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 GVSym->redefineIfPossible();
341 if (GVSym->isDefined() || GVSym->isVariable())
342 report_fatal_error("symbol '" + Twine(GVSym->getName()) +
343 "' is already defined");
345 if (MAI->hasDotTypeDotSizeDirective())
346 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
348 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
350 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
351 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
353 // If the alignment is specified, we *must* obey it. Overaligning a global
354 // with a specified alignment is a prompt way to break globals emitted to
355 // sections and expected to be contiguous (e.g. ObjC metadata).
356 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
358 for (const HandlerInfo &HI : Handlers) {
359 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
360 HI.Handler->setSymbolSize(GVSym, Size);
363 // Handle common and BSS local symbols (.lcomm).
364 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
365 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
366 unsigned Align = 1 << AlignLog;
368 // Handle common symbols.
369 if (GVKind.isCommon()) {
370 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
374 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
378 // Handle local BSS symbols.
379 if (MAI->hasMachoZeroFillDirective()) {
380 const MCSection *TheSection =
381 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
382 // .zerofill __DATA, __bss, _foo, 400, 5
383 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
387 // Use .lcomm only if it supports user-specified alignment.
388 // Otherwise, while it would still be correct to use .lcomm in some
389 // cases (e.g. when Align == 1), the external assembler might enfore
390 // some -unknown- default alignment behavior, which could cause
391 // spurious differences between external and integrated assembler.
392 // Prefer to simply fall back to .local / .comm in this case.
393 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
395 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
399 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
403 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
405 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
409 const MCSection *TheSection =
410 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
412 // Handle the zerofill directive on darwin, which is a special form of BSS
414 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
415 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
418 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
419 // .zerofill __DATA, __common, _foo, 400, 5
420 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
424 // Handle thread local data for mach-o which requires us to output an
425 // additional structure of data and mangle the original symbol so that we
426 // can reference it later.
428 // TODO: This should become an "emit thread local global" method on TLOF.
429 // All of this macho specific stuff should be sunk down into TLOFMachO and
430 // stuff like "TLSExtraDataSection" should no longer be part of the parent
431 // TLOF class. This will also make it more obvious that stuff like
432 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
434 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
435 // Emit the .tbss symbol
437 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
439 if (GVKind.isThreadBSS()) {
440 TheSection = getObjFileLowering().getTLSBSSSection();
441 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
442 } else if (GVKind.isThreadData()) {
443 OutStreamer.SwitchSection(TheSection);
445 EmitAlignment(AlignLog, GV);
446 OutStreamer.EmitLabel(MangSym);
448 EmitGlobalConstant(GV->getInitializer());
451 OutStreamer.AddBlankLine();
453 // Emit the variable struct for the runtime.
454 const MCSection *TLVSect
455 = getObjFileLowering().getTLSExtraDataSection();
457 OutStreamer.SwitchSection(TLVSect);
458 // Emit the linkage here.
459 EmitLinkage(GV, GVSym);
460 OutStreamer.EmitLabel(GVSym);
462 // Three pointers in size:
463 // - __tlv_bootstrap - used to make sure support exists
464 // - spare pointer, used when mapped by the runtime
465 // - pointer to mangled symbol above with initializer
466 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
467 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
469 OutStreamer.EmitIntValue(0, PtrSize);
470 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
472 OutStreamer.AddBlankLine();
476 OutStreamer.SwitchSection(TheSection);
478 EmitLinkage(GV, GVSym);
479 EmitAlignment(AlignLog, GV);
481 OutStreamer.EmitLabel(GVSym);
483 EmitGlobalConstant(GV->getInitializer());
485 if (MAI->hasDotTypeDotSizeDirective())
487 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
489 OutStreamer.AddBlankLine();
492 /// EmitFunctionHeader - This method emits the header for the current
494 void AsmPrinter::EmitFunctionHeader() {
495 // Print out constants referenced by the function
498 // Print the 'header' of function.
499 const Function *F = MF->getFunction();
501 OutStreamer.SwitchSection(
502 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
503 EmitVisibility(CurrentFnSym, F->getVisibility());
505 EmitLinkage(F, CurrentFnSym);
506 EmitAlignment(MF->getAlignment(), F);
508 if (MAI->hasDotTypeDotSizeDirective())
509 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
512 F->printAsOperand(OutStreamer.GetCommentOS(),
513 /*PrintType=*/false, F->getParent());
514 OutStreamer.GetCommentOS() << '\n';
517 // Emit the prefix data.
518 if (F->hasPrefixData())
519 EmitGlobalConstant(F->getPrefixData());
521 // Emit the CurrentFnSym. This is a virtual function to allow targets to
522 // do their wild and crazy things as required.
523 EmitFunctionEntryLabel();
525 // If the function had address-taken blocks that got deleted, then we have
526 // references to the dangling symbols. Emit them at the start of the function
527 // so that we don't get references to undefined symbols.
528 std::vector<MCSymbol*> DeadBlockSyms;
529 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
530 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
531 OutStreamer.AddComment("Address taken block that was later removed");
532 OutStreamer.EmitLabel(DeadBlockSyms[i]);
535 // Emit pre-function debug and/or EH information.
536 for (const HandlerInfo &HI : Handlers) {
537 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
538 HI.Handler->beginFunction(MF);
541 // Emit the prologue data.
542 if (F->hasPrologueData())
543 EmitGlobalConstant(F->getPrologueData());
546 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
547 /// function. This can be overridden by targets as required to do custom stuff.
548 void AsmPrinter::EmitFunctionEntryLabel() {
549 CurrentFnSym->redefineIfPossible();
551 // The function label could have already been emitted if two symbols end up
552 // conflicting due to asm renaming. Detect this and emit an error.
553 if (CurrentFnSym->isVariable())
554 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
555 "' is a protected alias");
556 if (CurrentFnSym->isDefined())
557 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
558 "' label emitted multiple times to assembly file");
560 return OutStreamer.EmitLabel(CurrentFnSym);
563 /// emitComments - Pretty-print comments for instructions.
564 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
565 const MachineFunction *MF = MI.getParent()->getParent();
566 const TargetMachine &TM = MF->getTarget();
568 // Check for spills and reloads
571 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
573 // We assume a single instruction only has a spill or reload, not
575 const MachineMemOperand *MMO;
576 if (TM.getSubtargetImpl()->getInstrInfo()->isLoadFromStackSlotPostFE(&MI,
578 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
579 MMO = *MI.memoperands_begin();
580 CommentOS << MMO->getSize() << "-byte Reload\n";
582 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasLoadFromStackSlot(
584 if (FrameInfo->isSpillSlotObjectIndex(FI))
585 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
586 } else if (TM.getSubtargetImpl()->getInstrInfo()->isStoreToStackSlotPostFE(
588 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
589 MMO = *MI.memoperands_begin();
590 CommentOS << MMO->getSize() << "-byte Spill\n";
592 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasStoreToStackSlot(
594 if (FrameInfo->isSpillSlotObjectIndex(FI))
595 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
598 // Check for spill-induced copies
599 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
600 CommentOS << " Reload Reuse\n";
603 /// emitImplicitDef - This method emits the specified machine instruction
604 /// that is an implicit def.
605 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
606 unsigned RegNo = MI->getOperand(0).getReg();
607 OutStreamer.AddComment(
608 Twine("implicit-def: ") +
609 TM.getSubtargetImpl()->getRegisterInfo()->getName(RegNo));
610 OutStreamer.AddBlankLine();
613 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
614 std::string Str = "kill:";
615 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
616 const MachineOperand &Op = MI->getOperand(i);
617 assert(Op.isReg() && "KILL instruction must have only register operands");
619 Str += AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Op.getReg());
620 Str += (Op.isDef() ? "<def>" : "<kill>");
622 AP.OutStreamer.AddComment(Str);
623 AP.OutStreamer.AddBlankLine();
626 /// emitDebugValueComment - This method handles the target-independent form
627 /// of DBG_VALUE, returning true if it was able to do so. A false return
628 /// means the target will need to handle MI in EmitInstruction.
629 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
630 // This code handles only the 4-operand target-independent form.
631 if (MI->getNumOperands() != 4)
634 SmallString<128> Str;
635 raw_svector_ostream OS(Str);
636 OS << "DEBUG_VALUE: ";
638 DIVariable V = MI->getDebugVariable();
639 if (V.getContext().isSubprogram()) {
640 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
646 DIExpression Expr = MI->getDebugExpression();
647 if (Expr.isVariablePiece())
648 OS << " [piece offset=" << Expr.getPieceOffset()
649 << " size=" << Expr.getPieceSize() << "]";
652 // The second operand is only an offset if it's an immediate.
653 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
654 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
656 // Register or immediate value. Register 0 means undef.
657 if (MI->getOperand(0).isFPImm()) {
658 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
659 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
660 OS << (double)APF.convertToFloat();
661 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
662 OS << APF.convertToDouble();
664 // There is no good way to print long double. Convert a copy to
665 // double. Ah well, it's only a comment.
667 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
669 OS << "(long double) " << APF.convertToDouble();
671 } else if (MI->getOperand(0).isImm()) {
672 OS << MI->getOperand(0).getImm();
673 } else if (MI->getOperand(0).isCImm()) {
674 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
677 if (MI->getOperand(0).isReg()) {
678 Reg = MI->getOperand(0).getReg();
680 assert(MI->getOperand(0).isFI() && "Unknown operand type");
681 const TargetFrameLowering *TFI =
682 AP.TM.getSubtargetImpl()->getFrameLowering();
683 Offset += TFI->getFrameIndexReference(*AP.MF,
684 MI->getOperand(0).getIndex(), Reg);
688 // Suppress offset, it is not meaningful here.
690 // NOTE: Want this comment at start of line, don't emit with AddComment.
691 AP.OutStreamer.emitRawComment(OS.str());
696 OS << AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Reg);
700 OS << '+' << Offset << ']';
702 // NOTE: Want this comment at start of line, don't emit with AddComment.
703 AP.OutStreamer.emitRawComment(OS.str());
707 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
708 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
709 MF->getFunction()->needsUnwindTableEntry())
712 if (MMI->hasDebugInfo())
718 bool AsmPrinter::needsSEHMoves() {
719 return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
722 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
723 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
724 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
725 ExceptionHandlingType != ExceptionHandling::ARM)
728 if (needsCFIMoves() == CFI_M_None)
731 const MachineModuleInfo &MMI = MF->getMMI();
732 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
733 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
734 const MCCFIInstruction &CFI = Instrs[CFIIndex];
735 emitCFIInstruction(CFI);
738 /// EmitFunctionBody - This method emits the body and trailer for a
740 void AsmPrinter::EmitFunctionBody() {
741 // Emit target-specific gunk before the function body.
742 EmitFunctionBodyStart();
744 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
746 // Print out code for the function.
747 bool HasAnyRealCode = false;
748 for (auto &MBB : *MF) {
749 // Print a label for the basic block.
750 EmitBasicBlockStart(MBB);
751 for (auto &MI : MBB) {
753 // Print the assembly for the instruction.
754 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
755 !MI.isDebugValue()) {
756 HasAnyRealCode = true;
760 if (ShouldPrintDebugScopes) {
761 for (const HandlerInfo &HI : Handlers) {
762 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
763 TimePassesIsEnabled);
764 HI.Handler->beginInstruction(&MI);
769 emitComments(MI, OutStreamer.GetCommentOS());
771 switch (MI.getOpcode()) {
772 case TargetOpcode::CFI_INSTRUCTION:
773 emitCFIInstruction(MI);
776 case TargetOpcode::EH_LABEL:
777 case TargetOpcode::GC_LABEL:
778 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
780 case TargetOpcode::INLINEASM:
783 case TargetOpcode::DBG_VALUE:
785 if (!emitDebugValueComment(&MI, *this))
786 EmitInstruction(&MI);
789 case TargetOpcode::IMPLICIT_DEF:
790 if (isVerbose()) emitImplicitDef(&MI);
792 case TargetOpcode::KILL:
793 if (isVerbose()) emitKill(&MI, *this);
796 EmitInstruction(&MI);
800 if (ShouldPrintDebugScopes) {
801 for (const HandlerInfo &HI : Handlers) {
802 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
803 TimePassesIsEnabled);
804 HI.Handler->endInstruction();
809 EmitBasicBlockEnd(MBB);
812 // If the function is empty and the object file uses .subsections_via_symbols,
813 // then we need to emit *something* to the function body to prevent the
814 // labels from collapsing together. Just emit a noop.
815 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
817 TM.getSubtargetImpl()->getInstrInfo()->getNoopForMachoTarget(Noop);
818 OutStreamer.AddComment("avoids zero-length function");
820 // Targets can opt-out of emitting the noop here by leaving the opcode
822 if (Noop.getOpcode())
823 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
826 const Function *F = MF->getFunction();
827 for (const auto &BB : *F) {
828 if (!BB.hasAddressTaken())
830 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
831 if (Sym->isDefined())
833 OutStreamer.AddComment("Address of block that was removed by CodeGen");
834 OutStreamer.EmitLabel(Sym);
837 // Emit target-specific gunk after the function body.
838 EmitFunctionBodyEnd();
840 // If the target wants a .size directive for the size of the function, emit
842 if (MAI->hasDotTypeDotSizeDirective()) {
843 // Create a symbol for the end of function, so we can get the size as
844 // difference between the function label and the temp label.
845 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
846 OutStreamer.EmitLabel(FnEndLabel);
848 const MCExpr *SizeExp =
849 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
850 MCSymbolRefExpr::Create(CurrentFnSymForSize,
853 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
856 // Emit post-function debug and/or EH information.
857 for (const HandlerInfo &HI : Handlers) {
858 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
859 HI.Handler->endFunction(MF);
863 // Print out jump tables referenced by the function.
866 OutStreamer.AddBlankLine();
869 bool AsmPrinter::doFinalization(Module &M) {
870 // Emit global variables.
871 for (const auto &G : M.globals())
872 EmitGlobalVariable(&G);
874 // Emit visibility info for declarations
875 for (const Function &F : M) {
876 if (!F.isDeclaration())
878 GlobalValue::VisibilityTypes V = F.getVisibility();
879 if (V == GlobalValue::DefaultVisibility)
882 MCSymbol *Name = getSymbol(&F);
883 EmitVisibility(Name, V, false);
886 // Get information about jump-instruction tables to print.
887 JumpInstrTableInfo *JITI = getAnalysisIfAvailable<JumpInstrTableInfo>();
889 if (JITI && !JITI->getTables().empty()) {
890 unsigned Arch = Triple(getTargetTriple()).getArch();
891 bool IsThumb = (Arch == Triple::thumb || Arch == Triple::thumbeb);
893 TM.getSubtargetImpl()->getInstrInfo()->getTrap(TrapInst);
894 unsigned LogAlignment = llvm::Log2_64(JITI->entryByteAlignment());
896 // Emit the right section for these functions.
897 OutStreamer.SwitchSection(OutContext.getObjectFileInfo()->getTextSection());
898 for (const auto &KV : JITI->getTables()) {
900 for (const auto &FunPair : KV.second) {
901 // Emit the function labels to make this be a function entry point.
903 OutContext.GetOrCreateSymbol(FunPair.second->getName());
904 EmitAlignment(LogAlignment);
906 OutStreamer.EmitThumbFunc(FunSym);
907 if (MAI->hasDotTypeDotSizeDirective())
908 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_ELF_TypeFunction);
909 OutStreamer.EmitLabel(FunSym);
911 // Emit the jump instruction to transfer control to the original
914 MCSymbol *TargetSymbol =
915 OutContext.GetOrCreateSymbol(FunPair.first->getName());
916 const MCSymbolRefExpr *TargetSymRef =
917 MCSymbolRefExpr::Create(TargetSymbol, MCSymbolRefExpr::VK_PLT,
919 TM.getSubtargetImpl()->getInstrInfo()->getUnconditionalBranch(
920 JumpToFun, TargetSymRef);
921 OutStreamer.EmitInstruction(JumpToFun, getSubtargetInfo());
925 // Emit enough padding instructions to fill up to the next power of two.
926 uint64_t Remaining = NextPowerOf2(Count) - Count;
927 for (uint64_t C = 0; C < Remaining; ++C) {
928 EmitAlignment(LogAlignment);
929 OutStreamer.EmitInstruction(TrapInst, getSubtargetInfo());
935 // Emit module flags.
936 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
937 M.getModuleFlagsMetadata(ModuleFlags);
938 if (!ModuleFlags.empty())
939 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
941 // Make sure we wrote out everything we need.
944 // Finalize debug and EH information.
945 for (const HandlerInfo &HI : Handlers) {
946 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
947 TimePassesIsEnabled);
948 HI.Handler->endModule();
954 // If the target wants to know about weak references, print them all.
955 if (MAI->getWeakRefDirective()) {
956 // FIXME: This is not lazy, it would be nice to only print weak references
957 // to stuff that is actually used. Note that doing so would require targets
958 // to notice uses in operands (due to constant exprs etc). This should
959 // happen with the MC stuff eventually.
961 // Print out module-level global variables here.
962 for (const auto &G : M.globals()) {
963 if (!G.hasExternalWeakLinkage())
965 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
968 for (const auto &F : M) {
969 if (!F.hasExternalWeakLinkage())
971 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
975 OutStreamer.AddBlankLine();
976 for (const auto &Alias : M.aliases()) {
977 MCSymbol *Name = getSymbol(&Alias);
979 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
980 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
981 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
982 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
984 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
986 EmitVisibility(Name, Alias.getVisibility());
988 // Emit the directives as assignments aka .set:
989 OutStreamer.EmitAssignment(Name, lowerConstant(Alias.getAliasee()));
992 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
993 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
994 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
995 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
996 MP->finishAssembly(M, *MI, *this);
998 // Emit llvm.ident metadata in an '.ident' directive.
1001 // If we don't have any trampolines, then we don't require stack memory
1002 // to be executable. Some targets have a directive to declare this.
1003 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1004 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1005 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1006 OutStreamer.SwitchSection(S);
1008 // Allow the target to emit any magic that it wants at the end of the file,
1009 // after everything else has gone out.
1010 EmitEndOfAsmFile(M);
1012 delete Mang; Mang = nullptr;
1015 OutStreamer.Finish();
1016 OutStreamer.reset();
1021 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1023 // Get the function symbol.
1024 CurrentFnSym = getSymbol(MF.getFunction());
1025 CurrentFnSymForSize = CurrentFnSym;
1028 LI = &getAnalysis<MachineLoopInfo>();
1032 // SectionCPs - Keep track the alignment, constpool entries per Section.
1036 SmallVector<unsigned, 4> CPEs;
1037 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1041 /// EmitConstantPool - Print to the current output stream assembly
1042 /// representations of the constants in the constant pool MCP. This is
1043 /// used to print out constants which have been "spilled to memory" by
1044 /// the code generator.
1046 void AsmPrinter::EmitConstantPool() {
1047 const MachineConstantPool *MCP = MF->getConstantPool();
1048 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1049 if (CP.empty()) return;
1051 // Calculate sections for constant pool entries. We collect entries to go into
1052 // the same section together to reduce amount of section switch statements.
1053 SmallVector<SectionCPs, 4> CPSections;
1054 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1055 const MachineConstantPoolEntry &CPE = CP[i];
1056 unsigned Align = CPE.getAlignment();
1059 CPE.getSectionKind(TM.getSubtargetImpl()->getDataLayout());
1061 const Constant *C = nullptr;
1062 if (!CPE.isMachineConstantPoolEntry())
1063 C = CPE.Val.ConstVal;
1065 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind, C);
1067 // The number of sections are small, just do a linear search from the
1068 // last section to the first.
1070 unsigned SecIdx = CPSections.size();
1071 while (SecIdx != 0) {
1072 if (CPSections[--SecIdx].S == S) {
1078 SecIdx = CPSections.size();
1079 CPSections.push_back(SectionCPs(S, Align));
1082 if (Align > CPSections[SecIdx].Alignment)
1083 CPSections[SecIdx].Alignment = Align;
1084 CPSections[SecIdx].CPEs.push_back(i);
1087 // Now print stuff into the calculated sections.
1088 const MCSection *CurSection = nullptr;
1089 unsigned Offset = 0;
1090 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1091 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1092 unsigned CPI = CPSections[i].CPEs[j];
1093 MCSymbol *Sym = GetCPISymbol(CPI);
1094 if (!Sym->isUndefined())
1097 if (CurSection != CPSections[i].S) {
1098 OutStreamer.SwitchSection(CPSections[i].S);
1099 EmitAlignment(Log2_32(CPSections[i].Alignment));
1100 CurSection = CPSections[i].S;
1104 MachineConstantPoolEntry CPE = CP[CPI];
1106 // Emit inter-object padding for alignment.
1107 unsigned AlignMask = CPE.getAlignment() - 1;
1108 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1109 OutStreamer.EmitZeros(NewOffset - Offset);
1111 Type *Ty = CPE.getType();
1112 Offset = NewOffset +
1113 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(Ty);
1115 OutStreamer.EmitLabel(Sym);
1116 if (CPE.isMachineConstantPoolEntry())
1117 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1119 EmitGlobalConstant(CPE.Val.ConstVal);
1124 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1125 /// by the current function to the current output stream.
1127 void AsmPrinter::EmitJumpTableInfo() {
1128 const DataLayout *DL = MF->getSubtarget().getDataLayout();
1129 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1131 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1132 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1133 if (JT.empty()) return;
1135 // Pick the directive to use to print the jump table entries, and switch to
1136 // the appropriate section.
1137 const Function *F = MF->getFunction();
1138 bool JTInDiffSection = false;
1139 if (// In PIC mode, we need to emit the jump table to the same section as the
1140 // function body itself, otherwise the label differences won't make sense.
1141 // FIXME: Need a better predicate for this: what about custom entries?
1142 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1143 // We should also do if the section name is NULL or function is declared
1144 // in discardable section
1145 // FIXME: this isn't the right predicate, should be based on the MCSection
1146 // for the function.
1147 F->isWeakForLinker()) {
1148 OutStreamer.SwitchSection(
1149 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1151 // Otherwise, drop it in the readonly section.
1152 const MCSection *ReadOnlySection =
1153 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
1155 OutStreamer.SwitchSection(ReadOnlySection);
1156 JTInDiffSection = true;
1159 EmitAlignment(Log2_32(
1160 MJTI->getEntryAlignment(*TM.getSubtargetImpl()->getDataLayout())));
1162 // Jump tables in code sections are marked with a data_region directive
1163 // where that's supported.
1164 if (!JTInDiffSection)
1165 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1167 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1168 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1170 // If this jump table was deleted, ignore it.
1171 if (JTBBs.empty()) continue;
1173 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1174 /// emit a .set directive for each unique entry.
1175 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1176 MAI->doesSetDirectiveSuppressesReloc()) {
1177 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1178 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1179 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1180 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1181 const MachineBasicBlock *MBB = JTBBs[ii];
1182 if (!EmittedSets.insert(MBB).second)
1185 // .set LJTSet, LBB32-base
1187 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1188 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1189 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1193 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1194 // before each jump table. The first label is never referenced, but tells
1195 // the assembler and linker the extents of the jump table object. The
1196 // second label is actually referenced by the code.
1197 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1198 // FIXME: This doesn't have to have any specific name, just any randomly
1199 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1200 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1202 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1204 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1205 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1207 if (!JTInDiffSection)
1208 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1211 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1213 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1214 const MachineBasicBlock *MBB,
1215 unsigned UID) const {
1216 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1217 const MCExpr *Value = nullptr;
1218 switch (MJTI->getEntryKind()) {
1219 case MachineJumpTableInfo::EK_Inline:
1220 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1221 case MachineJumpTableInfo::EK_Custom32:
1223 TM.getSubtargetImpl()->getTargetLowering()->LowerCustomJumpTableEntry(
1224 MJTI, MBB, UID, OutContext);
1226 case MachineJumpTableInfo::EK_BlockAddress:
1227 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1229 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1231 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1232 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1233 // with a relocation as gp-relative, e.g.:
1235 MCSymbol *MBBSym = MBB->getSymbol();
1236 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1240 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1241 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1242 // with a relocation as gp-relative, e.g.:
1244 MCSymbol *MBBSym = MBB->getSymbol();
1245 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1249 case MachineJumpTableInfo::EK_LabelDifference32: {
1250 // Each entry is the address of the block minus the address of the jump
1251 // table. This is used for PIC jump tables where gprel32 is not supported.
1253 // .word LBB123 - LJTI1_2
1254 // If the .set directive avoids relocations, this is emitted as:
1255 // .set L4_5_set_123, LBB123 - LJTI1_2
1256 // .word L4_5_set_123
1257 if (MAI->doesSetDirectiveSuppressesReloc()) {
1258 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1262 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1263 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1264 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1265 Value = MCBinaryExpr::CreateSub(Value, Base, OutContext);
1270 assert(Value && "Unknown entry kind!");
1272 unsigned EntrySize =
1273 MJTI->getEntrySize(*TM.getSubtargetImpl()->getDataLayout());
1274 OutStreamer.EmitValue(Value, EntrySize);
1278 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1279 /// special global used by LLVM. If so, emit it and return true, otherwise
1280 /// do nothing and return false.
1281 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1282 if (GV->getName() == "llvm.used") {
1283 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1284 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1288 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1289 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1290 GV->hasAvailableExternallyLinkage())
1293 if (!GV->hasAppendingLinkage()) return false;
1295 assert(GV->hasInitializer() && "Not a special LLVM global!");
1297 if (GV->getName() == "llvm.global_ctors") {
1298 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1300 if (TM.getRelocationModel() == Reloc::Static &&
1301 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1302 StringRef Sym(".constructors_used");
1303 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1309 if (GV->getName() == "llvm.global_dtors") {
1310 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1312 if (TM.getRelocationModel() == Reloc::Static &&
1313 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1314 StringRef Sym(".destructors_used");
1315 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1324 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1325 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1326 /// is true, as being used with this directive.
1327 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1328 // Should be an array of 'i8*'.
1329 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1330 const GlobalValue *GV =
1331 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1333 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1339 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1341 llvm::Constant *Func;
1342 llvm::GlobalValue *ComdatKey;
1346 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1348 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1349 // Should be an array of '{ int, void ()* }' structs. The first value is the
1351 if (!isa<ConstantArray>(List)) return;
1353 // Sanity check the structors list.
1354 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1355 if (!InitList) return; // Not an array!
1356 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1357 // FIXME: Only allow the 3-field form in LLVM 4.0.
1358 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1359 return; // Not an array of two or three elements!
1360 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1361 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1362 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1363 return; // Not (int, ptr, ptr).
1365 // Gather the structors in a form that's convenient for sorting by priority.
1366 SmallVector<Structor, 8> Structors;
1367 for (Value *O : InitList->operands()) {
1368 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1369 if (!CS) continue; // Malformed.
1370 if (CS->getOperand(1)->isNullValue())
1371 break; // Found a null terminator, skip the rest.
1372 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1373 if (!Priority) continue; // Malformed.
1374 Structors.push_back(Structor());
1375 Structor &S = Structors.back();
1376 S.Priority = Priority->getLimitedValue(65535);
1377 S.Func = CS->getOperand(1);
1378 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1379 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1382 // Emit the function pointers in the target-specific order
1383 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
1384 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1385 std::stable_sort(Structors.begin(), Structors.end(),
1386 [](const Structor &L,
1387 const Structor &R) { return L.Priority < R.Priority; });
1388 for (Structor &S : Structors) {
1389 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1390 const MCSymbol *KeySym = nullptr;
1391 if (GlobalValue *GV = S.ComdatKey) {
1392 if (GV->hasAvailableExternallyLinkage())
1393 // If the associated variable is available_externally, some other TU
1394 // will provide its dynamic initializer.
1397 KeySym = getSymbol(GV);
1399 const MCSection *OutputSection =
1400 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1401 : Obj.getStaticDtorSection(S.Priority, KeySym));
1402 OutStreamer.SwitchSection(OutputSection);
1403 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1404 EmitAlignment(Align);
1405 EmitXXStructor(S.Func);
1409 void AsmPrinter::EmitModuleIdents(Module &M) {
1410 if (!MAI->hasIdentDirective())
1413 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1414 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1415 const MDNode *N = NMD->getOperand(i);
1416 assert(N->getNumOperands() == 1 &&
1417 "llvm.ident metadata entry can have only one operand");
1418 const MDString *S = cast<MDString>(N->getOperand(0));
1419 OutStreamer.EmitIdent(S->getString());
1424 //===--------------------------------------------------------------------===//
1425 // Emission and print routines
1428 /// EmitInt8 - Emit a byte directive and value.
1430 void AsmPrinter::EmitInt8(int Value) const {
1431 OutStreamer.EmitIntValue(Value, 1);
1434 /// EmitInt16 - Emit a short directive and value.
1436 void AsmPrinter::EmitInt16(int Value) const {
1437 OutStreamer.EmitIntValue(Value, 2);
1440 /// EmitInt32 - Emit a long directive and value.
1442 void AsmPrinter::EmitInt32(int Value) const {
1443 OutStreamer.EmitIntValue(Value, 4);
1446 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1447 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1448 /// .set if it avoids relocations.
1449 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1450 unsigned Size) const {
1451 // Get the Hi-Lo expression.
1452 const MCExpr *Diff =
1453 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1454 MCSymbolRefExpr::Create(Lo, OutContext),
1457 if (!MAI->doesSetDirectiveSuppressesReloc()) {
1458 OutStreamer.EmitValue(Diff, Size);
1462 // Otherwise, emit with .set (aka assignment).
1463 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1464 OutStreamer.EmitAssignment(SetLabel, Diff);
1465 OutStreamer.EmitSymbolValue(SetLabel, Size);
1468 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1469 /// where the size in bytes of the directive is specified by Size and Label
1470 /// specifies the label. This implicitly uses .set if it is available.
1471 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1473 bool IsSectionRelative) const {
1474 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1475 OutStreamer.EmitCOFFSecRel32(Label);
1479 // Emit Label+Offset (or just Label if Offset is zero)
1480 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1482 Expr = MCBinaryExpr::CreateAdd(
1483 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1485 OutStreamer.EmitValue(Expr, Size);
1488 //===----------------------------------------------------------------------===//
1490 // EmitAlignment - Emit an alignment directive to the specified power of
1491 // two boundary. For example, if you pass in 3 here, you will get an 8
1492 // byte alignment. If a global value is specified, and if that global has
1493 // an explicit alignment requested, it will override the alignment request
1494 // if required for correctness.
1496 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1498 NumBits = getGVAlignmentLog2(GV, *TM.getSubtargetImpl()->getDataLayout(),
1501 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1504 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
1505 "undefined behavior");
1506 if (getCurrentSection()->getKind().isText())
1507 OutStreamer.EmitCodeAlignment(1u << NumBits);
1509 OutStreamer.EmitValueToAlignment(1u << NumBits);
1512 //===----------------------------------------------------------------------===//
1513 // Constant emission.
1514 //===----------------------------------------------------------------------===//
1516 const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1517 MCContext &Ctx = OutContext;
1519 if (CV->isNullValue() || isa<UndefValue>(CV))
1520 return MCConstantExpr::Create(0, Ctx);
1522 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1523 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1525 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1526 return MCSymbolRefExpr::Create(getSymbol(GV), Ctx);
1528 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1529 return MCSymbolRefExpr::Create(GetBlockAddressSymbol(BA), Ctx);
1531 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1533 llvm_unreachable("Unknown constant value to lower!");
1536 if (const MCExpr *RelocExpr
1537 = getObjFileLowering().getExecutableRelativeSymbol(CE, *Mang, TM))
1540 switch (CE->getOpcode()) {
1542 // If the code isn't optimized, there may be outstanding folding
1543 // opportunities. Attempt to fold the expression using DataLayout as a
1544 // last resort before giving up.
1545 if (Constant *C = ConstantFoldConstantExpression(
1546 CE, TM.getSubtargetImpl()->getDataLayout()))
1548 return lowerConstant(C);
1550 // Otherwise report the problem to the user.
1553 raw_string_ostream OS(S);
1554 OS << "Unsupported expression in static initializer: ";
1555 CE->printAsOperand(OS, /*PrintType=*/false,
1556 !MF ? nullptr : MF->getFunction()->getParent());
1557 report_fatal_error(OS.str());
1559 case Instruction::GetElementPtr: {
1560 const DataLayout &DL = *TM.getSubtargetImpl()->getDataLayout();
1561 // Generate a symbolic expression for the byte address
1562 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1563 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1565 const MCExpr *Base = lowerConstant(CE->getOperand(0));
1569 int64_t Offset = OffsetAI.getSExtValue();
1570 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1574 case Instruction::Trunc:
1575 // We emit the value and depend on the assembler to truncate the generated
1576 // expression properly. This is important for differences between
1577 // blockaddress labels. Since the two labels are in the same function, it
1578 // is reasonable to treat their delta as a 32-bit value.
1580 case Instruction::BitCast:
1581 return lowerConstant(CE->getOperand(0));
1583 case Instruction::IntToPtr: {
1584 const DataLayout &DL = *TM.getSubtargetImpl()->getDataLayout();
1585 // Handle casts to pointers by changing them into casts to the appropriate
1586 // integer type. This promotes constant folding and simplifies this code.
1587 Constant *Op = CE->getOperand(0);
1588 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1590 return lowerConstant(Op);
1593 case Instruction::PtrToInt: {
1594 const DataLayout &DL = *TM.getSubtargetImpl()->getDataLayout();
1595 // Support only foldable casts to/from pointers that can be eliminated by
1596 // changing the pointer to the appropriately sized integer type.
1597 Constant *Op = CE->getOperand(0);
1598 Type *Ty = CE->getType();
1600 const MCExpr *OpExpr = lowerConstant(Op);
1602 // We can emit the pointer value into this slot if the slot is an
1603 // integer slot equal to the size of the pointer.
1604 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1607 // Otherwise the pointer is smaller than the resultant integer, mask off
1608 // the high bits so we are sure to get a proper truncation if the input is
1610 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1611 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1612 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1615 // The MC library also has a right-shift operator, but it isn't consistently
1616 // signed or unsigned between different targets.
1617 case Instruction::Add:
1618 case Instruction::Sub:
1619 case Instruction::Mul:
1620 case Instruction::SDiv:
1621 case Instruction::SRem:
1622 case Instruction::Shl:
1623 case Instruction::And:
1624 case Instruction::Or:
1625 case Instruction::Xor: {
1626 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
1627 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
1628 switch (CE->getOpcode()) {
1629 default: llvm_unreachable("Unknown binary operator constant cast expr");
1630 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1631 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1632 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1633 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1634 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1635 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1636 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1637 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1638 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1644 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1646 /// isRepeatedByteSequence - Determine whether the given value is
1647 /// composed of a repeated sequence of identical bytes and return the
1648 /// byte value. If it is not a repeated sequence, return -1.
1649 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1650 StringRef Data = V->getRawDataValues();
1651 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1653 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1654 if (Data[i] != C) return -1;
1655 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1659 /// isRepeatedByteSequence - Determine whether the given value is
1660 /// composed of a repeated sequence of identical bytes and return the
1661 /// byte value. If it is not a repeated sequence, return -1.
1662 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1664 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1665 if (CI->getBitWidth() > 64) return -1;
1668 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(V->getType());
1669 uint64_t Value = CI->getZExtValue();
1671 // Make sure the constant is at least 8 bits long and has a power
1672 // of 2 bit width. This guarantees the constant bit width is
1673 // always a multiple of 8 bits, avoiding issues with padding out
1674 // to Size and other such corner cases.
1675 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1677 uint8_t Byte = static_cast<uint8_t>(Value);
1679 for (unsigned i = 1; i < Size; ++i) {
1681 if (static_cast<uint8_t>(Value) != Byte) return -1;
1685 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1686 // Make sure all array elements are sequences of the same repeated
1688 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1689 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1690 if (Byte == -1) return -1;
1692 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1693 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1694 if (ThisByte == -1) return -1;
1695 if (Byte != ThisByte) return -1;
1700 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1701 return isRepeatedByteSequence(CDS);
1706 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1709 // See if we can aggregate this into a .fill, if so, emit it as such.
1710 int Value = isRepeatedByteSequence(CDS, AP.TM);
1713 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1715 // Don't emit a 1-byte object as a .fill.
1717 return AP.OutStreamer.EmitFill(Bytes, Value);
1720 // If this can be emitted with .ascii/.asciz, emit it as such.
1721 if (CDS->isString())
1722 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1724 // Otherwise, emit the values in successive locations.
1725 unsigned ElementByteSize = CDS->getElementByteSize();
1726 if (isa<IntegerType>(CDS->getElementType())) {
1727 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1729 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1730 CDS->getElementAsInteger(i));
1731 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1734 } else if (ElementByteSize == 4) {
1735 // FP Constants are printed as integer constants to avoid losing
1737 assert(CDS->getElementType()->isFloatTy());
1738 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1744 F = CDS->getElementAsFloat(i);
1746 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1747 AP.OutStreamer.EmitIntValue(I, 4);
1750 assert(CDS->getElementType()->isDoubleTy());
1751 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1757 F = CDS->getElementAsDouble(i);
1759 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1760 AP.OutStreamer.EmitIntValue(I, 8);
1764 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1765 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1766 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1767 CDS->getNumElements();
1768 if (unsigned Padding = Size - EmittedSize)
1769 AP.OutStreamer.EmitZeros(Padding);
1773 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1774 // See if we can aggregate some values. Make sure it can be
1775 // represented as a series of bytes of the constant value.
1776 int Value = isRepeatedByteSequence(CA, AP.TM);
1780 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1782 AP.OutStreamer.EmitFill(Bytes, Value);
1785 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1786 emitGlobalConstantImpl(CA->getOperand(i), AP);
1790 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1791 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1792 emitGlobalConstantImpl(CV->getOperand(i), AP);
1794 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1795 unsigned Size = DL.getTypeAllocSize(CV->getType());
1796 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1797 CV->getType()->getNumElements();
1798 if (unsigned Padding = Size - EmittedSize)
1799 AP.OutStreamer.EmitZeros(Padding);
1802 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1803 // Print the fields in successive locations. Pad to align if needed!
1804 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1805 unsigned Size = DL->getTypeAllocSize(CS->getType());
1806 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1807 uint64_t SizeSoFar = 0;
1808 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1809 const Constant *Field = CS->getOperand(i);
1811 // Check if padding is needed and insert one or more 0s.
1812 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1813 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1814 - Layout->getElementOffset(i)) - FieldSize;
1815 SizeSoFar += FieldSize + PadSize;
1817 // Now print the actual field value.
1818 emitGlobalConstantImpl(Field, AP);
1820 // Insert padding - this may include padding to increase the size of the
1821 // current field up to the ABI size (if the struct is not packed) as well
1822 // as padding to ensure that the next field starts at the right offset.
1823 AP.OutStreamer.EmitZeros(PadSize);
1825 assert(SizeSoFar == Layout->getSizeInBytes() &&
1826 "Layout of constant struct may be incorrect!");
1829 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1830 APInt API = CFP->getValueAPF().bitcastToAPInt();
1832 // First print a comment with what we think the original floating-point value
1833 // should have been.
1834 if (AP.isVerbose()) {
1835 SmallString<8> StrVal;
1836 CFP->getValueAPF().toString(StrVal);
1839 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1841 AP.OutStreamer.GetCommentOS() << "Printing <null> Type";
1842 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1845 // Now iterate through the APInt chunks, emitting them in endian-correct
1846 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1848 unsigned NumBytes = API.getBitWidth() / 8;
1849 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1850 const uint64_t *p = API.getRawData();
1852 // PPC's long double has odd notions of endianness compared to how LLVM
1853 // handles it: p[0] goes first for *big* endian on PPC.
1854 if (AP.TM.getSubtargetImpl()->getDataLayout()->isBigEndian() &&
1855 !CFP->getType()->isPPC_FP128Ty()) {
1856 int Chunk = API.getNumWords() - 1;
1859 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1861 for (; Chunk >= 0; --Chunk)
1862 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1865 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1866 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1869 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1872 // Emit the tail padding for the long double.
1873 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1874 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1875 DL.getTypeStoreSize(CFP->getType()));
1878 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1879 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1880 unsigned BitWidth = CI->getBitWidth();
1882 // Copy the value as we may massage the layout for constants whose bit width
1883 // is not a multiple of 64-bits.
1884 APInt Realigned(CI->getValue());
1885 uint64_t ExtraBits = 0;
1886 unsigned ExtraBitsSize = BitWidth & 63;
1888 if (ExtraBitsSize) {
1889 // The bit width of the data is not a multiple of 64-bits.
1890 // The extra bits are expected to be at the end of the chunk of the memory.
1892 // * Nothing to be done, just record the extra bits to emit.
1894 // * Record the extra bits to emit.
1895 // * Realign the raw data to emit the chunks of 64-bits.
1896 if (DL->isBigEndian()) {
1897 // Basically the structure of the raw data is a chunk of 64-bits cells:
1898 // 0 1 BitWidth / 64
1899 // [chunk1][chunk2] ... [chunkN].
1900 // The most significant chunk is chunkN and it should be emitted first.
1901 // However, due to the alignment issue chunkN contains useless bits.
1902 // Realign the chunks so that they contain only useless information:
1903 // ExtraBits 0 1 (BitWidth / 64) - 1
1904 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1905 ExtraBits = Realigned.getRawData()[0] &
1906 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1907 Realigned = Realigned.lshr(ExtraBitsSize);
1909 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1912 // We don't expect assemblers to support integer data directives
1913 // for more than 64 bits, so we emit the data in at most 64-bit
1914 // quantities at a time.
1915 const uint64_t *RawData = Realigned.getRawData();
1916 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1917 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1918 AP.OutStreamer.EmitIntValue(Val, 8);
1921 if (ExtraBitsSize) {
1922 // Emit the extra bits after the 64-bits chunks.
1924 // Emit a directive that fills the expected size.
1925 uint64_t Size = AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1927 Size -= (BitWidth / 64) * 8;
1928 assert(Size && Size * 8 >= ExtraBitsSize &&
1929 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1930 == ExtraBits && "Directive too small for extra bits.");
1931 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1935 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1936 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1937 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1938 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1939 return AP.OutStreamer.EmitZeros(Size);
1941 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1948 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1949 CI->getZExtValue());
1950 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1953 emitGlobalConstantLargeInt(CI, AP);
1958 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1959 return emitGlobalConstantFP(CFP, AP);
1961 if (isa<ConstantPointerNull>(CV)) {
1962 AP.OutStreamer.EmitIntValue(0, Size);
1966 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1967 return emitGlobalConstantDataSequential(CDS, AP);
1969 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1970 return emitGlobalConstantArray(CVA, AP);
1972 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1973 return emitGlobalConstantStruct(CVS, AP);
1975 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
1976 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
1978 if (CE->getOpcode() == Instruction::BitCast)
1979 return emitGlobalConstantImpl(CE->getOperand(0), AP);
1982 // If the constant expression's size is greater than 64-bits, then we have
1983 // to emit the value in chunks. Try to constant fold the value and emit it
1985 Constant *New = ConstantFoldConstantExpression(CE, DL);
1986 if (New && New != CE)
1987 return emitGlobalConstantImpl(New, AP);
1991 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1992 return emitGlobalConstantVector(V, AP);
1994 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1995 // thread the streamer with EmitValue.
1996 AP.OutStreamer.EmitValue(AP.lowerConstant(CV), Size);
1999 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2000 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2002 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(CV->getType());
2004 emitGlobalConstantImpl(CV, *this);
2005 else if (MAI->hasSubsectionsViaSymbols()) {
2006 // If the global has zero size, emit a single byte so that two labels don't
2007 // look like they are at the same location.
2008 OutStreamer.EmitIntValue(0, 1);
2012 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2013 // Target doesn't support this yet!
2014 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2017 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2019 OS << '+' << Offset;
2020 else if (Offset < 0)
2024 //===----------------------------------------------------------------------===//
2025 // Symbol Lowering Routines.
2026 //===----------------------------------------------------------------------===//
2028 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2029 /// temporary label with the specified stem and unique ID.
2030 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const {
2031 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2032 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2036 /// GetTempSymbol - Return an assembler temporary label with the specified
2038 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const {
2039 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2040 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2045 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2046 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2049 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2050 return MMI->getAddrLabelSymbol(BB);
2053 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2054 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2055 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2056 return OutContext.GetOrCreateSymbol
2057 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2058 + "_" + Twine(CPID));
2061 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2062 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2063 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2066 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2067 /// FIXME: privatize to AsmPrinter.
2068 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2069 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2070 return OutContext.GetOrCreateSymbol
2071 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2072 Twine(UID) + "_set_" + Twine(MBBID));
2075 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2076 StringRef Suffix) const {
2077 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2081 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2083 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2084 SmallString<60> NameStr;
2085 Mang->getNameWithPrefix(NameStr, Sym);
2086 return OutContext.GetOrCreateSymbol(NameStr.str());
2091 /// PrintParentLoopComment - Print comments about parent loops of this one.
2092 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2093 unsigned FunctionNumber) {
2095 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2096 OS.indent(Loop->getLoopDepth()*2)
2097 << "Parent Loop BB" << FunctionNumber << "_"
2098 << Loop->getHeader()->getNumber()
2099 << " Depth=" << Loop->getLoopDepth() << '\n';
2103 /// PrintChildLoopComment - Print comments about child loops within
2104 /// the loop for this basic block, with nesting.
2105 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2106 unsigned FunctionNumber) {
2107 // Add child loop information
2108 for (const MachineLoop *CL : *Loop) {
2109 OS.indent(CL->getLoopDepth()*2)
2110 << "Child Loop BB" << FunctionNumber << "_"
2111 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2113 PrintChildLoopComment(OS, CL, FunctionNumber);
2117 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2118 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2119 const MachineLoopInfo *LI,
2120 const AsmPrinter &AP) {
2121 // Add loop depth information
2122 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2125 MachineBasicBlock *Header = Loop->getHeader();
2126 assert(Header && "No header for loop");
2128 // If this block is not a loop header, just print out what is the loop header
2130 if (Header != &MBB) {
2131 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2132 Twine(AP.getFunctionNumber())+"_" +
2133 Twine(Loop->getHeader()->getNumber())+
2134 " Depth="+Twine(Loop->getLoopDepth()));
2138 // Otherwise, it is a loop header. Print out information about child and
2140 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2142 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2145 OS.indent(Loop->getLoopDepth()*2-2);
2150 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2152 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2156 /// EmitBasicBlockStart - This method prints the label for the specified
2157 /// MachineBasicBlock, an alignment (if present) and a comment describing
2158 /// it if appropriate.
2159 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2160 // Emit an alignment directive for this block, if needed.
2161 if (unsigned Align = MBB.getAlignment())
2162 EmitAlignment(Align);
2164 // If the block has its address taken, emit any labels that were used to
2165 // reference the block. It is possible that there is more than one label
2166 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2167 // the references were generated.
2168 if (MBB.hasAddressTaken()) {
2169 const BasicBlock *BB = MBB.getBasicBlock();
2171 OutStreamer.AddComment("Block address taken");
2173 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2174 for (auto *Sym : Symbols)
2175 OutStreamer.EmitLabel(Sym);
2178 // Print some verbose block comments.
2180 if (const BasicBlock *BB = MBB.getBasicBlock())
2182 OutStreamer.AddComment("%" + BB->getName());
2183 emitBasicBlockLoopComments(MBB, LI, *this);
2186 // Print the main label for the block.
2187 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2189 // NOTE: Want this comment at start of line, don't emit with AddComment.
2190 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2193 OutStreamer.EmitLabel(MBB.getSymbol());
2197 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2198 bool IsDefinition) const {
2199 MCSymbolAttr Attr = MCSA_Invalid;
2201 switch (Visibility) {
2203 case GlobalValue::HiddenVisibility:
2205 Attr = MAI->getHiddenVisibilityAttr();
2207 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2209 case GlobalValue::ProtectedVisibility:
2210 Attr = MAI->getProtectedVisibilityAttr();
2214 if (Attr != MCSA_Invalid)
2215 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2218 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2219 /// exactly one predecessor and the control transfer mechanism between
2220 /// the predecessor and this block is a fall-through.
2222 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2223 // If this is a landing pad, it isn't a fall through. If it has no preds,
2224 // then nothing falls through to it.
2225 if (MBB->isLandingPad() || MBB->pred_empty())
2228 // If there isn't exactly one predecessor, it can't be a fall through.
2229 if (MBB->pred_size() > 1)
2232 // The predecessor has to be immediately before this block.
2233 MachineBasicBlock *Pred = *MBB->pred_begin();
2234 if (!Pred->isLayoutSuccessor(MBB))
2237 // If the block is completely empty, then it definitely does fall through.
2241 // Check the terminators in the previous blocks
2242 for (const auto &MI : Pred->terminators()) {
2243 // If it is not a simple branch, we are in a table somewhere.
2244 if (!MI.isBranch() || MI.isIndirectBranch())
2247 // If we are the operands of one of the branches, this is not a fall
2248 // through. Note that targets with delay slots will usually bundle
2249 // terminators with the delay slot instruction.
2250 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2253 if (OP->isMBB() && OP->getMBB() == MBB)
2263 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2264 if (!S.usesMetadata())
2267 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2268 gcp_map_type::iterator GCPI = GCMap.find(&S);
2269 if (GCPI != GCMap.end())
2270 return GCPI->second.get();
2272 const char *Name = S.getName().c_str();
2274 for (GCMetadataPrinterRegistry::iterator
2275 I = GCMetadataPrinterRegistry::begin(),
2276 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2277 if (strcmp(Name, I->getName()) == 0) {
2278 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2280 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2281 return IterBool.first->second.get();
2284 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2287 /// Pin vtable to this file.
2288 AsmPrinterHandler::~AsmPrinterHandler() {}