 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1331 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1332 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1333 /// is true, as being used with this directive.
1334 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1335 // Should be an array of 'i8*'.
1336 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1337 const GlobalValue *GV =
1338 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1340 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1346 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1348 llvm::Constant *Func;
1349 llvm::GlobalValue *ComdatKey;
1353 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1355 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1356 // Should be an array of '{ int, void ()* }' structs. The first value is the
1358 if (!isa<ConstantArray>(List)) return;
1360 // Sanity check the structors list.
1361 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1362 if (!InitList) return; // Not an array!
1363 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1364 // FIXME: Only allow the 3-field form in LLVM 4.0.
1365 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1366 return; // Not an array of two or three elements!
1367 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1368 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1369 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1370 return; // Not (int, ptr, ptr).
1372 // Gather the structors in a form that's convenient for sorting by priority.
1373 SmallVector<Structor, 8> Structors;
1374 for (Value *O : InitList->operands()) {
1375 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1376 if (!CS) continue; // Malformed.
1377 if (CS->getOperand(1)->isNullValue())
1378 break; // Found a null terminator, skip the rest.
1379 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1380 if (!Priority) continue; // Malformed.
1381 Structors.push_back(Structor());
1382 Structor &S = Structors.back();
1383 S.Priority = Priority->getLimitedValue(65535);
1384 S.Func = CS->getOperand(1);
1385 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1386 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1389 // Emit the function pointers in the target-specific order
1390 const DataLayout *DL = TM.getDataLayout();
1391 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1392 std::stable_sort(Structors.begin(), Structors.end(),
1393 [](const Structor &L,
1394 const Structor &R) { return L.Priority < R.Priority; });
1395 for (Structor &S : Structors) {
1396 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1397 const MCSymbol *KeySym = nullptr;
1398 if (GlobalValue *GV = S.ComdatKey) {
1399 if (GV->hasAvailableExternallyLinkage())
1400 // If the associated variable is available_externally, some other TU
1401 // will provide its dynamic initializer.
1404 KeySym = getSymbol(GV);
1406 const MCSection *OutputSection =
1407 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1408 : Obj.getStaticDtorSection(S.Priority, KeySym));
1409 OutStreamer.SwitchSection(OutputSection);
1410 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1411 EmitAlignment(Align);
1412 EmitXXStructor(S.Func);
1416 void AsmPrinter::EmitModuleIdents(Module &M) {
1417 if (!MAI->hasIdentDirective())
1420 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1421 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1422 const MDNode *N = NMD->getOperand(i);
1423 assert(N->getNumOperands() == 1 &&
1424 "llvm.ident metadata entry can have only one operand");
1425 const MDString *S = cast<MDString>(N->getOperand(0));
1426 OutStreamer.EmitIdent(S->getString());
1431 //===--------------------------------------------------------------------===//
1432 // Emission and print routines
1435 /// EmitInt8 - Emit a byte directive and value.
1437 void AsmPrinter::EmitInt8(int Value) const {
1438 OutStreamer.EmitIntValue(Value, 1);
1441 /// EmitInt16 - Emit a short directive and value.
1443 void AsmPrinter::EmitInt16(int Value) const {
1444 OutStreamer.EmitIntValue(Value, 2);
1447 /// EmitInt32 - Emit a long directive and value.
1449 void AsmPrinter::EmitInt32(int Value) const {
1450 OutStreamer.EmitIntValue(Value, 4);
1453 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1454 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1455 /// labels. This implicitly uses .set if it is available.
1456 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1457 unsigned Size) const {
1458 // Get the Hi-Lo expression.
1459 const MCExpr *Diff =
1460 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1461 MCSymbolRefExpr::Create(Lo, OutContext),
1464 if (!MAI->hasSetDirective()) {
1465 OutStreamer.EmitValue(Diff, Size);
1469 // Otherwise, emit with .set (aka assignment).
1470 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1471 OutStreamer.EmitAssignment(SetLabel, Diff);
1472 OutStreamer.EmitSymbolValue(SetLabel, Size);
1475 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1476 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1477 /// specify the labels. This implicitly uses .set if it is available.
1478 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1480 unsigned Size) const {
1482 // Emit Hi+Offset - Lo
1483 // Get the Hi+Offset expression.
1484 const MCExpr *Plus =
1485 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1486 MCConstantExpr::Create(Offset, OutContext),
1489 // Get the Hi+Offset-Lo expression.
1490 const MCExpr *Diff =
1491 MCBinaryExpr::CreateSub(Plus,
1492 MCSymbolRefExpr::Create(Lo, OutContext),
1495 if (!MAI->hasSetDirective())
1496 OutStreamer.EmitValue(Diff, Size);
1498 // Otherwise, emit with .set (aka assignment).
1499 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1500 OutStreamer.EmitAssignment(SetLabel, Diff);
1501 OutStreamer.EmitSymbolValue(SetLabel, Size);
1505 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1506 /// where the size in bytes of the directive is specified by Size and Label
1507 /// specifies the label. This implicitly uses .set if it is available.
1508 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1510 bool IsSectionRelative) const {
1511 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1512 OutStreamer.EmitCOFFSecRel32(Label);
1516 // Emit Label+Offset (or just Label if Offset is zero)
1517 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1519 Expr = MCBinaryExpr::CreateAdd(
1520 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1522 OutStreamer.EmitValue(Expr, Size);
1525 //===----------------------------------------------------------------------===//
1527 // EmitAlignment - Emit an alignment directive to the specified power of
1528 // two boundary. For example, if you pass in 3 here, you will get an 8
1529 // byte alignment. If a global value is specified, and if that global has
1530 // an explicit alignment requested, it will override the alignment request
1531 // if required for correctness.
1533 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1534 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits);
1536 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1538 if (getCurrentSection()->getKind().isText())
1539 OutStreamer.EmitCodeAlignment(1 << NumBits);
1541 OutStreamer.EmitValueToAlignment(1 << NumBits);
1544 //===----------------------------------------------------------------------===//
1545 // Constant emission.
1546 //===----------------------------------------------------------------------===//
1548 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1550 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1551 MCContext &Ctx = AP.OutContext;
1553 if (CV->isNullValue() || isa<UndefValue>(CV))
1554 return MCConstantExpr::Create(0, Ctx);
1556 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1557 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1559 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1560 return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx);
1562 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1563 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1565 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1567 llvm_unreachable("Unknown constant value to lower!");
1570 if (const MCExpr *RelocExpr =
1571 AP.getObjFileLowering().getExecutableRelativeSymbol(CE, *AP.Mang,
1575 switch (CE->getOpcode()) {
1577 // If the code isn't optimized, there may be outstanding folding
1578 // opportunities. Attempt to fold the expression using DataLayout as a
1579 // last resort before giving up.
1581 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout()))
1583 return lowerConstant(C, AP);
1585 // Otherwise report the problem to the user.
1588 raw_string_ostream OS(S);
1589 OS << "Unsupported expression in static initializer: ";
1590 CE->printAsOperand(OS, /*PrintType=*/false,
1591 !AP.MF ? nullptr : AP.MF->getFunction()->getParent());
1592 report_fatal_error(OS.str());
1594 case Instruction::GetElementPtr: {
1595 const DataLayout &DL = *AP.TM.getDataLayout();
1596 // Generate a symbolic expression for the byte address
1597 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1598 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1600 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1604 int64_t Offset = OffsetAI.getSExtValue();
1605 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1609 case Instruction::Trunc:
1610 // We emit the value and depend on the assembler to truncate the generated
1611 // expression properly. This is important for differences between
1612 // blockaddress labels. Since the two labels are in the same function, it
1613 // is reasonable to treat their delta as a 32-bit value.
1615 case Instruction::BitCast:
1616 return lowerConstant(CE->getOperand(0), AP);
1618 case Instruction::IntToPtr: {
1619 const DataLayout &DL = *AP.TM.getDataLayout();
1620 // Handle casts to pointers by changing them into casts to the appropriate
1621 // integer type. This promotes constant folding and simplifies this code.
1622 Constant *Op = CE->getOperand(0);
1623 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1625 return lowerConstant(Op, AP);
1628 case Instruction::PtrToInt: {
1629 const DataLayout &DL = *AP.TM.getDataLayout();
1630 // Support only foldable casts to/from pointers that can be eliminated by
1631 // changing the pointer to the appropriately sized integer type.
1632 Constant *Op = CE->getOperand(0);
1633 Type *Ty = CE->getType();
1635 const MCExpr *OpExpr = lowerConstant(Op, AP);
1637 // We can emit the pointer value into this slot if the slot is an
1638 // integer slot equal to the size of the pointer.
1639 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1642 // Otherwise the pointer is smaller than the resultant integer, mask off
1643 // the high bits so we are sure to get a proper truncation if the input is
1645 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1646 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1647 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1650 // The MC library also has a right-shift operator, but it isn't consistently
1651 // signed or unsigned between different targets.
1652 case Instruction::Add:
1653 case Instruction::Sub:
1654 case Instruction::Mul:
1655 case Instruction::SDiv:
1656 case Instruction::SRem:
1657 case Instruction::Shl:
1658 case Instruction::And:
1659 case Instruction::Or:
1660 case Instruction::Xor: {
1661 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1662 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1663 switch (CE->getOpcode()) {
1664 default: llvm_unreachable("Unknown binary operator constant cast expr");
1665 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1666 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1667 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1668 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1669 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1670 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1671 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1672 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1673 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1679 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1681 /// isRepeatedByteSequence - Determine whether the given value is
1682 /// composed of a repeated sequence of identical bytes and return the
1683 /// byte value. If it is not a repeated sequence, return -1.
1684 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1685 StringRef Data = V->getRawDataValues();
1686 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1688 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1689 if (Data[i] != C) return -1;
1690 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1694 /// isRepeatedByteSequence - Determine whether the given value is
1695 /// composed of a repeated sequence of identical bytes and return the
1696 /// byte value. If it is not a repeated sequence, return -1.
1697 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1699 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1700 if (CI->getBitWidth() > 64) return -1;
1702 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType());
1703 uint64_t Value = CI->getZExtValue();
1705 // Make sure the constant is at least 8 bits long and has a power
1706 // of 2 bit width. This guarantees the constant bit width is
1707 // always a multiple of 8 bits, avoiding issues with padding out
1708 // to Size and other such corner cases.
1709 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1711 uint8_t Byte = static_cast<uint8_t>(Value);
1713 for (unsigned i = 1; i < Size; ++i) {
1715 if (static_cast<uint8_t>(Value) != Byte) return -1;
1719 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1720 // Make sure all array elements are sequences of the same repeated
1722 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1723 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1724 if (Byte == -1) return -1;
1726 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1727 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1728 if (ThisByte == -1) return -1;
1729 if (Byte != ThisByte) return -1;
1734 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1735 return isRepeatedByteSequence(CDS);
1740 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1743 // See if we can aggregate this into a .fill, if so, emit it as such.
1744 int Value = isRepeatedByteSequence(CDS, AP.TM);
1746 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType());
1747 // Don't emit a 1-byte object as a .fill.
1749 return AP.OutStreamer.EmitFill(Bytes, Value);
1752 // If this can be emitted with .ascii/.asciz, emit it as such.
1753 if (CDS->isString())
1754 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1756 // Otherwise, emit the values in successive locations.
1757 unsigned ElementByteSize = CDS->getElementByteSize();
1758 if (isa<IntegerType>(CDS->getElementType())) {
1759 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1761 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1762 CDS->getElementAsInteger(i));
1763 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1766 } else if (ElementByteSize == 4) {
1767 // FP Constants are printed as integer constants to avoid losing
1769 assert(CDS->getElementType()->isFloatTy());
1770 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1776 F = CDS->getElementAsFloat(i);
1778 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1779 AP.OutStreamer.EmitIntValue(I, 4);
1782 assert(CDS->getElementType()->isDoubleTy());
1783 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1789 F = CDS->getElementAsDouble(i);
1791 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1792 AP.OutStreamer.EmitIntValue(I, 8);
1796 const DataLayout &DL = *AP.TM.getDataLayout();
1797 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1798 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1799 CDS->getNumElements();
1800 if (unsigned Padding = Size - EmittedSize)
1801 AP.OutStreamer.EmitZeros(Padding);
1805 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1806 // See if we can aggregate some values. Make sure it can be
1807 // represented as a series of bytes of the constant value.
1808 int Value = isRepeatedByteSequence(CA, AP.TM);
1811 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType());
1812 AP.OutStreamer.EmitFill(Bytes, Value);
1815 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1816 emitGlobalConstantImpl(CA->getOperand(i), AP);
1820 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1821 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1822 emitGlobalConstantImpl(CV->getOperand(i), AP);
1824 const DataLayout &DL = *AP.TM.getDataLayout();
1825 unsigned Size = DL.getTypeAllocSize(CV->getType());
1826 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1827 CV->getType()->getNumElements();
1828 if (unsigned Padding = Size - EmittedSize)
1829 AP.OutStreamer.EmitZeros(Padding);
1832 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1833 // Print the fields in successive locations. Pad to align if needed!
1834 const DataLayout *DL = AP.TM.getDataLayout();
1835 unsigned Size = DL->getTypeAllocSize(CS->getType());
1836 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1837 uint64_t SizeSoFar = 0;
1838 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1839 const Constant *Field = CS->getOperand(i);
1841 // Check if padding is needed and insert one or more 0s.
1842 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1843 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1844 - Layout->getElementOffset(i)) - FieldSize;
1845 SizeSoFar += FieldSize + PadSize;
1847 // Now print the actual field value.
1848 emitGlobalConstantImpl(Field, AP);
1850 // Insert padding - this may include padding to increase the size of the
1851 // current field up to the ABI size (if the struct is not packed) as well
1852 // as padding to ensure that the next field starts at the right offset.
1853 AP.OutStreamer.EmitZeros(PadSize);
1855 assert(SizeSoFar == Layout->getSizeInBytes() &&
1856 "Layout of constant struct may be incorrect!");
1859 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1860 APInt API = CFP->getValueAPF().bitcastToAPInt();
1862 // First print a comment with what we think the original floating-point value
1863 // should have been.
1864 if (AP.isVerbose()) {
1865 SmallString<8> StrVal;
1866 CFP->getValueAPF().toString(StrVal);
1869 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1871 AP.OutStreamer.GetCommentOS() << "Printing <null> Type";
1872 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1875 // Now iterate through the APInt chunks, emitting them in endian-correct
1876 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1878 unsigned NumBytes = API.getBitWidth() / 8;
1879 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1880 const uint64_t *p = API.getRawData();
1882 // PPC's long double has odd notions of endianness compared to how LLVM
1883 // handles it: p[0] goes first for *big* endian on PPC.
1884 if (AP.TM.getDataLayout()->isBigEndian() != CFP->getType()->isPPC_FP128Ty()) {
1885 int Chunk = API.getNumWords() - 1;
1888 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1890 for (; Chunk >= 0; --Chunk)
1891 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1894 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1895 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1898 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1901 // Emit the tail padding for the long double.
1902 const DataLayout &DL = *AP.TM.getDataLayout();
1903 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1904 DL.getTypeStoreSize(CFP->getType()));
1907 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1908 const DataLayout *DL = AP.TM.getDataLayout();
1909 unsigned BitWidth = CI->getBitWidth();
1911 // Copy the value as we may massage the layout for constants whose bit width
1912 // is not a multiple of 64-bits.
1913 APInt Realigned(CI->getValue());
1914 uint64_t ExtraBits = 0;
1915 unsigned ExtraBitsSize = BitWidth & 63;
1917 if (ExtraBitsSize) {
1918 // The bit width of the data is not a multiple of 64-bits.
1919 // The extra bits are expected to be at the end of the chunk of the memory.
1921 // * Nothing to be done, just record the extra bits to emit.
1923 // * Record the extra bits to emit.
1924 // * Realign the raw data to emit the chunks of 64-bits.
1925 if (DL->isBigEndian()) {
1926 // Basically the structure of the raw data is a chunk of 64-bits cells:
1927 // 0 1 BitWidth / 64
1928 // [chunk1][chunk2] ... [chunkN].
1929 // The most significant chunk is chunkN and it should be emitted first.
1930 // However, due to the alignment issue chunkN contains useless bits.
1931 // Realign the chunks so that they contain only useless information:
1932 // ExtraBits 0 1 (BitWidth / 64) - 1
1933 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1934 ExtraBits = Realigned.getRawData()[0] &
1935 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1936 Realigned = Realigned.lshr(ExtraBitsSize);
1938 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1941 // We don't expect assemblers to support integer data directives
1942 // for more than 64 bits, so we emit the data in at most 64-bit
1943 // quantities at a time.
1944 const uint64_t *RawData = Realigned.getRawData();
1945 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1946 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1947 AP.OutStreamer.EmitIntValue(Val, 8);
1950 if (ExtraBitsSize) {
1951 // Emit the extra bits after the 64-bits chunks.
1953 // Emit a directive that fills the expected size.
1954 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(CI->getType());
1955 Size -= (BitWidth / 64) * 8;
1956 assert(Size && Size * 8 >= ExtraBitsSize &&
1957 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1958 == ExtraBits && "Directive too small for extra bits.");
1959 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1963 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1964 const DataLayout *DL = AP.TM.getDataLayout();
1965 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1966 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1967 return AP.OutStreamer.EmitZeros(Size);
1969 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1976 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1977 CI->getZExtValue());
1978 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1981 emitGlobalConstantLargeInt(CI, AP);
1986 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1987 return emitGlobalConstantFP(CFP, AP);
1989 if (isa<ConstantPointerNull>(CV)) {
1990 AP.OutStreamer.EmitIntValue(0, Size);
1994 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1995 return emitGlobalConstantDataSequential(CDS, AP);
1997 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1998 return emitGlobalConstantArray(CVA, AP);
2000 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2001 return emitGlobalConstantStruct(CVS, AP);
2003 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2004 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2006 if (CE->getOpcode() == Instruction::BitCast)
2007 return emitGlobalConstantImpl(CE->getOperand(0), AP);
2010 // If the constant expression's size is greater than 64-bits, then we have
2011 // to emit the value in chunks. Try to constant fold the value and emit it
2013 Constant *New = ConstantFoldConstantExpression(CE, DL);
2014 if (New && New != CE)
2015 return emitGlobalConstantImpl(New, AP);
2019 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2020 return emitGlobalConstantVector(V, AP);
2022 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2023 // thread the streamer with EmitValue.
2024 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
2027 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2028 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2029 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType());
2031 emitGlobalConstantImpl(CV, *this);
2032 else if (MAI->hasSubsectionsViaSymbols()) {
2033 // If the global has zero size, emit a single byte so that two labels don't
2034 // look like they are at the same location.
2035 OutStreamer.EmitIntValue(0, 1);
2039 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2040 // Target doesn't support this yet!
2041 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2044 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2046 OS << '+' << Offset;
2047 else if (Offset < 0)
2051 //===----------------------------------------------------------------------===//
2052 // Symbol Lowering Routines.
2053 //===----------------------------------------------------------------------===//
2055 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2056 /// temporary label with the specified stem and unique ID.
2057 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const {
2058 const DataLayout *DL = TM.getDataLayout();
2059 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2063 /// GetTempSymbol - Return an assembler temporary label with the specified
2065 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const {
2066 const DataLayout *DL = TM.getDataLayout();
2067 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2072 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2073 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2076 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2077 return MMI->getAddrLabelSymbol(BB);
2080 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2081 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2082 const DataLayout *DL = TM.getDataLayout();
2083 return OutContext.GetOrCreateSymbol
2084 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2085 + "_" + Twine(CPID));
2088 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2089 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2090 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2093 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2094 /// FIXME: privatize to AsmPrinter.
2095 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2096 const DataLayout *DL = TM.getDataLayout();
2097 return OutContext.GetOrCreateSymbol
2098 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2099 Twine(UID) + "_set_" + Twine(MBBID));
2102 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2103 StringRef Suffix) const {
2104 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2108 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2110 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2111 SmallString<60> NameStr;
2112 Mang->getNameWithPrefix(NameStr, Sym);
2113 return OutContext.GetOrCreateSymbol(NameStr.str());
2118 /// PrintParentLoopComment - Print comments about parent loops of this one.
2119 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2120 unsigned FunctionNumber) {
2122 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2123 OS.indent(Loop->getLoopDepth()*2)
2124 << "Parent Loop BB" << FunctionNumber << "_"
2125 << Loop->getHeader()->getNumber()
2126 << " Depth=" << Loop->getLoopDepth() << '\n';
2130 /// PrintChildLoopComment - Print comments about child loops within
2131 /// the loop for this basic block, with nesting.
2132 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2133 unsigned FunctionNumber) {
2134 // Add child loop information
2135 for (const MachineLoop *CL : *Loop) {
2136 OS.indent(CL->getLoopDepth()*2)
2137 << "Child Loop BB" << FunctionNumber << "_"
2138 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2140 PrintChildLoopComment(OS, CL, FunctionNumber);
2144 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2145 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2146 const MachineLoopInfo *LI,
2147 const AsmPrinter &AP) {
2148 // Add loop depth information
2149 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2152 MachineBasicBlock *Header = Loop->getHeader();
2153 assert(Header && "No header for loop");
2155 // If this block is not a loop header, just print out what is the loop header
2157 if (Header != &MBB) {
2158 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2159 Twine(AP.getFunctionNumber())+"_" +
2160 Twine(Loop->getHeader()->getNumber())+
2161 " Depth="+Twine(Loop->getLoopDepth()));
2165 // Otherwise, it is a loop header. Print out information about child and
2167 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2169 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2172 OS.indent(Loop->getLoopDepth()*2-2);
2177 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2179 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2183 /// EmitBasicBlockStart - This method prints the label for the specified
2184 /// MachineBasicBlock, an alignment (if present) and a comment describing
2185 /// it if appropriate.
2186 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2187 // Emit an alignment directive for this block, if needed.
2188 if (unsigned Align = MBB.getAlignment())
2189 EmitAlignment(Align);
2191 // If the block has its address taken, emit any labels that were used to
2192 // reference the block. It is possible that there is more than one label
2193 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2194 // the references were generated.
2195 if (MBB.hasAddressTaken()) {
2196 const BasicBlock *BB = MBB.getBasicBlock();
2198 OutStreamer.AddComment("Block address taken");
2200 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2201 for (auto *Sym : Symbols)
2202 OutStreamer.EmitLabel(Sym);
2205 // Print some verbose block comments.
2207 if (const BasicBlock *BB = MBB.getBasicBlock())
2209 OutStreamer.AddComment("%" + BB->getName());
2210 emitBasicBlockLoopComments(MBB, LI, *this);
2213 // Print the main label for the block.
2214 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2216 // NOTE: Want this comment at start of line, don't emit with AddComment.
2217 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2220 OutStreamer.EmitLabel(MBB.getSymbol());
2224 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2225 bool IsDefinition) const {
2226 MCSymbolAttr Attr = MCSA_Invalid;
2228 switch (Visibility) {
2230 case GlobalValue::HiddenVisibility:
2232 Attr = MAI->getHiddenVisibilityAttr();
2234 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2236 case GlobalValue::ProtectedVisibility:
2237 Attr = MAI->getProtectedVisibilityAttr();
2241 if (Attr != MCSA_Invalid)
2242 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2245 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2246 /// exactly one predecessor and the control transfer mechanism between
2247 /// the predecessor and this block is a fall-through.
2249 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2250 // If this is a landing pad, it isn't a fall through. If it has no preds,
2251 // then nothing falls through to it.
2252 if (MBB->isLandingPad() || MBB->pred_empty())
2255 // If there isn't exactly one predecessor, it can't be a fall through.
2256 if (MBB->pred_size() > 1)
2259 // The predecessor has to be immediately before this block.
2260 MachineBasicBlock *Pred = *MBB->pred_begin();
2261 if (!Pred->isLayoutSuccessor(MBB))
2264 // If the block is completely empty, then it definitely does fall through.
2268 // Check the terminators in the previous blocks
2269 for (const auto &MI : Pred->terminators()) {
2270 // If it is not a simple branch, we are in a table somewhere.
2271 if (!MI.isBranch() || MI.isIndirectBranch())
2274 // If we are the operands of one of the branches, this is not a fall
2275 // through. Note that targets with delay slots will usually bundle
2276 // terminators with the delay slot instruction.
2277 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2280 if (OP->isMBB() && OP->getMBB() == MBB)
2290 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2291 if (!S.usesMetadata())
2294 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2295 gcp_map_type::iterator GCPI = GCMap.find(&S);
2296 if (GCPI != GCMap.end())
2297 return GCPI->second.get();
2299 const char *Name = S.getName().c_str();
2301 for (GCMetadataPrinterRegistry::iterator
2302 I = GCMetadataPrinterRegistry::begin(),
2303 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2304 if (strcmp(Name, I->getName()) == 0) {
2305 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2307 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2308 return IterBool.first->second.get();
2311 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2314 /// Pin vtable to this file.
2315 AsmPrinterHandler::~AsmPrinterHandler() {}