1 //===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the AsmPrinter class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/CodeGen/AsmPrinter.h"
15 #include "DwarfDebug.h"
16 #include "DwarfException.h"
17 #include "Win64Exception.h"
18 #include "WinCodeViewLineTables.h"
19 #include "llvm/ADT/SmallString.h"
20 #include "llvm/ADT/Statistic.h"
21 #include "llvm/Analysis/ConstantFolding.h"
22 #include "llvm/Analysis/JumpInstrTableInfo.h"
23 #include "llvm/CodeGen/Analysis.h"
24 #include "llvm/CodeGen/GCMetadataPrinter.h"
25 #include "llvm/CodeGen/MachineConstantPool.h"
26 #include "llvm/CodeGen/MachineFrameInfo.h"
27 #include "llvm/CodeGen/MachineFunction.h"
28 #include "llvm/CodeGen/MachineInstrBundle.h"
29 #include "llvm/CodeGen/MachineJumpTableInfo.h"
30 #include "llvm/CodeGen/MachineLoopInfo.h"
31 #include "llvm/CodeGen/MachineModuleInfo.h"
32 #include "llvm/IR/DataLayout.h"
33 #include "llvm/IR/DebugInfo.h"
34 #include "llvm/IR/Mangler.h"
35 #include "llvm/IR/Module.h"
36 #include "llvm/IR/Operator.h"
37 #include "llvm/MC/MCAsmInfo.h"
38 #include "llvm/MC/MCContext.h"
39 #include "llvm/MC/MCExpr.h"
40 #include "llvm/MC/MCInst.h"
41 #include "llvm/MC/MCSection.h"
42 #include "llvm/MC/MCStreamer.h"
43 #include "llvm/MC/MCSymbol.h"
44 #include "llvm/Support/ErrorHandling.h"
45 #include "llvm/Support/Format.h"
46 #include "llvm/Support/MathExtras.h"
47 #include "llvm/Support/Timer.h"
48 #include "llvm/Target/TargetFrameLowering.h"
49 #include "llvm/Target/TargetInstrInfo.h"
50 #include "llvm/Target/TargetLowering.h"
51 #include "llvm/Target/TargetLoweringObjectFile.h"
52 #include "llvm/Target/TargetRegisterInfo.h"
53 #include "llvm/Target/TargetSubtargetInfo.h"
56 #define DEBUG_TYPE "asm-printer"
58 static const char *const DWARFGroupName = "DWARF Emission";
59 static const char *const DbgTimerName = "Debug Info Emission";
60 static const char *const EHTimerName = "DWARF Exception Writer";
61 static const char *const CodeViewLineTablesGroupName = "CodeView Line Tables";
63 STATISTIC(EmittedInsts, "Number of machine instrs printed");
65 char AsmPrinter::ID = 0;
67 typedef DenseMap<GCStrategy*, std::unique_ptr<GCMetadataPrinter>> gcp_map_type;
68 static gcp_map_type &getGCMap(void *&P) {
70 P = new gcp_map_type();
71 return *(gcp_map_type*)P;
75 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
76 /// value in log2 form. This rounds up to the preferred alignment if possible
78 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD,
79 unsigned InBits = 0) {
81 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
82 NumBits = TD.getPreferredAlignmentLog(GVar);
84 // If InBits is specified, round it to it.
88 // If the GV has a specified alignment, take it into account.
89 if (GV->getAlignment() == 0)
92 unsigned GVAlign = Log2_32(GV->getAlignment());
94 // If the GVAlign is larger than NumBits, or if we are required to obey
95 // NumBits because the GV has an assigned section, obey it.
96 if (GVAlign > NumBits || GV->hasSection())
101 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
102 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
103 MII(tm.getSubtargetImpl()->getInstrInfo()),
104 OutContext(Streamer.getContext()), OutStreamer(Streamer), LastMI(nullptr),
105 LastFn(0), Counter(~0U), SetCounter(0) {
106 DD = nullptr; MMI = nullptr; LI = nullptr; MF = nullptr;
107 CurrentFnSym = CurrentFnSymForSize = nullptr;
108 GCMetadataPrinters = nullptr;
109 VerboseAsm = Streamer.isVerboseAsm();
112 AsmPrinter::~AsmPrinter() {
113 assert(!DD && Handlers.empty() && "Debug/EH info didn't get finalized");
115 if (GCMetadataPrinters) {
116 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
119 GCMetadataPrinters = nullptr;
125 /// getFunctionNumber - Return a unique ID for the current function.
127 unsigned AsmPrinter::getFunctionNumber() const {
128 return MF->getFunctionNumber();
131 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
132 return TM.getSubtargetImpl()->getTargetLowering()->getObjFileLowering();
135 /// getDataLayout - Return information about data layout.
136 const DataLayout &AsmPrinter::getDataLayout() const {
137 return *TM.getSubtargetImpl()->getDataLayout();
140 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
141 return TM.getSubtarget<MCSubtargetInfo>();
144 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
145 S.EmitInstruction(Inst, getSubtargetInfo());
148 StringRef AsmPrinter::getTargetTriple() const {
149 return TM.getTargetTriple();
152 /// getCurrentSection() - Return the current section we are emitting to.
153 const MCSection *AsmPrinter::getCurrentSection() const {
154 return OutStreamer.getCurrentSection().first;
159 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
160 AU.setPreservesAll();
161 MachineFunctionPass::getAnalysisUsage(AU);
162 AU.addRequired<MachineModuleInfo>();
163 AU.addRequired<GCModuleInfo>();
165 AU.addRequired<MachineLoopInfo>();
168 bool AsmPrinter::doInitialization(Module &M) {
169 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
170 MMI->AnalyzeModule(M);
172 // Initialize TargetLoweringObjectFile.
173 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
174 .Initialize(OutContext, TM);
176 OutStreamer.InitSections();
178 Mang = new Mangler(TM.getSubtargetImpl()->getDataLayout());
180 // Emit the version-min deplyment target directive if needed.
182 // FIXME: If we end up with a collection of these sorts of Darwin-specific
183 // or ELF-specific things, it may make sense to have a platform helper class
184 // that will work with the target helper class. For now keep it here, as the
185 // alternative is duplicated code in each of the target asm printers that
186 // use the directive, where it would need the same conditionalization
188 Triple TT(getTargetTriple());
189 if (TT.isOSDarwin()) {
190 unsigned Major, Minor, Update;
191 TT.getOSVersion(Major, Minor, Update);
192 // If there is a version specified, Major will be non-zero.
194 OutStreamer.EmitVersionMin((TT.isMacOSX() ?
195 MCVM_OSXVersionMin : MCVM_IOSVersionMin),
196 Major, Minor, Update);
199 // Allow the target to emit any magic that it wants at the start of the file.
200 EmitStartOfAsmFile(M);
202 // Very minimal debug info. It is ignored if we emit actual debug info. If we
203 // don't, this at least helps the user find where a global came from.
204 if (MAI->hasSingleParameterDotFile()) {
206 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
209 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
210 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
212 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
213 MP->beginAssembly(*this);
215 // Emit module-level inline asm if it exists.
216 if (!M.getModuleInlineAsm().empty()) {
217 OutStreamer.AddComment("Start of file scope inline assembly");
218 OutStreamer.AddBlankLine();
219 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
220 OutStreamer.AddComment("End of file scope inline assembly");
221 OutStreamer.AddBlankLine();
224 if (MAI->doesSupportDebugInformation()) {
225 if (Triple(TM.getTargetTriple()).isKnownWindowsMSVCEnvironment()) {
226 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this),
228 CodeViewLineTablesGroupName));
230 DD = new DwarfDebug(this, &M);
231 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
235 EHStreamer *ES = nullptr;
236 switch (MAI->getExceptionHandlingType()) {
237 case ExceptionHandling::None:
239 case ExceptionHandling::SjLj:
240 case ExceptionHandling::DwarfCFI:
241 ES = new DwarfCFIException(this);
243 case ExceptionHandling::ARM:
244 ES = new ARMException(this);
246 case ExceptionHandling::WinEH:
247 switch (MAI->getWinEHEncodingType()) {
248 default: llvm_unreachable("unsupported unwinding information encoding");
249 case WinEH::EncodingType::Itanium:
250 ES = new Win64Exception(this);
256 Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
260 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
261 if (!MAI.hasWeakDefCanBeHiddenDirective())
264 return canBeOmittedFromSymbolTable(GV);
267 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
268 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
270 case GlobalValue::CommonLinkage:
271 case GlobalValue::LinkOnceAnyLinkage:
272 case GlobalValue::LinkOnceODRLinkage:
273 case GlobalValue::WeakAnyLinkage:
274 case GlobalValue::WeakODRLinkage:
275 if (MAI->hasWeakDefDirective()) {
277 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
279 if (!canBeHidden(GV, *MAI))
280 // .weak_definition _foo
281 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
283 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
284 } else if (MAI->hasLinkOnceDirective()) {
286 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
287 //NOTE: linkonce is handled by the section the symbol was assigned to.
290 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
293 case GlobalValue::AppendingLinkage:
294 // FIXME: appending linkage variables should go into a section of
295 // their name or something. For now, just emit them as external.
296 case GlobalValue::ExternalLinkage:
297 // If external or appending, declare as a global symbol.
299 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
301 case GlobalValue::PrivateLinkage:
302 case GlobalValue::InternalLinkage:
304 case GlobalValue::AvailableExternallyLinkage:
305 llvm_unreachable("Should never emit this");
306 case GlobalValue::ExternalWeakLinkage:
307 llvm_unreachable("Don't know how to emit these");
309 llvm_unreachable("Unknown linkage type!");
312 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
313 const GlobalValue *GV) const {
314 TM.getNameWithPrefix(Name, GV, *Mang);
317 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
318 return TM.getSymbol(GV, *Mang);
321 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
322 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
323 if (GV->hasInitializer()) {
324 // Check to see if this is a special global used by LLVM, if so, emit it.
325 if (EmitSpecialLLVMGlobal(GV))
329 GV->printAsOperand(OutStreamer.GetCommentOS(),
330 /*PrintType=*/false, GV->getParent());
331 OutStreamer.GetCommentOS() << '\n';
335 MCSymbol *GVSym = getSymbol(GV);
336 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
338 if (!GV->hasInitializer()) // External globals require no extra code.
341 if (MAI->hasDotTypeDotSizeDirective())
342 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
344 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
346 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
347 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
349 // If the alignment is specified, we *must* obey it. Overaligning a global
350 // with a specified alignment is a prompt way to break globals emitted to
351 // sections and expected to be contiguous (e.g. ObjC metadata).
352 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
354 for (const HandlerInfo &HI : Handlers) {
355 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
356 HI.Handler->setSymbolSize(GVSym, Size);
359 // Handle common and BSS local symbols (.lcomm).
360 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
361 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
362 unsigned Align = 1 << AlignLog;
364 // Handle common symbols.
365 if (GVKind.isCommon()) {
366 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
370 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
374 // Handle local BSS symbols.
375 if (MAI->hasMachoZeroFillDirective()) {
376 const MCSection *TheSection =
377 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
378 // .zerofill __DATA, __bss, _foo, 400, 5
379 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
383 // Use .lcomm only if it supports user-specified alignment.
384 // Otherwise, while it would still be correct to use .lcomm in some
385 // cases (e.g. when Align == 1), the external assembler might enfore
386 // some -unknown- default alignment behavior, which could cause
387 // spurious differences between external and integrated assembler.
388 // Prefer to simply fall back to .local / .comm in this case.
389 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
391 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
395 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
399 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
401 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
405 const MCSection *TheSection =
406 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
408 // Handle the zerofill directive on darwin, which is a special form of BSS
410 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
411 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
414 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
415 // .zerofill __DATA, __common, _foo, 400, 5
416 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
420 // Handle thread local data for mach-o which requires us to output an
421 // additional structure of data and mangle the original symbol so that we
422 // can reference it later.
424 // TODO: This should become an "emit thread local global" method on TLOF.
425 // All of this macho specific stuff should be sunk down into TLOFMachO and
426 // stuff like "TLSExtraDataSection" should no longer be part of the parent
427 // TLOF class. This will also make it more obvious that stuff like
428 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
430 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
431 // Emit the .tbss symbol
433 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
435 if (GVKind.isThreadBSS()) {
436 TheSection = getObjFileLowering().getTLSBSSSection();
437 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
438 } else if (GVKind.isThreadData()) {
439 OutStreamer.SwitchSection(TheSection);
441 EmitAlignment(AlignLog, GV);
442 OutStreamer.EmitLabel(MangSym);
444 EmitGlobalConstant(GV->getInitializer());
447 OutStreamer.AddBlankLine();
449 // Emit the variable struct for the runtime.
450 const MCSection *TLVSect
451 = getObjFileLowering().getTLSExtraDataSection();
453 OutStreamer.SwitchSection(TLVSect);
454 // Emit the linkage here.
455 EmitLinkage(GV, GVSym);
456 OutStreamer.EmitLabel(GVSym);
458 // Three pointers in size:
459 // - __tlv_bootstrap - used to make sure support exists
460 // - spare pointer, used when mapped by the runtime
461 // - pointer to mangled symbol above with initializer
462 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
463 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
465 OutStreamer.EmitIntValue(0, PtrSize);
466 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
468 OutStreamer.AddBlankLine();
472 OutStreamer.SwitchSection(TheSection);
474 EmitLinkage(GV, GVSym);
475 EmitAlignment(AlignLog, GV);
477 OutStreamer.EmitLabel(GVSym);
479 EmitGlobalConstant(GV->getInitializer());
481 if (MAI->hasDotTypeDotSizeDirective())
483 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
485 OutStreamer.AddBlankLine();
488 /// EmitFunctionHeader - This method emits the header for the current
490 void AsmPrinter::EmitFunctionHeader() {
491 // Print out constants referenced by the function
494 // Print the 'header' of function.
495 const Function *F = MF->getFunction();
497 OutStreamer.SwitchSection(
498 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
499 EmitVisibility(CurrentFnSym, F->getVisibility());
501 EmitLinkage(F, CurrentFnSym);
502 EmitAlignment(MF->getAlignment(), F);
504 if (MAI->hasDotTypeDotSizeDirective())
505 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
508 F->printAsOperand(OutStreamer.GetCommentOS(),
509 /*PrintType=*/false, F->getParent());
510 OutStreamer.GetCommentOS() << '\n';
513 // Emit the CurrentFnSym. This is a virtual function to allow targets to
514 // do their wild and crazy things as required.
515 EmitFunctionEntryLabel();
517 // If the function had address-taken blocks that got deleted, then we have
518 // references to the dangling symbols. Emit them at the start of the function
519 // so that we don't get references to undefined symbols.
520 std::vector<MCSymbol*> DeadBlockSyms;
521 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
522 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
523 OutStreamer.AddComment("Address taken block that was later removed");
524 OutStreamer.EmitLabel(DeadBlockSyms[i]);
527 // Emit pre-function debug and/or EH information.
528 for (const HandlerInfo &HI : Handlers) {
529 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
530 HI.Handler->beginFunction(MF);
533 // Emit the prefix data.
534 if (F->hasPrefixData())
535 EmitGlobalConstant(F->getPrefixData());
538 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
539 /// function. This can be overridden by targets as required to do custom stuff.
540 void AsmPrinter::EmitFunctionEntryLabel() {
541 // The function label could have already been emitted if two symbols end up
542 // conflicting due to asm renaming. Detect this and emit an error.
543 if (CurrentFnSym->isUndefined())
544 return OutStreamer.EmitLabel(CurrentFnSym);
546 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
547 "' label emitted multiple times to assembly file");
550 /// emitComments - Pretty-print comments for instructions.
551 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
552 const MachineFunction *MF = MI.getParent()->getParent();
553 const TargetMachine &TM = MF->getTarget();
555 // Check for spills and reloads
558 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
560 // We assume a single instruction only has a spill or reload, not
562 const MachineMemOperand *MMO;
563 if (TM.getSubtargetImpl()->getInstrInfo()->isLoadFromStackSlotPostFE(&MI,
565 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
566 MMO = *MI.memoperands_begin();
567 CommentOS << MMO->getSize() << "-byte Reload\n";
569 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasLoadFromStackSlot(
571 if (FrameInfo->isSpillSlotObjectIndex(FI))
572 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
573 } else if (TM.getSubtargetImpl()->getInstrInfo()->isStoreToStackSlotPostFE(
575 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
576 MMO = *MI.memoperands_begin();
577 CommentOS << MMO->getSize() << "-byte Spill\n";
579 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasStoreToStackSlot(
581 if (FrameInfo->isSpillSlotObjectIndex(FI))
582 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
585 // Check for spill-induced copies
586 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
587 CommentOS << " Reload Reuse\n";
590 /// emitImplicitDef - This method emits the specified machine instruction
591 /// that is an implicit def.
592 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
593 unsigned RegNo = MI->getOperand(0).getReg();
594 OutStreamer.AddComment(
595 Twine("implicit-def: ") +
596 TM.getSubtargetImpl()->getRegisterInfo()->getName(RegNo));
597 OutStreamer.AddBlankLine();
600 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
601 std::string Str = "kill:";
602 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
603 const MachineOperand &Op = MI->getOperand(i);
604 assert(Op.isReg() && "KILL instruction must have only register operands");
606 Str += AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Op.getReg());
607 Str += (Op.isDef() ? "<def>" : "<kill>");
609 AP.OutStreamer.AddComment(Str);
610 AP.OutStreamer.AddBlankLine();
613 /// emitDebugValueComment - This method handles the target-independent form
614 /// of DBG_VALUE, returning true if it was able to do so. A false return
615 /// means the target will need to handle MI in EmitInstruction.
616 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
617 // This code handles only the 3-operand target-independent form.
618 if (MI->getNumOperands() != 3)
621 SmallString<128> Str;
622 raw_svector_ostream OS(Str);
623 OS << "DEBUG_VALUE: ";
625 DIVariable V = MI->getDebugVariable();
626 if (V.getContext().isSubprogram()) {
627 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
632 if (V.isVariablePiece())
633 OS << " [piece offset=" << V.getPieceOffset()
634 << " size="<<V.getPieceSize()<<"]";
637 // The second operand is only an offset if it's an immediate.
638 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
639 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
641 // Register or immediate value. Register 0 means undef.
642 if (MI->getOperand(0).isFPImm()) {
643 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
644 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
645 OS << (double)APF.convertToFloat();
646 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
647 OS << APF.convertToDouble();
649 // There is no good way to print long double. Convert a copy to
650 // double. Ah well, it's only a comment.
652 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
654 OS << "(long double) " << APF.convertToDouble();
656 } else if (MI->getOperand(0).isImm()) {
657 OS << MI->getOperand(0).getImm();
658 } else if (MI->getOperand(0).isCImm()) {
659 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
662 if (MI->getOperand(0).isReg()) {
663 Reg = MI->getOperand(0).getReg();
665 assert(MI->getOperand(0).isFI() && "Unknown operand type");
666 const TargetFrameLowering *TFI =
667 AP.TM.getSubtargetImpl()->getFrameLowering();
668 Offset += TFI->getFrameIndexReference(*AP.MF,
669 MI->getOperand(0).getIndex(), Reg);
673 // Suppress offset, it is not meaningful here.
675 // NOTE: Want this comment at start of line, don't emit with AddComment.
676 AP.OutStreamer.emitRawComment(OS.str());
681 OS << AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Reg);
685 OS << '+' << Offset << ']';
687 // NOTE: Want this comment at start of line, don't emit with AddComment.
688 AP.OutStreamer.emitRawComment(OS.str());
692 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
693 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
694 MF->getFunction()->needsUnwindTableEntry())
697 if (MMI->hasDebugInfo())
703 bool AsmPrinter::needsSEHMoves() {
704 return MAI->getExceptionHandlingType() == ExceptionHandling::WinEH &&
705 MF->getFunction()->needsUnwindTableEntry();
708 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
709 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
710 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
711 ExceptionHandlingType != ExceptionHandling::ARM)
714 if (needsCFIMoves() == CFI_M_None)
717 const MachineModuleInfo &MMI = MF->getMMI();
718 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
719 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
720 const MCCFIInstruction &CFI = Instrs[CFIIndex];
721 emitCFIInstruction(CFI);
724 /// EmitFunctionBody - This method emits the body and trailer for a
726 void AsmPrinter::EmitFunctionBody() {
727 // Emit target-specific gunk before the function body.
728 EmitFunctionBodyStart();
730 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
732 // Print out code for the function.
733 bool HasAnyRealCode = false;
734 for (auto &MBB : *MF) {
735 // Print a label for the basic block.
736 EmitBasicBlockStart(MBB);
737 for (auto &MI : MBB) {
739 // Print the assembly for the instruction.
740 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
741 !MI.isDebugValue()) {
742 HasAnyRealCode = true;
746 if (ShouldPrintDebugScopes) {
747 for (const HandlerInfo &HI : Handlers) {
748 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
749 TimePassesIsEnabled);
750 HI.Handler->beginInstruction(&MI);
755 emitComments(MI, OutStreamer.GetCommentOS());
757 switch (MI.getOpcode()) {
758 case TargetOpcode::CFI_INSTRUCTION:
759 emitCFIInstruction(MI);
762 case TargetOpcode::EH_LABEL:
763 case TargetOpcode::GC_LABEL:
764 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
766 case TargetOpcode::INLINEASM:
769 case TargetOpcode::DBG_VALUE:
771 if (!emitDebugValueComment(&MI, *this))
772 EmitInstruction(&MI);
775 case TargetOpcode::IMPLICIT_DEF:
776 if (isVerbose()) emitImplicitDef(&MI);
778 case TargetOpcode::KILL:
779 if (isVerbose()) emitKill(&MI, *this);
782 EmitInstruction(&MI);
786 if (ShouldPrintDebugScopes) {
787 for (const HandlerInfo &HI : Handlers) {
788 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
789 TimePassesIsEnabled);
790 HI.Handler->endInstruction();
795 EmitBasicBlockEnd(MBB);
798 // If the function is empty and the object file uses .subsections_via_symbols,
799 // then we need to emit *something* to the function body to prevent the
800 // labels from collapsing together. Just emit a noop.
801 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
803 TM.getSubtargetImpl()->getInstrInfo()->getNoopForMachoTarget(Noop);
804 OutStreamer.AddComment("avoids zero-length function");
805 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
808 const Function *F = MF->getFunction();
809 for (const auto &BB : *F) {
810 if (!BB.hasAddressTaken())
812 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
813 if (Sym->isDefined())
815 OutStreamer.AddComment("Address of block that was removed by CodeGen");
816 OutStreamer.EmitLabel(Sym);
819 // Emit target-specific gunk after the function body.
820 EmitFunctionBodyEnd();
822 // If the target wants a .size directive for the size of the function, emit
824 if (MAI->hasDotTypeDotSizeDirective()) {
825 // Create a symbol for the end of function, so we can get the size as
826 // difference between the function label and the temp label.
827 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
828 OutStreamer.EmitLabel(FnEndLabel);
830 const MCExpr *SizeExp =
831 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
832 MCSymbolRefExpr::Create(CurrentFnSymForSize,
835 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
838 // Emit post-function debug and/or EH information.
839 for (const HandlerInfo &HI : Handlers) {
840 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
841 HI.Handler->endFunction(MF);
845 // Print out jump tables referenced by the function.
848 OutStreamer.AddBlankLine();
851 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP);
853 bool AsmPrinter::doFinalization(Module &M) {
854 // Emit global variables.
855 for (const auto &G : M.globals())
856 EmitGlobalVariable(&G);
858 // Emit visibility info for declarations
859 for (const Function &F : M) {
860 if (!F.isDeclaration())
862 GlobalValue::VisibilityTypes V = F.getVisibility();
863 if (V == GlobalValue::DefaultVisibility)
866 MCSymbol *Name = getSymbol(&F);
867 EmitVisibility(Name, V, false);
870 // Get information about jump-instruction tables to print.
871 JumpInstrTableInfo *JITI = getAnalysisIfAvailable<JumpInstrTableInfo>();
873 if (JITI && !JITI->getTables().empty()) {
874 unsigned Arch = Triple(getTargetTriple()).getArch();
875 bool IsThumb = (Arch == Triple::thumb || Arch == Triple::thumbeb);
877 TM.getSubtargetImpl()->getInstrInfo()->getTrap(TrapInst);
878 for (const auto &KV : JITI->getTables()) {
880 for (const auto &FunPair : KV.second) {
881 // Emit the function labels to make this be a function entry point.
883 OutContext.GetOrCreateSymbol(FunPair.second->getName());
884 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_Global);
885 // FIXME: JumpTableInstrInfo should store information about the required
886 // alignment of table entries and the size of the padding instruction.
889 OutStreamer.EmitThumbFunc(FunSym);
890 if (MAI->hasDotTypeDotSizeDirective())
891 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_ELF_TypeFunction);
892 OutStreamer.EmitLabel(FunSym);
894 // Emit the jump instruction to transfer control to the original
897 MCSymbol *TargetSymbol =
898 OutContext.GetOrCreateSymbol(FunPair.first->getName());
899 const MCSymbolRefExpr *TargetSymRef =
900 MCSymbolRefExpr::Create(TargetSymbol, MCSymbolRefExpr::VK_PLT,
902 TM.getSubtargetImpl()->getInstrInfo()->getUnconditionalBranch(
903 JumpToFun, TargetSymRef);
904 OutStreamer.EmitInstruction(JumpToFun, getSubtargetInfo());
908 // Emit enough padding instructions to fill up to the next power of two.
909 // This assumes that the trap instruction takes 8 bytes or fewer.
910 uint64_t Remaining = NextPowerOf2(Count) - Count;
911 for (uint64_t C = 0; C < Remaining; ++C) {
913 OutStreamer.EmitInstruction(TrapInst, getSubtargetInfo());
919 // Emit module flags.
920 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
921 M.getModuleFlagsMetadata(ModuleFlags);
922 if (!ModuleFlags.empty())
923 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
925 // Make sure we wrote out everything we need.
928 // Finalize debug and EH information.
929 for (const HandlerInfo &HI : Handlers) {
930 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
931 TimePassesIsEnabled);
932 HI.Handler->endModule();
938 // If the target wants to know about weak references, print them all.
939 if (MAI->getWeakRefDirective()) {
940 // FIXME: This is not lazy, it would be nice to only print weak references
941 // to stuff that is actually used. Note that doing so would require targets
942 // to notice uses in operands (due to constant exprs etc). This should
943 // happen with the MC stuff eventually.
945 // Print out module-level global variables here.
946 for (const auto &G : M.globals()) {
947 if (!G.hasExternalWeakLinkage())
949 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
952 for (const auto &F : M) {
953 if (!F.hasExternalWeakLinkage())
955 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
959 if (MAI->hasSetDirective()) {
960 OutStreamer.AddBlankLine();
961 for (const auto &Alias : M.aliases()) {
962 MCSymbol *Name = getSymbol(&Alias);
964 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
965 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
966 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
967 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
969 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
971 EmitVisibility(Name, Alias.getVisibility());
973 // Emit the directives as assignments aka .set:
974 OutStreamer.EmitAssignment(Name,
975 lowerConstant(Alias.getAliasee(), *this));
979 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
980 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
981 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
982 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
983 MP->finishAssembly(*this);
985 // Emit llvm.ident metadata in an '.ident' directive.
988 // If we don't have any trampolines, then we don't require stack memory
989 // to be executable. Some targets have a directive to declare this.
990 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
991 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
992 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
993 OutStreamer.SwitchSection(S);
995 // Allow the target to emit any magic that it wants at the end of the file,
996 // after everything else has gone out.
999 delete Mang; Mang = nullptr;
1002 OutStreamer.Finish();
1003 OutStreamer.reset();
1008 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1010 // Get the function symbol.
1011 CurrentFnSym = getSymbol(MF.getFunction());
1012 CurrentFnSymForSize = CurrentFnSym;
1015 LI = &getAnalysis<MachineLoopInfo>();
1019 // SectionCPs - Keep track the alignment, constpool entries per Section.
1023 SmallVector<unsigned, 4> CPEs;
1024 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1028 /// EmitConstantPool - Print to the current output stream assembly
1029 /// representations of the constants in the constant pool MCP. This is
1030 /// used to print out constants which have been "spilled to memory" by
1031 /// the code generator.
1033 void AsmPrinter::EmitConstantPool() {
1034 const MachineConstantPool *MCP = MF->getConstantPool();
1035 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1036 if (CP.empty()) return;
1038 // Calculate sections for constant pool entries. We collect entries to go into
1039 // the same section together to reduce amount of section switch statements.
1040 SmallVector<SectionCPs, 4> CPSections;
1041 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1042 const MachineConstantPoolEntry &CPE = CP[i];
1043 unsigned Align = CPE.getAlignment();
1046 CPE.getSectionKind(TM.getSubtargetImpl()->getDataLayout());
1048 const Constant *C = nullptr;
1049 if (!CPE.isMachineConstantPoolEntry())
1050 C = CPE.Val.ConstVal;
1052 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind, C);
1054 // The number of sections are small, just do a linear search from the
1055 // last section to the first.
1057 unsigned SecIdx = CPSections.size();
1058 while (SecIdx != 0) {
1059 if (CPSections[--SecIdx].S == S) {
1065 SecIdx = CPSections.size();
1066 CPSections.push_back(SectionCPs(S, Align));
1069 if (Align > CPSections[SecIdx].Alignment)
1070 CPSections[SecIdx].Alignment = Align;
1071 CPSections[SecIdx].CPEs.push_back(i);
1074 // Now print stuff into the calculated sections.
1075 const MCSection *CurSection = nullptr;
1076 unsigned Offset = 0;
1077 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1078 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1079 unsigned CPI = CPSections[i].CPEs[j];
1080 MCSymbol *Sym = GetCPISymbol(CPI);
1081 if (!Sym->isUndefined())
1084 if (CurSection != CPSections[i].S) {
1085 OutStreamer.SwitchSection(CPSections[i].S);
1086 EmitAlignment(Log2_32(CPSections[i].Alignment));
1087 CurSection = CPSections[i].S;
1091 MachineConstantPoolEntry CPE = CP[CPI];
1093 // Emit inter-object padding for alignment.
1094 unsigned AlignMask = CPE.getAlignment() - 1;
1095 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1096 OutStreamer.EmitZeros(NewOffset - Offset);
1098 Type *Ty = CPE.getType();
1099 Offset = NewOffset +
1100 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(Ty);
1102 OutStreamer.EmitLabel(Sym);
1103 if (CPE.isMachineConstantPoolEntry())
1104 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1106 EmitGlobalConstant(CPE.Val.ConstVal);
1111 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1112 /// by the current function to the current output stream.
1114 void AsmPrinter::EmitJumpTableInfo() {
1115 const DataLayout *DL = MF->getSubtarget().getDataLayout();
1116 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1118 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1119 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1120 if (JT.empty()) return;
1122 // Pick the directive to use to print the jump table entries, and switch to
1123 // the appropriate section.
1124 const Function *F = MF->getFunction();
1125 bool JTInDiffSection = false;
1126 if (// In PIC mode, we need to emit the jump table to the same section as the
1127 // function body itself, otherwise the label differences won't make sense.
1128 // FIXME: Need a better predicate for this: what about custom entries?
1129 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1130 // We should also do if the section name is NULL or function is declared
1131 // in discardable section
1132 // FIXME: this isn't the right predicate, should be based on the MCSection
1133 // for the function.
1134 F->isWeakForLinker()) {
1135 OutStreamer.SwitchSection(
1136 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1138 // Otherwise, drop it in the readonly section.
1139 const MCSection *ReadOnlySection =
1140 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
1142 OutStreamer.SwitchSection(ReadOnlySection);
1143 JTInDiffSection = true;
1146 EmitAlignment(Log2_32(
1147 MJTI->getEntryAlignment(*TM.getSubtargetImpl()->getDataLayout())));
1149 // Jump tables in code sections are marked with a data_region directive
1150 // where that's supported.
1151 if (!JTInDiffSection)
1152 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1154 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1155 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1157 // If this jump table was deleted, ignore it.
1158 if (JTBBs.empty()) continue;
1160 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1161 // .set directive for each unique entry. This reduces the number of
1162 // relocations the assembler will generate for the jump table.
1163 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1164 MAI->hasSetDirective()) {
1165 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1166 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1167 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1168 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1169 const MachineBasicBlock *MBB = JTBBs[ii];
1170 if (!EmittedSets.insert(MBB)) continue;
1172 // .set LJTSet, LBB32-base
1174 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1175 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1176 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1180 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1181 // before each jump table. The first label is never referenced, but tells
1182 // the assembler and linker the extents of the jump table object. The
1183 // second label is actually referenced by the code.
1184 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1185 // FIXME: This doesn't have to have any specific name, just any randomly
1186 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1187 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1189 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1191 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1192 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1194 if (!JTInDiffSection)
1195 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1198 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1200 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1201 const MachineBasicBlock *MBB,
1202 unsigned UID) const {
1203 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1204 const MCExpr *Value = nullptr;
1205 switch (MJTI->getEntryKind()) {
1206 case MachineJumpTableInfo::EK_Inline:
1207 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1208 case MachineJumpTableInfo::EK_Custom32:
1210 TM.getSubtargetImpl()->getTargetLowering()->LowerCustomJumpTableEntry(
1211 MJTI, MBB, UID, OutContext);
1213 case MachineJumpTableInfo::EK_BlockAddress:
1214 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1216 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1218 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1219 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1220 // with a relocation as gp-relative, e.g.:
1222 MCSymbol *MBBSym = MBB->getSymbol();
1223 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1227 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1228 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1229 // with a relocation as gp-relative, e.g.:
1231 MCSymbol *MBBSym = MBB->getSymbol();
1232 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1236 case MachineJumpTableInfo::EK_LabelDifference32: {
1237 // EK_LabelDifference32 - Each entry is the address of the block minus
1238 // the address of the jump table. This is used for PIC jump tables where
1239 // gprel32 is not supported. e.g.:
1240 // .word LBB123 - LJTI1_2
1241 // If the .set directive is supported, this is emitted as:
1242 // .set L4_5_set_123, LBB123 - LJTI1_2
1243 // .word L4_5_set_123
1245 // If we have emitted set directives for the jump table entries, print
1246 // them rather than the entries themselves. If we're emitting PIC, then
1247 // emit the table entries as differences between two text section labels.
1248 if (MAI->hasSetDirective()) {
1249 // If we used .set, reference the .set's symbol.
1250 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1254 // Otherwise, use the difference as the jump table entry.
1255 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1256 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1257 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1262 assert(Value && "Unknown entry kind!");
1264 unsigned EntrySize =
1265 MJTI->getEntrySize(*TM.getSubtargetImpl()->getDataLayout());
1266 OutStreamer.EmitValue(Value, EntrySize);
1270 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1271 /// special global used by LLVM. If so, emit it and return true, otherwise
1272 /// do nothing and return false.
1273 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1274 if (GV->getName() == "llvm.used") {
1275 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1276 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1280 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1281 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1282 GV->hasAvailableExternallyLinkage())
1285 if (!GV->hasAppendingLinkage()) return false;
1287 assert(GV->hasInitializer() && "Not a special LLVM global!");
1289 if (GV->getName() == "llvm.global_ctors") {
1290 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1292 if (TM.getRelocationModel() == Reloc::Static &&
1293 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1294 StringRef Sym(".constructors_used");
1295 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1301 if (GV->getName() == "llvm.global_dtors") {
1302 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1304 if (TM.getRelocationModel() == Reloc::Static &&
1305 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1306 StringRef Sym(".destructors_used");
1307 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1316 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1317 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1318 /// is true, as being used with this directive.
1319 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1320 // Should be an array of 'i8*'.
1321 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1322 const GlobalValue *GV =
1323 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1325 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1331 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1333 llvm::Constant *Func;
1334 llvm::GlobalValue *ComdatKey;
1338 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1340 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1341 // Should be an array of '{ int, void ()* }' structs. The first value is the
1343 if (!isa<ConstantArray>(List)) return;
1345 // Sanity check the structors list.
1346 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1347 if (!InitList) return; // Not an array!
1348 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1349 // FIXME: Only allow the 3-field form in LLVM 4.0.
1350 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1351 return; // Not an array of two or three elements!
1352 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1353 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1354 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1355 return; // Not (int, ptr, ptr).
1357 // Gather the structors in a form that's convenient for sorting by priority.
1358 SmallVector<Structor, 8> Structors;
1359 for (Value *O : InitList->operands()) {
1360 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1361 if (!CS) continue; // Malformed.
1362 if (CS->getOperand(1)->isNullValue())
1363 break; // Found a null terminator, skip the rest.
1364 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1365 if (!Priority) continue; // Malformed.
1366 Structors.push_back(Structor());
1367 Structor &S = Structors.back();
1368 S.Priority = Priority->getLimitedValue(65535);
1369 S.Func = CS->getOperand(1);
1370 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1371 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1374 // Emit the function pointers in the target-specific order
1375 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
1376 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1377 std::stable_sort(Structors.begin(), Structors.end(),
1378 [](const Structor &L,
1379 const Structor &R) { return L.Priority < R.Priority; });
1380 for (Structor &S : Structors) {
1381 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1382 const MCSymbol *KeySym = nullptr;
1383 if (GlobalValue *GV = S.ComdatKey) {
1384 if (GV->hasAvailableExternallyLinkage())
1385 // If the associated variable is available_externally, some other TU
1386 // will provide its dynamic initializer.
1389 KeySym = getSymbol(GV);
1391 const MCSection *OutputSection =
1392 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1393 : Obj.getStaticDtorSection(S.Priority, KeySym));
1394 OutStreamer.SwitchSection(OutputSection);
1395 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1396 EmitAlignment(Align);
1397 EmitXXStructor(S.Func);
1401 void AsmPrinter::EmitModuleIdents(Module &M) {
1402 if (!MAI->hasIdentDirective())
1405 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1406 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1407 const MDNode *N = NMD->getOperand(i);
1408 assert(N->getNumOperands() == 1 &&
1409 "llvm.ident metadata entry can have only one operand");
1410 const MDString *S = cast<MDString>(N->getOperand(0));
1411 OutStreamer.EmitIdent(S->getString());
1416 //===--------------------------------------------------------------------===//
1417 // Emission and print routines
1420 /// EmitInt8 - Emit a byte directive and value.
1422 void AsmPrinter::EmitInt8(int Value) const {
1423 OutStreamer.EmitIntValue(Value, 1);
1426 /// EmitInt16 - Emit a short directive and value.
1428 void AsmPrinter::EmitInt16(int Value) const {
1429 OutStreamer.EmitIntValue(Value, 2);
1432 /// EmitInt32 - Emit a long directive and value.
1434 void AsmPrinter::EmitInt32(int Value) const {
1435 OutStreamer.EmitIntValue(Value, 4);
1438 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1439 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1440 /// labels. This implicitly uses .set if it is available.
1441 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1442 unsigned Size) const {
1443 // Get the Hi-Lo expression.
1444 const MCExpr *Diff =
1445 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1446 MCSymbolRefExpr::Create(Lo, OutContext),
1449 if (!MAI->hasSetDirective()) {
1450 OutStreamer.EmitValue(Diff, Size);
1454 // Otherwise, emit with .set (aka assignment).
1455 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1456 OutStreamer.EmitAssignment(SetLabel, Diff);
1457 OutStreamer.EmitSymbolValue(SetLabel, Size);
1460 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1461 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1462 /// specify the labels. This implicitly uses .set if it is available.
1463 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1465 unsigned Size) const {
1467 // Emit Hi+Offset - Lo
1468 // Get the Hi+Offset expression.
1469 const MCExpr *Plus =
1470 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1471 MCConstantExpr::Create(Offset, OutContext),
1474 // Get the Hi+Offset-Lo expression.
1475 const MCExpr *Diff =
1476 MCBinaryExpr::CreateSub(Plus,
1477 MCSymbolRefExpr::Create(Lo, OutContext),
1480 if (!MAI->hasSetDirective())
1481 OutStreamer.EmitValue(Diff, Size);
1483 // Otherwise, emit with .set (aka assignment).
1484 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1485 OutStreamer.EmitAssignment(SetLabel, Diff);
1486 OutStreamer.EmitSymbolValue(SetLabel, Size);
1490 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1491 /// where the size in bytes of the directive is specified by Size and Label
1492 /// specifies the label. This implicitly uses .set if it is available.
1493 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1495 bool IsSectionRelative) const {
1496 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1497 OutStreamer.EmitCOFFSecRel32(Label);
1501 // Emit Label+Offset (or just Label if Offset is zero)
1502 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1504 Expr = MCBinaryExpr::CreateAdd(
1505 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1507 OutStreamer.EmitValue(Expr, Size);
1510 //===----------------------------------------------------------------------===//
1512 // EmitAlignment - Emit an alignment directive to the specified power of
1513 // two boundary. For example, if you pass in 3 here, you will get an 8
1514 // byte alignment. If a global value is specified, and if that global has
1515 // an explicit alignment requested, it will override the alignment request
1516 // if required for correctness.
1518 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1520 NumBits = getGVAlignmentLog2(GV, *TM.getSubtargetImpl()->getDataLayout(),
1523 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1525 if (getCurrentSection()->getKind().isText())
1526 OutStreamer.EmitCodeAlignment(1 << NumBits);
1528 OutStreamer.EmitValueToAlignment(1 << NumBits);
1531 //===----------------------------------------------------------------------===//
1532 // Constant emission.
1533 //===----------------------------------------------------------------------===//
1535 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1537 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1538 MCContext &Ctx = AP.OutContext;
1540 if (CV->isNullValue() || isa<UndefValue>(CV))
1541 return MCConstantExpr::Create(0, Ctx);
1543 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1544 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1546 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1547 return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx);
1549 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1550 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1552 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1554 llvm_unreachable("Unknown constant value to lower!");
1557 if (const MCExpr *RelocExpr =
1558 AP.getObjFileLowering().getExecutableRelativeSymbol(CE, *AP.Mang,
1562 switch (CE->getOpcode()) {
1564 // If the code isn't optimized, there may be outstanding folding
1565 // opportunities. Attempt to fold the expression using DataLayout as a
1566 // last resort before giving up.
1567 if (Constant *C = ConstantFoldConstantExpression(
1568 CE, AP.TM.getSubtargetImpl()->getDataLayout()))
1570 return lowerConstant(C, AP);
1572 // Otherwise report the problem to the user.
1575 raw_string_ostream OS(S);
1576 OS << "Unsupported expression in static initializer: ";
1577 CE->printAsOperand(OS, /*PrintType=*/false,
1578 !AP.MF ? nullptr : AP.MF->getFunction()->getParent());
1579 report_fatal_error(OS.str());
1581 case Instruction::GetElementPtr: {
1582 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1583 // Generate a symbolic expression for the byte address
1584 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1585 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1587 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1591 int64_t Offset = OffsetAI.getSExtValue();
1592 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1596 case Instruction::Trunc:
1597 // We emit the value and depend on the assembler to truncate the generated
1598 // expression properly. This is important for differences between
1599 // blockaddress labels. Since the two labels are in the same function, it
1600 // is reasonable to treat their delta as a 32-bit value.
1602 case Instruction::BitCast:
1603 return lowerConstant(CE->getOperand(0), AP);
1605 case Instruction::IntToPtr: {
1606 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1607 // Handle casts to pointers by changing them into casts to the appropriate
1608 // integer type. This promotes constant folding and simplifies this code.
1609 Constant *Op = CE->getOperand(0);
1610 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1612 return lowerConstant(Op, AP);
1615 case Instruction::PtrToInt: {
1616 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1617 // Support only foldable casts to/from pointers that can be eliminated by
1618 // changing the pointer to the appropriately sized integer type.
1619 Constant *Op = CE->getOperand(0);
1620 Type *Ty = CE->getType();
1622 const MCExpr *OpExpr = lowerConstant(Op, AP);
1624 // We can emit the pointer value into this slot if the slot is an
1625 // integer slot equal to the size of the pointer.
1626 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1629 // Otherwise the pointer is smaller than the resultant integer, mask off
1630 // the high bits so we are sure to get a proper truncation if the input is
1632 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1633 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1634 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1637 // The MC library also has a right-shift operator, but it isn't consistently
1638 // signed or unsigned between different targets.
1639 case Instruction::Add:
1640 case Instruction::Sub:
1641 case Instruction::Mul:
1642 case Instruction::SDiv:
1643 case Instruction::SRem:
1644 case Instruction::Shl:
1645 case Instruction::And:
1646 case Instruction::Or:
1647 case Instruction::Xor: {
1648 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1649 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1650 switch (CE->getOpcode()) {
1651 default: llvm_unreachable("Unknown binary operator constant cast expr");
1652 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1653 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1654 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1655 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1656 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1657 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1658 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1659 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1660 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1666 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1668 /// isRepeatedByteSequence - Determine whether the given value is
1669 /// composed of a repeated sequence of identical bytes and return the
1670 /// byte value. If it is not a repeated sequence, return -1.
1671 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1672 StringRef Data = V->getRawDataValues();
1673 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1675 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1676 if (Data[i] != C) return -1;
1677 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
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 Value *V, TargetMachine &TM) {
1686 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1687 if (CI->getBitWidth() > 64) return -1;
1690 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(V->getType());
1691 uint64_t Value = CI->getZExtValue();
1693 // Make sure the constant is at least 8 bits long and has a power
1694 // of 2 bit width. This guarantees the constant bit width is
1695 // always a multiple of 8 bits, avoiding issues with padding out
1696 // to Size and other such corner cases.
1697 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1699 uint8_t Byte = static_cast<uint8_t>(Value);
1701 for (unsigned i = 1; i < Size; ++i) {
1703 if (static_cast<uint8_t>(Value) != Byte) return -1;
1707 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1708 // Make sure all array elements are sequences of the same repeated
1710 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1711 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1712 if (Byte == -1) return -1;
1714 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1715 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1716 if (ThisByte == -1) return -1;
1717 if (Byte != ThisByte) return -1;
1722 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1723 return isRepeatedByteSequence(CDS);
1728 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1731 // See if we can aggregate this into a .fill, if so, emit it as such.
1732 int Value = isRepeatedByteSequence(CDS, AP.TM);
1735 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1737 // Don't emit a 1-byte object as a .fill.
1739 return AP.OutStreamer.EmitFill(Bytes, Value);
1742 // If this can be emitted with .ascii/.asciz, emit it as such.
1743 if (CDS->isString())
1744 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1746 // Otherwise, emit the values in successive locations.
1747 unsigned ElementByteSize = CDS->getElementByteSize();
1748 if (isa<IntegerType>(CDS->getElementType())) {
1749 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1751 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1752 CDS->getElementAsInteger(i));
1753 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1756 } else if (ElementByteSize == 4) {
1757 // FP Constants are printed as integer constants to avoid losing
1759 assert(CDS->getElementType()->isFloatTy());
1760 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1766 F = CDS->getElementAsFloat(i);
1768 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1769 AP.OutStreamer.EmitIntValue(I, 4);
1772 assert(CDS->getElementType()->isDoubleTy());
1773 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1779 F = CDS->getElementAsDouble(i);
1781 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1782 AP.OutStreamer.EmitIntValue(I, 8);
1786 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1787 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1788 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1789 CDS->getNumElements();
1790 if (unsigned Padding = Size - EmittedSize)
1791 AP.OutStreamer.EmitZeros(Padding);
1795 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1796 // See if we can aggregate some values. Make sure it can be
1797 // represented as a series of bytes of the constant value.
1798 int Value = isRepeatedByteSequence(CA, AP.TM);
1802 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1804 AP.OutStreamer.EmitFill(Bytes, Value);
1807 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1808 emitGlobalConstantImpl(CA->getOperand(i), AP);
1812 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1813 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1814 emitGlobalConstantImpl(CV->getOperand(i), AP);
1816 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1817 unsigned Size = DL.getTypeAllocSize(CV->getType());
1818 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1819 CV->getType()->getNumElements();
1820 if (unsigned Padding = Size - EmittedSize)
1821 AP.OutStreamer.EmitZeros(Padding);
1824 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1825 // Print the fields in successive locations. Pad to align if needed!
1826 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1827 unsigned Size = DL->getTypeAllocSize(CS->getType());
1828 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1829 uint64_t SizeSoFar = 0;
1830 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1831 const Constant *Field = CS->getOperand(i);
1833 // Check if padding is needed and insert one or more 0s.
1834 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1835 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1836 - Layout->getElementOffset(i)) - FieldSize;
1837 SizeSoFar += FieldSize + PadSize;
1839 // Now print the actual field value.
1840 emitGlobalConstantImpl(Field, AP);
1842 // Insert padding - this may include padding to increase the size of the
1843 // current field up to the ABI size (if the struct is not packed) as well
1844 // as padding to ensure that the next field starts at the right offset.
1845 AP.OutStreamer.EmitZeros(PadSize);
1847 assert(SizeSoFar == Layout->getSizeInBytes() &&
1848 "Layout of constant struct may be incorrect!");
1851 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1852 APInt API = CFP->getValueAPF().bitcastToAPInt();
1854 // First print a comment with what we think the original floating-point value
1855 // should have been.
1856 if (AP.isVerbose()) {
1857 SmallString<8> StrVal;
1858 CFP->getValueAPF().toString(StrVal);
1861 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1863 AP.OutStreamer.GetCommentOS() << "Printing <null> Type";
1864 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1867 // Now iterate through the APInt chunks, emitting them in endian-correct
1868 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1870 unsigned NumBytes = API.getBitWidth() / 8;
1871 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1872 const uint64_t *p = API.getRawData();
1874 // PPC's long double has odd notions of endianness compared to how LLVM
1875 // handles it: p[0] goes first for *big* endian on PPC.
1876 if (AP.TM.getSubtargetImpl()->getDataLayout()->isBigEndian() &&
1877 !CFP->getType()->isPPC_FP128Ty()) {
1878 int Chunk = API.getNumWords() - 1;
1881 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1883 for (; Chunk >= 0; --Chunk)
1884 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1887 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1888 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1891 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1894 // Emit the tail padding for the long double.
1895 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1896 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1897 DL.getTypeStoreSize(CFP->getType()));
1900 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1901 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1902 unsigned BitWidth = CI->getBitWidth();
1904 // Copy the value as we may massage the layout for constants whose bit width
1905 // is not a multiple of 64-bits.
1906 APInt Realigned(CI->getValue());
1907 uint64_t ExtraBits = 0;
1908 unsigned ExtraBitsSize = BitWidth & 63;
1910 if (ExtraBitsSize) {
1911 // The bit width of the data is not a multiple of 64-bits.
1912 // The extra bits are expected to be at the end of the chunk of the memory.
1914 // * Nothing to be done, just record the extra bits to emit.
1916 // * Record the extra bits to emit.
1917 // * Realign the raw data to emit the chunks of 64-bits.
1918 if (DL->isBigEndian()) {
1919 // Basically the structure of the raw data is a chunk of 64-bits cells:
1920 // 0 1 BitWidth / 64
1921 // [chunk1][chunk2] ... [chunkN].
1922 // The most significant chunk is chunkN and it should be emitted first.
1923 // However, due to the alignment issue chunkN contains useless bits.
1924 // Realign the chunks so that they contain only useless information:
1925 // ExtraBits 0 1 (BitWidth / 64) - 1
1926 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1927 ExtraBits = Realigned.getRawData()[0] &
1928 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1929 Realigned = Realigned.lshr(ExtraBitsSize);
1931 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1934 // We don't expect assemblers to support integer data directives
1935 // for more than 64 bits, so we emit the data in at most 64-bit
1936 // quantities at a time.
1937 const uint64_t *RawData = Realigned.getRawData();
1938 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1939 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1940 AP.OutStreamer.EmitIntValue(Val, 8);
1943 if (ExtraBitsSize) {
1944 // Emit the extra bits after the 64-bits chunks.
1946 // Emit a directive that fills the expected size.
1947 uint64_t Size = AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1949 Size -= (BitWidth / 64) * 8;
1950 assert(Size && Size * 8 >= ExtraBitsSize &&
1951 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1952 == ExtraBits && "Directive too small for extra bits.");
1953 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1957 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1958 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1959 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1960 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1961 return AP.OutStreamer.EmitZeros(Size);
1963 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1970 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1971 CI->getZExtValue());
1972 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1975 emitGlobalConstantLargeInt(CI, AP);
1980 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1981 return emitGlobalConstantFP(CFP, AP);
1983 if (isa<ConstantPointerNull>(CV)) {
1984 AP.OutStreamer.EmitIntValue(0, Size);
1988 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1989 return emitGlobalConstantDataSequential(CDS, AP);
1991 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1992 return emitGlobalConstantArray(CVA, AP);
1994 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1995 return emitGlobalConstantStruct(CVS, AP);
1997 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
1998 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2000 if (CE->getOpcode() == Instruction::BitCast)
2001 return emitGlobalConstantImpl(CE->getOperand(0), AP);
2004 // If the constant expression's size is greater than 64-bits, then we have
2005 // to emit the value in chunks. Try to constant fold the value and emit it
2007 Constant *New = ConstantFoldConstantExpression(CE, DL);
2008 if (New && New != CE)
2009 return emitGlobalConstantImpl(New, AP);
2013 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2014 return emitGlobalConstantVector(V, AP);
2016 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2017 // thread the streamer with EmitValue.
2018 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
2021 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2022 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2024 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(CV->getType());
2026 emitGlobalConstantImpl(CV, *this);
2027 else if (MAI->hasSubsectionsViaSymbols()) {
2028 // If the global has zero size, emit a single byte so that two labels don't
2029 // look like they are at the same location.
2030 OutStreamer.EmitIntValue(0, 1);
2034 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2035 // Target doesn't support this yet!
2036 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2039 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2041 OS << '+' << Offset;
2042 else if (Offset < 0)
2046 //===----------------------------------------------------------------------===//
2047 // Symbol Lowering Routines.
2048 //===----------------------------------------------------------------------===//
2050 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2051 /// temporary label with the specified stem and unique ID.
2052 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const {
2053 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2054 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2058 /// GetTempSymbol - Return an assembler temporary label with the specified
2060 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const {
2061 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2062 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2067 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2068 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2071 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2072 return MMI->getAddrLabelSymbol(BB);
2075 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2076 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2077 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2078 return OutContext.GetOrCreateSymbol
2079 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2080 + "_" + Twine(CPID));
2083 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2084 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2085 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2088 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2089 /// FIXME: privatize to AsmPrinter.
2090 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2091 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2092 return OutContext.GetOrCreateSymbol
2093 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2094 Twine(UID) + "_set_" + Twine(MBBID));
2097 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2098 StringRef Suffix) const {
2099 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2103 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2105 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2106 SmallString<60> NameStr;
2107 Mang->getNameWithPrefix(NameStr, Sym);
2108 return OutContext.GetOrCreateSymbol(NameStr.str());
2113 /// PrintParentLoopComment - Print comments about parent loops of this one.
2114 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2115 unsigned FunctionNumber) {
2117 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2118 OS.indent(Loop->getLoopDepth()*2)
2119 << "Parent Loop BB" << FunctionNumber << "_"
2120 << Loop->getHeader()->getNumber()
2121 << " Depth=" << Loop->getLoopDepth() << '\n';
2125 /// PrintChildLoopComment - Print comments about child loops within
2126 /// the loop for this basic block, with nesting.
2127 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2128 unsigned FunctionNumber) {
2129 // Add child loop information
2130 for (const MachineLoop *CL : *Loop) {
2131 OS.indent(CL->getLoopDepth()*2)
2132 << "Child Loop BB" << FunctionNumber << "_"
2133 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2135 PrintChildLoopComment(OS, CL, FunctionNumber);
2139 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2140 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2141 const MachineLoopInfo *LI,
2142 const AsmPrinter &AP) {
2143 // Add loop depth information
2144 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2147 MachineBasicBlock *Header = Loop->getHeader();
2148 assert(Header && "No header for loop");
2150 // If this block is not a loop header, just print out what is the loop header
2152 if (Header != &MBB) {
2153 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2154 Twine(AP.getFunctionNumber())+"_" +
2155 Twine(Loop->getHeader()->getNumber())+
2156 " Depth="+Twine(Loop->getLoopDepth()));
2160 // Otherwise, it is a loop header. Print out information about child and
2162 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2164 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2167 OS.indent(Loop->getLoopDepth()*2-2);
2172 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2174 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2178 /// EmitBasicBlockStart - This method prints the label for the specified
2179 /// MachineBasicBlock, an alignment (if present) and a comment describing
2180 /// it if appropriate.
2181 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2182 // Emit an alignment directive for this block, if needed.
2183 if (unsigned Align = MBB.getAlignment())
2184 EmitAlignment(Align);
2186 // If the block has its address taken, emit any labels that were used to
2187 // reference the block. It is possible that there is more than one label
2188 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2189 // the references were generated.
2190 if (MBB.hasAddressTaken()) {
2191 const BasicBlock *BB = MBB.getBasicBlock();
2193 OutStreamer.AddComment("Block address taken");
2195 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2196 for (auto *Sym : Symbols)
2197 OutStreamer.EmitLabel(Sym);
2200 // Print some verbose block comments.
2202 if (const BasicBlock *BB = MBB.getBasicBlock())
2204 OutStreamer.AddComment("%" + BB->getName());
2205 emitBasicBlockLoopComments(MBB, LI, *this);
2208 // Print the main label for the block.
2209 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2211 // NOTE: Want this comment at start of line, don't emit with AddComment.
2212 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2215 OutStreamer.EmitLabel(MBB.getSymbol());
2219 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2220 bool IsDefinition) const {
2221 MCSymbolAttr Attr = MCSA_Invalid;
2223 switch (Visibility) {
2225 case GlobalValue::HiddenVisibility:
2227 Attr = MAI->getHiddenVisibilityAttr();
2229 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2231 case GlobalValue::ProtectedVisibility:
2232 Attr = MAI->getProtectedVisibilityAttr();
2236 if (Attr != MCSA_Invalid)
2237 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2240 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2241 /// exactly one predecessor and the control transfer mechanism between
2242 /// the predecessor and this block is a fall-through.
2244 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2245 // If this is a landing pad, it isn't a fall through. If it has no preds,
2246 // then nothing falls through to it.
2247 if (MBB->isLandingPad() || MBB->pred_empty())
2250 // If there isn't exactly one predecessor, it can't be a fall through.
2251 if (MBB->pred_size() > 1)
2254 // The predecessor has to be immediately before this block.
2255 MachineBasicBlock *Pred = *MBB->pred_begin();
2256 if (!Pred->isLayoutSuccessor(MBB))
2259 // If the block is completely empty, then it definitely does fall through.
2263 // Check the terminators in the previous blocks
2264 for (const auto &MI : Pred->terminators()) {
2265 // If it is not a simple branch, we are in a table somewhere.
2266 if (!MI.isBranch() || MI.isIndirectBranch())
2269 // If we are the operands of one of the branches, this is not a fall
2270 // through. Note that targets with delay slots will usually bundle
2271 // terminators with the delay slot instruction.
2272 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2275 if (OP->isMBB() && OP->getMBB() == MBB)
2285 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2286 if (!S.usesMetadata())
2289 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2290 gcp_map_type::iterator GCPI = GCMap.find(&S);
2291 if (GCPI != GCMap.end())
2292 return GCPI->second.get();
2294 const char *Name = S.getName().c_str();
2296 for (GCMetadataPrinterRegistry::iterator
2297 I = GCMetadataPrinterRegistry::begin(),
2298 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2299 if (strcmp(Name, I->getName()) == 0) {
2300 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2302 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2303 return IterBool.first->second.get();
2306 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2309 /// Pin vtable to this file.
2310 AsmPrinterHandler::~AsmPrinterHandler() {}