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(*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 switch (MAI->getWinEHEncodingType()) {
246 default: llvm_unreachable("unsupported unwinding information encoding");
247 case WinEH::EncodingType::Itanium:
248 ES = new Win64Exception(this);
254 Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
258 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
259 if (!MAI.hasWeakDefCanBeHiddenDirective())
262 return canBeOmittedFromSymbolTable(GV);
265 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
266 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
268 case GlobalValue::CommonLinkage:
269 case GlobalValue::LinkOnceAnyLinkage:
270 case GlobalValue::LinkOnceODRLinkage:
271 case GlobalValue::WeakAnyLinkage:
272 case GlobalValue::WeakODRLinkage:
273 if (MAI->hasWeakDefDirective()) {
275 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
277 if (!canBeHidden(GV, *MAI))
278 // .weak_definition _foo
279 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
281 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
282 } else if (MAI->hasLinkOnceDirective()) {
284 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
285 //NOTE: linkonce is handled by the section the symbol was assigned to.
288 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
291 case GlobalValue::AppendingLinkage:
292 // FIXME: appending linkage variables should go into a section of
293 // their name or something. For now, just emit them as external.
294 case GlobalValue::ExternalLinkage:
295 // If external or appending, declare as a global symbol.
297 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
299 case GlobalValue::PrivateLinkage:
300 case GlobalValue::InternalLinkage:
302 case GlobalValue::AvailableExternallyLinkage:
303 llvm_unreachable("Should never emit this");
304 case GlobalValue::ExternalWeakLinkage:
305 llvm_unreachable("Don't know how to emit these");
307 llvm_unreachable("Unknown linkage type!");
310 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
311 const GlobalValue *GV) const {
312 TM.getNameWithPrefix(Name, GV, *Mang);
315 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
316 return TM.getSymbol(GV, *Mang);
319 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
320 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
321 if (GV->hasInitializer()) {
322 // Check to see if this is a special global used by LLVM, if so, emit it.
323 if (EmitSpecialLLVMGlobal(GV))
327 GV->printAsOperand(OutStreamer.GetCommentOS(),
328 /*PrintType=*/false, GV->getParent());
329 OutStreamer.GetCommentOS() << '\n';
333 MCSymbol *GVSym = getSymbol(GV);
334 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
336 if (!GV->hasInitializer()) // External globals require no extra code.
339 if (MAI->hasDotTypeDotSizeDirective())
340 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
342 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
344 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
345 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
347 // If the alignment is specified, we *must* obey it. Overaligning a global
348 // with a specified alignment is a prompt way to break globals emitted to
349 // sections and expected to be contiguous (e.g. ObjC metadata).
350 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
352 for (const HandlerInfo &HI : Handlers) {
353 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
354 HI.Handler->setSymbolSize(GVSym, Size);
357 // Handle common and BSS local symbols (.lcomm).
358 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
359 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
360 unsigned Align = 1 << AlignLog;
362 // Handle common symbols.
363 if (GVKind.isCommon()) {
364 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
368 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
372 // Handle local BSS symbols.
373 if (MAI->hasMachoZeroFillDirective()) {
374 const MCSection *TheSection =
375 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
376 // .zerofill __DATA, __bss, _foo, 400, 5
377 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
381 // Use .lcomm only if it supports user-specified alignment.
382 // Otherwise, while it would still be correct to use .lcomm in some
383 // cases (e.g. when Align == 1), the external assembler might enfore
384 // some -unknown- default alignment behavior, which could cause
385 // spurious differences between external and integrated assembler.
386 // Prefer to simply fall back to .local / .comm in this case.
387 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
389 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
393 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
397 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
399 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
403 const MCSection *TheSection =
404 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
406 // Handle the zerofill directive on darwin, which is a special form of BSS
408 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
409 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
412 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
413 // .zerofill __DATA, __common, _foo, 400, 5
414 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
418 // Handle thread local data for mach-o which requires us to output an
419 // additional structure of data and mangle the original symbol so that we
420 // can reference it later.
422 // TODO: This should become an "emit thread local global" method on TLOF.
423 // All of this macho specific stuff should be sunk down into TLOFMachO and
424 // stuff like "TLSExtraDataSection" should no longer be part of the parent
425 // TLOF class. This will also make it more obvious that stuff like
426 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
428 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
429 // Emit the .tbss symbol
431 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
433 if (GVKind.isThreadBSS()) {
434 TheSection = getObjFileLowering().getTLSBSSSection();
435 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
436 } else if (GVKind.isThreadData()) {
437 OutStreamer.SwitchSection(TheSection);
439 EmitAlignment(AlignLog, GV);
440 OutStreamer.EmitLabel(MangSym);
442 EmitGlobalConstant(GV->getInitializer());
445 OutStreamer.AddBlankLine();
447 // Emit the variable struct for the runtime.
448 const MCSection *TLVSect
449 = getObjFileLowering().getTLSExtraDataSection();
451 OutStreamer.SwitchSection(TLVSect);
452 // Emit the linkage here.
453 EmitLinkage(GV, GVSym);
454 OutStreamer.EmitLabel(GVSym);
456 // Three pointers in size:
457 // - __tlv_bootstrap - used to make sure support exists
458 // - spare pointer, used when mapped by the runtime
459 // - pointer to mangled symbol above with initializer
460 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
461 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
463 OutStreamer.EmitIntValue(0, PtrSize);
464 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
466 OutStreamer.AddBlankLine();
470 OutStreamer.SwitchSection(TheSection);
472 EmitLinkage(GV, GVSym);
473 EmitAlignment(AlignLog, GV);
475 OutStreamer.EmitLabel(GVSym);
477 EmitGlobalConstant(GV->getInitializer());
479 if (MAI->hasDotTypeDotSizeDirective())
481 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
483 OutStreamer.AddBlankLine();
486 /// EmitFunctionHeader - This method emits the header for the current
488 void AsmPrinter::EmitFunctionHeader() {
489 // Print out constants referenced by the function
492 // Print the 'header' of function.
493 const Function *F = MF->getFunction();
495 OutStreamer.SwitchSection(
496 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
497 EmitVisibility(CurrentFnSym, F->getVisibility());
499 EmitLinkage(F, CurrentFnSym);
500 EmitAlignment(MF->getAlignment(), F);
502 if (MAI->hasDotTypeDotSizeDirective())
503 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
506 F->printAsOperand(OutStreamer.GetCommentOS(),
507 /*PrintType=*/false, F->getParent());
508 OutStreamer.GetCommentOS() << '\n';
511 // Emit the CurrentFnSym. This is a virtual function to allow targets to
512 // do their wild and crazy things as required.
513 EmitFunctionEntryLabel();
515 // If the function had address-taken blocks that got deleted, then we have
516 // references to the dangling symbols. Emit them at the start of the function
517 // so that we don't get references to undefined symbols.
518 std::vector<MCSymbol*> DeadBlockSyms;
519 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
520 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
521 OutStreamer.AddComment("Address taken block that was later removed");
522 OutStreamer.EmitLabel(DeadBlockSyms[i]);
525 // Emit pre-function debug and/or EH information.
526 for (const HandlerInfo &HI : Handlers) {
527 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
528 HI.Handler->beginFunction(MF);
531 // Emit the prefix data.
532 if (F->hasPrefixData())
533 EmitGlobalConstant(F->getPrefixData());
536 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
537 /// function. This can be overridden by targets as required to do custom stuff.
538 void AsmPrinter::EmitFunctionEntryLabel() {
539 // The function label could have already been emitted if two symbols end up
540 // conflicting due to asm renaming. Detect this and emit an error.
541 if (CurrentFnSym->isUndefined())
542 return OutStreamer.EmitLabel(CurrentFnSym);
544 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
545 "' label emitted multiple times to assembly file");
548 /// emitComments - Pretty-print comments for instructions.
549 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
550 const MachineFunction *MF = MI.getParent()->getParent();
551 const TargetMachine &TM = MF->getTarget();
553 // Check for spills and reloads
556 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
558 // We assume a single instruction only has a spill or reload, not
560 const MachineMemOperand *MMO;
561 if (TM.getSubtargetImpl()->getInstrInfo()->isLoadFromStackSlotPostFE(&MI,
563 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
564 MMO = *MI.memoperands_begin();
565 CommentOS << MMO->getSize() << "-byte Reload\n";
567 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasLoadFromStackSlot(
569 if (FrameInfo->isSpillSlotObjectIndex(FI))
570 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
571 } else if (TM.getSubtargetImpl()->getInstrInfo()->isStoreToStackSlotPostFE(
573 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
574 MMO = *MI.memoperands_begin();
575 CommentOS << MMO->getSize() << "-byte Spill\n";
577 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasStoreToStackSlot(
579 if (FrameInfo->isSpillSlotObjectIndex(FI))
580 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
583 // Check for spill-induced copies
584 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
585 CommentOS << " Reload Reuse\n";
588 /// emitImplicitDef - This method emits the specified machine instruction
589 /// that is an implicit def.
590 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
591 unsigned RegNo = MI->getOperand(0).getReg();
592 OutStreamer.AddComment(
593 Twine("implicit-def: ") +
594 TM.getSubtargetImpl()->getRegisterInfo()->getName(RegNo));
595 OutStreamer.AddBlankLine();
598 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
599 std::string Str = "kill:";
600 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
601 const MachineOperand &Op = MI->getOperand(i);
602 assert(Op.isReg() && "KILL instruction must have only register operands");
604 Str += AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Op.getReg());
605 Str += (Op.isDef() ? "<def>" : "<kill>");
607 AP.OutStreamer.AddComment(Str);
608 AP.OutStreamer.AddBlankLine();
611 /// emitDebugValueComment - This method handles the target-independent form
612 /// of DBG_VALUE, returning true if it was able to do so. A false return
613 /// means the target will need to handle MI in EmitInstruction.
614 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
615 // This code handles only the 4-operand target-independent form.
616 if (MI->getNumOperands() != 4)
619 SmallString<128> Str;
620 raw_svector_ostream OS(Str);
621 OS << "DEBUG_VALUE: ";
623 DIVariable V = MI->getDebugVariable();
624 if (V.getContext().isSubprogram()) {
625 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
631 DIExpression Expr = MI->getDebugExpression();
632 if (Expr.isVariablePiece())
633 OS << " [piece offset=" << Expr.getPieceOffset()
634 << " size=" << Expr.getPieceSize() << "]";
637 // The second operand is only an offset if it's an immediate.
638 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
639 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
641 // Register or immediate value. Register 0 means undef.
642 if (MI->getOperand(0).isFPImm()) {
643 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
644 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
645 OS << (double)APF.convertToFloat();
646 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
647 OS << APF.convertToDouble();
649 // There is no good way to print long double. Convert a copy to
650 // double. Ah well, it's only a comment.
652 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
654 OS << "(long double) " << APF.convertToDouble();
656 } else if (MI->getOperand(0).isImm()) {
657 OS << MI->getOperand(0).getImm();
658 } else if (MI->getOperand(0).isCImm()) {
659 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
662 if (MI->getOperand(0).isReg()) {
663 Reg = MI->getOperand(0).getReg();
665 assert(MI->getOperand(0).isFI() && "Unknown operand type");
666 const TargetFrameLowering *TFI =
667 AP.TM.getSubtargetImpl()->getFrameLowering();
668 Offset += TFI->getFrameIndexReference(*AP.MF,
669 MI->getOperand(0).getIndex(), Reg);
673 // Suppress offset, it is not meaningful here.
675 // NOTE: Want this comment at start of line, don't emit with AddComment.
676 AP.OutStreamer.emitRawComment(OS.str());
681 OS << AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Reg);
685 OS << '+' << Offset << ']';
687 // NOTE: Want this comment at start of line, don't emit with AddComment.
688 AP.OutStreamer.emitRawComment(OS.str());
692 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
693 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
694 MF->getFunction()->needsUnwindTableEntry())
697 if (MMI->hasDebugInfo())
703 bool AsmPrinter::needsSEHMoves() {
704 return MAI->getExceptionHandlingType() == ExceptionHandling::ItaniumWinEH &&
705 MF->getFunction()->needsUnwindTableEntry();
708 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
709 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
710 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
711 ExceptionHandlingType != ExceptionHandling::ARM)
714 if (needsCFIMoves() == CFI_M_None)
717 const MachineModuleInfo &MMI = MF->getMMI();
718 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
719 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
720 const MCCFIInstruction &CFI = Instrs[CFIIndex];
721 emitCFIInstruction(CFI);
724 /// EmitFunctionBody - This method emits the body and trailer for a
726 void AsmPrinter::EmitFunctionBody() {
727 // Emit target-specific gunk before the function body.
728 EmitFunctionBodyStart();
730 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
732 // Print out code for the function.
733 bool HasAnyRealCode = false;
734 for (auto &MBB : *MF) {
735 // Print a label for the basic block.
736 EmitBasicBlockStart(MBB);
737 for (auto &MI : MBB) {
739 // Print the assembly for the instruction.
740 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
741 !MI.isDebugValue()) {
742 HasAnyRealCode = true;
746 if (ShouldPrintDebugScopes) {
747 for (const HandlerInfo &HI : Handlers) {
748 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
749 TimePassesIsEnabled);
750 HI.Handler->beginInstruction(&MI);
755 emitComments(MI, OutStreamer.GetCommentOS());
757 switch (MI.getOpcode()) {
758 case TargetOpcode::CFI_INSTRUCTION:
759 emitCFIInstruction(MI);
762 case TargetOpcode::EH_LABEL:
763 case TargetOpcode::GC_LABEL:
764 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
766 case TargetOpcode::INLINEASM:
769 case TargetOpcode::DBG_VALUE:
771 if (!emitDebugValueComment(&MI, *this))
772 EmitInstruction(&MI);
775 case TargetOpcode::IMPLICIT_DEF:
776 if (isVerbose()) emitImplicitDef(&MI);
778 case TargetOpcode::KILL:
779 if (isVerbose()) emitKill(&MI, *this);
782 EmitInstruction(&MI);
786 if (ShouldPrintDebugScopes) {
787 for (const HandlerInfo &HI : Handlers) {
788 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
789 TimePassesIsEnabled);
790 HI.Handler->endInstruction();
795 EmitBasicBlockEnd(MBB);
798 // If the function is empty and the object file uses .subsections_via_symbols,
799 // then we need to emit *something* to the function body to prevent the
800 // labels from collapsing together. Just emit a noop.
801 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
803 TM.getSubtargetImpl()->getInstrInfo()->getNoopForMachoTarget(Noop);
804 OutStreamer.AddComment("avoids zero-length function");
806 // Targets can opt-out of emitting the noop here by leaving the opcode
808 if (Noop.getOpcode())
809 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
812 const Function *F = MF->getFunction();
813 for (const auto &BB : *F) {
814 if (!BB.hasAddressTaken())
816 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
817 if (Sym->isDefined())
819 OutStreamer.AddComment("Address of block that was removed by CodeGen");
820 OutStreamer.EmitLabel(Sym);
823 // Emit target-specific gunk after the function body.
824 EmitFunctionBodyEnd();
826 // If the target wants a .size directive for the size of the function, emit
828 if (MAI->hasDotTypeDotSizeDirective()) {
829 // Create a symbol for the end of function, so we can get the size as
830 // difference between the function label and the temp label.
831 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
832 OutStreamer.EmitLabel(FnEndLabel);
834 const MCExpr *SizeExp =
835 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
836 MCSymbolRefExpr::Create(CurrentFnSymForSize,
839 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
842 // Emit post-function debug and/or EH information.
843 for (const HandlerInfo &HI : Handlers) {
844 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
845 HI.Handler->endFunction(MF);
849 // Print out jump tables referenced by the function.
852 OutStreamer.AddBlankLine();
855 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP);
857 bool AsmPrinter::doFinalization(Module &M) {
858 // Emit global variables.
859 for (const auto &G : M.globals())
860 EmitGlobalVariable(&G);
862 // Emit visibility info for declarations
863 for (const Function &F : M) {
864 if (!F.isDeclaration())
866 GlobalValue::VisibilityTypes V = F.getVisibility();
867 if (V == GlobalValue::DefaultVisibility)
870 MCSymbol *Name = getSymbol(&F);
871 EmitVisibility(Name, V, false);
874 // Get information about jump-instruction tables to print.
875 JumpInstrTableInfo *JITI = getAnalysisIfAvailable<JumpInstrTableInfo>();
877 if (JITI && !JITI->getTables().empty()) {
878 unsigned Arch = Triple(getTargetTriple()).getArch();
879 bool IsThumb = (Arch == Triple::thumb || Arch == Triple::thumbeb);
881 TM.getSubtargetImpl()->getInstrInfo()->getTrap(TrapInst);
882 unsigned LogAlignment = llvm::Log2_64(JITI->entryByteAlignment());
884 // Emit the right section for these functions.
885 OutStreamer.SwitchSection(OutContext.getObjectFileInfo()->getTextSection());
886 for (const auto &KV : JITI->getTables()) {
888 for (const auto &FunPair : KV.second) {
889 // Emit the function labels to make this be a function entry point.
891 OutContext.GetOrCreateSymbol(FunPair.second->getName());
892 EmitAlignment(LogAlignment);
894 OutStreamer.EmitThumbFunc(FunSym);
895 if (MAI->hasDotTypeDotSizeDirective())
896 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_ELF_TypeFunction);
897 OutStreamer.EmitLabel(FunSym);
899 // Emit the jump instruction to transfer control to the original
902 MCSymbol *TargetSymbol =
903 OutContext.GetOrCreateSymbol(FunPair.first->getName());
904 const MCSymbolRefExpr *TargetSymRef =
905 MCSymbolRefExpr::Create(TargetSymbol, MCSymbolRefExpr::VK_PLT,
907 TM.getSubtargetImpl()->getInstrInfo()->getUnconditionalBranch(
908 JumpToFun, TargetSymRef);
909 OutStreamer.EmitInstruction(JumpToFun, getSubtargetInfo());
913 // Emit enough padding instructions to fill up to the next power of two.
914 uint64_t Remaining = NextPowerOf2(Count) - Count;
915 for (uint64_t C = 0; C < Remaining; ++C) {
916 EmitAlignment(LogAlignment);
917 OutStreamer.EmitInstruction(TrapInst, getSubtargetInfo());
923 // Emit module flags.
924 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
925 M.getModuleFlagsMetadata(ModuleFlags);
926 if (!ModuleFlags.empty())
927 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
929 // Make sure we wrote out everything we need.
932 // Finalize debug and EH information.
933 for (const HandlerInfo &HI : Handlers) {
934 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
935 TimePassesIsEnabled);
936 HI.Handler->endModule();
942 // If the target wants to know about weak references, print them all.
943 if (MAI->getWeakRefDirective()) {
944 // FIXME: This is not lazy, it would be nice to only print weak references
945 // to stuff that is actually used. Note that doing so would require targets
946 // to notice uses in operands (due to constant exprs etc). This should
947 // happen with the MC stuff eventually.
949 // Print out module-level global variables here.
950 for (const auto &G : M.globals()) {
951 if (!G.hasExternalWeakLinkage())
953 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
956 for (const auto &F : M) {
957 if (!F.hasExternalWeakLinkage())
959 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
963 OutStreamer.AddBlankLine();
964 for (const auto &Alias : M.aliases()) {
965 MCSymbol *Name = getSymbol(&Alias);
967 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
968 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
969 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
970 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
972 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
974 EmitVisibility(Name, Alias.getVisibility());
976 // Emit the directives as assignments aka .set:
977 OutStreamer.EmitAssignment(Name, lowerConstant(Alias.getAliasee(), *this));
980 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
981 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
982 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
983 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
984 MP->finishAssembly(*this);
986 // Emit llvm.ident metadata in an '.ident' directive.
989 // If we don't have any trampolines, then we don't require stack memory
990 // to be executable. Some targets have a directive to declare this.
991 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
992 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
993 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
994 OutStreamer.SwitchSection(S);
996 // Allow the target to emit any magic that it wants at the end of the file,
997 // after everything else has gone out.
1000 delete Mang; Mang = nullptr;
1003 OutStreamer.Finish();
1004 OutStreamer.reset();
1009 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1011 // Get the function symbol.
1012 CurrentFnSym = getSymbol(MF.getFunction());
1013 CurrentFnSymForSize = CurrentFnSym;
1016 LI = &getAnalysis<MachineLoopInfo>();
1020 // SectionCPs - Keep track the alignment, constpool entries per Section.
1024 SmallVector<unsigned, 4> CPEs;
1025 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1029 /// EmitConstantPool - Print to the current output stream assembly
1030 /// representations of the constants in the constant pool MCP. This is
1031 /// used to print out constants which have been "spilled to memory" by
1032 /// the code generator.
1034 void AsmPrinter::EmitConstantPool() {
1035 const MachineConstantPool *MCP = MF->getConstantPool();
1036 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1037 if (CP.empty()) return;
1039 // Calculate sections for constant pool entries. We collect entries to go into
1040 // the same section together to reduce amount of section switch statements.
1041 SmallVector<SectionCPs, 4> CPSections;
1042 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1043 const MachineConstantPoolEntry &CPE = CP[i];
1044 unsigned Align = CPE.getAlignment();
1047 CPE.getSectionKind(TM.getSubtargetImpl()->getDataLayout());
1049 const Constant *C = nullptr;
1050 if (!CPE.isMachineConstantPoolEntry())
1051 C = CPE.Val.ConstVal;
1053 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind, C);
1055 // The number of sections are small, just do a linear search from the
1056 // last section to the first.
1058 unsigned SecIdx = CPSections.size();
1059 while (SecIdx != 0) {
1060 if (CPSections[--SecIdx].S == S) {
1066 SecIdx = CPSections.size();
1067 CPSections.push_back(SectionCPs(S, Align));
1070 if (Align > CPSections[SecIdx].Alignment)
1071 CPSections[SecIdx].Alignment = Align;
1072 CPSections[SecIdx].CPEs.push_back(i);
1075 // Now print stuff into the calculated sections.
1076 const MCSection *CurSection = nullptr;
1077 unsigned Offset = 0;
1078 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1079 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1080 unsigned CPI = CPSections[i].CPEs[j];
1081 MCSymbol *Sym = GetCPISymbol(CPI);
1082 if (!Sym->isUndefined())
1085 if (CurSection != CPSections[i].S) {
1086 OutStreamer.SwitchSection(CPSections[i].S);
1087 EmitAlignment(Log2_32(CPSections[i].Alignment));
1088 CurSection = CPSections[i].S;
1092 MachineConstantPoolEntry CPE = CP[CPI];
1094 // Emit inter-object padding for alignment.
1095 unsigned AlignMask = CPE.getAlignment() - 1;
1096 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1097 OutStreamer.EmitZeros(NewOffset - Offset);
1099 Type *Ty = CPE.getType();
1100 Offset = NewOffset +
1101 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(Ty);
1103 OutStreamer.EmitLabel(Sym);
1104 if (CPE.isMachineConstantPoolEntry())
1105 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1107 EmitGlobalConstant(CPE.Val.ConstVal);
1112 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1113 /// by the current function to the current output stream.
1115 void AsmPrinter::EmitJumpTableInfo() {
1116 const DataLayout *DL = MF->getSubtarget().getDataLayout();
1117 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1119 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1120 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1121 if (JT.empty()) return;
1123 // Pick the directive to use to print the jump table entries, and switch to
1124 // the appropriate section.
1125 const Function *F = MF->getFunction();
1126 bool JTInDiffSection = false;
1127 if (// In PIC mode, we need to emit the jump table to the same section as the
1128 // function body itself, otherwise the label differences won't make sense.
1129 // FIXME: Need a better predicate for this: what about custom entries?
1130 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1131 // We should also do if the section name is NULL or function is declared
1132 // in discardable section
1133 // FIXME: this isn't the right predicate, should be based on the MCSection
1134 // for the function.
1135 F->isWeakForLinker()) {
1136 OutStreamer.SwitchSection(
1137 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1139 // Otherwise, drop it in the readonly section.
1140 const MCSection *ReadOnlySection =
1141 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
1143 OutStreamer.SwitchSection(ReadOnlySection);
1144 JTInDiffSection = true;
1147 EmitAlignment(Log2_32(
1148 MJTI->getEntryAlignment(*TM.getSubtargetImpl()->getDataLayout())));
1150 // Jump tables in code sections are marked with a data_region directive
1151 // where that's supported.
1152 if (!JTInDiffSection)
1153 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1155 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1156 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1158 // If this jump table was deleted, ignore it.
1159 if (JTBBs.empty()) continue;
1161 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1162 /// emit a .set directive for each unique entry.
1163 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1164 MAI->doesSetDirectiveSuppressesReloc()) {
1165 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1166 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1167 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1168 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1169 const MachineBasicBlock *MBB = JTBBs[ii];
1170 if (!EmittedSets.insert(MBB).second)
1173 // .set LJTSet, LBB32-base
1175 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1176 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1177 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1181 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1182 // before each jump table. The first label is never referenced, but tells
1183 // the assembler and linker the extents of the jump table object. The
1184 // second label is actually referenced by the code.
1185 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1186 // FIXME: This doesn't have to have any specific name, just any randomly
1187 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1188 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1190 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1192 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1193 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1195 if (!JTInDiffSection)
1196 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1199 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1201 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1202 const MachineBasicBlock *MBB,
1203 unsigned UID) const {
1204 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1205 const MCExpr *Value = nullptr;
1206 switch (MJTI->getEntryKind()) {
1207 case MachineJumpTableInfo::EK_Inline:
1208 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1209 case MachineJumpTableInfo::EK_Custom32:
1211 TM.getSubtargetImpl()->getTargetLowering()->LowerCustomJumpTableEntry(
1212 MJTI, MBB, UID, OutContext);
1214 case MachineJumpTableInfo::EK_BlockAddress:
1215 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1217 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1219 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1220 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1221 // with a relocation as gp-relative, e.g.:
1223 MCSymbol *MBBSym = MBB->getSymbol();
1224 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1228 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1229 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1230 // with a relocation as gp-relative, e.g.:
1232 MCSymbol *MBBSym = MBB->getSymbol();
1233 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1237 case MachineJumpTableInfo::EK_LabelDifference32: {
1238 // Each entry is the address of the block minus the address of the jump
1239 // table. This is used for PIC jump tables where gprel32 is not supported.
1241 // .word LBB123 - LJTI1_2
1242 // If the .set directive avoids relocations, this is emitted as:
1243 // .set L4_5_set_123, LBB123 - LJTI1_2
1244 // .word L4_5_set_123
1245 if (MAI->doesSetDirectiveSuppressesReloc()) {
1246 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1250 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1251 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1252 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1253 Value = MCBinaryExpr::CreateSub(Value, Base, OutContext);
1258 assert(Value && "Unknown entry kind!");
1260 unsigned EntrySize =
1261 MJTI->getEntrySize(*TM.getSubtargetImpl()->getDataLayout());
1262 OutStreamer.EmitValue(Value, EntrySize);
1266 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1267 /// special global used by LLVM. If so, emit it and return true, otherwise
1268 /// do nothing and return false.
1269 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1270 if (GV->getName() == "llvm.used") {
1271 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1272 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1276 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1277 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1278 GV->hasAvailableExternallyLinkage())
1281 if (!GV->hasAppendingLinkage()) return false;
1283 assert(GV->hasInitializer() && "Not a special LLVM global!");
1285 if (GV->getName() == "llvm.global_ctors") {
1286 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1288 if (TM.getRelocationModel() == Reloc::Static &&
1289 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1290 StringRef Sym(".constructors_used");
1291 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1297 if (GV->getName() == "llvm.global_dtors") {
1298 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1300 if (TM.getRelocationModel() == Reloc::Static &&
1301 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1302 StringRef Sym(".destructors_used");
1303 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1312 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1313 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1314 /// is true, as being used with this directive.
1315 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1316 // Should be an array of 'i8*'.
1317 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1318 const GlobalValue *GV =
1319 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1321 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1327 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1329 llvm::Constant *Func;
1330 llvm::GlobalValue *ComdatKey;
1334 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1336 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1337 // Should be an array of '{ int, void ()* }' structs. The first value is the
1339 if (!isa<ConstantArray>(List)) return;
1341 // Sanity check the structors list.
1342 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1343 if (!InitList) return; // Not an array!
1344 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1345 // FIXME: Only allow the 3-field form in LLVM 4.0.
1346 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1347 return; // Not an array of two or three elements!
1348 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1349 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1350 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1351 return; // Not (int, ptr, ptr).
1353 // Gather the structors in a form that's convenient for sorting by priority.
1354 SmallVector<Structor, 8> Structors;
1355 for (Value *O : InitList->operands()) {
1356 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1357 if (!CS) continue; // Malformed.
1358 if (CS->getOperand(1)->isNullValue())
1359 break; // Found a null terminator, skip the rest.
1360 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1361 if (!Priority) continue; // Malformed.
1362 Structors.push_back(Structor());
1363 Structor &S = Structors.back();
1364 S.Priority = Priority->getLimitedValue(65535);
1365 S.Func = CS->getOperand(1);
1366 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1367 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1370 // Emit the function pointers in the target-specific order
1371 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
1372 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1373 std::stable_sort(Structors.begin(), Structors.end(),
1374 [](const Structor &L,
1375 const Structor &R) { return L.Priority < R.Priority; });
1376 for (Structor &S : Structors) {
1377 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1378 const MCSymbol *KeySym = nullptr;
1379 if (GlobalValue *GV = S.ComdatKey) {
1380 if (GV->hasAvailableExternallyLinkage())
1381 // If the associated variable is available_externally, some other TU
1382 // will provide its dynamic initializer.
1385 KeySym = getSymbol(GV);
1387 const MCSection *OutputSection =
1388 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1389 : Obj.getStaticDtorSection(S.Priority, KeySym));
1390 OutStreamer.SwitchSection(OutputSection);
1391 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1392 EmitAlignment(Align);
1393 EmitXXStructor(S.Func);
1397 void AsmPrinter::EmitModuleIdents(Module &M) {
1398 if (!MAI->hasIdentDirective())
1401 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1402 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1403 const MDNode *N = NMD->getOperand(i);
1404 assert(N->getNumOperands() == 1 &&
1405 "llvm.ident metadata entry can have only one operand");
1406 const MDString *S = cast<MDString>(N->getOperand(0));
1407 OutStreamer.EmitIdent(S->getString());
1412 //===--------------------------------------------------------------------===//
1413 // Emission and print routines
1416 /// EmitInt8 - Emit a byte directive and value.
1418 void AsmPrinter::EmitInt8(int Value) const {
1419 OutStreamer.EmitIntValue(Value, 1);
1422 /// EmitInt16 - Emit a short directive and value.
1424 void AsmPrinter::EmitInt16(int Value) const {
1425 OutStreamer.EmitIntValue(Value, 2);
1428 /// EmitInt32 - Emit a long directive and value.
1430 void AsmPrinter::EmitInt32(int Value) const {
1431 OutStreamer.EmitIntValue(Value, 4);
1434 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1435 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1436 /// .set if it avoids relocations.
1437 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1438 unsigned Size) const {
1439 // Get the Hi-Lo expression.
1440 const MCExpr *Diff =
1441 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1442 MCSymbolRefExpr::Create(Lo, OutContext),
1445 if (!MAI->doesSetDirectiveSuppressesReloc()) {
1446 OutStreamer.EmitValue(Diff, Size);
1450 // Otherwise, emit with .set (aka assignment).
1451 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1452 OutStreamer.EmitAssignment(SetLabel, Diff);
1453 OutStreamer.EmitSymbolValue(SetLabel, Size);
1456 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1457 /// where the size in bytes of the directive is specified by Size and Label
1458 /// specifies the label. This implicitly uses .set if it is available.
1459 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1461 bool IsSectionRelative) const {
1462 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1463 OutStreamer.EmitCOFFSecRel32(Label);
1467 // Emit Label+Offset (or just Label if Offset is zero)
1468 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1470 Expr = MCBinaryExpr::CreateAdd(
1471 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1473 OutStreamer.EmitValue(Expr, Size);
1476 //===----------------------------------------------------------------------===//
1478 // EmitAlignment - Emit an alignment directive to the specified power of
1479 // two boundary. For example, if you pass in 3 here, you will get an 8
1480 // byte alignment. If a global value is specified, and if that global has
1481 // an explicit alignment requested, it will override the alignment request
1482 // if required for correctness.
1484 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1486 NumBits = getGVAlignmentLog2(GV, *TM.getSubtargetImpl()->getDataLayout(),
1489 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1491 if (getCurrentSection()->getKind().isText())
1492 OutStreamer.EmitCodeAlignment(1 << NumBits);
1494 OutStreamer.EmitValueToAlignment(1 << NumBits);
1497 //===----------------------------------------------------------------------===//
1498 // Constant emission.
1499 //===----------------------------------------------------------------------===//
1501 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1503 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1504 MCContext &Ctx = AP.OutContext;
1506 if (CV->isNullValue() || isa<UndefValue>(CV))
1507 return MCConstantExpr::Create(0, Ctx);
1509 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1510 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1512 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1513 return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx);
1515 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1516 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1518 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1520 llvm_unreachable("Unknown constant value to lower!");
1523 if (const MCExpr *RelocExpr =
1524 AP.getObjFileLowering().getExecutableRelativeSymbol(CE, *AP.Mang,
1528 switch (CE->getOpcode()) {
1530 // If the code isn't optimized, there may be outstanding folding
1531 // opportunities. Attempt to fold the expression using DataLayout as a
1532 // last resort before giving up.
1533 if (Constant *C = ConstantFoldConstantExpression(
1534 CE, AP.TM.getSubtargetImpl()->getDataLayout()))
1536 return lowerConstant(C, AP);
1538 // Otherwise report the problem to the user.
1541 raw_string_ostream OS(S);
1542 OS << "Unsupported expression in static initializer: ";
1543 CE->printAsOperand(OS, /*PrintType=*/false,
1544 !AP.MF ? nullptr : AP.MF->getFunction()->getParent());
1545 report_fatal_error(OS.str());
1547 case Instruction::GetElementPtr: {
1548 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1549 // Generate a symbolic expression for the byte address
1550 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1551 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1553 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1557 int64_t Offset = OffsetAI.getSExtValue();
1558 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1562 case Instruction::Trunc:
1563 // We emit the value and depend on the assembler to truncate the generated
1564 // expression properly. This is important for differences between
1565 // blockaddress labels. Since the two labels are in the same function, it
1566 // is reasonable to treat their delta as a 32-bit value.
1568 case Instruction::BitCast:
1569 return lowerConstant(CE->getOperand(0), AP);
1571 case Instruction::IntToPtr: {
1572 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1573 // Handle casts to pointers by changing them into casts to the appropriate
1574 // integer type. This promotes constant folding and simplifies this code.
1575 Constant *Op = CE->getOperand(0);
1576 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1578 return lowerConstant(Op, AP);
1581 case Instruction::PtrToInt: {
1582 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1583 // Support only foldable casts to/from pointers that can be eliminated by
1584 // changing the pointer to the appropriately sized integer type.
1585 Constant *Op = CE->getOperand(0);
1586 Type *Ty = CE->getType();
1588 const MCExpr *OpExpr = lowerConstant(Op, AP);
1590 // We can emit the pointer value into this slot if the slot is an
1591 // integer slot equal to the size of the pointer.
1592 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1595 // Otherwise the pointer is smaller than the resultant integer, mask off
1596 // the high bits so we are sure to get a proper truncation if the input is
1598 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1599 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1600 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1603 // The MC library also has a right-shift operator, but it isn't consistently
1604 // signed or unsigned between different targets.
1605 case Instruction::Add:
1606 case Instruction::Sub:
1607 case Instruction::Mul:
1608 case Instruction::SDiv:
1609 case Instruction::SRem:
1610 case Instruction::Shl:
1611 case Instruction::And:
1612 case Instruction::Or:
1613 case Instruction::Xor: {
1614 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1615 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1616 switch (CE->getOpcode()) {
1617 default: llvm_unreachable("Unknown binary operator constant cast expr");
1618 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1619 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1620 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1621 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1622 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1623 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1624 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1625 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1626 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1632 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1634 /// isRepeatedByteSequence - Determine whether the given value is
1635 /// composed of a repeated sequence of identical bytes and return the
1636 /// byte value. If it is not a repeated sequence, return -1.
1637 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1638 StringRef Data = V->getRawDataValues();
1639 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1641 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1642 if (Data[i] != C) return -1;
1643 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1647 /// isRepeatedByteSequence - Determine whether the given value is
1648 /// composed of a repeated sequence of identical bytes and return the
1649 /// byte value. If it is not a repeated sequence, return -1.
1650 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1652 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1653 if (CI->getBitWidth() > 64) return -1;
1656 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(V->getType());
1657 uint64_t Value = CI->getZExtValue();
1659 // Make sure the constant is at least 8 bits long and has a power
1660 // of 2 bit width. This guarantees the constant bit width is
1661 // always a multiple of 8 bits, avoiding issues with padding out
1662 // to Size and other such corner cases.
1663 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1665 uint8_t Byte = static_cast<uint8_t>(Value);
1667 for (unsigned i = 1; i < Size; ++i) {
1669 if (static_cast<uint8_t>(Value) != Byte) return -1;
1673 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1674 // Make sure all array elements are sequences of the same repeated
1676 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1677 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1678 if (Byte == -1) return -1;
1680 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1681 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1682 if (ThisByte == -1) return -1;
1683 if (Byte != ThisByte) return -1;
1688 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1689 return isRepeatedByteSequence(CDS);
1694 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1697 // See if we can aggregate this into a .fill, if so, emit it as such.
1698 int Value = isRepeatedByteSequence(CDS, AP.TM);
1701 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1703 // Don't emit a 1-byte object as a .fill.
1705 return AP.OutStreamer.EmitFill(Bytes, Value);
1708 // If this can be emitted with .ascii/.asciz, emit it as such.
1709 if (CDS->isString())
1710 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1712 // Otherwise, emit the values in successive locations.
1713 unsigned ElementByteSize = CDS->getElementByteSize();
1714 if (isa<IntegerType>(CDS->getElementType())) {
1715 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1717 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1718 CDS->getElementAsInteger(i));
1719 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1722 } else if (ElementByteSize == 4) {
1723 // FP Constants are printed as integer constants to avoid losing
1725 assert(CDS->getElementType()->isFloatTy());
1726 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1732 F = CDS->getElementAsFloat(i);
1734 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1735 AP.OutStreamer.EmitIntValue(I, 4);
1738 assert(CDS->getElementType()->isDoubleTy());
1739 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1745 F = CDS->getElementAsDouble(i);
1747 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1748 AP.OutStreamer.EmitIntValue(I, 8);
1752 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1753 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1754 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1755 CDS->getNumElements();
1756 if (unsigned Padding = Size - EmittedSize)
1757 AP.OutStreamer.EmitZeros(Padding);
1761 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1762 // See if we can aggregate some values. Make sure it can be
1763 // represented as a series of bytes of the constant value.
1764 int Value = isRepeatedByteSequence(CA, AP.TM);
1768 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1770 AP.OutStreamer.EmitFill(Bytes, Value);
1773 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1774 emitGlobalConstantImpl(CA->getOperand(i), AP);
1778 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1779 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1780 emitGlobalConstantImpl(CV->getOperand(i), AP);
1782 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1783 unsigned Size = DL.getTypeAllocSize(CV->getType());
1784 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1785 CV->getType()->getNumElements();
1786 if (unsigned Padding = Size - EmittedSize)
1787 AP.OutStreamer.EmitZeros(Padding);
1790 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1791 // Print the fields in successive locations. Pad to align if needed!
1792 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1793 unsigned Size = DL->getTypeAllocSize(CS->getType());
1794 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1795 uint64_t SizeSoFar = 0;
1796 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1797 const Constant *Field = CS->getOperand(i);
1799 // Check if padding is needed and insert one or more 0s.
1800 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1801 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1802 - Layout->getElementOffset(i)) - FieldSize;
1803 SizeSoFar += FieldSize + PadSize;
1805 // Now print the actual field value.
1806 emitGlobalConstantImpl(Field, AP);
1808 // Insert padding - this may include padding to increase the size of the
1809 // current field up to the ABI size (if the struct is not packed) as well
1810 // as padding to ensure that the next field starts at the right offset.
1811 AP.OutStreamer.EmitZeros(PadSize);
1813 assert(SizeSoFar == Layout->getSizeInBytes() &&
1814 "Layout of constant struct may be incorrect!");
1817 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1818 APInt API = CFP->getValueAPF().bitcastToAPInt();
1820 // First print a comment with what we think the original floating-point value
1821 // should have been.
1822 if (AP.isVerbose()) {
1823 SmallString<8> StrVal;
1824 CFP->getValueAPF().toString(StrVal);
1827 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1829 AP.OutStreamer.GetCommentOS() << "Printing <null> Type";
1830 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1833 // Now iterate through the APInt chunks, emitting them in endian-correct
1834 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1836 unsigned NumBytes = API.getBitWidth() / 8;
1837 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1838 const uint64_t *p = API.getRawData();
1840 // PPC's long double has odd notions of endianness compared to how LLVM
1841 // handles it: p[0] goes first for *big* endian on PPC.
1842 if (AP.TM.getSubtargetImpl()->getDataLayout()->isBigEndian() &&
1843 !CFP->getType()->isPPC_FP128Ty()) {
1844 int Chunk = API.getNumWords() - 1;
1847 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1849 for (; Chunk >= 0; --Chunk)
1850 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1853 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1854 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1857 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1860 // Emit the tail padding for the long double.
1861 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1862 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1863 DL.getTypeStoreSize(CFP->getType()));
1866 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1867 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1868 unsigned BitWidth = CI->getBitWidth();
1870 // Copy the value as we may massage the layout for constants whose bit width
1871 // is not a multiple of 64-bits.
1872 APInt Realigned(CI->getValue());
1873 uint64_t ExtraBits = 0;
1874 unsigned ExtraBitsSize = BitWidth & 63;
1876 if (ExtraBitsSize) {
1877 // The bit width of the data is not a multiple of 64-bits.
1878 // The extra bits are expected to be at the end of the chunk of the memory.
1880 // * Nothing to be done, just record the extra bits to emit.
1882 // * Record the extra bits to emit.
1883 // * Realign the raw data to emit the chunks of 64-bits.
1884 if (DL->isBigEndian()) {
1885 // Basically the structure of the raw data is a chunk of 64-bits cells:
1886 // 0 1 BitWidth / 64
1887 // [chunk1][chunk2] ... [chunkN].
1888 // The most significant chunk is chunkN and it should be emitted first.
1889 // However, due to the alignment issue chunkN contains useless bits.
1890 // Realign the chunks so that they contain only useless information:
1891 // ExtraBits 0 1 (BitWidth / 64) - 1
1892 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1893 ExtraBits = Realigned.getRawData()[0] &
1894 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1895 Realigned = Realigned.lshr(ExtraBitsSize);
1897 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1900 // We don't expect assemblers to support integer data directives
1901 // for more than 64 bits, so we emit the data in at most 64-bit
1902 // quantities at a time.
1903 const uint64_t *RawData = Realigned.getRawData();
1904 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1905 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1906 AP.OutStreamer.EmitIntValue(Val, 8);
1909 if (ExtraBitsSize) {
1910 // Emit the extra bits after the 64-bits chunks.
1912 // Emit a directive that fills the expected size.
1913 uint64_t Size = AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1915 Size -= (BitWidth / 64) * 8;
1916 assert(Size && Size * 8 >= ExtraBitsSize &&
1917 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1918 == ExtraBits && "Directive too small for extra bits.");
1919 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1923 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1924 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1925 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1926 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1927 return AP.OutStreamer.EmitZeros(Size);
1929 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1936 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1937 CI->getZExtValue());
1938 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1941 emitGlobalConstantLargeInt(CI, AP);
1946 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1947 return emitGlobalConstantFP(CFP, AP);
1949 if (isa<ConstantPointerNull>(CV)) {
1950 AP.OutStreamer.EmitIntValue(0, Size);
1954 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1955 return emitGlobalConstantDataSequential(CDS, AP);
1957 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1958 return emitGlobalConstantArray(CVA, AP);
1960 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1961 return emitGlobalConstantStruct(CVS, AP);
1963 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
1964 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
1966 if (CE->getOpcode() == Instruction::BitCast)
1967 return emitGlobalConstantImpl(CE->getOperand(0), AP);
1970 // If the constant expression's size is greater than 64-bits, then we have
1971 // to emit the value in chunks. Try to constant fold the value and emit it
1973 Constant *New = ConstantFoldConstantExpression(CE, DL);
1974 if (New && New != CE)
1975 return emitGlobalConstantImpl(New, AP);
1979 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1980 return emitGlobalConstantVector(V, AP);
1982 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1983 // thread the streamer with EmitValue.
1984 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
1987 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1988 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
1990 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(CV->getType());
1992 emitGlobalConstantImpl(CV, *this);
1993 else if (MAI->hasSubsectionsViaSymbols()) {
1994 // If the global has zero size, emit a single byte so that two labels don't
1995 // look like they are at the same location.
1996 OutStreamer.EmitIntValue(0, 1);
2000 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2001 // Target doesn't support this yet!
2002 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2005 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2007 OS << '+' << Offset;
2008 else if (Offset < 0)
2012 //===----------------------------------------------------------------------===//
2013 // Symbol Lowering Routines.
2014 //===----------------------------------------------------------------------===//
2016 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2017 /// temporary label with the specified stem and unique ID.
2018 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const {
2019 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2020 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2024 /// GetTempSymbol - Return an assembler temporary label with the specified
2026 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const {
2027 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2028 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2033 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2034 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2037 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2038 return MMI->getAddrLabelSymbol(BB);
2041 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2042 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2043 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2044 return OutContext.GetOrCreateSymbol
2045 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2046 + "_" + Twine(CPID));
2049 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2050 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2051 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2054 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2055 /// FIXME: privatize to AsmPrinter.
2056 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2057 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2058 return OutContext.GetOrCreateSymbol
2059 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2060 Twine(UID) + "_set_" + Twine(MBBID));
2063 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2064 StringRef Suffix) const {
2065 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2069 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2071 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2072 SmallString<60> NameStr;
2073 Mang->getNameWithPrefix(NameStr, Sym);
2074 return OutContext.GetOrCreateSymbol(NameStr.str());
2079 /// PrintParentLoopComment - Print comments about parent loops of this one.
2080 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2081 unsigned FunctionNumber) {
2083 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2084 OS.indent(Loop->getLoopDepth()*2)
2085 << "Parent Loop BB" << FunctionNumber << "_"
2086 << Loop->getHeader()->getNumber()
2087 << " Depth=" << Loop->getLoopDepth() << '\n';
2091 /// PrintChildLoopComment - Print comments about child loops within
2092 /// the loop for this basic block, with nesting.
2093 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2094 unsigned FunctionNumber) {
2095 // Add child loop information
2096 for (const MachineLoop *CL : *Loop) {
2097 OS.indent(CL->getLoopDepth()*2)
2098 << "Child Loop BB" << FunctionNumber << "_"
2099 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2101 PrintChildLoopComment(OS, CL, FunctionNumber);
2105 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2106 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2107 const MachineLoopInfo *LI,
2108 const AsmPrinter &AP) {
2109 // Add loop depth information
2110 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2113 MachineBasicBlock *Header = Loop->getHeader();
2114 assert(Header && "No header for loop");
2116 // If this block is not a loop header, just print out what is the loop header
2118 if (Header != &MBB) {
2119 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2120 Twine(AP.getFunctionNumber())+"_" +
2121 Twine(Loop->getHeader()->getNumber())+
2122 " Depth="+Twine(Loop->getLoopDepth()));
2126 // Otherwise, it is a loop header. Print out information about child and
2128 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2130 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2133 OS.indent(Loop->getLoopDepth()*2-2);
2138 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2140 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2144 /// EmitBasicBlockStart - This method prints the label for the specified
2145 /// MachineBasicBlock, an alignment (if present) and a comment describing
2146 /// it if appropriate.
2147 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2148 // Emit an alignment directive for this block, if needed.
2149 if (unsigned Align = MBB.getAlignment())
2150 EmitAlignment(Align);
2152 // If the block has its address taken, emit any labels that were used to
2153 // reference the block. It is possible that there is more than one label
2154 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2155 // the references were generated.
2156 if (MBB.hasAddressTaken()) {
2157 const BasicBlock *BB = MBB.getBasicBlock();
2159 OutStreamer.AddComment("Block address taken");
2161 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2162 for (auto *Sym : Symbols)
2163 OutStreamer.EmitLabel(Sym);
2166 // Print some verbose block comments.
2168 if (const BasicBlock *BB = MBB.getBasicBlock())
2170 OutStreamer.AddComment("%" + BB->getName());
2171 emitBasicBlockLoopComments(MBB, LI, *this);
2174 // Print the main label for the block.
2175 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2177 // NOTE: Want this comment at start of line, don't emit with AddComment.
2178 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2181 OutStreamer.EmitLabel(MBB.getSymbol());
2185 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2186 bool IsDefinition) const {
2187 MCSymbolAttr Attr = MCSA_Invalid;
2189 switch (Visibility) {
2191 case GlobalValue::HiddenVisibility:
2193 Attr = MAI->getHiddenVisibilityAttr();
2195 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2197 case GlobalValue::ProtectedVisibility:
2198 Attr = MAI->getProtectedVisibilityAttr();
2202 if (Attr != MCSA_Invalid)
2203 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2206 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2207 /// exactly one predecessor and the control transfer mechanism between
2208 /// the predecessor and this block is a fall-through.
2210 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2211 // If this is a landing pad, it isn't a fall through. If it has no preds,
2212 // then nothing falls through to it.
2213 if (MBB->isLandingPad() || MBB->pred_empty())
2216 // If there isn't exactly one predecessor, it can't be a fall through.
2217 if (MBB->pred_size() > 1)
2220 // The predecessor has to be immediately before this block.
2221 MachineBasicBlock *Pred = *MBB->pred_begin();
2222 if (!Pred->isLayoutSuccessor(MBB))
2225 // If the block is completely empty, then it definitely does fall through.
2229 // Check the terminators in the previous blocks
2230 for (const auto &MI : Pred->terminators()) {
2231 // If it is not a simple branch, we are in a table somewhere.
2232 if (!MI.isBranch() || MI.isIndirectBranch())
2235 // If we are the operands of one of the branches, this is not a fall
2236 // through. Note that targets with delay slots will usually bundle
2237 // terminators with the delay slot instruction.
2238 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2241 if (OP->isMBB() && OP->getMBB() == MBB)
2251 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2252 if (!S.usesMetadata())
2255 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2256 gcp_map_type::iterator GCPI = GCMap.find(&S);
2257 if (GCPI != GCMap.end())
2258 return GCPI->second.get();
2260 const char *Name = S.getName().c_str();
2262 for (GCMetadataPrinterRegistry::iterator
2263 I = GCMetadataPrinterRegistry::begin(),
2264 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2265 if (strcmp(Name, I->getName()) == 0) {
2266 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2268 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2269 return IterBool.first->second.get();
2272 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2275 /// Pin vtable to this file.
2276 AsmPrinterHandler::~AsmPrinterHandler() {}