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(false);
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(M, *MI, *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));
229 DD = new DwarfDebug(this, &M);
230 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
233 EHStreamer *ES = nullptr;
234 switch (MAI->getExceptionHandlingType()) {
235 case ExceptionHandling::None:
237 case ExceptionHandling::SjLj:
238 case ExceptionHandling::DwarfCFI:
239 ES = new DwarfCFIException(this);
241 case ExceptionHandling::ARM:
242 ES = new ARMException(this);
244 case ExceptionHandling::ItaniumWinEH:
245 case ExceptionHandling::MSVC:
246 switch (MAI->getWinEHEncodingType()) {
247 default: llvm_unreachable("unsupported unwinding information encoding");
248 case WinEH::EncodingType::Itanium:
249 ES = new Win64Exception(this);
255 Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
259 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
260 if (!MAI.hasWeakDefCanBeHiddenDirective())
263 return canBeOmittedFromSymbolTable(GV);
266 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
267 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
269 case GlobalValue::CommonLinkage:
270 case GlobalValue::LinkOnceAnyLinkage:
271 case GlobalValue::LinkOnceODRLinkage:
272 case GlobalValue::WeakAnyLinkage:
273 case GlobalValue::WeakODRLinkage:
274 if (MAI->hasWeakDefDirective()) {
276 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
278 if (!canBeHidden(GV, *MAI))
279 // .weak_definition _foo
280 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
282 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
283 } else if (MAI->hasLinkOnceDirective()) {
285 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
286 //NOTE: linkonce is handled by the section the symbol was assigned to.
289 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
292 case GlobalValue::AppendingLinkage:
293 // FIXME: appending linkage variables should go into a section of
294 // their name or something. For now, just emit them as external.
295 case GlobalValue::ExternalLinkage:
296 // If external or appending, declare as a global symbol.
298 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
300 case GlobalValue::PrivateLinkage:
301 case GlobalValue::InternalLinkage:
303 case GlobalValue::AvailableExternallyLinkage:
304 llvm_unreachable("Should never emit this");
305 case GlobalValue::ExternalWeakLinkage:
306 llvm_unreachable("Don't know how to emit these");
308 llvm_unreachable("Unknown linkage type!");
311 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
312 const GlobalValue *GV) const {
313 TM.getNameWithPrefix(Name, GV, *Mang);
316 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
317 return TM.getSymbol(GV, *Mang);
320 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
321 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
322 if (GV->hasInitializer()) {
323 // Check to see if this is a special global used by LLVM, if so, emit it.
324 if (EmitSpecialLLVMGlobal(GV))
328 GV->printAsOperand(OutStreamer.GetCommentOS(),
329 /*PrintType=*/false, GV->getParent());
330 OutStreamer.GetCommentOS() << '\n';
334 MCSymbol *GVSym = getSymbol(GV);
335 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
337 if (!GV->hasInitializer()) // External globals require no extra code.
340 if (MAI->hasDotTypeDotSizeDirective())
341 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
343 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
345 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
346 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
348 // If the alignment is specified, we *must* obey it. Overaligning a global
349 // with a specified alignment is a prompt way to break globals emitted to
350 // sections and expected to be contiguous (e.g. ObjC metadata).
351 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
353 for (const HandlerInfo &HI : Handlers) {
354 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
355 HI.Handler->setSymbolSize(GVSym, Size);
358 // Handle common and BSS local symbols (.lcomm).
359 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
360 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
361 unsigned Align = 1 << AlignLog;
363 // Handle common symbols.
364 if (GVKind.isCommon()) {
365 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
369 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
373 // Handle local BSS symbols.
374 if (MAI->hasMachoZeroFillDirective()) {
375 const MCSection *TheSection =
376 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
377 // .zerofill __DATA, __bss, _foo, 400, 5
378 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
382 // Use .lcomm only if it supports user-specified alignment.
383 // Otherwise, while it would still be correct to use .lcomm in some
384 // cases (e.g. when Align == 1), the external assembler might enfore
385 // some -unknown- default alignment behavior, which could cause
386 // spurious differences between external and integrated assembler.
387 // Prefer to simply fall back to .local / .comm in this case.
388 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
390 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
394 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
398 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
400 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
404 const MCSection *TheSection =
405 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
407 // Handle the zerofill directive on darwin, which is a special form of BSS
409 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
410 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
413 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
414 // .zerofill __DATA, __common, _foo, 400, 5
415 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
419 // Handle thread local data for mach-o which requires us to output an
420 // additional structure of data and mangle the original symbol so that we
421 // can reference it later.
423 // TODO: This should become an "emit thread local global" method on TLOF.
424 // All of this macho specific stuff should be sunk down into TLOFMachO and
425 // stuff like "TLSExtraDataSection" should no longer be part of the parent
426 // TLOF class. This will also make it more obvious that stuff like
427 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
429 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
430 // Emit the .tbss symbol
432 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
434 if (GVKind.isThreadBSS()) {
435 TheSection = getObjFileLowering().getTLSBSSSection();
436 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
437 } else if (GVKind.isThreadData()) {
438 OutStreamer.SwitchSection(TheSection);
440 EmitAlignment(AlignLog, GV);
441 OutStreamer.EmitLabel(MangSym);
443 EmitGlobalConstant(GV->getInitializer());
446 OutStreamer.AddBlankLine();
448 // Emit the variable struct for the runtime.
449 const MCSection *TLVSect
450 = getObjFileLowering().getTLSExtraDataSection();
452 OutStreamer.SwitchSection(TLVSect);
453 // Emit the linkage here.
454 EmitLinkage(GV, GVSym);
455 OutStreamer.EmitLabel(GVSym);
457 // Three pointers in size:
458 // - __tlv_bootstrap - used to make sure support exists
459 // - spare pointer, used when mapped by the runtime
460 // - pointer to mangled symbol above with initializer
461 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
462 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
464 OutStreamer.EmitIntValue(0, PtrSize);
465 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
467 OutStreamer.AddBlankLine();
471 OutStreamer.SwitchSection(TheSection);
473 EmitLinkage(GV, GVSym);
474 EmitAlignment(AlignLog, GV);
476 OutStreamer.EmitLabel(GVSym);
478 EmitGlobalConstant(GV->getInitializer());
480 if (MAI->hasDotTypeDotSizeDirective())
482 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
484 OutStreamer.AddBlankLine();
487 /// EmitFunctionHeader - This method emits the header for the current
489 void AsmPrinter::EmitFunctionHeader() {
490 // Print out constants referenced by the function
493 // Print the 'header' of function.
494 const Function *F = MF->getFunction();
496 OutStreamer.SwitchSection(
497 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
498 EmitVisibility(CurrentFnSym, F->getVisibility());
500 EmitLinkage(F, CurrentFnSym);
501 EmitAlignment(MF->getAlignment(), F);
503 if (MAI->hasDotTypeDotSizeDirective())
504 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
507 F->printAsOperand(OutStreamer.GetCommentOS(),
508 /*PrintType=*/false, F->getParent());
509 OutStreamer.GetCommentOS() << '\n';
512 // Emit the prefix data.
513 if (F->hasPrefixData())
514 EmitGlobalConstant(F->getPrefixData());
516 // Emit the CurrentFnSym. This is a virtual function to allow targets to
517 // do their wild and crazy things as required.
518 EmitFunctionEntryLabel();
520 // If the function had address-taken blocks that got deleted, then we have
521 // references to the dangling symbols. Emit them at the start of the function
522 // so that we don't get references to undefined symbols.
523 std::vector<MCSymbol*> DeadBlockSyms;
524 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
525 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
526 OutStreamer.AddComment("Address taken block that was later removed");
527 OutStreamer.EmitLabel(DeadBlockSyms[i]);
530 // Emit pre-function debug and/or EH information.
531 for (const HandlerInfo &HI : Handlers) {
532 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
533 HI.Handler->beginFunction(MF);
536 // Emit the prologue data.
537 if (F->hasPrologueData())
538 EmitGlobalConstant(F->getPrologueData());
541 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
542 /// function. This can be overridden by targets as required to do custom stuff.
543 void AsmPrinter::EmitFunctionEntryLabel() {
544 // The function label could have already been emitted if two symbols end up
545 // conflicting due to asm renaming. Detect this and emit an error.
546 if (CurrentFnSym->isUndefined())
547 return OutStreamer.EmitLabel(CurrentFnSym);
549 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
550 "' label emitted multiple times to assembly file");
553 /// emitComments - Pretty-print comments for instructions.
554 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
555 const MachineFunction *MF = MI.getParent()->getParent();
556 const TargetMachine &TM = MF->getTarget();
558 // Check for spills and reloads
561 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
563 // We assume a single instruction only has a spill or reload, not
565 const MachineMemOperand *MMO;
566 if (TM.getSubtargetImpl()->getInstrInfo()->isLoadFromStackSlotPostFE(&MI,
568 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
569 MMO = *MI.memoperands_begin();
570 CommentOS << MMO->getSize() << "-byte Reload\n";
572 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasLoadFromStackSlot(
574 if (FrameInfo->isSpillSlotObjectIndex(FI))
575 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
576 } else if (TM.getSubtargetImpl()->getInstrInfo()->isStoreToStackSlotPostFE(
578 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
579 MMO = *MI.memoperands_begin();
580 CommentOS << MMO->getSize() << "-byte Spill\n";
582 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasStoreToStackSlot(
584 if (FrameInfo->isSpillSlotObjectIndex(FI))
585 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
588 // Check for spill-induced copies
589 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
590 CommentOS << " Reload Reuse\n";
593 /// emitImplicitDef - This method emits the specified machine instruction
594 /// that is an implicit def.
595 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
596 unsigned RegNo = MI->getOperand(0).getReg();
597 OutStreamer.AddComment(
598 Twine("implicit-def: ") +
599 TM.getSubtargetImpl()->getRegisterInfo()->getName(RegNo));
600 OutStreamer.AddBlankLine();
603 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
604 std::string Str = "kill:";
605 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
606 const MachineOperand &Op = MI->getOperand(i);
607 assert(Op.isReg() && "KILL instruction must have only register operands");
609 Str += AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Op.getReg());
610 Str += (Op.isDef() ? "<def>" : "<kill>");
612 AP.OutStreamer.AddComment(Str);
613 AP.OutStreamer.AddBlankLine();
616 /// emitDebugValueComment - This method handles the target-independent form
617 /// of DBG_VALUE, returning true if it was able to do so. A false return
618 /// means the target will need to handle MI in EmitInstruction.
619 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
620 // This code handles only the 4-operand target-independent form.
621 if (MI->getNumOperands() != 4)
624 SmallString<128> Str;
625 raw_svector_ostream OS(Str);
626 OS << "DEBUG_VALUE: ";
628 DIVariable V = MI->getDebugVariable();
629 if (V.getContext().isSubprogram()) {
630 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
636 DIExpression Expr = MI->getDebugExpression();
637 if (Expr.isVariablePiece())
638 OS << " [piece offset=" << Expr.getPieceOffset()
639 << " size=" << Expr.getPieceSize() << "]";
642 // The second operand is only an offset if it's an immediate.
643 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
644 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
646 // Register or immediate value. Register 0 means undef.
647 if (MI->getOperand(0).isFPImm()) {
648 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
649 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
650 OS << (double)APF.convertToFloat();
651 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
652 OS << APF.convertToDouble();
654 // There is no good way to print long double. Convert a copy to
655 // double. Ah well, it's only a comment.
657 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
659 OS << "(long double) " << APF.convertToDouble();
661 } else if (MI->getOperand(0).isImm()) {
662 OS << MI->getOperand(0).getImm();
663 } else if (MI->getOperand(0).isCImm()) {
664 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
667 if (MI->getOperand(0).isReg()) {
668 Reg = MI->getOperand(0).getReg();
670 assert(MI->getOperand(0).isFI() && "Unknown operand type");
671 const TargetFrameLowering *TFI =
672 AP.TM.getSubtargetImpl()->getFrameLowering();
673 Offset += TFI->getFrameIndexReference(*AP.MF,
674 MI->getOperand(0).getIndex(), Reg);
678 // Suppress offset, it is not meaningful here.
680 // NOTE: Want this comment at start of line, don't emit with AddComment.
681 AP.OutStreamer.emitRawComment(OS.str());
686 OS << AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Reg);
690 OS << '+' << Offset << ']';
692 // NOTE: Want this comment at start of line, don't emit with AddComment.
693 AP.OutStreamer.emitRawComment(OS.str());
697 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
698 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
699 MF->getFunction()->needsUnwindTableEntry())
702 if (MMI->hasDebugInfo())
708 bool AsmPrinter::needsSEHMoves() {
709 return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
712 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
713 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
714 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
715 ExceptionHandlingType != ExceptionHandling::ARM)
718 if (needsCFIMoves() == CFI_M_None)
721 const MachineModuleInfo &MMI = MF->getMMI();
722 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
723 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
724 const MCCFIInstruction &CFI = Instrs[CFIIndex];
725 emitCFIInstruction(CFI);
728 /// EmitFunctionBody - This method emits the body and trailer for a
730 void AsmPrinter::EmitFunctionBody() {
731 // Emit target-specific gunk before the function body.
732 EmitFunctionBodyStart();
734 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
736 // Print out code for the function.
737 bool HasAnyRealCode = false;
738 for (auto &MBB : *MF) {
739 // Print a label for the basic block.
740 EmitBasicBlockStart(MBB);
741 for (auto &MI : MBB) {
743 // Print the assembly for the instruction.
744 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
745 !MI.isDebugValue()) {
746 HasAnyRealCode = true;
750 if (ShouldPrintDebugScopes) {
751 for (const HandlerInfo &HI : Handlers) {
752 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
753 TimePassesIsEnabled);
754 HI.Handler->beginInstruction(&MI);
759 emitComments(MI, OutStreamer.GetCommentOS());
761 switch (MI.getOpcode()) {
762 case TargetOpcode::CFI_INSTRUCTION:
763 emitCFIInstruction(MI);
766 case TargetOpcode::EH_LABEL:
767 case TargetOpcode::GC_LABEL:
768 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
770 case TargetOpcode::INLINEASM:
773 case TargetOpcode::DBG_VALUE:
775 if (!emitDebugValueComment(&MI, *this))
776 EmitInstruction(&MI);
779 case TargetOpcode::IMPLICIT_DEF:
780 if (isVerbose()) emitImplicitDef(&MI);
782 case TargetOpcode::KILL:
783 if (isVerbose()) emitKill(&MI, *this);
786 EmitInstruction(&MI);
790 if (ShouldPrintDebugScopes) {
791 for (const HandlerInfo &HI : Handlers) {
792 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
793 TimePassesIsEnabled);
794 HI.Handler->endInstruction();
799 EmitBasicBlockEnd(MBB);
802 // If the function is empty and the object file uses .subsections_via_symbols,
803 // then we need to emit *something* to the function body to prevent the
804 // labels from collapsing together. Just emit a noop.
805 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
807 TM.getSubtargetImpl()->getInstrInfo()->getNoopForMachoTarget(Noop);
808 OutStreamer.AddComment("avoids zero-length function");
810 // Targets can opt-out of emitting the noop here by leaving the opcode
812 if (Noop.getOpcode())
813 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
816 const Function *F = MF->getFunction();
817 for (const auto &BB : *F) {
818 if (!BB.hasAddressTaken())
820 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
821 if (Sym->isDefined())
823 OutStreamer.AddComment("Address of block that was removed by CodeGen");
824 OutStreamer.EmitLabel(Sym);
827 // Emit target-specific gunk after the function body.
828 EmitFunctionBodyEnd();
830 // If the target wants a .size directive for the size of the function, emit
832 if (MAI->hasDotTypeDotSizeDirective()) {
833 // Create a symbol for the end of function, so we can get the size as
834 // difference between the function label and the temp label.
835 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
836 OutStreamer.EmitLabel(FnEndLabel);
838 const MCExpr *SizeExp =
839 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
840 MCSymbolRefExpr::Create(CurrentFnSymForSize,
843 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
846 // Emit post-function debug and/or EH information.
847 for (const HandlerInfo &HI : Handlers) {
848 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
849 HI.Handler->endFunction(MF);
853 // Print out jump tables referenced by the function.
856 OutStreamer.AddBlankLine();
859 bool AsmPrinter::doFinalization(Module &M) {
860 // Emit global variables.
861 for (const auto &G : M.globals())
862 EmitGlobalVariable(&G);
864 // Emit visibility info for declarations
865 for (const Function &F : M) {
866 if (!F.isDeclaration())
868 GlobalValue::VisibilityTypes V = F.getVisibility();
869 if (V == GlobalValue::DefaultVisibility)
872 MCSymbol *Name = getSymbol(&F);
873 EmitVisibility(Name, V, false);
876 // Get information about jump-instruction tables to print.
877 JumpInstrTableInfo *JITI = getAnalysisIfAvailable<JumpInstrTableInfo>();
879 if (JITI && !JITI->getTables().empty()) {
880 unsigned Arch = Triple(getTargetTriple()).getArch();
881 bool IsThumb = (Arch == Triple::thumb || Arch == Triple::thumbeb);
883 TM.getSubtargetImpl()->getInstrInfo()->getTrap(TrapInst);
884 unsigned LogAlignment = llvm::Log2_64(JITI->entryByteAlignment());
886 // Emit the right section for these functions.
887 OutStreamer.SwitchSection(OutContext.getObjectFileInfo()->getTextSection());
888 for (const auto &KV : JITI->getTables()) {
890 for (const auto &FunPair : KV.second) {
891 // Emit the function labels to make this be a function entry point.
893 OutContext.GetOrCreateSymbol(FunPair.second->getName());
894 EmitAlignment(LogAlignment);
896 OutStreamer.EmitThumbFunc(FunSym);
897 if (MAI->hasDotTypeDotSizeDirective())
898 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_ELF_TypeFunction);
899 OutStreamer.EmitLabel(FunSym);
901 // Emit the jump instruction to transfer control to the original
904 MCSymbol *TargetSymbol =
905 OutContext.GetOrCreateSymbol(FunPair.first->getName());
906 const MCSymbolRefExpr *TargetSymRef =
907 MCSymbolRefExpr::Create(TargetSymbol, MCSymbolRefExpr::VK_PLT,
909 TM.getSubtargetImpl()->getInstrInfo()->getUnconditionalBranch(
910 JumpToFun, TargetSymRef);
911 OutStreamer.EmitInstruction(JumpToFun, getSubtargetInfo());
915 // Emit enough padding instructions to fill up to the next power of two.
916 uint64_t Remaining = NextPowerOf2(Count) - Count;
917 for (uint64_t C = 0; C < Remaining; ++C) {
918 EmitAlignment(LogAlignment);
919 OutStreamer.EmitInstruction(TrapInst, getSubtargetInfo());
925 // Emit module flags.
926 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
927 M.getModuleFlagsMetadata(ModuleFlags);
928 if (!ModuleFlags.empty())
929 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
931 // Make sure we wrote out everything we need.
934 // Finalize debug and EH information.
935 for (const HandlerInfo &HI : Handlers) {
936 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
937 TimePassesIsEnabled);
938 HI.Handler->endModule();
944 // If the target wants to know about weak references, print them all.
945 if (MAI->getWeakRefDirective()) {
946 // FIXME: This is not lazy, it would be nice to only print weak references
947 // to stuff that is actually used. Note that doing so would require targets
948 // to notice uses in operands (due to constant exprs etc). This should
949 // happen with the MC stuff eventually.
951 // Print out module-level global variables here.
952 for (const auto &G : M.globals()) {
953 if (!G.hasExternalWeakLinkage())
955 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
958 for (const auto &F : M) {
959 if (!F.hasExternalWeakLinkage())
961 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
965 OutStreamer.AddBlankLine();
966 for (const auto &Alias : M.aliases()) {
967 MCSymbol *Name = getSymbol(&Alias);
969 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
970 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
971 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
972 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
974 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
976 EmitVisibility(Name, Alias.getVisibility());
978 // Emit the directives as assignments aka .set:
979 OutStreamer.EmitAssignment(Name, lowerConstant(Alias.getAliasee()));
982 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
983 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
984 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
985 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
986 MP->finishAssembly(M, *MI, *this);
988 // Emit llvm.ident metadata in an '.ident' directive.
991 // If we don't have any trampolines, then we don't require stack memory
992 // to be executable. Some targets have a directive to declare this.
993 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
994 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
995 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
996 OutStreamer.SwitchSection(S);
998 // Allow the target to emit any magic that it wants at the end of the file,
999 // after everything else has gone out.
1000 EmitEndOfAsmFile(M);
1002 delete Mang; Mang = nullptr;
1005 OutStreamer.Finish();
1006 OutStreamer.reset();
1011 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1013 // Get the function symbol.
1014 CurrentFnSym = getSymbol(MF.getFunction());
1015 CurrentFnSymForSize = CurrentFnSym;
1018 LI = &getAnalysis<MachineLoopInfo>();
1022 // SectionCPs - Keep track the alignment, constpool entries per Section.
1026 SmallVector<unsigned, 4> CPEs;
1027 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1031 /// EmitConstantPool - Print to the current output stream assembly
1032 /// representations of the constants in the constant pool MCP. This is
1033 /// used to print out constants which have been "spilled to memory" by
1034 /// the code generator.
1036 void AsmPrinter::EmitConstantPool() {
1037 const MachineConstantPool *MCP = MF->getConstantPool();
1038 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1039 if (CP.empty()) return;
1041 // Calculate sections for constant pool entries. We collect entries to go into
1042 // the same section together to reduce amount of section switch statements.
1043 SmallVector<SectionCPs, 4> CPSections;
1044 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1045 const MachineConstantPoolEntry &CPE = CP[i];
1046 unsigned Align = CPE.getAlignment();
1049 CPE.getSectionKind(TM.getSubtargetImpl()->getDataLayout());
1051 const Constant *C = nullptr;
1052 if (!CPE.isMachineConstantPoolEntry())
1053 C = CPE.Val.ConstVal;
1055 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind, C);
1057 // The number of sections are small, just do a linear search from the
1058 // last section to the first.
1060 unsigned SecIdx = CPSections.size();
1061 while (SecIdx != 0) {
1062 if (CPSections[--SecIdx].S == S) {
1068 SecIdx = CPSections.size();
1069 CPSections.push_back(SectionCPs(S, Align));
1072 if (Align > CPSections[SecIdx].Alignment)
1073 CPSections[SecIdx].Alignment = Align;
1074 CPSections[SecIdx].CPEs.push_back(i);
1077 // Now print stuff into the calculated sections.
1078 const MCSection *CurSection = nullptr;
1079 unsigned Offset = 0;
1080 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1081 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1082 unsigned CPI = CPSections[i].CPEs[j];
1083 MCSymbol *Sym = GetCPISymbol(CPI);
1084 if (!Sym->isUndefined())
1087 if (CurSection != CPSections[i].S) {
1088 OutStreamer.SwitchSection(CPSections[i].S);
1089 EmitAlignment(Log2_32(CPSections[i].Alignment));
1090 CurSection = CPSections[i].S;
1094 MachineConstantPoolEntry CPE = CP[CPI];
1096 // Emit inter-object padding for alignment.
1097 unsigned AlignMask = CPE.getAlignment() - 1;
1098 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1099 OutStreamer.EmitZeros(NewOffset - Offset);
1101 Type *Ty = CPE.getType();
1102 Offset = NewOffset +
1103 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(Ty);
1105 OutStreamer.EmitLabel(Sym);
1106 if (CPE.isMachineConstantPoolEntry())
1107 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1109 EmitGlobalConstant(CPE.Val.ConstVal);
1114 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1115 /// by the current function to the current output stream.
1117 void AsmPrinter::EmitJumpTableInfo() {
1118 const DataLayout *DL = MF->getSubtarget().getDataLayout();
1119 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1121 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1122 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1123 if (JT.empty()) return;
1125 // Pick the directive to use to print the jump table entries, and switch to
1126 // the appropriate section.
1127 const Function *F = MF->getFunction();
1128 bool JTInDiffSection = false;
1129 if (// In PIC mode, we need to emit the jump table to the same section as the
1130 // function body itself, otherwise the label differences won't make sense.
1131 // FIXME: Need a better predicate for this: what about custom entries?
1132 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1133 // We should also do if the section name is NULL or function is declared
1134 // in discardable section
1135 // FIXME: this isn't the right predicate, should be based on the MCSection
1136 // for the function.
1137 F->isWeakForLinker()) {
1138 OutStreamer.SwitchSection(
1139 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1141 // Otherwise, drop it in the readonly section.
1142 const MCSection *ReadOnlySection =
1143 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
1145 OutStreamer.SwitchSection(ReadOnlySection);
1146 JTInDiffSection = true;
1149 EmitAlignment(Log2_32(
1150 MJTI->getEntryAlignment(*TM.getSubtargetImpl()->getDataLayout())));
1152 // Jump tables in code sections are marked with a data_region directive
1153 // where that's supported.
1154 if (!JTInDiffSection)
1155 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1157 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1158 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1160 // If this jump table was deleted, ignore it.
1161 if (JTBBs.empty()) continue;
1163 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1164 /// emit a .set directive for each unique entry.
1165 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1166 MAI->doesSetDirectiveSuppressesReloc()) {
1167 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1168 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1169 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1170 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1171 const MachineBasicBlock *MBB = JTBBs[ii];
1172 if (!EmittedSets.insert(MBB).second)
1175 // .set LJTSet, LBB32-base
1177 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1178 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1179 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1183 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1184 // before each jump table. The first label is never referenced, but tells
1185 // the assembler and linker the extents of the jump table object. The
1186 // second label is actually referenced by the code.
1187 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1188 // FIXME: This doesn't have to have any specific name, just any randomly
1189 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1190 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1192 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1194 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1195 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1197 if (!JTInDiffSection)
1198 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1201 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1203 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1204 const MachineBasicBlock *MBB,
1205 unsigned UID) const {
1206 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1207 const MCExpr *Value = nullptr;
1208 switch (MJTI->getEntryKind()) {
1209 case MachineJumpTableInfo::EK_Inline:
1210 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1211 case MachineJumpTableInfo::EK_Custom32:
1213 TM.getSubtargetImpl()->getTargetLowering()->LowerCustomJumpTableEntry(
1214 MJTI, MBB, UID, OutContext);
1216 case MachineJumpTableInfo::EK_BlockAddress:
1217 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1219 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1221 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1222 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1223 // with a relocation as gp-relative, e.g.:
1225 MCSymbol *MBBSym = MBB->getSymbol();
1226 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1230 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1231 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1232 // with a relocation as gp-relative, e.g.:
1234 MCSymbol *MBBSym = MBB->getSymbol();
1235 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1239 case MachineJumpTableInfo::EK_LabelDifference32: {
1240 // Each entry is the address of the block minus the address of the jump
1241 // table. This is used for PIC jump tables where gprel32 is not supported.
1243 // .word LBB123 - LJTI1_2
1244 // If the .set directive avoids relocations, this is emitted as:
1245 // .set L4_5_set_123, LBB123 - LJTI1_2
1246 // .word L4_5_set_123
1247 if (MAI->doesSetDirectiveSuppressesReloc()) {
1248 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1252 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1253 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1254 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1255 Value = MCBinaryExpr::CreateSub(Value, Base, OutContext);
1260 assert(Value && "Unknown entry kind!");
1262 unsigned EntrySize =
1263 MJTI->getEntrySize(*TM.getSubtargetImpl()->getDataLayout());
1264 OutStreamer.EmitValue(Value, EntrySize);
1268 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1269 /// special global used by LLVM. If so, emit it and return true, otherwise
1270 /// do nothing and return false.
1271 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1272 if (GV->getName() == "llvm.used") {
1273 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1274 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1278 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1279 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1280 GV->hasAvailableExternallyLinkage())
1283 if (!GV->hasAppendingLinkage()) return false;
1285 assert(GV->hasInitializer() && "Not a special LLVM global!");
1287 if (GV->getName() == "llvm.global_ctors") {
1288 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1290 if (TM.getRelocationModel() == Reloc::Static &&
1291 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1292 StringRef Sym(".constructors_used");
1293 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1299 if (GV->getName() == "llvm.global_dtors") {
1300 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1302 if (TM.getRelocationModel() == Reloc::Static &&
1303 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1304 StringRef Sym(".destructors_used");
1305 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1314 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1315 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1316 /// is true, as being used with this directive.
1317 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1318 // Should be an array of 'i8*'.
1319 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1320 const GlobalValue *GV =
1321 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1323 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1329 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1331 llvm::Constant *Func;
1332 llvm::GlobalValue *ComdatKey;
1336 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1338 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1339 // Should be an array of '{ int, void ()* }' structs. The first value is the
1341 if (!isa<ConstantArray>(List)) return;
1343 // Sanity check the structors list.
1344 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1345 if (!InitList) return; // Not an array!
1346 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1347 // FIXME: Only allow the 3-field form in LLVM 4.0.
1348 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1349 return; // Not an array of two or three elements!
1350 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1351 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1352 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1353 return; // Not (int, ptr, ptr).
1355 // Gather the structors in a form that's convenient for sorting by priority.
1356 SmallVector<Structor, 8> Structors;
1357 for (Value *O : InitList->operands()) {
1358 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1359 if (!CS) continue; // Malformed.
1360 if (CS->getOperand(1)->isNullValue())
1361 break; // Found a null terminator, skip the rest.
1362 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1363 if (!Priority) continue; // Malformed.
1364 Structors.push_back(Structor());
1365 Structor &S = Structors.back();
1366 S.Priority = Priority->getLimitedValue(65535);
1367 S.Func = CS->getOperand(1);
1368 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1369 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1372 // Emit the function pointers in the target-specific order
1373 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
1374 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1375 std::stable_sort(Structors.begin(), Structors.end(),
1376 [](const Structor &L,
1377 const Structor &R) { return L.Priority < R.Priority; });
1378 for (Structor &S : Structors) {
1379 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1380 const MCSymbol *KeySym = nullptr;
1381 if (GlobalValue *GV = S.ComdatKey) {
1382 if (GV->hasAvailableExternallyLinkage())
1383 // If the associated variable is available_externally, some other TU
1384 // will provide its dynamic initializer.
1387 KeySym = getSymbol(GV);
1389 const MCSection *OutputSection =
1390 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1391 : Obj.getStaticDtorSection(S.Priority, KeySym));
1392 OutStreamer.SwitchSection(OutputSection);
1393 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1394 EmitAlignment(Align);
1395 EmitXXStructor(S.Func);
1399 void AsmPrinter::EmitModuleIdents(Module &M) {
1400 if (!MAI->hasIdentDirective())
1403 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1404 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1405 const MDNode *N = NMD->getOperand(i);
1406 assert(N->getNumOperands() == 1 &&
1407 "llvm.ident metadata entry can have only one operand");
1408 const MDString *S = cast<MDString>(N->getOperand(0));
1409 OutStreamer.EmitIdent(S->getString());
1414 //===--------------------------------------------------------------------===//
1415 // Emission and print routines
1418 /// EmitInt8 - Emit a byte directive and value.
1420 void AsmPrinter::EmitInt8(int Value) const {
1421 OutStreamer.EmitIntValue(Value, 1);
1424 /// EmitInt16 - Emit a short directive and value.
1426 void AsmPrinter::EmitInt16(int Value) const {
1427 OutStreamer.EmitIntValue(Value, 2);
1430 /// EmitInt32 - Emit a long directive and value.
1432 void AsmPrinter::EmitInt32(int Value) const {
1433 OutStreamer.EmitIntValue(Value, 4);
1436 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1437 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1438 /// .set if it avoids relocations.
1439 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1440 unsigned Size) const {
1441 // Get the Hi-Lo expression.
1442 const MCExpr *Diff =
1443 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1444 MCSymbolRefExpr::Create(Lo, OutContext),
1447 if (!MAI->doesSetDirectiveSuppressesReloc()) {
1448 OutStreamer.EmitValue(Diff, Size);
1452 // Otherwise, emit with .set (aka assignment).
1453 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1454 OutStreamer.EmitAssignment(SetLabel, Diff);
1455 OutStreamer.EmitSymbolValue(SetLabel, Size);
1458 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1459 /// where the size in bytes of the directive is specified by Size and Label
1460 /// specifies the label. This implicitly uses .set if it is available.
1461 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1463 bool IsSectionRelative) const {
1464 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1465 OutStreamer.EmitCOFFSecRel32(Label);
1469 // Emit Label+Offset (or just Label if Offset is zero)
1470 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1472 Expr = MCBinaryExpr::CreateAdd(
1473 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1475 OutStreamer.EmitValue(Expr, Size);
1478 //===----------------------------------------------------------------------===//
1480 // EmitAlignment - Emit an alignment directive to the specified power of
1481 // two boundary. For example, if you pass in 3 here, you will get an 8
1482 // byte alignment. If a global value is specified, and if that global has
1483 // an explicit alignment requested, it will override the alignment request
1484 // if required for correctness.
1486 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1488 NumBits = getGVAlignmentLog2(GV, *TM.getSubtargetImpl()->getDataLayout(),
1491 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1494 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
1495 "undefined behavior");
1496 if (getCurrentSection()->getKind().isText())
1497 OutStreamer.EmitCodeAlignment(1u << NumBits);
1499 OutStreamer.EmitValueToAlignment(1u << NumBits);
1502 //===----------------------------------------------------------------------===//
1503 // Constant emission.
1504 //===----------------------------------------------------------------------===//
1506 const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1507 MCContext &Ctx = OutContext;
1509 if (CV->isNullValue() || isa<UndefValue>(CV))
1510 return MCConstantExpr::Create(0, Ctx);
1512 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1513 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1515 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1516 return MCSymbolRefExpr::Create(getSymbol(GV), Ctx);
1518 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1519 return MCSymbolRefExpr::Create(GetBlockAddressSymbol(BA), Ctx);
1521 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1523 llvm_unreachable("Unknown constant value to lower!");
1526 if (const MCExpr *RelocExpr
1527 = getObjFileLowering().getExecutableRelativeSymbol(CE, *Mang, TM))
1530 switch (CE->getOpcode()) {
1532 // If the code isn't optimized, there may be outstanding folding
1533 // opportunities. Attempt to fold the expression using DataLayout as a
1534 // last resort before giving up.
1535 if (Constant *C = ConstantFoldConstantExpression(
1536 CE, TM.getSubtargetImpl()->getDataLayout()))
1538 return lowerConstant(C);
1540 // Otherwise report the problem to the user.
1543 raw_string_ostream OS(S);
1544 OS << "Unsupported expression in static initializer: ";
1545 CE->printAsOperand(OS, /*PrintType=*/false,
1546 !MF ? nullptr : MF->getFunction()->getParent());
1547 report_fatal_error(OS.str());
1549 case Instruction::GetElementPtr: {
1550 const DataLayout &DL = *TM.getSubtargetImpl()->getDataLayout();
1551 // Generate a symbolic expression for the byte address
1552 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1553 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1555 const MCExpr *Base = lowerConstant(CE->getOperand(0));
1559 int64_t Offset = OffsetAI.getSExtValue();
1560 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1564 case Instruction::Trunc:
1565 // We emit the value and depend on the assembler to truncate the generated
1566 // expression properly. This is important for differences between
1567 // blockaddress labels. Since the two labels are in the same function, it
1568 // is reasonable to treat their delta as a 32-bit value.
1570 case Instruction::BitCast:
1571 return lowerConstant(CE->getOperand(0));
1573 case Instruction::IntToPtr: {
1574 const DataLayout &DL = *TM.getSubtargetImpl()->getDataLayout();
1575 // Handle casts to pointers by changing them into casts to the appropriate
1576 // integer type. This promotes constant folding and simplifies this code.
1577 Constant *Op = CE->getOperand(0);
1578 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1580 return lowerConstant(Op);
1583 case Instruction::PtrToInt: {
1584 const DataLayout &DL = *TM.getSubtargetImpl()->getDataLayout();
1585 // Support only foldable casts to/from pointers that can be eliminated by
1586 // changing the pointer to the appropriately sized integer type.
1587 Constant *Op = CE->getOperand(0);
1588 Type *Ty = CE->getType();
1590 const MCExpr *OpExpr = lowerConstant(Op);
1592 // We can emit the pointer value into this slot if the slot is an
1593 // integer slot equal to the size of the pointer.
1594 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1597 // Otherwise the pointer is smaller than the resultant integer, mask off
1598 // the high bits so we are sure to get a proper truncation if the input is
1600 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1601 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1602 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1605 // The MC library also has a right-shift operator, but it isn't consistently
1606 // signed or unsigned between different targets.
1607 case Instruction::Add:
1608 case Instruction::Sub:
1609 case Instruction::Mul:
1610 case Instruction::SDiv:
1611 case Instruction::SRem:
1612 case Instruction::Shl:
1613 case Instruction::And:
1614 case Instruction::Or:
1615 case Instruction::Xor: {
1616 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
1617 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
1618 switch (CE->getOpcode()) {
1619 default: llvm_unreachable("Unknown binary operator constant cast expr");
1620 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1621 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1622 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1623 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1624 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1625 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1626 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1627 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1628 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1634 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1636 /// isRepeatedByteSequence - Determine whether the given value is
1637 /// composed of a repeated sequence of identical bytes and return the
1638 /// byte value. If it is not a repeated sequence, return -1.
1639 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1640 StringRef Data = V->getRawDataValues();
1641 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1643 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1644 if (Data[i] != C) return -1;
1645 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1649 /// isRepeatedByteSequence - Determine whether the given value is
1650 /// composed of a repeated sequence of identical bytes and return the
1651 /// byte value. If it is not a repeated sequence, return -1.
1652 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1654 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1655 if (CI->getBitWidth() > 64) return -1;
1658 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(V->getType());
1659 uint64_t Value = CI->getZExtValue();
1661 // Make sure the constant is at least 8 bits long and has a power
1662 // of 2 bit width. This guarantees the constant bit width is
1663 // always a multiple of 8 bits, avoiding issues with padding out
1664 // to Size and other such corner cases.
1665 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1667 uint8_t Byte = static_cast<uint8_t>(Value);
1669 for (unsigned i = 1; i < Size; ++i) {
1671 if (static_cast<uint8_t>(Value) != Byte) return -1;
1675 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1676 // Make sure all array elements are sequences of the same repeated
1678 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1679 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1680 if (Byte == -1) return -1;
1682 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1683 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1684 if (ThisByte == -1) return -1;
1685 if (Byte != ThisByte) return -1;
1690 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1691 return isRepeatedByteSequence(CDS);
1696 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1699 // See if we can aggregate this into a .fill, if so, emit it as such.
1700 int Value = isRepeatedByteSequence(CDS, AP.TM);
1703 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1705 // Don't emit a 1-byte object as a .fill.
1707 return AP.OutStreamer.EmitFill(Bytes, Value);
1710 // If this can be emitted with .ascii/.asciz, emit it as such.
1711 if (CDS->isString())
1712 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1714 // Otherwise, emit the values in successive locations.
1715 unsigned ElementByteSize = CDS->getElementByteSize();
1716 if (isa<IntegerType>(CDS->getElementType())) {
1717 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1719 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1720 CDS->getElementAsInteger(i));
1721 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1724 } else if (ElementByteSize == 4) {
1725 // FP Constants are printed as integer constants to avoid losing
1727 assert(CDS->getElementType()->isFloatTy());
1728 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1734 F = CDS->getElementAsFloat(i);
1736 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1737 AP.OutStreamer.EmitIntValue(I, 4);
1740 assert(CDS->getElementType()->isDoubleTy());
1741 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1747 F = CDS->getElementAsDouble(i);
1749 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1750 AP.OutStreamer.EmitIntValue(I, 8);
1754 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1755 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1756 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1757 CDS->getNumElements();
1758 if (unsigned Padding = Size - EmittedSize)
1759 AP.OutStreamer.EmitZeros(Padding);
1763 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1764 // See if we can aggregate some values. Make sure it can be
1765 // represented as a series of bytes of the constant value.
1766 int Value = isRepeatedByteSequence(CA, AP.TM);
1770 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1772 AP.OutStreamer.EmitFill(Bytes, Value);
1775 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1776 emitGlobalConstantImpl(CA->getOperand(i), AP);
1780 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1781 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1782 emitGlobalConstantImpl(CV->getOperand(i), AP);
1784 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1785 unsigned Size = DL.getTypeAllocSize(CV->getType());
1786 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1787 CV->getType()->getNumElements();
1788 if (unsigned Padding = Size - EmittedSize)
1789 AP.OutStreamer.EmitZeros(Padding);
1792 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1793 // Print the fields in successive locations. Pad to align if needed!
1794 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1795 unsigned Size = DL->getTypeAllocSize(CS->getType());
1796 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1797 uint64_t SizeSoFar = 0;
1798 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1799 const Constant *Field = CS->getOperand(i);
1801 // Check if padding is needed and insert one or more 0s.
1802 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1803 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1804 - Layout->getElementOffset(i)) - FieldSize;
1805 SizeSoFar += FieldSize + PadSize;
1807 // Now print the actual field value.
1808 emitGlobalConstantImpl(Field, AP);
1810 // Insert padding - this may include padding to increase the size of the
1811 // current field up to the ABI size (if the struct is not packed) as well
1812 // as padding to ensure that the next field starts at the right offset.
1813 AP.OutStreamer.EmitZeros(PadSize);
1815 assert(SizeSoFar == Layout->getSizeInBytes() &&
1816 "Layout of constant struct may be incorrect!");
1819 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1820 APInt API = CFP->getValueAPF().bitcastToAPInt();
1822 // First print a comment with what we think the original floating-point value
1823 // should have been.
1824 if (AP.isVerbose()) {
1825 SmallString<8> StrVal;
1826 CFP->getValueAPF().toString(StrVal);
1829 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1831 AP.OutStreamer.GetCommentOS() << "Printing <null> Type";
1832 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1835 // Now iterate through the APInt chunks, emitting them in endian-correct
1836 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1838 unsigned NumBytes = API.getBitWidth() / 8;
1839 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1840 const uint64_t *p = API.getRawData();
1842 // PPC's long double has odd notions of endianness compared to how LLVM
1843 // handles it: p[0] goes first for *big* endian on PPC.
1844 if (AP.TM.getSubtargetImpl()->getDataLayout()->isBigEndian() &&
1845 !CFP->getType()->isPPC_FP128Ty()) {
1846 int Chunk = API.getNumWords() - 1;
1849 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1851 for (; Chunk >= 0; --Chunk)
1852 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1855 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1856 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1859 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1862 // Emit the tail padding for the long double.
1863 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1864 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1865 DL.getTypeStoreSize(CFP->getType()));
1868 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1869 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1870 unsigned BitWidth = CI->getBitWidth();
1872 // Copy the value as we may massage the layout for constants whose bit width
1873 // is not a multiple of 64-bits.
1874 APInt Realigned(CI->getValue());
1875 uint64_t ExtraBits = 0;
1876 unsigned ExtraBitsSize = BitWidth & 63;
1878 if (ExtraBitsSize) {
1879 // The bit width of the data is not a multiple of 64-bits.
1880 // The extra bits are expected to be at the end of the chunk of the memory.
1882 // * Nothing to be done, just record the extra bits to emit.
1884 // * Record the extra bits to emit.
1885 // * Realign the raw data to emit the chunks of 64-bits.
1886 if (DL->isBigEndian()) {
1887 // Basically the structure of the raw data is a chunk of 64-bits cells:
1888 // 0 1 BitWidth / 64
1889 // [chunk1][chunk2] ... [chunkN].
1890 // The most significant chunk is chunkN and it should be emitted first.
1891 // However, due to the alignment issue chunkN contains useless bits.
1892 // Realign the chunks so that they contain only useless information:
1893 // ExtraBits 0 1 (BitWidth / 64) - 1
1894 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1895 ExtraBits = Realigned.getRawData()[0] &
1896 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1897 Realigned = Realigned.lshr(ExtraBitsSize);
1899 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1902 // We don't expect assemblers to support integer data directives
1903 // for more than 64 bits, so we emit the data in at most 64-bit
1904 // quantities at a time.
1905 const uint64_t *RawData = Realigned.getRawData();
1906 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1907 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1908 AP.OutStreamer.EmitIntValue(Val, 8);
1911 if (ExtraBitsSize) {
1912 // Emit the extra bits after the 64-bits chunks.
1914 // Emit a directive that fills the expected size.
1915 uint64_t Size = AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1917 Size -= (BitWidth / 64) * 8;
1918 assert(Size && Size * 8 >= ExtraBitsSize &&
1919 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1920 == ExtraBits && "Directive too small for extra bits.");
1921 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1925 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1926 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1927 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1928 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1929 return AP.OutStreamer.EmitZeros(Size);
1931 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1938 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1939 CI->getZExtValue());
1940 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1943 emitGlobalConstantLargeInt(CI, AP);
1948 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1949 return emitGlobalConstantFP(CFP, AP);
1951 if (isa<ConstantPointerNull>(CV)) {
1952 AP.OutStreamer.EmitIntValue(0, Size);
1956 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1957 return emitGlobalConstantDataSequential(CDS, AP);
1959 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1960 return emitGlobalConstantArray(CVA, AP);
1962 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1963 return emitGlobalConstantStruct(CVS, AP);
1965 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
1966 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
1968 if (CE->getOpcode() == Instruction::BitCast)
1969 return emitGlobalConstantImpl(CE->getOperand(0), AP);
1972 // If the constant expression's size is greater than 64-bits, then we have
1973 // to emit the value in chunks. Try to constant fold the value and emit it
1975 Constant *New = ConstantFoldConstantExpression(CE, DL);
1976 if (New && New != CE)
1977 return emitGlobalConstantImpl(New, AP);
1981 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1982 return emitGlobalConstantVector(V, AP);
1984 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1985 // thread the streamer with EmitValue.
1986 AP.OutStreamer.EmitValue(AP.lowerConstant(CV), Size);
1989 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1990 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
1992 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(CV->getType());
1994 emitGlobalConstantImpl(CV, *this);
1995 else if (MAI->hasSubsectionsViaSymbols()) {
1996 // If the global has zero size, emit a single byte so that two labels don't
1997 // look like they are at the same location.
1998 OutStreamer.EmitIntValue(0, 1);
2002 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2003 // Target doesn't support this yet!
2004 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2007 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2009 OS << '+' << Offset;
2010 else if (Offset < 0)
2014 //===----------------------------------------------------------------------===//
2015 // Symbol Lowering Routines.
2016 //===----------------------------------------------------------------------===//
2018 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2019 /// temporary label with the specified stem and unique ID.
2020 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const {
2021 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2022 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2026 /// GetTempSymbol - Return an assembler temporary label with the specified
2028 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const {
2029 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2030 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2035 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2036 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2039 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2040 return MMI->getAddrLabelSymbol(BB);
2043 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2044 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2045 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2046 return OutContext.GetOrCreateSymbol
2047 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2048 + "_" + Twine(CPID));
2051 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2052 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2053 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2056 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2057 /// FIXME: privatize to AsmPrinter.
2058 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2059 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2060 return OutContext.GetOrCreateSymbol
2061 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2062 Twine(UID) + "_set_" + Twine(MBBID));
2065 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2066 StringRef Suffix) const {
2067 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2071 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2073 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2074 SmallString<60> NameStr;
2075 Mang->getNameWithPrefix(NameStr, Sym);
2076 return OutContext.GetOrCreateSymbol(NameStr.str());
2081 /// PrintParentLoopComment - Print comments about parent loops of this one.
2082 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2083 unsigned FunctionNumber) {
2085 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2086 OS.indent(Loop->getLoopDepth()*2)
2087 << "Parent Loop BB" << FunctionNumber << "_"
2088 << Loop->getHeader()->getNumber()
2089 << " Depth=" << Loop->getLoopDepth() << '\n';
2093 /// PrintChildLoopComment - Print comments about child loops within
2094 /// the loop for this basic block, with nesting.
2095 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2096 unsigned FunctionNumber) {
2097 // Add child loop information
2098 for (const MachineLoop *CL : *Loop) {
2099 OS.indent(CL->getLoopDepth()*2)
2100 << "Child Loop BB" << FunctionNumber << "_"
2101 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2103 PrintChildLoopComment(OS, CL, FunctionNumber);
2107 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2108 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2109 const MachineLoopInfo *LI,
2110 const AsmPrinter &AP) {
2111 // Add loop depth information
2112 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2115 MachineBasicBlock *Header = Loop->getHeader();
2116 assert(Header && "No header for loop");
2118 // If this block is not a loop header, just print out what is the loop header
2120 if (Header != &MBB) {
2121 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2122 Twine(AP.getFunctionNumber())+"_" +
2123 Twine(Loop->getHeader()->getNumber())+
2124 " Depth="+Twine(Loop->getLoopDepth()));
2128 // Otherwise, it is a loop header. Print out information about child and
2130 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2132 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2135 OS.indent(Loop->getLoopDepth()*2-2);
2140 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2142 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2146 /// EmitBasicBlockStart - This method prints the label for the specified
2147 /// MachineBasicBlock, an alignment (if present) and a comment describing
2148 /// it if appropriate.
2149 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2150 // Emit an alignment directive for this block, if needed.
2151 if (unsigned Align = MBB.getAlignment())
2152 EmitAlignment(Align);
2154 // If the block has its address taken, emit any labels that were used to
2155 // reference the block. It is possible that there is more than one label
2156 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2157 // the references were generated.
2158 if (MBB.hasAddressTaken()) {
2159 const BasicBlock *BB = MBB.getBasicBlock();
2161 OutStreamer.AddComment("Block address taken");
2163 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2164 for (auto *Sym : Symbols)
2165 OutStreamer.EmitLabel(Sym);
2168 // Print some verbose block comments.
2170 if (const BasicBlock *BB = MBB.getBasicBlock())
2172 OutStreamer.AddComment("%" + BB->getName());
2173 emitBasicBlockLoopComments(MBB, LI, *this);
2176 // Print the main label for the block.
2177 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2179 // NOTE: Want this comment at start of line, don't emit with AddComment.
2180 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2183 OutStreamer.EmitLabel(MBB.getSymbol());
2187 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2188 bool IsDefinition) const {
2189 MCSymbolAttr Attr = MCSA_Invalid;
2191 switch (Visibility) {
2193 case GlobalValue::HiddenVisibility:
2195 Attr = MAI->getHiddenVisibilityAttr();
2197 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2199 case GlobalValue::ProtectedVisibility:
2200 Attr = MAI->getProtectedVisibilityAttr();
2204 if (Attr != MCSA_Invalid)
2205 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2208 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2209 /// exactly one predecessor and the control transfer mechanism between
2210 /// the predecessor and this block is a fall-through.
2212 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2213 // If this is a landing pad, it isn't a fall through. If it has no preds,
2214 // then nothing falls through to it.
2215 if (MBB->isLandingPad() || MBB->pred_empty())
2218 // If there isn't exactly one predecessor, it can't be a fall through.
2219 if (MBB->pred_size() > 1)
2222 // The predecessor has to be immediately before this block.
2223 MachineBasicBlock *Pred = *MBB->pred_begin();
2224 if (!Pred->isLayoutSuccessor(MBB))
2227 // If the block is completely empty, then it definitely does fall through.
2231 // Check the terminators in the previous blocks
2232 for (const auto &MI : Pred->terminators()) {
2233 // If it is not a simple branch, we are in a table somewhere.
2234 if (!MI.isBranch() || MI.isIndirectBranch())
2237 // If we are the operands of one of the branches, this is not a fall
2238 // through. Note that targets with delay slots will usually bundle
2239 // terminators with the delay slot instruction.
2240 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2243 if (OP->isMBB() && OP->getMBB() == MBB)
2253 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2254 if (!S.usesMetadata())
2257 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2258 gcp_map_type::iterator GCPI = GCMap.find(&S);
2259 if (GCPI != GCMap.end())
2260 return GCPI->second.get();
2262 const char *Name = S.getName().c_str();
2264 for (GCMetadataPrinterRegistry::iterator
2265 I = GCMetadataPrinterRegistry::begin(),
2266 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2267 if (strcmp(Name, I->getName()) == 0) {
2268 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2270 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2271 return IterBool.first->second.get();
2274 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2277 /// Pin vtable to this file.
2278 AsmPrinterHandler::~AsmPrinterHandler() {}