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/Analysis.h"
23 #include "llvm/CodeGen/GCMetadataPrinter.h"
24 #include "llvm/CodeGen/MachineConstantPool.h"
25 #include "llvm/CodeGen/MachineFrameInfo.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/CodeGen/MachineInstrBundle.h"
28 #include "llvm/CodeGen/MachineJumpTableInfo.h"
29 #include "llvm/CodeGen/MachineLoopInfo.h"
30 #include "llvm/CodeGen/MachineModuleInfo.h"
31 #include "llvm/IR/DataLayout.h"
32 #include "llvm/IR/DebugInfo.h"
33 #include "llvm/IR/Mangler.h"
34 #include "llvm/IR/Module.h"
35 #include "llvm/IR/Operator.h"
36 #include "llvm/MC/MCAsmInfo.h"
37 #include "llvm/MC/MCContext.h"
38 #include "llvm/MC/MCExpr.h"
39 #include "llvm/MC/MCInst.h"
40 #include "llvm/MC/MCSection.h"
41 #include "llvm/MC/MCStreamer.h"
42 #include "llvm/MC/MCSymbol.h"
43 #include "llvm/Support/ErrorHandling.h"
44 #include "llvm/Support/Format.h"
45 #include "llvm/Support/MathExtras.h"
46 #include "llvm/Support/Timer.h"
47 #include "llvm/Target/TargetFrameLowering.h"
48 #include "llvm/Target/TargetInstrInfo.h"
49 #include "llvm/Target/TargetLowering.h"
50 #include "llvm/Target/TargetLoweringObjectFile.h"
51 #include "llvm/Target/TargetRegisterInfo.h"
52 #include "llvm/Target/TargetSubtargetInfo.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), TM(tm), MAI(tm.getMCAsmInfo()),
102 MII(tm.getSubtargetImpl()->getInstrInfo()),
103 OutContext(Streamer.getContext()), OutStreamer(Streamer), LastMI(nullptr),
104 LastFn(0), Counter(~0U), SetCounter(0) {
105 DD = nullptr; MMI = nullptr; LI = nullptr; MF = nullptr;
106 CurrentFnSym = CurrentFnSymForSize = nullptr;
107 GCMetadataPrinters = nullptr;
108 VerboseAsm = Streamer.isVerboseAsm();
111 AsmPrinter::~AsmPrinter() {
112 assert(!DD && Handlers.empty() && "Debug/EH info didn't get finalized");
114 if (GCMetadataPrinters) {
115 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
118 GCMetadataPrinters = nullptr;
124 /// getFunctionNumber - Return a unique ID for the current function.
126 unsigned AsmPrinter::getFunctionNumber() const {
127 return MF->getFunctionNumber();
130 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
131 return TM.getSubtargetImpl()->getTargetLowering()->getObjFileLowering();
134 /// getDataLayout - Return information about data layout.
135 const DataLayout &AsmPrinter::getDataLayout() const {
136 return *TM.getSubtargetImpl()->getDataLayout();
139 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
140 return TM.getSubtarget<MCSubtargetInfo>();
143 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
144 S.EmitInstruction(Inst, getSubtargetInfo());
147 StringRef AsmPrinter::getTargetTriple() const {
148 return TM.getTargetTriple();
151 /// getCurrentSection() - Return the current section we are emitting to.
152 const MCSection *AsmPrinter::getCurrentSection() const {
153 return OutStreamer.getCurrentSection().first;
158 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
159 AU.setPreservesAll();
160 MachineFunctionPass::getAnalysisUsage(AU);
161 AU.addRequired<MachineModuleInfo>();
162 AU.addRequired<GCModuleInfo>();
164 AU.addRequired<MachineLoopInfo>();
167 bool AsmPrinter::doInitialization(Module &M) {
168 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
169 MMI->AnalyzeModule(M);
171 // Initialize TargetLoweringObjectFile.
172 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
173 .Initialize(OutContext, TM);
175 OutStreamer.InitSections();
177 Mang = new Mangler(TM.getSubtargetImpl()->getDataLayout());
179 // Emit the version-min deplyment target directive if needed.
181 // FIXME: If we end up with a collection of these sorts of Darwin-specific
182 // or ELF-specific things, it may make sense to have a platform helper class
183 // that will work with the target helper class. For now keep it here, as the
184 // alternative is duplicated code in each of the target asm printers that
185 // use the directive, where it would need the same conditionalization
187 Triple TT(getTargetTriple());
188 if (TT.isOSDarwin()) {
189 unsigned Major, Minor, Update;
190 TT.getOSVersion(Major, Minor, Update);
191 // If there is a version specified, Major will be non-zero.
193 OutStreamer.EmitVersionMin((TT.isMacOSX() ?
194 MCVM_OSXVersionMin : MCVM_IOSVersionMin),
195 Major, Minor, Update);
198 // Allow the target to emit any magic that it wants at the start of the file.
199 EmitStartOfAsmFile(M);
201 // Very minimal debug info. It is ignored if we emit actual debug info. If we
202 // don't, this at least helps the user find where a global came from.
203 if (MAI->hasSingleParameterDotFile()) {
205 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
208 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
209 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
211 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
212 MP->beginAssembly(*this);
214 // Emit module-level inline asm if it exists.
215 if (!M.getModuleInlineAsm().empty()) {
216 OutStreamer.AddComment("Start of file scope inline assembly");
217 OutStreamer.AddBlankLine();
218 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
219 OutStreamer.AddComment("End of file scope inline assembly");
220 OutStreamer.AddBlankLine();
223 if (MAI->doesSupportDebugInformation()) {
224 if (Triple(TM.getTargetTriple()).isKnownWindowsMSVCEnvironment()) {
225 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this),
227 CodeViewLineTablesGroupName));
229 DD = new DwarfDebug(this, &M);
230 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
234 EHStreamer *ES = nullptr;
235 switch (MAI->getExceptionHandlingType()) {
236 case ExceptionHandling::None:
238 case ExceptionHandling::SjLj:
239 case ExceptionHandling::DwarfCFI:
240 ES = new DwarfCFIException(this);
242 case ExceptionHandling::ARM:
243 ES = new ARMException(this);
245 case ExceptionHandling::WinEH:
246 ES = new Win64Exception(this);
250 Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
254 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
255 if (!MAI.hasWeakDefCanBeHiddenDirective())
258 return canBeOmittedFromSymbolTable(GV);
261 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
262 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
264 case GlobalValue::CommonLinkage:
265 case GlobalValue::LinkOnceAnyLinkage:
266 case GlobalValue::LinkOnceODRLinkage:
267 case GlobalValue::WeakAnyLinkage:
268 case GlobalValue::WeakODRLinkage:
269 if (MAI->hasWeakDefDirective()) {
271 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
273 if (!canBeHidden(GV, *MAI))
274 // .weak_definition _foo
275 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
277 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
278 } else if (MAI->hasLinkOnceDirective()) {
280 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
281 //NOTE: linkonce is handled by the section the symbol was assigned to.
284 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
287 case GlobalValue::AppendingLinkage:
288 // FIXME: appending linkage variables should go into a section of
289 // their name or something. For now, just emit them as external.
290 case GlobalValue::ExternalLinkage:
291 // If external or appending, declare as a global symbol.
293 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
295 case GlobalValue::PrivateLinkage:
296 case GlobalValue::InternalLinkage:
298 case GlobalValue::AvailableExternallyLinkage:
299 llvm_unreachable("Should never emit this");
300 case GlobalValue::ExternalWeakLinkage:
301 llvm_unreachable("Don't know how to emit these");
303 llvm_unreachable("Unknown linkage type!");
306 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
307 const GlobalValue *GV) const {
308 TM.getNameWithPrefix(Name, GV, *Mang);
311 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
312 return TM.getSymbol(GV, *Mang);
315 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
316 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
317 if (GV->hasInitializer()) {
318 // Check to see if this is a special global used by LLVM, if so, emit it.
319 if (EmitSpecialLLVMGlobal(GV))
323 GV->printAsOperand(OutStreamer.GetCommentOS(),
324 /*PrintType=*/false, GV->getParent());
325 OutStreamer.GetCommentOS() << '\n';
329 MCSymbol *GVSym = getSymbol(GV);
330 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
332 if (!GV->hasInitializer()) // External globals require no extra code.
335 if (MAI->hasDotTypeDotSizeDirective())
336 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
338 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
340 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
341 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
343 // If the alignment is specified, we *must* obey it. Overaligning a global
344 // with a specified alignment is a prompt way to break globals emitted to
345 // sections and expected to be contiguous (e.g. ObjC metadata).
346 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
348 for (const HandlerInfo &HI : Handlers) {
349 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
350 HI.Handler->setSymbolSize(GVSym, Size);
353 // Handle common and BSS local symbols (.lcomm).
354 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
355 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
356 unsigned Align = 1 << AlignLog;
358 // Handle common symbols.
359 if (GVKind.isCommon()) {
360 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
364 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
368 // Handle local BSS symbols.
369 if (MAI->hasMachoZeroFillDirective()) {
370 const MCSection *TheSection =
371 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
372 // .zerofill __DATA, __bss, _foo, 400, 5
373 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
377 // Use .lcomm only if it supports user-specified alignment.
378 // Otherwise, while it would still be correct to use .lcomm in some
379 // cases (e.g. when Align == 1), the external assembler might enfore
380 // some -unknown- default alignment behavior, which could cause
381 // spurious differences between external and integrated assembler.
382 // Prefer to simply fall back to .local / .comm in this case.
383 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
385 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
389 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
393 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
395 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
399 const MCSection *TheSection =
400 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
402 // Handle the zerofill directive on darwin, which is a special form of BSS
404 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
405 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
408 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
409 // .zerofill __DATA, __common, _foo, 400, 5
410 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
414 // Handle thread local data for mach-o which requires us to output an
415 // additional structure of data and mangle the original symbol so that we
416 // can reference it later.
418 // TODO: This should become an "emit thread local global" method on TLOF.
419 // All of this macho specific stuff should be sunk down into TLOFMachO and
420 // stuff like "TLSExtraDataSection" should no longer be part of the parent
421 // TLOF class. This will also make it more obvious that stuff like
422 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
424 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
425 // Emit the .tbss symbol
427 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
429 if (GVKind.isThreadBSS()) {
430 TheSection = getObjFileLowering().getTLSBSSSection();
431 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
432 } else if (GVKind.isThreadData()) {
433 OutStreamer.SwitchSection(TheSection);
435 EmitAlignment(AlignLog, GV);
436 OutStreamer.EmitLabel(MangSym);
438 EmitGlobalConstant(GV->getInitializer());
441 OutStreamer.AddBlankLine();
443 // Emit the variable struct for the runtime.
444 const MCSection *TLVSect
445 = getObjFileLowering().getTLSExtraDataSection();
447 OutStreamer.SwitchSection(TLVSect);
448 // Emit the linkage here.
449 EmitLinkage(GV, GVSym);
450 OutStreamer.EmitLabel(GVSym);
452 // Three pointers in size:
453 // - __tlv_bootstrap - used to make sure support exists
454 // - spare pointer, used when mapped by the runtime
455 // - pointer to mangled symbol above with initializer
456 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
457 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
459 OutStreamer.EmitIntValue(0, PtrSize);
460 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
462 OutStreamer.AddBlankLine();
466 OutStreamer.SwitchSection(TheSection);
468 EmitLinkage(GV, GVSym);
469 EmitAlignment(AlignLog, GV);
471 OutStreamer.EmitLabel(GVSym);
473 EmitGlobalConstant(GV->getInitializer());
475 if (MAI->hasDotTypeDotSizeDirective())
477 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
479 OutStreamer.AddBlankLine();
482 /// EmitFunctionHeader - This method emits the header for the current
484 void AsmPrinter::EmitFunctionHeader() {
485 // Print out constants referenced by the function
488 // Print the 'header' of function.
489 const Function *F = MF->getFunction();
491 OutStreamer.SwitchSection(
492 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
493 EmitVisibility(CurrentFnSym, F->getVisibility());
495 EmitLinkage(F, CurrentFnSym);
496 EmitAlignment(MF->getAlignment(), F);
498 if (MAI->hasDotTypeDotSizeDirective())
499 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
502 F->printAsOperand(OutStreamer.GetCommentOS(),
503 /*PrintType=*/false, F->getParent());
504 OutStreamer.GetCommentOS() << '\n';
507 // Emit the CurrentFnSym. This is a virtual function to allow targets to
508 // do their wild and crazy things as required.
509 EmitFunctionEntryLabel();
511 // If the function had address-taken blocks that got deleted, then we have
512 // references to the dangling symbols. Emit them at the start of the function
513 // so that we don't get references to undefined symbols.
514 std::vector<MCSymbol*> DeadBlockSyms;
515 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
516 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
517 OutStreamer.AddComment("Address taken block that was later removed");
518 OutStreamer.EmitLabel(DeadBlockSyms[i]);
521 // Emit pre-function debug and/or EH information.
522 for (const HandlerInfo &HI : Handlers) {
523 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
524 HI.Handler->beginFunction(MF);
527 // Emit the prefix data.
528 if (F->hasPrefixData())
529 EmitGlobalConstant(F->getPrefixData());
532 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
533 /// function. This can be overridden by targets as required to do custom stuff.
534 void AsmPrinter::EmitFunctionEntryLabel() {
535 // The function label could have already been emitted if two symbols end up
536 // conflicting due to asm renaming. Detect this and emit an error.
537 if (CurrentFnSym->isUndefined())
538 return OutStreamer.EmitLabel(CurrentFnSym);
540 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
541 "' label emitted multiple times to assembly file");
544 /// emitComments - Pretty-print comments for instructions.
545 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
546 const MachineFunction *MF = MI.getParent()->getParent();
547 const TargetMachine &TM = MF->getTarget();
549 // Check for spills and reloads
552 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
554 // We assume a single instruction only has a spill or reload, not
556 const MachineMemOperand *MMO;
557 if (TM.getSubtargetImpl()->getInstrInfo()->isLoadFromStackSlotPostFE(&MI,
559 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
560 MMO = *MI.memoperands_begin();
561 CommentOS << MMO->getSize() << "-byte Reload\n";
563 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasLoadFromStackSlot(
565 if (FrameInfo->isSpillSlotObjectIndex(FI))
566 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
567 } else if (TM.getSubtargetImpl()->getInstrInfo()->isStoreToStackSlotPostFE(
569 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
570 MMO = *MI.memoperands_begin();
571 CommentOS << MMO->getSize() << "-byte Spill\n";
573 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasStoreToStackSlot(
575 if (FrameInfo->isSpillSlotObjectIndex(FI))
576 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
579 // Check for spill-induced copies
580 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
581 CommentOS << " Reload Reuse\n";
584 /// emitImplicitDef - This method emits the specified machine instruction
585 /// that is an implicit def.
586 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
587 unsigned RegNo = MI->getOperand(0).getReg();
588 OutStreamer.AddComment(
589 Twine("implicit-def: ") +
590 TM.getSubtargetImpl()->getRegisterInfo()->getName(RegNo));
591 OutStreamer.AddBlankLine();
594 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
595 std::string Str = "kill:";
596 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
597 const MachineOperand &Op = MI->getOperand(i);
598 assert(Op.isReg() && "KILL instruction must have only register operands");
600 Str += AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Op.getReg());
601 Str += (Op.isDef() ? "<def>" : "<kill>");
603 AP.OutStreamer.AddComment(Str);
604 AP.OutStreamer.AddBlankLine();
607 /// emitDebugValueComment - This method handles the target-independent form
608 /// of DBG_VALUE, returning true if it was able to do so. A false return
609 /// means the target will need to handle MI in EmitInstruction.
610 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
611 // This code handles only the 3-operand target-independent form.
612 if (MI->getNumOperands() != 3)
615 SmallString<128> Str;
616 raw_svector_ostream OS(Str);
617 OS << "DEBUG_VALUE: ";
619 DIVariable V(MI->getOperand(2).getMetadata());
620 if (V.getContext().isSubprogram()) {
621 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
626 if (V.isVariablePiece())
627 OS << " [piece offset=" << V.getPieceOffset()
628 << " size="<<V.getPieceSize()<<"]";
631 // The second operand is only an offset if it's an immediate.
632 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
633 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
635 // Register or immediate value. Register 0 means undef.
636 if (MI->getOperand(0).isFPImm()) {
637 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
638 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
639 OS << (double)APF.convertToFloat();
640 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
641 OS << APF.convertToDouble();
643 // There is no good way to print long double. Convert a copy to
644 // double. Ah well, it's only a comment.
646 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
648 OS << "(long double) " << APF.convertToDouble();
650 } else if (MI->getOperand(0).isImm()) {
651 OS << MI->getOperand(0).getImm();
652 } else if (MI->getOperand(0).isCImm()) {
653 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
656 if (MI->getOperand(0).isReg()) {
657 Reg = MI->getOperand(0).getReg();
659 assert(MI->getOperand(0).isFI() && "Unknown operand type");
660 const TargetFrameLowering *TFI =
661 AP.TM.getSubtargetImpl()->getFrameLowering();
662 Offset += TFI->getFrameIndexReference(*AP.MF,
663 MI->getOperand(0).getIndex(), Reg);
667 // Suppress offset, it is not meaningful here.
669 // NOTE: Want this comment at start of line, don't emit with AddComment.
670 AP.OutStreamer.emitRawComment(OS.str());
675 OS << AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Reg);
679 OS << '+' << Offset << ']';
681 // NOTE: Want this comment at start of line, don't emit with AddComment.
682 AP.OutStreamer.emitRawComment(OS.str());
686 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
687 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
688 MF->getFunction()->needsUnwindTableEntry())
691 if (MMI->hasDebugInfo())
697 bool AsmPrinter::needsSEHMoves() {
698 return MAI->getExceptionHandlingType() == ExceptionHandling::WinEH &&
699 MF->getFunction()->needsUnwindTableEntry();
702 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
703 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
704 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
705 ExceptionHandlingType != ExceptionHandling::ARM)
708 if (needsCFIMoves() == CFI_M_None)
711 if (MMI->getCompactUnwindEncoding() != 0)
712 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding());
714 const MachineModuleInfo &MMI = MF->getMMI();
715 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
716 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
717 const MCCFIInstruction &CFI = Instrs[CFIIndex];
718 emitCFIInstruction(CFI);
721 /// EmitFunctionBody - This method emits the body and trailer for a
723 void AsmPrinter::EmitFunctionBody() {
724 // Emit target-specific gunk before the function body.
725 EmitFunctionBodyStart();
727 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
729 // Print out code for the function.
730 bool HasAnyRealCode = false;
731 const MachineInstr *LastMI = nullptr;
732 for (auto &MBB : *MF) {
733 // Print a label for the basic block.
734 EmitBasicBlockStart(MBB);
735 for (auto &MI : MBB) {
738 // Print the assembly for the instruction.
739 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
740 !MI.isDebugValue()) {
741 HasAnyRealCode = true;
745 if (ShouldPrintDebugScopes) {
746 for (const HandlerInfo &HI : Handlers) {
747 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
748 TimePassesIsEnabled);
749 HI.Handler->beginInstruction(&MI);
754 emitComments(MI, OutStreamer.GetCommentOS());
756 switch (MI.getOpcode()) {
757 case TargetOpcode::CFI_INSTRUCTION:
758 emitCFIInstruction(MI);
761 case TargetOpcode::EH_LABEL:
762 case TargetOpcode::GC_LABEL:
763 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
765 case TargetOpcode::INLINEASM:
768 case TargetOpcode::DBG_VALUE:
770 if (!emitDebugValueComment(&MI, *this))
771 EmitInstruction(&MI);
774 case TargetOpcode::IMPLICIT_DEF:
775 if (isVerbose()) emitImplicitDef(&MI);
777 case TargetOpcode::KILL:
778 if (isVerbose()) emitKill(&MI, *this);
781 EmitInstruction(&MI);
785 if (ShouldPrintDebugScopes) {
786 for (const HandlerInfo &HI : Handlers) {
787 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
788 TimePassesIsEnabled);
789 HI.Handler->endInstruction();
794 EmitBasicBlockEnd(MBB);
797 // If the last instruction was a prolog label, then we have a situation where
798 // we emitted a prolog but no function body. This results in the ending prolog
799 // label equaling the end of function label and an invalid "row" in the
800 // FDE. We need to emit a noop in this situation so that the FDE's rows are
802 bool RequiresNoop = LastMI && LastMI->isCFIInstruction();
804 // If the function is empty and the object file uses .subsections_via_symbols,
805 // then we need to emit *something* to the function body to prevent the
806 // labels from collapsing together. Just emit a noop.
807 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
809 TM.getSubtargetImpl()->getInstrInfo()->getNoopForMachoTarget(Noop);
810 if (Noop.getOpcode()) {
811 OutStreamer.AddComment("avoids zero-length function");
812 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
813 } else // Target not mc-ized yet.
814 OutStreamer.EmitRawText(StringRef("\tnop\n"));
817 const Function *F = MF->getFunction();
818 for (const auto &BB : *F) {
819 if (!BB.hasAddressTaken())
821 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
822 if (Sym->isDefined())
824 OutStreamer.AddComment("Address of block that was removed by CodeGen");
825 OutStreamer.EmitLabel(Sym);
828 // Emit target-specific gunk after the function body.
829 EmitFunctionBodyEnd();
831 // If the target wants a .size directive for the size of the function, emit
833 if (MAI->hasDotTypeDotSizeDirective()) {
834 // Create a symbol for the end of function, so we can get the size as
835 // difference between the function label and the temp label.
836 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
837 OutStreamer.EmitLabel(FnEndLabel);
839 const MCExpr *SizeExp =
840 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
841 MCSymbolRefExpr::Create(CurrentFnSymForSize,
844 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
847 // Emit post-function debug and/or EH information.
848 for (const HandlerInfo &HI : Handlers) {
849 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
850 HI.Handler->endFunction(MF);
854 // Print out jump tables referenced by the function.
857 OutStreamer.AddBlankLine();
860 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP);
862 bool AsmPrinter::doFinalization(Module &M) {
863 // Emit global variables.
864 for (const auto &G : M.globals())
865 EmitGlobalVariable(&G);
867 // Emit visibility info for declarations
868 for (const Function &F : M) {
869 if (!F.isDeclaration())
871 GlobalValue::VisibilityTypes V = F.getVisibility();
872 if (V == GlobalValue::DefaultVisibility)
875 MCSymbol *Name = getSymbol(&F);
876 EmitVisibility(Name, V, false);
879 // Get information about jump-instruction tables to print.
880 JumpInstrTableInfo *JITI = getAnalysisIfAvailable<JumpInstrTableInfo>();
882 if (JITI && !JITI->getTables().empty()) {
883 unsigned Arch = Triple(getTargetTriple()).getArch();
884 bool IsThumb = (Arch == Triple::thumb || Arch == Triple::thumbeb);
886 TM.getSubtargetImpl()->getInstrInfo()->getTrap(TrapInst);
887 for (const auto &KV : JITI->getTables()) {
889 for (const auto &FunPair : KV.second) {
890 // Emit the function labels to make this be a function entry point.
892 OutContext.GetOrCreateSymbol(FunPair.second->getName());
893 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_Global);
894 // FIXME: JumpTableInstrInfo should store information about the required
895 // alignment of table entries and the size of the padding instruction.
898 OutStreamer.EmitThumbFunc(FunSym);
899 if (MAI->hasDotTypeDotSizeDirective())
900 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_ELF_TypeFunction);
901 OutStreamer.EmitLabel(FunSym);
903 // Emit the jump instruction to transfer control to the original
906 MCSymbol *TargetSymbol =
907 OutContext.GetOrCreateSymbol(FunPair.first->getName());
908 const MCSymbolRefExpr *TargetSymRef =
909 MCSymbolRefExpr::Create(TargetSymbol, MCSymbolRefExpr::VK_PLT,
911 TM.getSubtargetImpl()->getInstrInfo()->getUnconditionalBranch(
912 JumpToFun, TargetSymRef);
913 OutStreamer.EmitInstruction(JumpToFun, getSubtargetInfo());
917 // Emit enough padding instructions to fill up to the next power of two.
918 // This assumes that the trap instruction takes 8 bytes or fewer.
919 uint64_t Remaining = NextPowerOf2(Count) - Count;
920 for (uint64_t C = 0; C < Remaining; ++C) {
922 OutStreamer.EmitInstruction(TrapInst, getSubtargetInfo());
928 // Emit module flags.
929 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
930 M.getModuleFlagsMetadata(ModuleFlags);
931 if (!ModuleFlags.empty())
932 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
934 // Make sure we wrote out everything we need.
937 // Finalize debug and EH information.
938 for (const HandlerInfo &HI : Handlers) {
939 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
940 TimePassesIsEnabled);
941 HI.Handler->endModule();
947 // If the target wants to know about weak references, print them all.
948 if (MAI->getWeakRefDirective()) {
949 // FIXME: This is not lazy, it would be nice to only print weak references
950 // to stuff that is actually used. Note that doing so would require targets
951 // to notice uses in operands (due to constant exprs etc). This should
952 // happen with the MC stuff eventually.
954 // Print out module-level global variables here.
955 for (const auto &G : M.globals()) {
956 if (!G.hasExternalWeakLinkage())
958 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
961 for (const auto &F : M) {
962 if (!F.hasExternalWeakLinkage())
964 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
968 if (MAI->hasSetDirective()) {
969 OutStreamer.AddBlankLine();
970 for (const auto &Alias : M.aliases()) {
971 MCSymbol *Name = getSymbol(&Alias);
973 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
974 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
975 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
976 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
978 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
980 EmitVisibility(Name, Alias.getVisibility());
982 // Emit the directives as assignments aka .set:
983 OutStreamer.EmitAssignment(Name,
984 lowerConstant(Alias.getAliasee(), *this));
988 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
989 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
990 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
991 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
992 MP->finishAssembly(*this);
994 // Emit llvm.ident metadata in an '.ident' directive.
997 // If we don't have any trampolines, then we don't require stack memory
998 // to be executable. Some targets have a directive to declare this.
999 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1000 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1001 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1002 OutStreamer.SwitchSection(S);
1004 // Allow the target to emit any magic that it wants at the end of the file,
1005 // after everything else has gone out.
1006 EmitEndOfAsmFile(M);
1008 delete Mang; Mang = nullptr;
1011 OutStreamer.Finish();
1012 OutStreamer.reset();
1017 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1019 // Get the function symbol.
1020 CurrentFnSym = getSymbol(MF.getFunction());
1021 CurrentFnSymForSize = CurrentFnSym;
1024 LI = &getAnalysis<MachineLoopInfo>();
1028 // SectionCPs - Keep track the alignment, constpool entries per Section.
1032 SmallVector<unsigned, 4> CPEs;
1033 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1037 /// EmitConstantPool - Print to the current output stream assembly
1038 /// representations of the constants in the constant pool MCP. This is
1039 /// used to print out constants which have been "spilled to memory" by
1040 /// the code generator.
1042 void AsmPrinter::EmitConstantPool() {
1043 const MachineConstantPool *MCP = MF->getConstantPool();
1044 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1045 if (CP.empty()) return;
1047 // Calculate sections for constant pool entries. We collect entries to go into
1048 // the same section together to reduce amount of section switch statements.
1049 SmallVector<SectionCPs, 4> CPSections;
1050 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1051 const MachineConstantPoolEntry &CPE = CP[i];
1052 unsigned Align = CPE.getAlignment();
1055 CPE.getSectionKind(TM.getSubtargetImpl()->getDataLayout());
1057 const Constant *C = nullptr;
1058 if (!CPE.isMachineConstantPoolEntry())
1059 C = CPE.Val.ConstVal;
1061 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind, C);
1063 // The number of sections are small, just do a linear search from the
1064 // last section to the first.
1066 unsigned SecIdx = CPSections.size();
1067 while (SecIdx != 0) {
1068 if (CPSections[--SecIdx].S == S) {
1074 SecIdx = CPSections.size();
1075 CPSections.push_back(SectionCPs(S, Align));
1078 if (Align > CPSections[SecIdx].Alignment)
1079 CPSections[SecIdx].Alignment = Align;
1080 CPSections[SecIdx].CPEs.push_back(i);
1083 // Now print stuff into the calculated sections.
1084 const MCSection *CurSection = nullptr;
1085 unsigned Offset = 0;
1086 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1087 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1088 unsigned CPI = CPSections[i].CPEs[j];
1089 MCSymbol *Sym = GetCPISymbol(CPI);
1090 if (!Sym->isUndefined())
1093 if (CurSection != CPSections[i].S) {
1094 OutStreamer.SwitchSection(CPSections[i].S);
1095 EmitAlignment(Log2_32(CPSections[i].Alignment));
1096 CurSection = CPSections[i].S;
1100 MachineConstantPoolEntry CPE = CP[CPI];
1102 // Emit inter-object padding for alignment.
1103 unsigned AlignMask = CPE.getAlignment() - 1;
1104 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1105 OutStreamer.EmitZeros(NewOffset - Offset);
1107 Type *Ty = CPE.getType();
1108 Offset = NewOffset +
1109 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(Ty);
1111 OutStreamer.EmitLabel(Sym);
1112 if (CPE.isMachineConstantPoolEntry())
1113 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1115 EmitGlobalConstant(CPE.Val.ConstVal);
1120 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1121 /// by the current function to the current output stream.
1123 void AsmPrinter::EmitJumpTableInfo() {
1124 const DataLayout *DL = MF->getSubtarget().getDataLayout();
1125 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1127 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1128 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1129 if (JT.empty()) return;
1131 // Pick the directive to use to print the jump table entries, and switch to
1132 // the appropriate section.
1133 const Function *F = MF->getFunction();
1134 bool JTInDiffSection = false;
1135 if (// In PIC mode, we need to emit the jump table to the same section as the
1136 // function body itself, otherwise the label differences won't make sense.
1137 // FIXME: Need a better predicate for this: what about custom entries?
1138 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1139 // We should also do if the section name is NULL or function is declared
1140 // in discardable section
1141 // FIXME: this isn't the right predicate, should be based on the MCSection
1142 // for the function.
1143 F->isWeakForLinker()) {
1144 OutStreamer.SwitchSection(
1145 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1147 // Otherwise, drop it in the readonly section.
1148 const MCSection *ReadOnlySection =
1149 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
1151 OutStreamer.SwitchSection(ReadOnlySection);
1152 JTInDiffSection = true;
1155 EmitAlignment(Log2_32(
1156 MJTI->getEntryAlignment(*TM.getSubtargetImpl()->getDataLayout())));
1158 // Jump tables in code sections are marked with a data_region directive
1159 // where that's supported.
1160 if (!JTInDiffSection)
1161 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1163 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1164 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1166 // If this jump table was deleted, ignore it.
1167 if (JTBBs.empty()) continue;
1169 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1170 // .set directive for each unique entry. This reduces the number of
1171 // relocations the assembler will generate for the jump table.
1172 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1173 MAI->hasSetDirective()) {
1174 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1175 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1176 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1177 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1178 const MachineBasicBlock *MBB = JTBBs[ii];
1179 if (!EmittedSets.insert(MBB)) continue;
1181 // .set LJTSet, LBB32-base
1183 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1184 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1185 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1189 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1190 // before each jump table. The first label is never referenced, but tells
1191 // the assembler and linker the extents of the jump table object. The
1192 // second label is actually referenced by the code.
1193 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1194 // FIXME: This doesn't have to have any specific name, just any randomly
1195 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1196 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1198 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1200 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1201 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1203 if (!JTInDiffSection)
1204 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1207 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1209 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1210 const MachineBasicBlock *MBB,
1211 unsigned UID) const {
1212 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1213 const MCExpr *Value = nullptr;
1214 switch (MJTI->getEntryKind()) {
1215 case MachineJumpTableInfo::EK_Inline:
1216 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1217 case MachineJumpTableInfo::EK_Custom32:
1219 TM.getSubtargetImpl()->getTargetLowering()->LowerCustomJumpTableEntry(
1220 MJTI, MBB, UID, OutContext);
1222 case MachineJumpTableInfo::EK_BlockAddress:
1223 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1225 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1227 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1228 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1229 // with a relocation as gp-relative, e.g.:
1231 MCSymbol *MBBSym = MBB->getSymbol();
1232 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1236 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1237 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1238 // with a relocation as gp-relative, e.g.:
1240 MCSymbol *MBBSym = MBB->getSymbol();
1241 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1245 case MachineJumpTableInfo::EK_LabelDifference32: {
1246 // EK_LabelDifference32 - Each entry is the address of the block minus
1247 // the address of the jump table. This is used for PIC jump tables where
1248 // gprel32 is not supported. e.g.:
1249 // .word LBB123 - LJTI1_2
1250 // If the .set directive is supported, this is emitted as:
1251 // .set L4_5_set_123, LBB123 - LJTI1_2
1252 // .word L4_5_set_123
1254 // If we have emitted set directives for the jump table entries, print
1255 // them rather than the entries themselves. If we're emitting PIC, then
1256 // emit the table entries as differences between two text section labels.
1257 if (MAI->hasSetDirective()) {
1258 // If we used .set, reference the .set's symbol.
1259 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1263 // Otherwise, use the difference as the jump table entry.
1264 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1265 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1266 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1271 assert(Value && "Unknown entry kind!");
1273 unsigned EntrySize =
1274 MJTI->getEntrySize(*TM.getSubtargetImpl()->getDataLayout());
1275 OutStreamer.EmitValue(Value, EntrySize);
1279 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1280 /// special global used by LLVM. If so, emit it and return true, otherwise
1281 /// do nothing and return false.
1282 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1283 if (GV->getName() == "llvm.used") {
1284 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1285 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1289 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1290 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1291 GV->hasAvailableExternallyLinkage())
1294 if (!GV->hasAppendingLinkage()) return false;
1296 assert(GV->hasInitializer() && "Not a special LLVM global!");
1298 if (GV->getName() == "llvm.global_ctors") {
1299 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1301 if (TM.getRelocationModel() == Reloc::Static &&
1302 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1303 StringRef Sym(".constructors_used");
1304 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1310 if (GV->getName() == "llvm.global_dtors") {
1311 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1313 if (TM.getRelocationModel() == Reloc::Static &&
1314 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1315 StringRef Sym(".destructors_used");
1316 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1325 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1326 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1327 /// is true, as being used with this directive.
1328 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1329 // Should be an array of 'i8*'.
1330 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1331 const GlobalValue *GV =
1332 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1334 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1340 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1342 llvm::Constant *Func;
1343 llvm::GlobalValue *ComdatKey;
1347 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1349 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1350 // Should be an array of '{ int, void ()* }' structs. The first value is the
1352 if (!isa<ConstantArray>(List)) return;
1354 // Sanity check the structors list.
1355 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1356 if (!InitList) return; // Not an array!
1357 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1358 // FIXME: Only allow the 3-field form in LLVM 4.0.
1359 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1360 return; // Not an array of two or three elements!
1361 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1362 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1363 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1364 return; // Not (int, ptr, ptr).
1366 // Gather the structors in a form that's convenient for sorting by priority.
1367 SmallVector<Structor, 8> Structors;
1368 for (Value *O : InitList->operands()) {
1369 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1370 if (!CS) continue; // Malformed.
1371 if (CS->getOperand(1)->isNullValue())
1372 break; // Found a null terminator, skip the rest.
1373 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1374 if (!Priority) continue; // Malformed.
1375 Structors.push_back(Structor());
1376 Structor &S = Structors.back();
1377 S.Priority = Priority->getLimitedValue(65535);
1378 S.Func = CS->getOperand(1);
1379 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1380 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1383 // Emit the function pointers in the target-specific order
1384 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
1385 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1386 std::stable_sort(Structors.begin(), Structors.end(),
1387 [](const Structor &L,
1388 const Structor &R) { return L.Priority < R.Priority; });
1389 for (Structor &S : Structors) {
1390 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1391 const MCSymbol *KeySym = nullptr;
1392 if (GlobalValue *GV = S.ComdatKey) {
1393 if (GV->hasAvailableExternallyLinkage())
1394 // If the associated variable is available_externally, some other TU
1395 // will provide its dynamic initializer.
1398 KeySym = getSymbol(GV);
1400 const MCSection *OutputSection =
1401 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1402 : Obj.getStaticDtorSection(S.Priority, KeySym));
1403 OutStreamer.SwitchSection(OutputSection);
1404 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1405 EmitAlignment(Align);
1406 EmitXXStructor(S.Func);
1410 void AsmPrinter::EmitModuleIdents(Module &M) {
1411 if (!MAI->hasIdentDirective())
1414 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1415 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1416 const MDNode *N = NMD->getOperand(i);
1417 assert(N->getNumOperands() == 1 &&
1418 "llvm.ident metadata entry can have only one operand");
1419 const MDString *S = cast<MDString>(N->getOperand(0));
1420 OutStreamer.EmitIdent(S->getString());
1425 //===--------------------------------------------------------------------===//
1426 // Emission and print routines
1429 /// EmitInt8 - Emit a byte directive and value.
1431 void AsmPrinter::EmitInt8(int Value) const {
1432 OutStreamer.EmitIntValue(Value, 1);
1435 /// EmitInt16 - Emit a short directive and value.
1437 void AsmPrinter::EmitInt16(int Value) const {
1438 OutStreamer.EmitIntValue(Value, 2);
1441 /// EmitInt32 - Emit a long directive and value.
1443 void AsmPrinter::EmitInt32(int Value) const {
1444 OutStreamer.EmitIntValue(Value, 4);
1447 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1448 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1449 /// labels. This implicitly uses .set if it is available.
1450 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1451 unsigned Size) const {
1452 // Get the Hi-Lo expression.
1453 const MCExpr *Diff =
1454 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1455 MCSymbolRefExpr::Create(Lo, OutContext),
1458 if (!MAI->hasSetDirective()) {
1459 OutStreamer.EmitValue(Diff, Size);
1463 // Otherwise, emit with .set (aka assignment).
1464 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1465 OutStreamer.EmitAssignment(SetLabel, Diff);
1466 OutStreamer.EmitSymbolValue(SetLabel, Size);
1469 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1470 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1471 /// specify the labels. This implicitly uses .set if it is available.
1472 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1474 unsigned Size) const {
1476 // Emit Hi+Offset - Lo
1477 // Get the Hi+Offset expression.
1478 const MCExpr *Plus =
1479 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1480 MCConstantExpr::Create(Offset, OutContext),
1483 // Get the Hi+Offset-Lo expression.
1484 const MCExpr *Diff =
1485 MCBinaryExpr::CreateSub(Plus,
1486 MCSymbolRefExpr::Create(Lo, OutContext),
1489 if (!MAI->hasSetDirective())
1490 OutStreamer.EmitValue(Diff, Size);
1492 // Otherwise, emit with .set (aka assignment).
1493 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1494 OutStreamer.EmitAssignment(SetLabel, Diff);
1495 OutStreamer.EmitSymbolValue(SetLabel, Size);
1499 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1500 /// where the size in bytes of the directive is specified by Size and Label
1501 /// specifies the label. This implicitly uses .set if it is available.
1502 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1504 bool IsSectionRelative) const {
1505 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1506 OutStreamer.EmitCOFFSecRel32(Label);
1510 // Emit Label+Offset (or just Label if Offset is zero)
1511 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1513 Expr = MCBinaryExpr::CreateAdd(
1514 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1516 OutStreamer.EmitValue(Expr, Size);
1519 //===----------------------------------------------------------------------===//
1521 // EmitAlignment - Emit an alignment directive to the specified power of
1522 // two boundary. For example, if you pass in 3 here, you will get an 8
1523 // byte alignment. If a global value is specified, and if that global has
1524 // an explicit alignment requested, it will override the alignment request
1525 // if required for correctness.
1527 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1529 NumBits = getGVAlignmentLog2(GV, *TM.getSubtargetImpl()->getDataLayout(),
1532 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1534 if (getCurrentSection()->getKind().isText())
1535 OutStreamer.EmitCodeAlignment(1 << NumBits);
1537 OutStreamer.EmitValueToAlignment(1 << NumBits);
1540 //===----------------------------------------------------------------------===//
1541 // Constant emission.
1542 //===----------------------------------------------------------------------===//
1544 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1546 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1547 MCContext &Ctx = AP.OutContext;
1549 if (CV->isNullValue() || isa<UndefValue>(CV))
1550 return MCConstantExpr::Create(0, Ctx);
1552 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1553 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1555 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1556 return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx);
1558 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1559 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1561 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1563 llvm_unreachable("Unknown constant value to lower!");
1566 if (const MCExpr *RelocExpr =
1567 AP.getObjFileLowering().getExecutableRelativeSymbol(CE, *AP.Mang,
1571 switch (CE->getOpcode()) {
1573 // If the code isn't optimized, there may be outstanding folding
1574 // opportunities. Attempt to fold the expression using DataLayout as a
1575 // last resort before giving up.
1576 if (Constant *C = ConstantFoldConstantExpression(
1577 CE, AP.TM.getSubtargetImpl()->getDataLayout()))
1579 return lowerConstant(C, AP);
1581 // Otherwise report the problem to the user.
1584 raw_string_ostream OS(S);
1585 OS << "Unsupported expression in static initializer: ";
1586 CE->printAsOperand(OS, /*PrintType=*/false,
1587 !AP.MF ? nullptr : AP.MF->getFunction()->getParent());
1588 report_fatal_error(OS.str());
1590 case Instruction::GetElementPtr: {
1591 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1592 // Generate a symbolic expression for the byte address
1593 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1594 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1596 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1600 int64_t Offset = OffsetAI.getSExtValue();
1601 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1605 case Instruction::Trunc:
1606 // We emit the value and depend on the assembler to truncate the generated
1607 // expression properly. This is important for differences between
1608 // blockaddress labels. Since the two labels are in the same function, it
1609 // is reasonable to treat their delta as a 32-bit value.
1611 case Instruction::BitCast:
1612 return lowerConstant(CE->getOperand(0), AP);
1614 case Instruction::IntToPtr: {
1615 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1616 // Handle casts to pointers by changing them into casts to the appropriate
1617 // integer type. This promotes constant folding and simplifies this code.
1618 Constant *Op = CE->getOperand(0);
1619 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1621 return lowerConstant(Op, AP);
1624 case Instruction::PtrToInt: {
1625 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1626 // Support only foldable casts to/from pointers that can be eliminated by
1627 // changing the pointer to the appropriately sized integer type.
1628 Constant *Op = CE->getOperand(0);
1629 Type *Ty = CE->getType();
1631 const MCExpr *OpExpr = lowerConstant(Op, AP);
1633 // We can emit the pointer value into this slot if the slot is an
1634 // integer slot equal to the size of the pointer.
1635 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1638 // Otherwise the pointer is smaller than the resultant integer, mask off
1639 // the high bits so we are sure to get a proper truncation if the input is
1641 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1642 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1643 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1646 // The MC library also has a right-shift operator, but it isn't consistently
1647 // signed or unsigned between different targets.
1648 case Instruction::Add:
1649 case Instruction::Sub:
1650 case Instruction::Mul:
1651 case Instruction::SDiv:
1652 case Instruction::SRem:
1653 case Instruction::Shl:
1654 case Instruction::And:
1655 case Instruction::Or:
1656 case Instruction::Xor: {
1657 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1658 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1659 switch (CE->getOpcode()) {
1660 default: llvm_unreachable("Unknown binary operator constant cast expr");
1661 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1662 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1663 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1664 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1665 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1666 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1667 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1668 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1669 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1675 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1677 /// isRepeatedByteSequence - Determine whether the given value is
1678 /// composed of a repeated sequence of identical bytes and return the
1679 /// byte value. If it is not a repeated sequence, return -1.
1680 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1681 StringRef Data = V->getRawDataValues();
1682 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1684 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1685 if (Data[i] != C) return -1;
1686 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1690 /// isRepeatedByteSequence - Determine whether the given value is
1691 /// composed of a repeated sequence of identical bytes and return the
1692 /// byte value. If it is not a repeated sequence, return -1.
1693 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1695 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1696 if (CI->getBitWidth() > 64) return -1;
1699 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(V->getType());
1700 uint64_t Value = CI->getZExtValue();
1702 // Make sure the constant is at least 8 bits long and has a power
1703 // of 2 bit width. This guarantees the constant bit width is
1704 // always a multiple of 8 bits, avoiding issues with padding out
1705 // to Size and other such corner cases.
1706 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1708 uint8_t Byte = static_cast<uint8_t>(Value);
1710 for (unsigned i = 1; i < Size; ++i) {
1712 if (static_cast<uint8_t>(Value) != Byte) return -1;
1716 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1717 // Make sure all array elements are sequences of the same repeated
1719 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1720 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1721 if (Byte == -1) return -1;
1723 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1724 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1725 if (ThisByte == -1) return -1;
1726 if (Byte != ThisByte) return -1;
1731 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1732 return isRepeatedByteSequence(CDS);
1737 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1740 // See if we can aggregate this into a .fill, if so, emit it as such.
1741 int Value = isRepeatedByteSequence(CDS, AP.TM);
1744 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1746 // Don't emit a 1-byte object as a .fill.
1748 return AP.OutStreamer.EmitFill(Bytes, Value);
1751 // If this can be emitted with .ascii/.asciz, emit it as such.
1752 if (CDS->isString())
1753 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1755 // Otherwise, emit the values in successive locations.
1756 unsigned ElementByteSize = CDS->getElementByteSize();
1757 if (isa<IntegerType>(CDS->getElementType())) {
1758 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1760 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1761 CDS->getElementAsInteger(i));
1762 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1765 } else if (ElementByteSize == 4) {
1766 // FP Constants are printed as integer constants to avoid losing
1768 assert(CDS->getElementType()->isFloatTy());
1769 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1775 F = CDS->getElementAsFloat(i);
1777 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1778 AP.OutStreamer.EmitIntValue(I, 4);
1781 assert(CDS->getElementType()->isDoubleTy());
1782 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1788 F = CDS->getElementAsDouble(i);
1790 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1791 AP.OutStreamer.EmitIntValue(I, 8);
1795 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1796 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1797 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1798 CDS->getNumElements();
1799 if (unsigned Padding = Size - EmittedSize)
1800 AP.OutStreamer.EmitZeros(Padding);
1804 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1805 // See if we can aggregate some values. Make sure it can be
1806 // represented as a series of bytes of the constant value.
1807 int Value = isRepeatedByteSequence(CA, AP.TM);
1811 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1813 AP.OutStreamer.EmitFill(Bytes, Value);
1816 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1817 emitGlobalConstantImpl(CA->getOperand(i), AP);
1821 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1822 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1823 emitGlobalConstantImpl(CV->getOperand(i), AP);
1825 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1826 unsigned Size = DL.getTypeAllocSize(CV->getType());
1827 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1828 CV->getType()->getNumElements();
1829 if (unsigned Padding = Size - EmittedSize)
1830 AP.OutStreamer.EmitZeros(Padding);
1833 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1834 // Print the fields in successive locations. Pad to align if needed!
1835 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1836 unsigned Size = DL->getTypeAllocSize(CS->getType());
1837 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1838 uint64_t SizeSoFar = 0;
1839 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1840 const Constant *Field = CS->getOperand(i);
1842 // Check if padding is needed and insert one or more 0s.
1843 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1844 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1845 - Layout->getElementOffset(i)) - FieldSize;
1846 SizeSoFar += FieldSize + PadSize;
1848 // Now print the actual field value.
1849 emitGlobalConstantImpl(Field, AP);
1851 // Insert padding - this may include padding to increase the size of the
1852 // current field up to the ABI size (if the struct is not packed) as well
1853 // as padding to ensure that the next field starts at the right offset.
1854 AP.OutStreamer.EmitZeros(PadSize);
1856 assert(SizeSoFar == Layout->getSizeInBytes() &&
1857 "Layout of constant struct may be incorrect!");
1860 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1861 APInt API = CFP->getValueAPF().bitcastToAPInt();
1863 // First print a comment with what we think the original floating-point value
1864 // should have been.
1865 if (AP.isVerbose()) {
1866 SmallString<8> StrVal;
1867 CFP->getValueAPF().toString(StrVal);
1870 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1872 AP.OutStreamer.GetCommentOS() << "Printing <null> Type";
1873 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1876 // Now iterate through the APInt chunks, emitting them in endian-correct
1877 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1879 unsigned NumBytes = API.getBitWidth() / 8;
1880 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1881 const uint64_t *p = API.getRawData();
1883 // PPC's long double has odd notions of endianness compared to how LLVM
1884 // handles it: p[0] goes first for *big* endian on PPC.
1885 if (AP.TM.getSubtargetImpl()->getDataLayout()->isBigEndian() &&
1886 !CFP->getType()->isPPC_FP128Ty()) {
1887 int Chunk = API.getNumWords() - 1;
1890 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1892 for (; Chunk >= 0; --Chunk)
1893 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1896 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1897 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1900 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1903 // Emit the tail padding for the long double.
1904 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1905 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1906 DL.getTypeStoreSize(CFP->getType()));
1909 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1910 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1911 unsigned BitWidth = CI->getBitWidth();
1913 // Copy the value as we may massage the layout for constants whose bit width
1914 // is not a multiple of 64-bits.
1915 APInt Realigned(CI->getValue());
1916 uint64_t ExtraBits = 0;
1917 unsigned ExtraBitsSize = BitWidth & 63;
1919 if (ExtraBitsSize) {
1920 // The bit width of the data is not a multiple of 64-bits.
1921 // The extra bits are expected to be at the end of the chunk of the memory.
1923 // * Nothing to be done, just record the extra bits to emit.
1925 // * Record the extra bits to emit.
1926 // * Realign the raw data to emit the chunks of 64-bits.
1927 if (DL->isBigEndian()) {
1928 // Basically the structure of the raw data is a chunk of 64-bits cells:
1929 // 0 1 BitWidth / 64
1930 // [chunk1][chunk2] ... [chunkN].
1931 // The most significant chunk is chunkN and it should be emitted first.
1932 // However, due to the alignment issue chunkN contains useless bits.
1933 // Realign the chunks so that they contain only useless information:
1934 // ExtraBits 0 1 (BitWidth / 64) - 1
1935 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1936 ExtraBits = Realigned.getRawData()[0] &
1937 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1938 Realigned = Realigned.lshr(ExtraBitsSize);
1940 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1943 // We don't expect assemblers to support integer data directives
1944 // for more than 64 bits, so we emit the data in at most 64-bit
1945 // quantities at a time.
1946 const uint64_t *RawData = Realigned.getRawData();
1947 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1948 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1949 AP.OutStreamer.EmitIntValue(Val, 8);
1952 if (ExtraBitsSize) {
1953 // Emit the extra bits after the 64-bits chunks.
1955 // Emit a directive that fills the expected size.
1956 uint64_t Size = AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1958 Size -= (BitWidth / 64) * 8;
1959 assert(Size && Size * 8 >= ExtraBitsSize &&
1960 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1961 == ExtraBits && "Directive too small for extra bits.");
1962 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1966 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1967 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1968 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1969 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1970 return AP.OutStreamer.EmitZeros(Size);
1972 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1979 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1980 CI->getZExtValue());
1981 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1984 emitGlobalConstantLargeInt(CI, AP);
1989 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1990 return emitGlobalConstantFP(CFP, AP);
1992 if (isa<ConstantPointerNull>(CV)) {
1993 AP.OutStreamer.EmitIntValue(0, Size);
1997 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1998 return emitGlobalConstantDataSequential(CDS, AP);
2000 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2001 return emitGlobalConstantArray(CVA, AP);
2003 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2004 return emitGlobalConstantStruct(CVS, AP);
2006 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2007 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2009 if (CE->getOpcode() == Instruction::BitCast)
2010 return emitGlobalConstantImpl(CE->getOperand(0), AP);
2013 // If the constant expression's size is greater than 64-bits, then we have
2014 // to emit the value in chunks. Try to constant fold the value and emit it
2016 Constant *New = ConstantFoldConstantExpression(CE, DL);
2017 if (New && New != CE)
2018 return emitGlobalConstantImpl(New, AP);
2022 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2023 return emitGlobalConstantVector(V, AP);
2025 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2026 // thread the streamer with EmitValue.
2027 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
2030 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2031 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2033 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(CV->getType());
2035 emitGlobalConstantImpl(CV, *this);
2036 else if (MAI->hasSubsectionsViaSymbols()) {
2037 // If the global has zero size, emit a single byte so that two labels don't
2038 // look like they are at the same location.
2039 OutStreamer.EmitIntValue(0, 1);
2043 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2044 // Target doesn't support this yet!
2045 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2048 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2050 OS << '+' << Offset;
2051 else if (Offset < 0)
2055 //===----------------------------------------------------------------------===//
2056 // Symbol Lowering Routines.
2057 //===----------------------------------------------------------------------===//
2059 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2060 /// temporary label with the specified stem and unique ID.
2061 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const {
2062 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2063 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2067 /// GetTempSymbol - Return an assembler temporary label with the specified
2069 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const {
2070 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2071 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2076 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2077 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2080 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2081 return MMI->getAddrLabelSymbol(BB);
2084 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2085 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2086 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2087 return OutContext.GetOrCreateSymbol
2088 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2089 + "_" + Twine(CPID));
2092 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2093 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2094 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2097 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2098 /// FIXME: privatize to AsmPrinter.
2099 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2100 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2101 return OutContext.GetOrCreateSymbol
2102 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2103 Twine(UID) + "_set_" + Twine(MBBID));
2106 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2107 StringRef Suffix) const {
2108 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2112 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2114 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2115 SmallString<60> NameStr;
2116 Mang->getNameWithPrefix(NameStr, Sym);
2117 return OutContext.GetOrCreateSymbol(NameStr.str());
2122 /// PrintParentLoopComment - Print comments about parent loops of this one.
2123 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2124 unsigned FunctionNumber) {
2126 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2127 OS.indent(Loop->getLoopDepth()*2)
2128 << "Parent Loop BB" << FunctionNumber << "_"
2129 << Loop->getHeader()->getNumber()
2130 << " Depth=" << Loop->getLoopDepth() << '\n';
2134 /// PrintChildLoopComment - Print comments about child loops within
2135 /// the loop for this basic block, with nesting.
2136 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2137 unsigned FunctionNumber) {
2138 // Add child loop information
2139 for (const MachineLoop *CL : *Loop) {
2140 OS.indent(CL->getLoopDepth()*2)
2141 << "Child Loop BB" << FunctionNumber << "_"
2142 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2144 PrintChildLoopComment(OS, CL, FunctionNumber);
2148 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2149 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2150 const MachineLoopInfo *LI,
2151 const AsmPrinter &AP) {
2152 // Add loop depth information
2153 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2156 MachineBasicBlock *Header = Loop->getHeader();
2157 assert(Header && "No header for loop");
2159 // If this block is not a loop header, just print out what is the loop header
2161 if (Header != &MBB) {
2162 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2163 Twine(AP.getFunctionNumber())+"_" +
2164 Twine(Loop->getHeader()->getNumber())+
2165 " Depth="+Twine(Loop->getLoopDepth()));
2169 // Otherwise, it is a loop header. Print out information about child and
2171 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2173 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2176 OS.indent(Loop->getLoopDepth()*2-2);
2181 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2183 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2187 /// EmitBasicBlockStart - This method prints the label for the specified
2188 /// MachineBasicBlock, an alignment (if present) and a comment describing
2189 /// it if appropriate.
2190 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2191 // Emit an alignment directive for this block, if needed.
2192 if (unsigned Align = MBB.getAlignment())
2193 EmitAlignment(Align);
2195 // If the block has its address taken, emit any labels that were used to
2196 // reference the block. It is possible that there is more than one label
2197 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2198 // the references were generated.
2199 if (MBB.hasAddressTaken()) {
2200 const BasicBlock *BB = MBB.getBasicBlock();
2202 OutStreamer.AddComment("Block address taken");
2204 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2205 for (auto *Sym : Symbols)
2206 OutStreamer.EmitLabel(Sym);
2209 // Print some verbose block comments.
2211 if (const BasicBlock *BB = MBB.getBasicBlock())
2213 OutStreamer.AddComment("%" + BB->getName());
2214 emitBasicBlockLoopComments(MBB, LI, *this);
2217 // Print the main label for the block.
2218 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2220 // NOTE: Want this comment at start of line, don't emit with AddComment.
2221 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2224 OutStreamer.EmitLabel(MBB.getSymbol());
2228 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2229 bool IsDefinition) const {
2230 MCSymbolAttr Attr = MCSA_Invalid;
2232 switch (Visibility) {
2234 case GlobalValue::HiddenVisibility:
2236 Attr = MAI->getHiddenVisibilityAttr();
2238 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2240 case GlobalValue::ProtectedVisibility:
2241 Attr = MAI->getProtectedVisibilityAttr();
2245 if (Attr != MCSA_Invalid)
2246 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2249 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2250 /// exactly one predecessor and the control transfer mechanism between
2251 /// the predecessor and this block is a fall-through.
2253 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2254 // If this is a landing pad, it isn't a fall through. If it has no preds,
2255 // then nothing falls through to it.
2256 if (MBB->isLandingPad() || MBB->pred_empty())
2259 // If there isn't exactly one predecessor, it can't be a fall through.
2260 if (MBB->pred_size() > 1)
2263 // The predecessor has to be immediately before this block.
2264 MachineBasicBlock *Pred = *MBB->pred_begin();
2265 if (!Pred->isLayoutSuccessor(MBB))
2268 // If the block is completely empty, then it definitely does fall through.
2272 // Check the terminators in the previous blocks
2273 for (const auto &MI : Pred->terminators()) {
2274 // If it is not a simple branch, we are in a table somewhere.
2275 if (!MI.isBranch() || MI.isIndirectBranch())
2278 // If we are the operands of one of the branches, this is not a fall
2279 // through. Note that targets with delay slots will usually bundle
2280 // terminators with the delay slot instruction.
2281 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2284 if (OP->isMBB() && OP->getMBB() == MBB)
2294 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2295 if (!S.usesMetadata())
2298 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2299 gcp_map_type::iterator GCPI = GCMap.find(&S);
2300 if (GCPI != GCMap.end())
2301 return GCPI->second.get();
2303 const char *Name = S.getName().c_str();
2305 for (GCMetadataPrinterRegistry::iterator
2306 I = GCMetadataPrinterRegistry::begin(),
2307 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2308 if (strcmp(Name, I->getName()) == 0) {
2309 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2311 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2312 return IterBool.first->second.get();
2315 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2318 /// Pin vtable to this file.
2319 AsmPrinterHandler::~AsmPrinterHandler() {}