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, std::unique_ptr<MCStreamer> Streamer)
102 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
103 MII(tm.getSubtargetImpl()->getInstrInfo()),
104 OutContext(Streamer->getContext()), OutStreamer(*Streamer.release()),
105 LastMI(nullptr), LastFn(0), Counter(~0U), SetCounter(0) {
106 DD = nullptr; MMI = nullptr; LI = nullptr; MF = nullptr;
107 CurrentFnSym = CurrentFnSymForSize = nullptr;
108 GCMetadataPrinters = nullptr;
109 VerboseAsm = OutStreamer.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.getObjFileLowering();
135 /// getDataLayout - Return information about data layout.
136 const DataLayout &AsmPrinter::getDataLayout() const {
137 return *TM.getDataLayout();
140 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
141 return TM.getSubtarget<MCSubtargetInfo>();
144 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
145 S.EmitInstruction(Inst, getSubtargetInfo());
148 StringRef AsmPrinter::getTargetTriple() const {
149 return TM.getTargetTriple();
152 /// getCurrentSection() - Return the current section we are emitting to.
153 const MCSection *AsmPrinter::getCurrentSection() const {
154 return OutStreamer.getCurrentSection().first;
159 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
160 AU.setPreservesAll();
161 MachineFunctionPass::getAnalysisUsage(AU);
162 AU.addRequired<MachineModuleInfo>();
163 AU.addRequired<GCModuleInfo>();
165 AU.addRequired<MachineLoopInfo>();
168 bool AsmPrinter::doInitialization(Module &M) {
169 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
170 MMI->AnalyzeModule(M);
172 // Initialize TargetLoweringObjectFile.
173 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
174 .Initialize(OutContext, TM);
176 OutStreamer.InitSections(false);
178 Mang = new Mangler(TM.getDataLayout());
180 // Emit the version-min deplyment target directive if needed.
182 // FIXME: If we end up with a collection of these sorts of Darwin-specific
183 // or ELF-specific things, it may make sense to have a platform helper class
184 // that will work with the target helper class. For now keep it here, as the
185 // alternative is duplicated code in each of the target asm printers that
186 // use the directive, where it would need the same conditionalization
188 Triple TT(getTargetTriple());
189 if (TT.isOSDarwin()) {
190 unsigned Major, Minor, Update;
191 TT.getOSVersion(Major, Minor, Update);
192 // If there is a version specified, Major will be non-zero.
194 OutStreamer.EmitVersionMin((TT.isMacOSX() ?
195 MCVM_OSXVersionMin : MCVM_IOSVersionMin),
196 Major, Minor, Update);
199 // Allow the target to emit any magic that it wants at the start of the file.
200 EmitStartOfAsmFile(M);
202 // Very minimal debug info. It is ignored if we emit actual debug info. If we
203 // don't, this at least helps the user find where a global came from.
204 if (MAI->hasSingleParameterDotFile()) {
206 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
209 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
210 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
212 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
213 MP->beginAssembly(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 bool skip_dwarf = false;
226 if (Triple(TM.getTargetTriple()).isKnownWindowsMSVCEnvironment()) {
227 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this),
229 CodeViewLineTablesGroupName));
230 // FIXME: Don't emit DWARF debug info if there's at least one function
231 // with AddressSanitizer instrumentation.
232 // This is a band-aid fix for PR22032.
233 for (auto &F : M.functions()) {
234 if (F.hasFnAttribute(Attribute::SanitizeAddress)) {
241 DD = new DwarfDebug(this, &M);
242 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
246 EHStreamer *ES = nullptr;
247 switch (MAI->getExceptionHandlingType()) {
248 case ExceptionHandling::None:
250 case ExceptionHandling::SjLj:
251 case ExceptionHandling::DwarfCFI:
252 ES = new DwarfCFIException(this);
254 case ExceptionHandling::ARM:
255 ES = new ARMException(this);
257 case ExceptionHandling::WinEH:
258 switch (MAI->getWinEHEncodingType()) {
259 default: llvm_unreachable("unsupported unwinding information encoding");
260 case WinEH::EncodingType::Itanium:
261 ES = new Win64Exception(this);
267 Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
271 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
272 if (!MAI.hasWeakDefCanBeHiddenDirective())
275 return canBeOmittedFromSymbolTable(GV);
278 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
279 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
281 case GlobalValue::CommonLinkage:
282 case GlobalValue::LinkOnceAnyLinkage:
283 case GlobalValue::LinkOnceODRLinkage:
284 case GlobalValue::WeakAnyLinkage:
285 case GlobalValue::WeakODRLinkage:
286 if (MAI->hasWeakDefDirective()) {
288 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
290 if (!canBeHidden(GV, *MAI))
291 // .weak_definition _foo
292 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
294 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
295 } else if (MAI->hasLinkOnceDirective()) {
297 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
298 //NOTE: linkonce is handled by the section the symbol was assigned to.
301 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
304 case GlobalValue::AppendingLinkage:
305 // FIXME: appending linkage variables should go into a section of
306 // their name or something. For now, just emit them as external.
307 case GlobalValue::ExternalLinkage:
308 // If external or appending, declare as a global symbol.
310 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
312 case GlobalValue::PrivateLinkage:
313 case GlobalValue::InternalLinkage:
315 case GlobalValue::AvailableExternallyLinkage:
316 llvm_unreachable("Should never emit this");
317 case GlobalValue::ExternalWeakLinkage:
318 llvm_unreachable("Don't know how to emit these");
320 llvm_unreachable("Unknown linkage type!");
323 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
324 const GlobalValue *GV) const {
325 TM.getNameWithPrefix(Name, GV, *Mang);
328 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
329 return TM.getSymbol(GV, *Mang);
332 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
333 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
334 if (GV->hasInitializer()) {
335 // Check to see if this is a special global used by LLVM, if so, emit it.
336 if (EmitSpecialLLVMGlobal(GV))
340 GV->printAsOperand(OutStreamer.GetCommentOS(),
341 /*PrintType=*/false, GV->getParent());
342 OutStreamer.GetCommentOS() << '\n';
346 MCSymbol *GVSym = getSymbol(GV);
347 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
349 if (!GV->hasInitializer()) // External globals require no extra code.
352 GVSym->redefineIfPossible();
353 if (GVSym->isDefined() || GVSym->isVariable())
354 report_fatal_error("symbol '" + Twine(GVSym->getName()) +
355 "' is already defined");
357 if (MAI->hasDotTypeDotSizeDirective())
358 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
360 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
362 const DataLayout *DL = TM.getDataLayout();
363 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
365 // If the alignment is specified, we *must* obey it. Overaligning a global
366 // with a specified alignment is a prompt way to break globals emitted to
367 // sections and expected to be contiguous (e.g. ObjC metadata).
368 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
370 for (const HandlerInfo &HI : Handlers) {
371 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
372 HI.Handler->setSymbolSize(GVSym, Size);
375 // Handle common and BSS local symbols (.lcomm).
376 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
377 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
378 unsigned Align = 1 << AlignLog;
380 // Handle common symbols.
381 if (GVKind.isCommon()) {
382 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
386 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
390 // Handle local BSS symbols.
391 if (MAI->hasMachoZeroFillDirective()) {
392 const MCSection *TheSection =
393 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
394 // .zerofill __DATA, __bss, _foo, 400, 5
395 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
399 // Use .lcomm only if it supports user-specified alignment.
400 // Otherwise, while it would still be correct to use .lcomm in some
401 // cases (e.g. when Align == 1), the external assembler might enfore
402 // some -unknown- default alignment behavior, which could cause
403 // spurious differences between external and integrated assembler.
404 // Prefer to simply fall back to .local / .comm in this case.
405 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
407 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
411 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
415 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
417 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
421 const MCSection *TheSection =
422 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
424 // Handle the zerofill directive on darwin, which is a special form of BSS
426 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
427 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
430 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
431 // .zerofill __DATA, __common, _foo, 400, 5
432 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
436 // Handle thread local data for mach-o which requires us to output an
437 // additional structure of data and mangle the original symbol so that we
438 // can reference it later.
440 // TODO: This should become an "emit thread local global" method on TLOF.
441 // All of this macho specific stuff should be sunk down into TLOFMachO and
442 // stuff like "TLSExtraDataSection" should no longer be part of the parent
443 // TLOF class. This will also make it more obvious that stuff like
444 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
446 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
447 // Emit the .tbss symbol
449 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
451 if (GVKind.isThreadBSS()) {
452 TheSection = getObjFileLowering().getTLSBSSSection();
453 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
454 } else if (GVKind.isThreadData()) {
455 OutStreamer.SwitchSection(TheSection);
457 EmitAlignment(AlignLog, GV);
458 OutStreamer.EmitLabel(MangSym);
460 EmitGlobalConstant(GV->getInitializer());
463 OutStreamer.AddBlankLine();
465 // Emit the variable struct for the runtime.
466 const MCSection *TLVSect
467 = getObjFileLowering().getTLSExtraDataSection();
469 OutStreamer.SwitchSection(TLVSect);
470 // Emit the linkage here.
471 EmitLinkage(GV, GVSym);
472 OutStreamer.EmitLabel(GVSym);
474 // Three pointers in size:
475 // - __tlv_bootstrap - used to make sure support exists
476 // - spare pointer, used when mapped by the runtime
477 // - pointer to mangled symbol above with initializer
478 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
479 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
481 OutStreamer.EmitIntValue(0, PtrSize);
482 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
484 OutStreamer.AddBlankLine();
488 OutStreamer.SwitchSection(TheSection);
490 EmitLinkage(GV, GVSym);
491 EmitAlignment(AlignLog, GV);
493 OutStreamer.EmitLabel(GVSym);
495 EmitGlobalConstant(GV->getInitializer());
497 if (MAI->hasDotTypeDotSizeDirective())
499 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
501 OutStreamer.AddBlankLine();
504 /// EmitFunctionHeader - This method emits the header for the current
506 void AsmPrinter::EmitFunctionHeader() {
507 // Print out constants referenced by the function
510 // Print the 'header' of function.
511 const Function *F = MF->getFunction();
513 OutStreamer.SwitchSection(
514 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
515 EmitVisibility(CurrentFnSym, F->getVisibility());
517 EmitLinkage(F, CurrentFnSym);
518 EmitAlignment(MF->getAlignment(), F);
520 if (MAI->hasDotTypeDotSizeDirective())
521 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
524 F->printAsOperand(OutStreamer.GetCommentOS(),
525 /*PrintType=*/false, F->getParent());
526 OutStreamer.GetCommentOS() << '\n';
529 // Emit the prefix data.
530 if (F->hasPrefixData())
531 EmitGlobalConstant(F->getPrefixData());
533 // Emit the CurrentFnSym. This is a virtual function to allow targets to
534 // do their wild and crazy things as required.
535 EmitFunctionEntryLabel();
537 // If the function had address-taken blocks that got deleted, then we have
538 // references to the dangling symbols. Emit them at the start of the function
539 // so that we don't get references to undefined symbols.
540 std::vector<MCSymbol*> DeadBlockSyms;
541 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
542 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
543 OutStreamer.AddComment("Address taken block that was later removed");
544 OutStreamer.EmitLabel(DeadBlockSyms[i]);
547 // Emit pre-function debug and/or EH information.
548 for (const HandlerInfo &HI : Handlers) {
549 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
550 HI.Handler->beginFunction(MF);
553 // Emit the prologue data.
554 if (F->hasPrologueData())
555 EmitGlobalConstant(F->getPrologueData());
558 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
559 /// function. This can be overridden by targets as required to do custom stuff.
560 void AsmPrinter::EmitFunctionEntryLabel() {
561 CurrentFnSym->redefineIfPossible();
563 // The function label could have already been emitted if two symbols end up
564 // conflicting due to asm renaming. Detect this and emit an error.
565 if (CurrentFnSym->isVariable())
566 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
567 "' is a protected alias");
568 if (CurrentFnSym->isDefined())
569 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
570 "' label emitted multiple times to assembly file");
572 return OutStreamer.EmitLabel(CurrentFnSym);
575 /// emitComments - Pretty-print comments for instructions.
576 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
577 const MachineFunction *MF = MI.getParent()->getParent();
578 const TargetMachine &TM = MF->getTarget();
580 // Check for spills and reloads
583 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
585 // We assume a single instruction only has a spill or reload, not
587 const MachineMemOperand *MMO;
588 if (TM.getSubtargetImpl()->getInstrInfo()->isLoadFromStackSlotPostFE(&MI,
590 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
591 MMO = *MI.memoperands_begin();
592 CommentOS << MMO->getSize() << "-byte Reload\n";
594 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasLoadFromStackSlot(
596 if (FrameInfo->isSpillSlotObjectIndex(FI))
597 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
598 } else if (TM.getSubtargetImpl()->getInstrInfo()->isStoreToStackSlotPostFE(
600 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
601 MMO = *MI.memoperands_begin();
602 CommentOS << MMO->getSize() << "-byte Spill\n";
604 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasStoreToStackSlot(
606 if (FrameInfo->isSpillSlotObjectIndex(FI))
607 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
610 // Check for spill-induced copies
611 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
612 CommentOS << " Reload Reuse\n";
615 /// emitImplicitDef - This method emits the specified machine instruction
616 /// that is an implicit def.
617 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
618 unsigned RegNo = MI->getOperand(0).getReg();
619 OutStreamer.AddComment(
620 Twine("implicit-def: ") +
621 TM.getSubtargetImpl()->getRegisterInfo()->getName(RegNo));
622 OutStreamer.AddBlankLine();
625 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
626 std::string Str = "kill:";
627 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
628 const MachineOperand &Op = MI->getOperand(i);
629 assert(Op.isReg() && "KILL instruction must have only register operands");
631 Str += AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Op.getReg());
632 Str += (Op.isDef() ? "<def>" : "<kill>");
634 AP.OutStreamer.AddComment(Str);
635 AP.OutStreamer.AddBlankLine();
638 /// emitDebugValueComment - This method handles the target-independent form
639 /// of DBG_VALUE, returning true if it was able to do so. A false return
640 /// means the target will need to handle MI in EmitInstruction.
641 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
642 // This code handles only the 4-operand target-independent form.
643 if (MI->getNumOperands() != 4)
646 SmallString<128> Str;
647 raw_svector_ostream OS(Str);
648 OS << "DEBUG_VALUE: ";
650 DIVariable V = MI->getDebugVariable();
651 if (V.getContext().isSubprogram()) {
652 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
658 DIExpression Expr = MI->getDebugExpression();
659 if (Expr.isVariablePiece())
660 OS << " [piece offset=" << Expr.getPieceOffset()
661 << " size=" << Expr.getPieceSize() << "]";
664 // The second operand is only an offset if it's an immediate.
665 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
666 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
668 // Register or immediate value. Register 0 means undef.
669 if (MI->getOperand(0).isFPImm()) {
670 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
671 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
672 OS << (double)APF.convertToFloat();
673 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
674 OS << APF.convertToDouble();
676 // There is no good way to print long double. Convert a copy to
677 // double. Ah well, it's only a comment.
679 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
681 OS << "(long double) " << APF.convertToDouble();
683 } else if (MI->getOperand(0).isImm()) {
684 OS << MI->getOperand(0).getImm();
685 } else if (MI->getOperand(0).isCImm()) {
686 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
689 if (MI->getOperand(0).isReg()) {
690 Reg = MI->getOperand(0).getReg();
692 assert(MI->getOperand(0).isFI() && "Unknown operand type");
693 const TargetFrameLowering *TFI =
694 AP.TM.getSubtargetImpl()->getFrameLowering();
695 Offset += TFI->getFrameIndexReference(*AP.MF,
696 MI->getOperand(0).getIndex(), Reg);
700 // Suppress offset, it is not meaningful here.
702 // NOTE: Want this comment at start of line, don't emit with AddComment.
703 AP.OutStreamer.emitRawComment(OS.str());
708 OS << AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Reg);
712 OS << '+' << Offset << ']';
714 // NOTE: Want this comment at start of line, don't emit with AddComment.
715 AP.OutStreamer.emitRawComment(OS.str());
719 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
720 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
721 MF->getFunction()->needsUnwindTableEntry())
724 if (MMI->hasDebugInfo())
730 bool AsmPrinter::needsSEHMoves() {
731 return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
734 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
735 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
736 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
737 ExceptionHandlingType != ExceptionHandling::ARM)
740 if (needsCFIMoves() == CFI_M_None)
743 const MachineModuleInfo &MMI = MF->getMMI();
744 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
745 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
746 const MCCFIInstruction &CFI = Instrs[CFIIndex];
747 emitCFIInstruction(CFI);
750 void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
751 // The operands are the MCSymbol and the frame offset of the allocation.
752 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
753 int FrameOffset = MI.getOperand(1).getImm();
755 // Emit a symbol assignment.
756 OutStreamer.EmitAssignment(FrameAllocSym,
757 MCConstantExpr::Create(FrameOffset, OutContext));
760 /// EmitFunctionBody - This method emits the body and trailer for a
762 void AsmPrinter::EmitFunctionBody() {
763 // Emit target-specific gunk before the function body.
764 EmitFunctionBodyStart();
766 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
768 // Print out code for the function.
769 bool HasAnyRealCode = false;
770 for (auto &MBB : *MF) {
771 // Print a label for the basic block.
772 EmitBasicBlockStart(MBB);
773 for (auto &MI : MBB) {
775 // Print the assembly for the instruction.
776 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
777 !MI.isDebugValue()) {
778 HasAnyRealCode = true;
782 if (ShouldPrintDebugScopes) {
783 for (const HandlerInfo &HI : Handlers) {
784 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
785 TimePassesIsEnabled);
786 HI.Handler->beginInstruction(&MI);
791 emitComments(MI, OutStreamer.GetCommentOS());
793 switch (MI.getOpcode()) {
794 case TargetOpcode::CFI_INSTRUCTION:
795 emitCFIInstruction(MI);
798 case TargetOpcode::FRAME_ALLOC:
802 case TargetOpcode::EH_LABEL:
803 case TargetOpcode::GC_LABEL:
804 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
806 case TargetOpcode::INLINEASM:
809 case TargetOpcode::DBG_VALUE:
811 if (!emitDebugValueComment(&MI, *this))
812 EmitInstruction(&MI);
815 case TargetOpcode::IMPLICIT_DEF:
816 if (isVerbose()) emitImplicitDef(&MI);
818 case TargetOpcode::KILL:
819 if (isVerbose()) emitKill(&MI, *this);
822 EmitInstruction(&MI);
826 if (ShouldPrintDebugScopes) {
827 for (const HandlerInfo &HI : Handlers) {
828 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
829 TimePassesIsEnabled);
830 HI.Handler->endInstruction();
835 EmitBasicBlockEnd(MBB);
838 // If the function is empty and the object file uses .subsections_via_symbols,
839 // then we need to emit *something* to the function body to prevent the
840 // labels from collapsing together. Just emit a noop.
841 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
843 TM.getSubtargetImpl()->getInstrInfo()->getNoopForMachoTarget(Noop);
844 OutStreamer.AddComment("avoids zero-length function");
846 // Targets can opt-out of emitting the noop here by leaving the opcode
848 if (Noop.getOpcode())
849 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
852 const Function *F = MF->getFunction();
853 for (const auto &BB : *F) {
854 if (!BB.hasAddressTaken())
856 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
857 if (Sym->isDefined())
859 OutStreamer.AddComment("Address of block that was removed by CodeGen");
860 OutStreamer.EmitLabel(Sym);
863 // Emit target-specific gunk after the function body.
864 EmitFunctionBodyEnd();
866 // If the target wants a .size directive for the size of the function, emit
868 if (MAI->hasDotTypeDotSizeDirective()) {
869 // Create a symbol for the end of function, so we can get the size as
870 // difference between the function label and the temp label.
871 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
872 OutStreamer.EmitLabel(FnEndLabel);
874 const MCExpr *SizeExp =
875 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
876 MCSymbolRefExpr::Create(CurrentFnSymForSize,
879 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
882 // Emit post-function debug and/or EH information.
883 for (const HandlerInfo &HI : Handlers) {
884 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
885 HI.Handler->endFunction(MF);
889 // Print out jump tables referenced by the function.
892 OutStreamer.AddBlankLine();
895 bool AsmPrinter::doFinalization(Module &M) {
896 // Emit global variables.
897 for (const auto &G : M.globals())
898 EmitGlobalVariable(&G);
900 // Emit visibility info for declarations
901 for (const Function &F : M) {
902 if (!F.isDeclaration())
904 GlobalValue::VisibilityTypes V = F.getVisibility();
905 if (V == GlobalValue::DefaultVisibility)
908 MCSymbol *Name = getSymbol(&F);
909 EmitVisibility(Name, V, false);
912 // Get information about jump-instruction tables to print.
913 JumpInstrTableInfo *JITI = getAnalysisIfAvailable<JumpInstrTableInfo>();
915 if (JITI && !JITI->getTables().empty()) {
916 unsigned Arch = Triple(getTargetTriple()).getArch();
917 bool IsThumb = (Arch == Triple::thumb || Arch == Triple::thumbeb);
919 TM.getSubtargetImpl()->getInstrInfo()->getTrap(TrapInst);
920 unsigned LogAlignment = llvm::Log2_64(JITI->entryByteAlignment());
922 // Emit the right section for these functions.
923 OutStreamer.SwitchSection(OutContext.getObjectFileInfo()->getTextSection());
924 for (const auto &KV : JITI->getTables()) {
926 for (const auto &FunPair : KV.second) {
927 // Emit the function labels to make this be a function entry point.
929 OutContext.GetOrCreateSymbol(FunPair.second->getName());
930 EmitAlignment(LogAlignment);
932 OutStreamer.EmitThumbFunc(FunSym);
933 if (MAI->hasDotTypeDotSizeDirective())
934 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_ELF_TypeFunction);
935 OutStreamer.EmitLabel(FunSym);
937 // Emit the jump instruction to transfer control to the original
940 MCSymbol *TargetSymbol =
941 OutContext.GetOrCreateSymbol(FunPair.first->getName());
942 const MCSymbolRefExpr *TargetSymRef =
943 MCSymbolRefExpr::Create(TargetSymbol, MCSymbolRefExpr::VK_PLT,
945 TM.getSubtargetImpl()->getInstrInfo()->getUnconditionalBranch(
946 JumpToFun, TargetSymRef);
947 OutStreamer.EmitInstruction(JumpToFun, getSubtargetInfo());
951 // Emit enough padding instructions to fill up to the next power of two.
952 uint64_t Remaining = NextPowerOf2(Count) - Count;
953 for (uint64_t C = 0; C < Remaining; ++C) {
954 EmitAlignment(LogAlignment);
955 OutStreamer.EmitInstruction(TrapInst, getSubtargetInfo());
961 // Emit module flags.
962 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
963 M.getModuleFlagsMetadata(ModuleFlags);
964 if (!ModuleFlags.empty())
965 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
967 // Make sure we wrote out everything we need.
970 // Finalize debug and EH information.
971 for (const HandlerInfo &HI : Handlers) {
972 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
973 TimePassesIsEnabled);
974 HI.Handler->endModule();
980 // If the target wants to know about weak references, print them all.
981 if (MAI->getWeakRefDirective()) {
982 // FIXME: This is not lazy, it would be nice to only print weak references
983 // to stuff that is actually used. Note that doing so would require targets
984 // to notice uses in operands (due to constant exprs etc). This should
985 // happen with the MC stuff eventually.
987 // Print out module-level global variables here.
988 for (const auto &G : M.globals()) {
989 if (!G.hasExternalWeakLinkage())
991 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
994 for (const auto &F : M) {
995 if (!F.hasExternalWeakLinkage())
997 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
1001 OutStreamer.AddBlankLine();
1002 for (const auto &Alias : M.aliases()) {
1003 MCSymbol *Name = getSymbol(&Alias);
1005 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
1006 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
1007 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
1008 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
1010 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
1012 EmitVisibility(Name, Alias.getVisibility());
1014 // Emit the directives as assignments aka .set:
1015 OutStreamer.EmitAssignment(Name, lowerConstant(Alias.getAliasee()));
1018 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1019 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1020 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1021 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1022 MP->finishAssembly(M, *MI, *this);
1024 // Emit llvm.ident metadata in an '.ident' directive.
1025 EmitModuleIdents(M);
1027 // Emit __morestack address if needed for indirect calls.
1028 if (MMI->usesMorestackAddr()) {
1029 const MCSection *ReadOnlySection =
1030 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
1032 OutStreamer.SwitchSection(ReadOnlySection);
1034 MCSymbol *AddrSymbol =
1035 OutContext.GetOrCreateSymbol(StringRef("__morestack_addr"));
1036 OutStreamer.EmitLabel(AddrSymbol);
1038 unsigned PtrSize = TM.getDataLayout()->getPointerSize(0);
1039 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("__morestack"),
1043 // If we don't have any trampolines, then we don't require stack memory
1044 // to be executable. Some targets have a directive to declare this.
1045 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1046 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1047 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1048 OutStreamer.SwitchSection(S);
1050 // Allow the target to emit any magic that it wants at the end of the file,
1051 // after everything else has gone out.
1052 EmitEndOfAsmFile(M);
1054 delete Mang; Mang = nullptr;
1057 OutStreamer.Finish();
1058 OutStreamer.reset();
1063 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1065 // Get the function symbol.
1066 CurrentFnSym = getSymbol(MF.getFunction());
1067 CurrentFnSymForSize = CurrentFnSym;
1070 LI = &getAnalysis<MachineLoopInfo>();
1074 // SectionCPs - Keep track the alignment, constpool entries per Section.
1078 SmallVector<unsigned, 4> CPEs;
1079 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1083 /// EmitConstantPool - Print to the current output stream assembly
1084 /// representations of the constants in the constant pool MCP. This is
1085 /// used to print out constants which have been "spilled to memory" by
1086 /// the code generator.
1088 void AsmPrinter::EmitConstantPool() {
1089 const MachineConstantPool *MCP = MF->getConstantPool();
1090 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1091 if (CP.empty()) return;
1093 // Calculate sections for constant pool entries. We collect entries to go into
1094 // the same section together to reduce amount of section switch statements.
1095 SmallVector<SectionCPs, 4> CPSections;
1096 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1097 const MachineConstantPoolEntry &CPE = CP[i];
1098 unsigned Align = CPE.getAlignment();
1101 CPE.getSectionKind(TM.getDataLayout());
1103 const Constant *C = nullptr;
1104 if (!CPE.isMachineConstantPoolEntry())
1105 C = CPE.Val.ConstVal;
1107 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind, C);
1109 // The number of sections are small, just do a linear search from the
1110 // last section to the first.
1112 unsigned SecIdx = CPSections.size();
1113 while (SecIdx != 0) {
1114 if (CPSections[--SecIdx].S == S) {
1120 SecIdx = CPSections.size();
1121 CPSections.push_back(SectionCPs(S, Align));
1124 if (Align > CPSections[SecIdx].Alignment)
1125 CPSections[SecIdx].Alignment = Align;
1126 CPSections[SecIdx].CPEs.push_back(i);
1129 // Now print stuff into the calculated sections.
1130 const MCSection *CurSection = nullptr;
1131 unsigned Offset = 0;
1132 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1133 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1134 unsigned CPI = CPSections[i].CPEs[j];
1135 MCSymbol *Sym = GetCPISymbol(CPI);
1136 if (!Sym->isUndefined())
1139 if (CurSection != CPSections[i].S) {
1140 OutStreamer.SwitchSection(CPSections[i].S);
1141 EmitAlignment(Log2_32(CPSections[i].Alignment));
1142 CurSection = CPSections[i].S;
1146 MachineConstantPoolEntry CPE = CP[CPI];
1148 // Emit inter-object padding for alignment.
1149 unsigned AlignMask = CPE.getAlignment() - 1;
1150 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1151 OutStreamer.EmitZeros(NewOffset - Offset);
1153 Type *Ty = CPE.getType();
1154 Offset = NewOffset +
1155 TM.getDataLayout()->getTypeAllocSize(Ty);
1157 OutStreamer.EmitLabel(Sym);
1158 if (CPE.isMachineConstantPoolEntry())
1159 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1161 EmitGlobalConstant(CPE.Val.ConstVal);
1166 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1167 /// by the current function to the current output stream.
1169 void AsmPrinter::EmitJumpTableInfo() {
1170 const DataLayout *DL = MF->getTarget().getDataLayout();
1171 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1173 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1174 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1175 if (JT.empty()) return;
1177 // Pick the directive to use to print the jump table entries, and switch to
1178 // the appropriate section.
1179 const Function *F = MF->getFunction();
1180 bool JTInDiffSection = false;
1181 if (// In PIC mode, we need to emit the jump table to the same section as the
1182 // function body itself, otherwise the label differences won't make sense.
1183 // FIXME: Need a better predicate for this: what about custom entries?
1184 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1185 // We should also do if the section name is NULL or function is declared
1186 // in discardable section
1187 // FIXME: this isn't the right predicate, should be based on the MCSection
1188 // for the function.
1189 F->isWeakForLinker()) {
1190 OutStreamer.SwitchSection(
1191 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1193 // Otherwise, drop it in the readonly section.
1194 const MCSection *ReadOnlySection =
1195 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
1197 OutStreamer.SwitchSection(ReadOnlySection);
1198 JTInDiffSection = true;
1201 EmitAlignment(Log2_32(
1202 MJTI->getEntryAlignment(*TM.getDataLayout())));
1204 // Jump tables in code sections are marked with a data_region directive
1205 // where that's supported.
1206 if (!JTInDiffSection)
1207 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1209 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1210 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1212 // If this jump table was deleted, ignore it.
1213 if (JTBBs.empty()) continue;
1215 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1216 /// emit a .set directive for each unique entry.
1217 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1218 MAI->doesSetDirectiveSuppressesReloc()) {
1219 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1220 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1221 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1222 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1223 const MachineBasicBlock *MBB = JTBBs[ii];
1224 if (!EmittedSets.insert(MBB).second)
1227 // .set LJTSet, LBB32-base
1229 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1230 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1231 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1235 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1236 // before each jump table. The first label is never referenced, but tells
1237 // the assembler and linker the extents of the jump table object. The
1238 // second label is actually referenced by the code.
1239 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1240 // FIXME: This doesn't have to have any specific name, just any randomly
1241 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1242 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1244 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1246 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1247 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1249 if (!JTInDiffSection)
1250 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1253 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1255 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1256 const MachineBasicBlock *MBB,
1257 unsigned UID) const {
1258 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1259 const MCExpr *Value = nullptr;
1260 switch (MJTI->getEntryKind()) {
1261 case MachineJumpTableInfo::EK_Inline:
1262 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1263 case MachineJumpTableInfo::EK_Custom32:
1265 TM.getSubtargetImpl()->getTargetLowering()->LowerCustomJumpTableEntry(
1266 MJTI, MBB, UID, OutContext);
1268 case MachineJumpTableInfo::EK_BlockAddress:
1269 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1271 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1273 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1274 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1275 // with a relocation as gp-relative, e.g.:
1277 MCSymbol *MBBSym = MBB->getSymbol();
1278 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1282 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1283 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1284 // with a relocation as gp-relative, e.g.:
1286 MCSymbol *MBBSym = MBB->getSymbol();
1287 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1291 case MachineJumpTableInfo::EK_LabelDifference32: {
1292 // Each entry is the address of the block minus the address of the jump
1293 // table. This is used for PIC jump tables where gprel32 is not supported.
1295 // .word LBB123 - LJTI1_2
1296 // If the .set directive avoids relocations, this is emitted as:
1297 // .set L4_5_set_123, LBB123 - LJTI1_2
1298 // .word L4_5_set_123
1299 if (MAI->doesSetDirectiveSuppressesReloc()) {
1300 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1304 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1305 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1306 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1307 Value = MCBinaryExpr::CreateSub(Value, Base, OutContext);
1312 assert(Value && "Unknown entry kind!");
1314 unsigned EntrySize =
1315 MJTI->getEntrySize(*TM.getDataLayout());
1316 OutStreamer.EmitValue(Value, EntrySize);
1320 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1321 /// special global used by LLVM. If so, emit it and return true, otherwise
1322 /// do nothing and return false.
1323 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1324 if (GV->getName() == "llvm.used") {
1325 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1326 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1330 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1331 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1332 GV->hasAvailableExternallyLinkage())
1335 if (!GV->hasAppendingLinkage()) return false;
1337 assert(GV->hasInitializer() && "Not a special LLVM global!");
1339 if (GV->getName() == "llvm.global_ctors") {
1340 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1342 if (TM.getRelocationModel() == Reloc::Static &&
1343 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1344 StringRef Sym(".constructors_used");
1345 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1351 if (GV->getName() == "llvm.global_dtors") {
1352 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1354 if (TM.getRelocationModel() == Reloc::Static &&
1355 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1356 StringRef Sym(".destructors_used");
1357 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1366 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1367 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1368 /// is true, as being used with this directive.
1369 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1370 // Should be an array of 'i8*'.
1371 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1372 const GlobalValue *GV =
1373 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1375 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1381 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1383 llvm::Constant *Func;
1384 llvm::GlobalValue *ComdatKey;
1388 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1390 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1391 // Should be an array of '{ int, void ()* }' structs. The first value is the
1393 if (!isa<ConstantArray>(List)) return;
1395 // Sanity check the structors list.
1396 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1397 if (!InitList) return; // Not an array!
1398 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1399 // FIXME: Only allow the 3-field form in LLVM 4.0.
1400 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1401 return; // Not an array of two or three elements!
1402 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1403 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1404 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1405 return; // Not (int, ptr, ptr).
1407 // Gather the structors in a form that's convenient for sorting by priority.
1408 SmallVector<Structor, 8> Structors;
1409 for (Value *O : InitList->operands()) {
1410 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1411 if (!CS) continue; // Malformed.
1412 if (CS->getOperand(1)->isNullValue())
1413 break; // Found a null terminator, skip the rest.
1414 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1415 if (!Priority) continue; // Malformed.
1416 Structors.push_back(Structor());
1417 Structor &S = Structors.back();
1418 S.Priority = Priority->getLimitedValue(65535);
1419 S.Func = CS->getOperand(1);
1420 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1421 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1424 // Emit the function pointers in the target-specific order
1425 const DataLayout *DL = TM.getDataLayout();
1426 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1427 std::stable_sort(Structors.begin(), Structors.end(),
1428 [](const Structor &L,
1429 const Structor &R) { return L.Priority < R.Priority; });
1430 for (Structor &S : Structors) {
1431 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1432 const MCSymbol *KeySym = nullptr;
1433 if (GlobalValue *GV = S.ComdatKey) {
1434 if (GV->hasAvailableExternallyLinkage())
1435 // If the associated variable is available_externally, some other TU
1436 // will provide its dynamic initializer.
1439 KeySym = getSymbol(GV);
1441 const MCSection *OutputSection =
1442 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1443 : Obj.getStaticDtorSection(S.Priority, KeySym));
1444 OutStreamer.SwitchSection(OutputSection);
1445 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1446 EmitAlignment(Align);
1447 EmitXXStructor(S.Func);
1451 void AsmPrinter::EmitModuleIdents(Module &M) {
1452 if (!MAI->hasIdentDirective())
1455 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1456 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1457 const MDNode *N = NMD->getOperand(i);
1458 assert(N->getNumOperands() == 1 &&
1459 "llvm.ident metadata entry can have only one operand");
1460 const MDString *S = cast<MDString>(N->getOperand(0));
1461 OutStreamer.EmitIdent(S->getString());
1466 //===--------------------------------------------------------------------===//
1467 // Emission and print routines
1470 /// EmitInt8 - Emit a byte directive and value.
1472 void AsmPrinter::EmitInt8(int Value) const {
1473 OutStreamer.EmitIntValue(Value, 1);
1476 /// EmitInt16 - Emit a short directive and value.
1478 void AsmPrinter::EmitInt16(int Value) const {
1479 OutStreamer.EmitIntValue(Value, 2);
1482 /// EmitInt32 - Emit a long directive and value.
1484 void AsmPrinter::EmitInt32(int Value) const {
1485 OutStreamer.EmitIntValue(Value, 4);
1488 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1489 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1490 /// .set if it avoids relocations.
1491 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1492 unsigned Size) const {
1493 // Get the Hi-Lo expression.
1494 const MCExpr *Diff =
1495 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1496 MCSymbolRefExpr::Create(Lo, OutContext),
1499 if (!MAI->doesSetDirectiveSuppressesReloc()) {
1500 OutStreamer.EmitValue(Diff, Size);
1504 // Otherwise, emit with .set (aka assignment).
1505 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1506 OutStreamer.EmitAssignment(SetLabel, Diff);
1507 OutStreamer.EmitSymbolValue(SetLabel, Size);
1510 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1511 /// where the size in bytes of the directive is specified by Size and Label
1512 /// specifies the label. This implicitly uses .set if it is available.
1513 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1515 bool IsSectionRelative) const {
1516 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1517 OutStreamer.EmitCOFFSecRel32(Label);
1521 // Emit Label+Offset (or just Label if Offset is zero)
1522 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1524 Expr = MCBinaryExpr::CreateAdd(
1525 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1527 OutStreamer.EmitValue(Expr, Size);
1530 //===----------------------------------------------------------------------===//
1532 // EmitAlignment - Emit an alignment directive to the specified power of
1533 // two boundary. For example, if you pass in 3 here, you will get an 8
1534 // byte alignment. If a global value is specified, and if that global has
1535 // an explicit alignment requested, it will override the alignment request
1536 // if required for correctness.
1538 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1540 NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(),
1543 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1546 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
1547 "undefined behavior");
1548 if (getCurrentSection()->getKind().isText())
1549 OutStreamer.EmitCodeAlignment(1u << NumBits);
1551 OutStreamer.EmitValueToAlignment(1u << NumBits);
1554 //===----------------------------------------------------------------------===//
1555 // Constant emission.
1556 //===----------------------------------------------------------------------===//
1558 const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1559 MCContext &Ctx = OutContext;
1561 if (CV->isNullValue() || isa<UndefValue>(CV))
1562 return MCConstantExpr::Create(0, Ctx);
1564 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1565 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1567 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1568 return MCSymbolRefExpr::Create(getSymbol(GV), Ctx);
1570 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1571 return MCSymbolRefExpr::Create(GetBlockAddressSymbol(BA), Ctx);
1573 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1575 llvm_unreachable("Unknown constant value to lower!");
1578 if (const MCExpr *RelocExpr
1579 = getObjFileLowering().getExecutableRelativeSymbol(CE, *Mang, TM))
1582 switch (CE->getOpcode()) {
1584 // If the code isn't optimized, there may be outstanding folding
1585 // opportunities. Attempt to fold the expression using DataLayout as a
1586 // last resort before giving up.
1587 if (Constant *C = ConstantFoldConstantExpression(
1588 CE, TM.getDataLayout()))
1590 return lowerConstant(C);
1592 // Otherwise report the problem to the user.
1595 raw_string_ostream OS(S);
1596 OS << "Unsupported expression in static initializer: ";
1597 CE->printAsOperand(OS, /*PrintType=*/false,
1598 !MF ? nullptr : MF->getFunction()->getParent());
1599 report_fatal_error(OS.str());
1601 case Instruction::GetElementPtr: {
1602 const DataLayout &DL = *TM.getDataLayout();
1604 // Generate a symbolic expression for the byte address
1605 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1606 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1608 const MCExpr *Base = lowerConstant(CE->getOperand(0));
1612 int64_t Offset = OffsetAI.getSExtValue();
1613 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1617 case Instruction::Trunc:
1618 // We emit the value and depend on the assembler to truncate the generated
1619 // expression properly. This is important for differences between
1620 // blockaddress labels. Since the two labels are in the same function, it
1621 // is reasonable to treat their delta as a 32-bit value.
1623 case Instruction::BitCast:
1624 return lowerConstant(CE->getOperand(0));
1626 case Instruction::IntToPtr: {
1627 const DataLayout &DL = *TM.getDataLayout();
1629 // Handle casts to pointers by changing them into casts to the appropriate
1630 // integer type. This promotes constant folding and simplifies this code.
1631 Constant *Op = CE->getOperand(0);
1632 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1634 return lowerConstant(Op);
1637 case Instruction::PtrToInt: {
1638 const DataLayout &DL = *TM.getDataLayout();
1640 // Support only foldable casts to/from pointers that can be eliminated by
1641 // changing the pointer to the appropriately sized integer type.
1642 Constant *Op = CE->getOperand(0);
1643 Type *Ty = CE->getType();
1645 const MCExpr *OpExpr = lowerConstant(Op);
1647 // We can emit the pointer value into this slot if the slot is an
1648 // integer slot equal to the size of the pointer.
1649 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1652 // Otherwise the pointer is smaller than the resultant integer, mask off
1653 // the high bits so we are sure to get a proper truncation if the input is
1655 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1656 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1657 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1660 // The MC library also has a right-shift operator, but it isn't consistently
1661 // signed or unsigned between different targets.
1662 case Instruction::Add:
1663 case Instruction::Sub:
1664 case Instruction::Mul:
1665 case Instruction::SDiv:
1666 case Instruction::SRem:
1667 case Instruction::Shl:
1668 case Instruction::And:
1669 case Instruction::Or:
1670 case Instruction::Xor: {
1671 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
1672 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
1673 switch (CE->getOpcode()) {
1674 default: llvm_unreachable("Unknown binary operator constant cast expr");
1675 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1676 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1677 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1678 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1679 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1680 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1681 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1682 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1683 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1689 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1691 /// isRepeatedByteSequence - Determine whether the given value is
1692 /// composed of a repeated sequence of identical bytes and return the
1693 /// byte value. If it is not a repeated sequence, return -1.
1694 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1695 StringRef Data = V->getRawDataValues();
1696 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1698 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1699 if (Data[i] != C) return -1;
1700 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1704 /// isRepeatedByteSequence - Determine whether the given value is
1705 /// composed of a repeated sequence of identical bytes and return the
1706 /// byte value. If it is not a repeated sequence, return -1.
1707 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1709 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1710 if (CI->getBitWidth() > 64) return -1;
1713 TM.getDataLayout()->getTypeAllocSize(V->getType());
1714 uint64_t Value = CI->getZExtValue();
1716 // Make sure the constant is at least 8 bits long and has a power
1717 // of 2 bit width. This guarantees the constant bit width is
1718 // always a multiple of 8 bits, avoiding issues with padding out
1719 // to Size and other such corner cases.
1720 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1722 uint8_t Byte = static_cast<uint8_t>(Value);
1724 for (unsigned i = 1; i < Size; ++i) {
1726 if (static_cast<uint8_t>(Value) != Byte) return -1;
1730 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1731 // Make sure all array elements are sequences of the same repeated
1733 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1734 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1735 if (Byte == -1) return -1;
1737 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1738 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1739 if (ThisByte == -1) return -1;
1740 if (Byte != ThisByte) return -1;
1745 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1746 return isRepeatedByteSequence(CDS);
1751 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1754 // See if we can aggregate this into a .fill, if so, emit it as such.
1755 int Value = isRepeatedByteSequence(CDS, AP.TM);
1758 AP.TM.getDataLayout()->getTypeAllocSize(
1760 // Don't emit a 1-byte object as a .fill.
1762 return AP.OutStreamer.EmitFill(Bytes, Value);
1765 // If this can be emitted with .ascii/.asciz, emit it as such.
1766 if (CDS->isString())
1767 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1769 // Otherwise, emit the values in successive locations.
1770 unsigned ElementByteSize = CDS->getElementByteSize();
1771 if (isa<IntegerType>(CDS->getElementType())) {
1772 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1774 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1775 CDS->getElementAsInteger(i));
1776 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1779 } else if (ElementByteSize == 4) {
1780 // FP Constants are printed as integer constants to avoid losing
1782 assert(CDS->getElementType()->isFloatTy());
1783 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1789 F = CDS->getElementAsFloat(i);
1791 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1792 AP.OutStreamer.EmitIntValue(I, 4);
1795 assert(CDS->getElementType()->isDoubleTy());
1796 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1802 F = CDS->getElementAsDouble(i);
1804 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1805 AP.OutStreamer.EmitIntValue(I, 8);
1809 const DataLayout &DL = *AP.TM.getDataLayout();
1810 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1811 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1812 CDS->getNumElements();
1813 if (unsigned Padding = Size - EmittedSize)
1814 AP.OutStreamer.EmitZeros(Padding);
1818 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1819 // See if we can aggregate some values. Make sure it can be
1820 // represented as a series of bytes of the constant value.
1821 int Value = isRepeatedByteSequence(CA, AP.TM);
1825 AP.TM.getDataLayout()->getTypeAllocSize(
1827 AP.OutStreamer.EmitFill(Bytes, Value);
1830 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1831 emitGlobalConstantImpl(CA->getOperand(i), AP);
1835 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1836 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1837 emitGlobalConstantImpl(CV->getOperand(i), AP);
1839 const DataLayout &DL = *AP.TM.getDataLayout();
1840 unsigned Size = DL.getTypeAllocSize(CV->getType());
1841 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1842 CV->getType()->getNumElements();
1843 if (unsigned Padding = Size - EmittedSize)
1844 AP.OutStreamer.EmitZeros(Padding);
1847 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1848 // Print the fields in successive locations. Pad to align if needed!
1849 const DataLayout *DL = AP.TM.getDataLayout();
1850 unsigned Size = DL->getTypeAllocSize(CS->getType());
1851 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1852 uint64_t SizeSoFar = 0;
1853 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1854 const Constant *Field = CS->getOperand(i);
1856 // Check if padding is needed and insert one or more 0s.
1857 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1858 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1859 - Layout->getElementOffset(i)) - FieldSize;
1860 SizeSoFar += FieldSize + PadSize;
1862 // Now print the actual field value.
1863 emitGlobalConstantImpl(Field, AP);
1865 // Insert padding - this may include padding to increase the size of the
1866 // current field up to the ABI size (if the struct is not packed) as well
1867 // as padding to ensure that the next field starts at the right offset.
1868 AP.OutStreamer.EmitZeros(PadSize);
1870 assert(SizeSoFar == Layout->getSizeInBytes() &&
1871 "Layout of constant struct may be incorrect!");
1874 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1875 APInt API = CFP->getValueAPF().bitcastToAPInt();
1877 // First print a comment with what we think the original floating-point value
1878 // should have been.
1879 if (AP.isVerbose()) {
1880 SmallString<8> StrVal;
1881 CFP->getValueAPF().toString(StrVal);
1884 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1886 AP.OutStreamer.GetCommentOS() << "Printing <null> Type";
1887 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1890 // Now iterate through the APInt chunks, emitting them in endian-correct
1891 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1893 unsigned NumBytes = API.getBitWidth() / 8;
1894 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1895 const uint64_t *p = API.getRawData();
1897 // PPC's long double has odd notions of endianness compared to how LLVM
1898 // handles it: p[0] goes first for *big* endian on PPC.
1899 if (AP.TM.getDataLayout()->isBigEndian() &&
1900 !CFP->getType()->isPPC_FP128Ty()) {
1901 int Chunk = API.getNumWords() - 1;
1904 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1906 for (; Chunk >= 0; --Chunk)
1907 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1910 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1911 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1914 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1917 // Emit the tail padding for the long double.
1918 const DataLayout &DL = *AP.TM.getDataLayout();
1919 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1920 DL.getTypeStoreSize(CFP->getType()));
1923 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1924 const DataLayout *DL = AP.TM.getDataLayout();
1925 unsigned BitWidth = CI->getBitWidth();
1927 // Copy the value as we may massage the layout for constants whose bit width
1928 // is not a multiple of 64-bits.
1929 APInt Realigned(CI->getValue());
1930 uint64_t ExtraBits = 0;
1931 unsigned ExtraBitsSize = BitWidth & 63;
1933 if (ExtraBitsSize) {
1934 // The bit width of the data is not a multiple of 64-bits.
1935 // The extra bits are expected to be at the end of the chunk of the memory.
1937 // * Nothing to be done, just record the extra bits to emit.
1939 // * Record the extra bits to emit.
1940 // * Realign the raw data to emit the chunks of 64-bits.
1941 if (DL->isBigEndian()) {
1942 // Basically the structure of the raw data is a chunk of 64-bits cells:
1943 // 0 1 BitWidth / 64
1944 // [chunk1][chunk2] ... [chunkN].
1945 // The most significant chunk is chunkN and it should be emitted first.
1946 // However, due to the alignment issue chunkN contains useless bits.
1947 // Realign the chunks so that they contain only useless information:
1948 // ExtraBits 0 1 (BitWidth / 64) - 1
1949 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1950 ExtraBits = Realigned.getRawData()[0] &
1951 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1952 Realigned = Realigned.lshr(ExtraBitsSize);
1954 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1957 // We don't expect assemblers to support integer data directives
1958 // for more than 64 bits, so we emit the data in at most 64-bit
1959 // quantities at a time.
1960 const uint64_t *RawData = Realigned.getRawData();
1961 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1962 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1963 AP.OutStreamer.EmitIntValue(Val, 8);
1966 if (ExtraBitsSize) {
1967 // Emit the extra bits after the 64-bits chunks.
1969 // Emit a directive that fills the expected size.
1970 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(
1972 Size -= (BitWidth / 64) * 8;
1973 assert(Size && Size * 8 >= ExtraBitsSize &&
1974 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1975 == ExtraBits && "Directive too small for extra bits.");
1976 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1980 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1981 const DataLayout *DL = AP.TM.getDataLayout();
1982 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1983 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1984 return AP.OutStreamer.EmitZeros(Size);
1986 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1993 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1994 CI->getZExtValue());
1995 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1998 emitGlobalConstantLargeInt(CI, AP);
2003 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
2004 return emitGlobalConstantFP(CFP, AP);
2006 if (isa<ConstantPointerNull>(CV)) {
2007 AP.OutStreamer.EmitIntValue(0, Size);
2011 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
2012 return emitGlobalConstantDataSequential(CDS, AP);
2014 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2015 return emitGlobalConstantArray(CVA, AP);
2017 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2018 return emitGlobalConstantStruct(CVS, AP);
2020 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2021 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2023 if (CE->getOpcode() == Instruction::BitCast)
2024 return emitGlobalConstantImpl(CE->getOperand(0), AP);
2027 // If the constant expression's size is greater than 64-bits, then we have
2028 // to emit the value in chunks. Try to constant fold the value and emit it
2030 Constant *New = ConstantFoldConstantExpression(CE, DL);
2031 if (New && New != CE)
2032 return emitGlobalConstantImpl(New, AP);
2036 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2037 return emitGlobalConstantVector(V, AP);
2039 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2040 // thread the streamer with EmitValue.
2041 AP.OutStreamer.EmitValue(AP.lowerConstant(CV), Size);
2044 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2045 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2047 TM.getDataLayout()->getTypeAllocSize(CV->getType());
2049 emitGlobalConstantImpl(CV, *this);
2050 else if (MAI->hasSubsectionsViaSymbols()) {
2051 // If the global has zero size, emit a single byte so that two labels don't
2052 // look like they are at the same location.
2053 OutStreamer.EmitIntValue(0, 1);
2057 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2058 // Target doesn't support this yet!
2059 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2062 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2064 OS << '+' << Offset;
2065 else if (Offset < 0)
2069 //===----------------------------------------------------------------------===//
2070 // Symbol Lowering Routines.
2071 //===----------------------------------------------------------------------===//
2073 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2074 /// temporary label with the specified stem and unique ID.
2075 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const {
2076 const DataLayout *DL = TM.getDataLayout();
2077 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2081 /// GetTempSymbol - Return an assembler temporary label with the specified
2083 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const {
2084 const DataLayout *DL = TM.getDataLayout();
2085 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2090 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2091 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2094 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2095 return MMI->getAddrLabelSymbol(BB);
2098 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2099 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2100 const DataLayout *DL = TM.getDataLayout();
2101 return OutContext.GetOrCreateSymbol
2102 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2103 + "_" + Twine(CPID));
2106 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2107 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2108 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2111 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2112 /// FIXME: privatize to AsmPrinter.
2113 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2114 const DataLayout *DL = TM.getDataLayout();
2115 return OutContext.GetOrCreateSymbol
2116 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2117 Twine(UID) + "_set_" + Twine(MBBID));
2120 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2121 StringRef Suffix) const {
2122 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2126 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2128 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2129 SmallString<60> NameStr;
2130 Mang->getNameWithPrefix(NameStr, Sym);
2131 return OutContext.GetOrCreateSymbol(NameStr.str());
2136 /// PrintParentLoopComment - Print comments about parent loops of this one.
2137 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2138 unsigned FunctionNumber) {
2140 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2141 OS.indent(Loop->getLoopDepth()*2)
2142 << "Parent Loop BB" << FunctionNumber << "_"
2143 << Loop->getHeader()->getNumber()
2144 << " Depth=" << Loop->getLoopDepth() << '\n';
2148 /// PrintChildLoopComment - Print comments about child loops within
2149 /// the loop for this basic block, with nesting.
2150 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2151 unsigned FunctionNumber) {
2152 // Add child loop information
2153 for (const MachineLoop *CL : *Loop) {
2154 OS.indent(CL->getLoopDepth()*2)
2155 << "Child Loop BB" << FunctionNumber << "_"
2156 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2158 PrintChildLoopComment(OS, CL, FunctionNumber);
2162 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2163 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2164 const MachineLoopInfo *LI,
2165 const AsmPrinter &AP) {
2166 // Add loop depth information
2167 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2170 MachineBasicBlock *Header = Loop->getHeader();
2171 assert(Header && "No header for loop");
2173 // If this block is not a loop header, just print out what is the loop header
2175 if (Header != &MBB) {
2176 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2177 Twine(AP.getFunctionNumber())+"_" +
2178 Twine(Loop->getHeader()->getNumber())+
2179 " Depth="+Twine(Loop->getLoopDepth()));
2183 // Otherwise, it is a loop header. Print out information about child and
2185 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2187 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2190 OS.indent(Loop->getLoopDepth()*2-2);
2195 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2197 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2201 /// EmitBasicBlockStart - This method prints the label for the specified
2202 /// MachineBasicBlock, an alignment (if present) and a comment describing
2203 /// it if appropriate.
2204 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2205 // Emit an alignment directive for this block, if needed.
2206 if (unsigned Align = MBB.getAlignment())
2207 EmitAlignment(Align);
2209 // If the block has its address taken, emit any labels that were used to
2210 // reference the block. It is possible that there is more than one label
2211 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2212 // the references were generated.
2213 if (MBB.hasAddressTaken()) {
2214 const BasicBlock *BB = MBB.getBasicBlock();
2216 OutStreamer.AddComment("Block address taken");
2218 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2219 for (auto *Sym : Symbols)
2220 OutStreamer.EmitLabel(Sym);
2223 // Print some verbose block comments.
2225 if (const BasicBlock *BB = MBB.getBasicBlock())
2227 OutStreamer.AddComment("%" + BB->getName());
2228 emitBasicBlockLoopComments(MBB, LI, *this);
2231 // Print the main label for the block.
2232 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2234 // NOTE: Want this comment at start of line, don't emit with AddComment.
2235 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2238 OutStreamer.EmitLabel(MBB.getSymbol());
2242 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2243 bool IsDefinition) const {
2244 MCSymbolAttr Attr = MCSA_Invalid;
2246 switch (Visibility) {
2248 case GlobalValue::HiddenVisibility:
2250 Attr = MAI->getHiddenVisibilityAttr();
2252 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2254 case GlobalValue::ProtectedVisibility:
2255 Attr = MAI->getProtectedVisibilityAttr();
2259 if (Attr != MCSA_Invalid)
2260 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2263 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2264 /// exactly one predecessor and the control transfer mechanism between
2265 /// the predecessor and this block is a fall-through.
2267 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2268 // If this is a landing pad, it isn't a fall through. If it has no preds,
2269 // then nothing falls through to it.
2270 if (MBB->isLandingPad() || MBB->pred_empty())
2273 // If there isn't exactly one predecessor, it can't be a fall through.
2274 if (MBB->pred_size() > 1)
2277 // The predecessor has to be immediately before this block.
2278 MachineBasicBlock *Pred = *MBB->pred_begin();
2279 if (!Pred->isLayoutSuccessor(MBB))
2282 // If the block is completely empty, then it definitely does fall through.
2286 // Check the terminators in the previous blocks
2287 for (const auto &MI : Pred->terminators()) {
2288 // If it is not a simple branch, we are in a table somewhere.
2289 if (!MI.isBranch() || MI.isIndirectBranch())
2292 // If we are the operands of one of the branches, this is not a fall
2293 // through. Note that targets with delay slots will usually bundle
2294 // terminators with the delay slot instruction.
2295 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2298 if (OP->isMBB() && OP->getMBB() == MBB)
2308 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2309 if (!S.usesMetadata())
2312 assert(!S.useStatepoints() && "statepoints do not currently support custom"
2313 " stackmap formats, please see the documentation for a description of"
2314 " the default format. If you really need a custom serialized format,"
2315 " please file a bug");
2317 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2318 gcp_map_type::iterator GCPI = GCMap.find(&S);
2319 if (GCPI != GCMap.end())
2320 return GCPI->second.get();
2322 const char *Name = S.getName().c_str();
2324 for (GCMetadataPrinterRegistry::iterator
2325 I = GCMetadataPrinterRegistry::begin(),
2326 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2327 if (strcmp(Name, I->getName()) == 0) {
2328 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2330 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2331 return IterBool.first->second.get();
2334 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2337 /// Pin vtable to this file.
2338 AsmPrinterHandler::~AsmPrinterHandler() {}