1 //===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the AsmPrinter class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/CodeGen/AsmPrinter.h"
15 #include "DwarfDebug.h"
16 #include "DwarfException.h"
17 #include "Win64Exception.h"
18 #include "WinCodeViewLineTables.h"
19 #include "llvm/ADT/SmallString.h"
20 #include "llvm/ADT/Statistic.h"
21 #include "llvm/Analysis/ConstantFolding.h"
22 #include "llvm/Analysis/JumpInstrTableInfo.h"
23 #include "llvm/CodeGen/Analysis.h"
24 #include "llvm/CodeGen/GCMetadataPrinter.h"
25 #include "llvm/CodeGen/MachineConstantPool.h"
26 #include "llvm/CodeGen/MachineFrameInfo.h"
27 #include "llvm/CodeGen/MachineFunction.h"
28 #include "llvm/CodeGen/MachineInstrBundle.h"
29 #include "llvm/CodeGen/MachineJumpTableInfo.h"
30 #include "llvm/CodeGen/MachineLoopInfo.h"
31 #include "llvm/CodeGen/MachineModuleInfo.h"
32 #include "llvm/IR/DataLayout.h"
33 #include "llvm/IR/DebugInfo.h"
34 #include "llvm/IR/Mangler.h"
35 #include "llvm/IR/Module.h"
36 #include "llvm/IR/Operator.h"
37 #include "llvm/MC/MCAsmInfo.h"
38 #include "llvm/MC/MCContext.h"
39 #include "llvm/MC/MCExpr.h"
40 #include "llvm/MC/MCInst.h"
41 #include "llvm/MC/MCSection.h"
42 #include "llvm/MC/MCStreamer.h"
43 #include "llvm/MC/MCSymbol.h"
44 #include "llvm/Support/ErrorHandling.h"
45 #include "llvm/Support/Format.h"
46 #include "llvm/Support/MathExtras.h"
47 #include "llvm/Support/Timer.h"
48 #include "llvm/Target/TargetFrameLowering.h"
49 #include "llvm/Target/TargetInstrInfo.h"
50 #include "llvm/Target/TargetLowering.h"
51 #include "llvm/Target/TargetLoweringObjectFile.h"
52 #include "llvm/Target/TargetRegisterInfo.h"
53 #include "llvm/Target/TargetSubtargetInfo.h"
56 #define DEBUG_TYPE "asm-printer"
58 static const char *const DWARFGroupName = "DWARF Emission";
59 static const char *const DbgTimerName = "Debug Info Emission";
60 static const char *const EHTimerName = "DWARF Exception Writer";
61 static const char *const CodeViewLineTablesGroupName = "CodeView Line Tables";
63 STATISTIC(EmittedInsts, "Number of machine instrs printed");
65 char AsmPrinter::ID = 0;
67 typedef DenseMap<GCStrategy*, std::unique_ptr<GCMetadataPrinter>> gcp_map_type;
68 static gcp_map_type &getGCMap(void *&P) {
70 P = new gcp_map_type();
71 return *(gcp_map_type*)P;
75 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
76 /// value in log2 form. This rounds up to the preferred alignment if possible
78 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD,
79 unsigned InBits = 0) {
81 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
82 NumBits = TD.getPreferredAlignmentLog(GVar);
84 // If InBits is specified, round it to it.
88 // If the GV has a specified alignment, take it into account.
89 if (GV->getAlignment() == 0)
92 unsigned GVAlign = Log2_32(GV->getAlignment());
94 // If the GVAlign is larger than NumBits, or if we are required to obey
95 // NumBits because the GV has an assigned section, obey it.
96 if (GVAlign > NumBits || GV->hasSection())
101 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
102 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
103 MII(tm.getSubtargetImpl()->getInstrInfo()),
104 OutContext(Streamer.getContext()), OutStreamer(Streamer), LastMI(nullptr),
105 LastFn(0), Counter(~0U), SetCounter(0) {
106 DD = nullptr; MMI = nullptr; LI = nullptr; MF = nullptr;
107 CurrentFnSym = CurrentFnSymForSize = nullptr;
108 GCMetadataPrinters = nullptr;
109 VerboseAsm = Streamer.isVerboseAsm();
112 AsmPrinter::~AsmPrinter() {
113 assert(!DD && Handlers.empty() && "Debug/EH info didn't get finalized");
115 if (GCMetadataPrinters) {
116 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
119 GCMetadataPrinters = nullptr;
125 /// getFunctionNumber - Return a unique ID for the current function.
127 unsigned AsmPrinter::getFunctionNumber() const {
128 return MF->getFunctionNumber();
131 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
132 return TM.getSubtargetImpl()->getTargetLowering()->getObjFileLowering();
135 /// getDataLayout - Return information about data layout.
136 const DataLayout &AsmPrinter::getDataLayout() const {
137 return *TM.getSubtargetImpl()->getDataLayout();
140 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
141 return TM.getSubtarget<MCSubtargetInfo>();
144 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
145 S.EmitInstruction(Inst, getSubtargetInfo());
148 StringRef AsmPrinter::getTargetTriple() const {
149 return TM.getTargetTriple();
152 /// getCurrentSection() - Return the current section we are emitting to.
153 const MCSection *AsmPrinter::getCurrentSection() const {
154 return OutStreamer.getCurrentSection().first;
159 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
160 AU.setPreservesAll();
161 MachineFunctionPass::getAnalysisUsage(AU);
162 AU.addRequired<MachineModuleInfo>();
163 AU.addRequired<GCModuleInfo>();
165 AU.addRequired<MachineLoopInfo>();
168 bool AsmPrinter::doInitialization(Module &M) {
169 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
170 MMI->AnalyzeModule(M);
172 // Initialize TargetLoweringObjectFile.
173 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
174 .Initialize(OutContext, TM);
176 OutStreamer.InitSections(false);
178 Mang = new Mangler(TM.getSubtargetImpl()->getDataLayout());
180 // Emit the version-min deplyment target directive if needed.
182 // FIXME: If we end up with a collection of these sorts of Darwin-specific
183 // or ELF-specific things, it may make sense to have a platform helper class
184 // that will work with the target helper class. For now keep it here, as the
185 // alternative is duplicated code in each of the target asm printers that
186 // use the directive, where it would need the same conditionalization
188 Triple TT(getTargetTriple());
189 if (TT.isOSDarwin()) {
190 unsigned Major, Minor, Update;
191 TT.getOSVersion(Major, Minor, Update);
192 // If there is a version specified, Major will be non-zero.
194 OutStreamer.EmitVersionMin((TT.isMacOSX() ?
195 MCVM_OSXVersionMin : MCVM_IOSVersionMin),
196 Major, Minor, Update);
199 // Allow the target to emit any magic that it wants at the start of the file.
200 EmitStartOfAsmFile(M);
202 // Very minimal debug info. It is ignored if we emit actual debug info. If we
203 // don't, this at least helps the user find where a global came from.
204 if (MAI->hasSingleParameterDotFile()) {
206 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
209 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
210 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
212 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
213 MP->beginAssembly(M, *MI, *this);
215 // Emit module-level inline asm if it exists.
216 if (!M.getModuleInlineAsm().empty()) {
217 OutStreamer.AddComment("Start of file scope inline assembly");
218 OutStreamer.AddBlankLine();
219 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
220 OutStreamer.AddComment("End of file scope inline assembly");
221 OutStreamer.AddBlankLine();
224 if (MAI->doesSupportDebugInformation()) {
225 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::ItaniumWinEH:
258 case ExceptionHandling::MSVC:
259 switch (MAI->getWinEHEncodingType()) {
260 default: llvm_unreachable("unsupported unwinding information encoding");
261 case WinEH::EncodingType::Itanium:
262 ES = new Win64Exception(this);
268 Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
272 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
273 if (!MAI.hasWeakDefCanBeHiddenDirective())
276 return canBeOmittedFromSymbolTable(GV);
279 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
280 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
282 case GlobalValue::CommonLinkage:
283 case GlobalValue::LinkOnceAnyLinkage:
284 case GlobalValue::LinkOnceODRLinkage:
285 case GlobalValue::WeakAnyLinkage:
286 case GlobalValue::WeakODRLinkage:
287 if (MAI->hasWeakDefDirective()) {
289 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
291 if (!canBeHidden(GV, *MAI))
292 // .weak_definition _foo
293 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
295 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
296 } else if (MAI->hasLinkOnceDirective()) {
298 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
299 //NOTE: linkonce is handled by the section the symbol was assigned to.
302 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
305 case GlobalValue::AppendingLinkage:
306 // FIXME: appending linkage variables should go into a section of
307 // their name or something. For now, just emit them as external.
308 case GlobalValue::ExternalLinkage:
309 // If external or appending, declare as a global symbol.
311 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
313 case GlobalValue::PrivateLinkage:
314 case GlobalValue::InternalLinkage:
316 case GlobalValue::AvailableExternallyLinkage:
317 llvm_unreachable("Should never emit this");
318 case GlobalValue::ExternalWeakLinkage:
319 llvm_unreachable("Don't know how to emit these");
321 llvm_unreachable("Unknown linkage type!");
324 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
325 const GlobalValue *GV) const {
326 TM.getNameWithPrefix(Name, GV, *Mang);
329 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
330 return TM.getSymbol(GV, *Mang);
333 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
334 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
335 if (GV->hasInitializer()) {
336 // Check to see if this is a special global used by LLVM, if so, emit it.
337 if (EmitSpecialLLVMGlobal(GV))
341 GV->printAsOperand(OutStreamer.GetCommentOS(),
342 /*PrintType=*/false, GV->getParent());
343 OutStreamer.GetCommentOS() << '\n';
347 MCSymbol *GVSym = getSymbol(GV);
348 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
350 if (!GV->hasInitializer()) // External globals require no extra code.
353 GVSym->redefineIfPossible();
354 if (GVSym->isDefined() || GVSym->isVariable())
355 report_fatal_error("symbol '" + Twine(GVSym->getName()) +
356 "' is already defined");
358 if (MAI->hasDotTypeDotSizeDirective())
359 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
361 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
363 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
364 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
366 // If the alignment is specified, we *must* obey it. Overaligning a global
367 // with a specified alignment is a prompt way to break globals emitted to
368 // sections and expected to be contiguous (e.g. ObjC metadata).
369 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
371 for (const HandlerInfo &HI : Handlers) {
372 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
373 HI.Handler->setSymbolSize(GVSym, Size);
376 // Handle common and BSS local symbols (.lcomm).
377 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
378 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
379 unsigned Align = 1 << AlignLog;
381 // Handle common symbols.
382 if (GVKind.isCommon()) {
383 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
387 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
391 // Handle local BSS symbols.
392 if (MAI->hasMachoZeroFillDirective()) {
393 const MCSection *TheSection =
394 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
395 // .zerofill __DATA, __bss, _foo, 400, 5
396 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
400 // Use .lcomm only if it supports user-specified alignment.
401 // Otherwise, while it would still be correct to use .lcomm in some
402 // cases (e.g. when Align == 1), the external assembler might enfore
403 // some -unknown- default alignment behavior, which could cause
404 // spurious differences between external and integrated assembler.
405 // Prefer to simply fall back to .local / .comm in this case.
406 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
408 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
412 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
416 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
418 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
422 const MCSection *TheSection =
423 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
425 // Handle the zerofill directive on darwin, which is a special form of BSS
427 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
428 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
431 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
432 // .zerofill __DATA, __common, _foo, 400, 5
433 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
437 // Handle thread local data for mach-o which requires us to output an
438 // additional structure of data and mangle the original symbol so that we
439 // can reference it later.
441 // TODO: This should become an "emit thread local global" method on TLOF.
442 // All of this macho specific stuff should be sunk down into TLOFMachO and
443 // stuff like "TLSExtraDataSection" should no longer be part of the parent
444 // TLOF class. This will also make it more obvious that stuff like
445 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
447 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
448 // Emit the .tbss symbol
450 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
452 if (GVKind.isThreadBSS()) {
453 TheSection = getObjFileLowering().getTLSBSSSection();
454 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
455 } else if (GVKind.isThreadData()) {
456 OutStreamer.SwitchSection(TheSection);
458 EmitAlignment(AlignLog, GV);
459 OutStreamer.EmitLabel(MangSym);
461 EmitGlobalConstant(GV->getInitializer());
464 OutStreamer.AddBlankLine();
466 // Emit the variable struct for the runtime.
467 const MCSection *TLVSect
468 = getObjFileLowering().getTLSExtraDataSection();
470 OutStreamer.SwitchSection(TLVSect);
471 // Emit the linkage here.
472 EmitLinkage(GV, GVSym);
473 OutStreamer.EmitLabel(GVSym);
475 // Three pointers in size:
476 // - __tlv_bootstrap - used to make sure support exists
477 // - spare pointer, used when mapped by the runtime
478 // - pointer to mangled symbol above with initializer
479 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
480 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
482 OutStreamer.EmitIntValue(0, PtrSize);
483 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
485 OutStreamer.AddBlankLine();
489 OutStreamer.SwitchSection(TheSection);
491 EmitLinkage(GV, GVSym);
492 EmitAlignment(AlignLog, GV);
494 OutStreamer.EmitLabel(GVSym);
496 EmitGlobalConstant(GV->getInitializer());
498 if (MAI->hasDotTypeDotSizeDirective())
500 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
502 OutStreamer.AddBlankLine();
505 /// EmitFunctionHeader - This method emits the header for the current
507 void AsmPrinter::EmitFunctionHeader() {
508 // Print out constants referenced by the function
511 // Print the 'header' of function.
512 const Function *F = MF->getFunction();
514 OutStreamer.SwitchSection(
515 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
516 EmitVisibility(CurrentFnSym, F->getVisibility());
518 EmitLinkage(F, CurrentFnSym);
519 EmitAlignment(MF->getAlignment(), F);
521 if (MAI->hasDotTypeDotSizeDirective())
522 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
525 F->printAsOperand(OutStreamer.GetCommentOS(),
526 /*PrintType=*/false, F->getParent());
527 OutStreamer.GetCommentOS() << '\n';
530 // Emit the prefix data.
531 if (F->hasPrefixData())
532 EmitGlobalConstant(F->getPrefixData());
534 // Emit the CurrentFnSym. This is a virtual function to allow targets to
535 // do their wild and crazy things as required.
536 EmitFunctionEntryLabel();
538 // If the function had address-taken blocks that got deleted, then we have
539 // references to the dangling symbols. Emit them at the start of the function
540 // so that we don't get references to undefined symbols.
541 std::vector<MCSymbol*> DeadBlockSyms;
542 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
543 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
544 OutStreamer.AddComment("Address taken block that was later removed");
545 OutStreamer.EmitLabel(DeadBlockSyms[i]);
548 // Emit pre-function debug and/or EH information.
549 for (const HandlerInfo &HI : Handlers) {
550 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
551 HI.Handler->beginFunction(MF);
554 // Emit the prologue data.
555 if (F->hasPrologueData())
556 EmitGlobalConstant(F->getPrologueData());
559 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
560 /// function. This can be overridden by targets as required to do custom stuff.
561 void AsmPrinter::EmitFunctionEntryLabel() {
562 CurrentFnSym->redefineIfPossible();
564 // The function label could have already been emitted if two symbols end up
565 // conflicting due to asm renaming. Detect this and emit an error.
566 if (CurrentFnSym->isVariable())
567 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
568 "' is a protected alias");
569 if (CurrentFnSym->isDefined())
570 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
571 "' label emitted multiple times to assembly file");
573 return OutStreamer.EmitLabel(CurrentFnSym);
576 /// emitComments - Pretty-print comments for instructions.
577 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
578 const MachineFunction *MF = MI.getParent()->getParent();
579 const TargetMachine &TM = MF->getTarget();
581 // Check for spills and reloads
584 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
586 // We assume a single instruction only has a spill or reload, not
588 const MachineMemOperand *MMO;
589 if (TM.getSubtargetImpl()->getInstrInfo()->isLoadFromStackSlotPostFE(&MI,
591 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
592 MMO = *MI.memoperands_begin();
593 CommentOS << MMO->getSize() << "-byte Reload\n";
595 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasLoadFromStackSlot(
597 if (FrameInfo->isSpillSlotObjectIndex(FI))
598 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
599 } else if (TM.getSubtargetImpl()->getInstrInfo()->isStoreToStackSlotPostFE(
601 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
602 MMO = *MI.memoperands_begin();
603 CommentOS << MMO->getSize() << "-byte Spill\n";
605 } else if (TM.getSubtargetImpl()->getInstrInfo()->hasStoreToStackSlot(
607 if (FrameInfo->isSpillSlotObjectIndex(FI))
608 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
611 // Check for spill-induced copies
612 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
613 CommentOS << " Reload Reuse\n";
616 /// emitImplicitDef - This method emits the specified machine instruction
617 /// that is an implicit def.
618 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
619 unsigned RegNo = MI->getOperand(0).getReg();
620 OutStreamer.AddComment(
621 Twine("implicit-def: ") +
622 TM.getSubtargetImpl()->getRegisterInfo()->getName(RegNo));
623 OutStreamer.AddBlankLine();
626 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
627 std::string Str = "kill:";
628 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
629 const MachineOperand &Op = MI->getOperand(i);
630 assert(Op.isReg() && "KILL instruction must have only register operands");
632 Str += AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Op.getReg());
633 Str += (Op.isDef() ? "<def>" : "<kill>");
635 AP.OutStreamer.AddComment(Str);
636 AP.OutStreamer.AddBlankLine();
639 /// emitDebugValueComment - This method handles the target-independent form
640 /// of DBG_VALUE, returning true if it was able to do so. A false return
641 /// means the target will need to handle MI in EmitInstruction.
642 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
643 // This code handles only the 4-operand target-independent form.
644 if (MI->getNumOperands() != 4)
647 SmallString<128> Str;
648 raw_svector_ostream OS(Str);
649 OS << "DEBUG_VALUE: ";
651 DIVariable V = MI->getDebugVariable();
652 if (V.getContext().isSubprogram()) {
653 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
659 DIExpression Expr = MI->getDebugExpression();
660 if (Expr.isVariablePiece())
661 OS << " [piece offset=" << Expr.getPieceOffset()
662 << " size=" << Expr.getPieceSize() << "]";
665 // The second operand is only an offset if it's an immediate.
666 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
667 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
669 // Register or immediate value. Register 0 means undef.
670 if (MI->getOperand(0).isFPImm()) {
671 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
672 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
673 OS << (double)APF.convertToFloat();
674 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
675 OS << APF.convertToDouble();
677 // There is no good way to print long double. Convert a copy to
678 // double. Ah well, it's only a comment.
680 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
682 OS << "(long double) " << APF.convertToDouble();
684 } else if (MI->getOperand(0).isImm()) {
685 OS << MI->getOperand(0).getImm();
686 } else if (MI->getOperand(0).isCImm()) {
687 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
690 if (MI->getOperand(0).isReg()) {
691 Reg = MI->getOperand(0).getReg();
693 assert(MI->getOperand(0).isFI() && "Unknown operand type");
694 const TargetFrameLowering *TFI =
695 AP.TM.getSubtargetImpl()->getFrameLowering();
696 Offset += TFI->getFrameIndexReference(*AP.MF,
697 MI->getOperand(0).getIndex(), Reg);
701 // Suppress offset, it is not meaningful here.
703 // NOTE: Want this comment at start of line, don't emit with AddComment.
704 AP.OutStreamer.emitRawComment(OS.str());
709 OS << AP.TM.getSubtargetImpl()->getRegisterInfo()->getName(Reg);
713 OS << '+' << Offset << ']';
715 // NOTE: Want this comment at start of line, don't emit with AddComment.
716 AP.OutStreamer.emitRawComment(OS.str());
720 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
721 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
722 MF->getFunction()->needsUnwindTableEntry())
725 if (MMI->hasDebugInfo())
731 bool AsmPrinter::needsSEHMoves() {
732 return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
735 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
736 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
737 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
738 ExceptionHandlingType != ExceptionHandling::ARM)
741 if (needsCFIMoves() == CFI_M_None)
744 const MachineModuleInfo &MMI = MF->getMMI();
745 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
746 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
747 const MCCFIInstruction &CFI = Instrs[CFIIndex];
748 emitCFIInstruction(CFI);
751 /// EmitFunctionBody - This method emits the body and trailer for a
753 void AsmPrinter::EmitFunctionBody() {
754 // Emit target-specific gunk before the function body.
755 EmitFunctionBodyStart();
757 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
759 // Print out code for the function.
760 bool HasAnyRealCode = false;
761 for (auto &MBB : *MF) {
762 // Print a label for the basic block.
763 EmitBasicBlockStart(MBB);
764 for (auto &MI : MBB) {
766 // Print the assembly for the instruction.
767 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
768 !MI.isDebugValue()) {
769 HasAnyRealCode = true;
773 if (ShouldPrintDebugScopes) {
774 for (const HandlerInfo &HI : Handlers) {
775 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
776 TimePassesIsEnabled);
777 HI.Handler->beginInstruction(&MI);
782 emitComments(MI, OutStreamer.GetCommentOS());
784 switch (MI.getOpcode()) {
785 case TargetOpcode::CFI_INSTRUCTION:
786 emitCFIInstruction(MI);
789 case TargetOpcode::EH_LABEL:
790 case TargetOpcode::GC_LABEL:
791 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
793 case TargetOpcode::INLINEASM:
796 case TargetOpcode::DBG_VALUE:
798 if (!emitDebugValueComment(&MI, *this))
799 EmitInstruction(&MI);
802 case TargetOpcode::IMPLICIT_DEF:
803 if (isVerbose()) emitImplicitDef(&MI);
805 case TargetOpcode::KILL:
806 if (isVerbose()) emitKill(&MI, *this);
809 EmitInstruction(&MI);
813 if (ShouldPrintDebugScopes) {
814 for (const HandlerInfo &HI : Handlers) {
815 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
816 TimePassesIsEnabled);
817 HI.Handler->endInstruction();
822 EmitBasicBlockEnd(MBB);
825 // If the function is empty and the object file uses .subsections_via_symbols,
826 // then we need to emit *something* to the function body to prevent the
827 // labels from collapsing together. Just emit a noop.
828 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
830 TM.getSubtargetImpl()->getInstrInfo()->getNoopForMachoTarget(Noop);
831 OutStreamer.AddComment("avoids zero-length function");
833 // Targets can opt-out of emitting the noop here by leaving the opcode
835 if (Noop.getOpcode())
836 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
839 const Function *F = MF->getFunction();
840 for (const auto &BB : *F) {
841 if (!BB.hasAddressTaken())
843 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
844 if (Sym->isDefined())
846 OutStreamer.AddComment("Address of block that was removed by CodeGen");
847 OutStreamer.EmitLabel(Sym);
850 // Emit target-specific gunk after the function body.
851 EmitFunctionBodyEnd();
853 // If the target wants a .size directive for the size of the function, emit
855 if (MAI->hasDotTypeDotSizeDirective()) {
856 // Create a symbol for the end of function, so we can get the size as
857 // difference between the function label and the temp label.
858 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
859 OutStreamer.EmitLabel(FnEndLabel);
861 const MCExpr *SizeExp =
862 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
863 MCSymbolRefExpr::Create(CurrentFnSymForSize,
866 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
869 // Emit post-function debug and/or EH information.
870 for (const HandlerInfo &HI : Handlers) {
871 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
872 HI.Handler->endFunction(MF);
876 // Print out jump tables referenced by the function.
879 OutStreamer.AddBlankLine();
882 bool AsmPrinter::doFinalization(Module &M) {
883 // Emit global variables.
884 for (const auto &G : M.globals())
885 EmitGlobalVariable(&G);
887 // Emit visibility info for declarations
888 for (const Function &F : M) {
889 if (!F.isDeclaration())
891 GlobalValue::VisibilityTypes V = F.getVisibility();
892 if (V == GlobalValue::DefaultVisibility)
895 MCSymbol *Name = getSymbol(&F);
896 EmitVisibility(Name, V, false);
899 // Get information about jump-instruction tables to print.
900 JumpInstrTableInfo *JITI = getAnalysisIfAvailable<JumpInstrTableInfo>();
902 if (JITI && !JITI->getTables().empty()) {
903 unsigned Arch = Triple(getTargetTriple()).getArch();
904 bool IsThumb = (Arch == Triple::thumb || Arch == Triple::thumbeb);
906 TM.getSubtargetImpl()->getInstrInfo()->getTrap(TrapInst);
907 unsigned LogAlignment = llvm::Log2_64(JITI->entryByteAlignment());
909 // Emit the right section for these functions.
910 OutStreamer.SwitchSection(OutContext.getObjectFileInfo()->getTextSection());
911 for (const auto &KV : JITI->getTables()) {
913 for (const auto &FunPair : KV.second) {
914 // Emit the function labels to make this be a function entry point.
916 OutContext.GetOrCreateSymbol(FunPair.second->getName());
917 EmitAlignment(LogAlignment);
919 OutStreamer.EmitThumbFunc(FunSym);
920 if (MAI->hasDotTypeDotSizeDirective())
921 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_ELF_TypeFunction);
922 OutStreamer.EmitLabel(FunSym);
924 // Emit the jump instruction to transfer control to the original
927 MCSymbol *TargetSymbol =
928 OutContext.GetOrCreateSymbol(FunPair.first->getName());
929 const MCSymbolRefExpr *TargetSymRef =
930 MCSymbolRefExpr::Create(TargetSymbol, MCSymbolRefExpr::VK_PLT,
932 TM.getSubtargetImpl()->getInstrInfo()->getUnconditionalBranch(
933 JumpToFun, TargetSymRef);
934 OutStreamer.EmitInstruction(JumpToFun, getSubtargetInfo());
938 // Emit enough padding instructions to fill up to the next power of two.
939 uint64_t Remaining = NextPowerOf2(Count) - Count;
940 for (uint64_t C = 0; C < Remaining; ++C) {
941 EmitAlignment(LogAlignment);
942 OutStreamer.EmitInstruction(TrapInst, getSubtargetInfo());
948 // Emit module flags.
949 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
950 M.getModuleFlagsMetadata(ModuleFlags);
951 if (!ModuleFlags.empty())
952 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
954 // Make sure we wrote out everything we need.
957 // Finalize debug and EH information.
958 for (const HandlerInfo &HI : Handlers) {
959 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
960 TimePassesIsEnabled);
961 HI.Handler->endModule();
967 // If the target wants to know about weak references, print them all.
968 if (MAI->getWeakRefDirective()) {
969 // FIXME: This is not lazy, it would be nice to only print weak references
970 // to stuff that is actually used. Note that doing so would require targets
971 // to notice uses in operands (due to constant exprs etc). This should
972 // happen with the MC stuff eventually.
974 // Print out module-level global variables here.
975 for (const auto &G : M.globals()) {
976 if (!G.hasExternalWeakLinkage())
978 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
981 for (const auto &F : M) {
982 if (!F.hasExternalWeakLinkage())
984 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
988 OutStreamer.AddBlankLine();
989 for (const auto &Alias : M.aliases()) {
990 MCSymbol *Name = getSymbol(&Alias);
992 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
993 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
994 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
995 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
997 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
999 EmitVisibility(Name, Alias.getVisibility());
1001 // Emit the directives as assignments aka .set:
1002 OutStreamer.EmitAssignment(Name, lowerConstant(Alias.getAliasee()));
1005 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1006 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1007 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1008 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1009 MP->finishAssembly(M, *MI, *this);
1011 // Emit llvm.ident metadata in an '.ident' directive.
1012 EmitModuleIdents(M);
1014 // Emit __morestack address if needed for indirect calls.
1015 if (MMI->usesMorestackAddr()) {
1016 const MCSection *ReadOnlySection =
1017 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
1019 OutStreamer.SwitchSection(ReadOnlySection);
1021 MCSymbol *AddrSymbol =
1022 OutContext.GetOrCreateSymbol(StringRef("__morestack_addr"));
1023 OutStreamer.EmitLabel(AddrSymbol);
1025 const DataLayout &DL = *TM.getSubtargetImpl()->getDataLayout();
1026 unsigned PtrSize = DL.getPointerSize(0);
1027 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("__morestack"),
1031 // If we don't have any trampolines, then we don't require stack memory
1032 // to be executable. Some targets have a directive to declare this.
1033 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1034 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1035 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1036 OutStreamer.SwitchSection(S);
1038 // Allow the target to emit any magic that it wants at the end of the file,
1039 // after everything else has gone out.
1040 EmitEndOfAsmFile(M);
1042 delete Mang; Mang = nullptr;
1045 OutStreamer.Finish();
1046 OutStreamer.reset();
1051 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1053 // Get the function symbol.
1054 CurrentFnSym = getSymbol(MF.getFunction());
1055 CurrentFnSymForSize = CurrentFnSym;
1058 LI = &getAnalysis<MachineLoopInfo>();
1062 // SectionCPs - Keep track the alignment, constpool entries per Section.
1066 SmallVector<unsigned, 4> CPEs;
1067 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1071 /// EmitConstantPool - Print to the current output stream assembly
1072 /// representations of the constants in the constant pool MCP. This is
1073 /// used to print out constants which have been "spilled to memory" by
1074 /// the code generator.
1076 void AsmPrinter::EmitConstantPool() {
1077 const MachineConstantPool *MCP = MF->getConstantPool();
1078 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1079 if (CP.empty()) return;
1081 // Calculate sections for constant pool entries. We collect entries to go into
1082 // the same section together to reduce amount of section switch statements.
1083 SmallVector<SectionCPs, 4> CPSections;
1084 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1085 const MachineConstantPoolEntry &CPE = CP[i];
1086 unsigned Align = CPE.getAlignment();
1089 CPE.getSectionKind(TM.getSubtargetImpl()->getDataLayout());
1091 const Constant *C = nullptr;
1092 if (!CPE.isMachineConstantPoolEntry())
1093 C = CPE.Val.ConstVal;
1095 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind, C);
1097 // The number of sections are small, just do a linear search from the
1098 // last section to the first.
1100 unsigned SecIdx = CPSections.size();
1101 while (SecIdx != 0) {
1102 if (CPSections[--SecIdx].S == S) {
1108 SecIdx = CPSections.size();
1109 CPSections.push_back(SectionCPs(S, Align));
1112 if (Align > CPSections[SecIdx].Alignment)
1113 CPSections[SecIdx].Alignment = Align;
1114 CPSections[SecIdx].CPEs.push_back(i);
1117 // Now print stuff into the calculated sections.
1118 const MCSection *CurSection = nullptr;
1119 unsigned Offset = 0;
1120 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1121 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1122 unsigned CPI = CPSections[i].CPEs[j];
1123 MCSymbol *Sym = GetCPISymbol(CPI);
1124 if (!Sym->isUndefined())
1127 if (CurSection != CPSections[i].S) {
1128 OutStreamer.SwitchSection(CPSections[i].S);
1129 EmitAlignment(Log2_32(CPSections[i].Alignment));
1130 CurSection = CPSections[i].S;
1134 MachineConstantPoolEntry CPE = CP[CPI];
1136 // Emit inter-object padding for alignment.
1137 unsigned AlignMask = CPE.getAlignment() - 1;
1138 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1139 OutStreamer.EmitZeros(NewOffset - Offset);
1141 Type *Ty = CPE.getType();
1142 Offset = NewOffset +
1143 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(Ty);
1145 OutStreamer.EmitLabel(Sym);
1146 if (CPE.isMachineConstantPoolEntry())
1147 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1149 EmitGlobalConstant(CPE.Val.ConstVal);
1154 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1155 /// by the current function to the current output stream.
1157 void AsmPrinter::EmitJumpTableInfo() {
1158 const DataLayout *DL = MF->getSubtarget().getDataLayout();
1159 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1161 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1162 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1163 if (JT.empty()) return;
1165 // Pick the directive to use to print the jump table entries, and switch to
1166 // the appropriate section.
1167 const Function *F = MF->getFunction();
1168 bool JTInDiffSection = false;
1169 if (// In PIC mode, we need to emit the jump table to the same section as the
1170 // function body itself, otherwise the label differences won't make sense.
1171 // FIXME: Need a better predicate for this: what about custom entries?
1172 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1173 // We should also do if the section name is NULL or function is declared
1174 // in discardable section
1175 // FIXME: this isn't the right predicate, should be based on the MCSection
1176 // for the function.
1177 F->isWeakForLinker()) {
1178 OutStreamer.SwitchSection(
1179 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1181 // Otherwise, drop it in the readonly section.
1182 const MCSection *ReadOnlySection =
1183 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly(),
1185 OutStreamer.SwitchSection(ReadOnlySection);
1186 JTInDiffSection = true;
1189 EmitAlignment(Log2_32(
1190 MJTI->getEntryAlignment(*TM.getSubtargetImpl()->getDataLayout())));
1192 // Jump tables in code sections are marked with a data_region directive
1193 // where that's supported.
1194 if (!JTInDiffSection)
1195 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1197 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1198 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1200 // If this jump table was deleted, ignore it.
1201 if (JTBBs.empty()) continue;
1203 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1204 /// emit a .set directive for each unique entry.
1205 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1206 MAI->doesSetDirectiveSuppressesReloc()) {
1207 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1208 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1209 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1210 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1211 const MachineBasicBlock *MBB = JTBBs[ii];
1212 if (!EmittedSets.insert(MBB).second)
1215 // .set LJTSet, LBB32-base
1217 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1218 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1219 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1223 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1224 // before each jump table. The first label is never referenced, but tells
1225 // the assembler and linker the extents of the jump table object. The
1226 // second label is actually referenced by the code.
1227 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1228 // FIXME: This doesn't have to have any specific name, just any randomly
1229 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1230 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1232 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1234 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1235 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1237 if (!JTInDiffSection)
1238 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1241 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1243 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1244 const MachineBasicBlock *MBB,
1245 unsigned UID) const {
1246 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1247 const MCExpr *Value = nullptr;
1248 switch (MJTI->getEntryKind()) {
1249 case MachineJumpTableInfo::EK_Inline:
1250 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1251 case MachineJumpTableInfo::EK_Custom32:
1253 TM.getSubtargetImpl()->getTargetLowering()->LowerCustomJumpTableEntry(
1254 MJTI, MBB, UID, OutContext);
1256 case MachineJumpTableInfo::EK_BlockAddress:
1257 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1259 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1261 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1262 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1263 // with a relocation as gp-relative, e.g.:
1265 MCSymbol *MBBSym = MBB->getSymbol();
1266 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1270 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1271 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1272 // with a relocation as gp-relative, e.g.:
1274 MCSymbol *MBBSym = MBB->getSymbol();
1275 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1279 case MachineJumpTableInfo::EK_LabelDifference32: {
1280 // Each entry is the address of the block minus the address of the jump
1281 // table. This is used for PIC jump tables where gprel32 is not supported.
1283 // .word LBB123 - LJTI1_2
1284 // If the .set directive avoids relocations, this is emitted as:
1285 // .set L4_5_set_123, LBB123 - LJTI1_2
1286 // .word L4_5_set_123
1287 if (MAI->doesSetDirectiveSuppressesReloc()) {
1288 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1292 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1293 const TargetLowering *TLI = TM.getSubtargetImpl()->getTargetLowering();
1294 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1295 Value = MCBinaryExpr::CreateSub(Value, Base, OutContext);
1300 assert(Value && "Unknown entry kind!");
1302 unsigned EntrySize =
1303 MJTI->getEntrySize(*TM.getSubtargetImpl()->getDataLayout());
1304 OutStreamer.EmitValue(Value, EntrySize);
1308 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1309 /// special global used by LLVM. If so, emit it and return true, otherwise
1310 /// do nothing and return false.
1311 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1312 if (GV->getName() == "llvm.used") {
1313 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1314 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1318 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1319 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1320 GV->hasAvailableExternallyLinkage())
1323 if (!GV->hasAppendingLinkage()) return false;
1325 assert(GV->hasInitializer() && "Not a special LLVM global!");
1327 if (GV->getName() == "llvm.global_ctors") {
1328 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1330 if (TM.getRelocationModel() == Reloc::Static &&
1331 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1332 StringRef Sym(".constructors_used");
1333 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1339 if (GV->getName() == "llvm.global_dtors") {
1340 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1342 if (TM.getRelocationModel() == Reloc::Static &&
1343 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1344 StringRef Sym(".destructors_used");
1345 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1354 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1355 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1356 /// is true, as being used with this directive.
1357 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1358 // Should be an array of 'i8*'.
1359 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1360 const GlobalValue *GV =
1361 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1363 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1369 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1371 llvm::Constant *Func;
1372 llvm::GlobalValue *ComdatKey;
1376 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1378 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1379 // Should be an array of '{ int, void ()* }' structs. The first value is the
1381 if (!isa<ConstantArray>(List)) return;
1383 // Sanity check the structors list.
1384 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1385 if (!InitList) return; // Not an array!
1386 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1387 // FIXME: Only allow the 3-field form in LLVM 4.0.
1388 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1389 return; // Not an array of two or three elements!
1390 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1391 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1392 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1393 return; // Not (int, ptr, ptr).
1395 // Gather the structors in a form that's convenient for sorting by priority.
1396 SmallVector<Structor, 8> Structors;
1397 for (Value *O : InitList->operands()) {
1398 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1399 if (!CS) continue; // Malformed.
1400 if (CS->getOperand(1)->isNullValue())
1401 break; // Found a null terminator, skip the rest.
1402 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1403 if (!Priority) continue; // Malformed.
1404 Structors.push_back(Structor());
1405 Structor &S = Structors.back();
1406 S.Priority = Priority->getLimitedValue(65535);
1407 S.Func = CS->getOperand(1);
1408 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1409 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1412 // Emit the function pointers in the target-specific order
1413 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
1414 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1415 std::stable_sort(Structors.begin(), Structors.end(),
1416 [](const Structor &L,
1417 const Structor &R) { return L.Priority < R.Priority; });
1418 for (Structor &S : Structors) {
1419 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1420 const MCSymbol *KeySym = nullptr;
1421 if (GlobalValue *GV = S.ComdatKey) {
1422 if (GV->hasAvailableExternallyLinkage())
1423 // If the associated variable is available_externally, some other TU
1424 // will provide its dynamic initializer.
1427 KeySym = getSymbol(GV);
1429 const MCSection *OutputSection =
1430 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1431 : Obj.getStaticDtorSection(S.Priority, KeySym));
1432 OutStreamer.SwitchSection(OutputSection);
1433 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1434 EmitAlignment(Align);
1435 EmitXXStructor(S.Func);
1439 void AsmPrinter::EmitModuleIdents(Module &M) {
1440 if (!MAI->hasIdentDirective())
1443 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1444 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1445 const MDNode *N = NMD->getOperand(i);
1446 assert(N->getNumOperands() == 1 &&
1447 "llvm.ident metadata entry can have only one operand");
1448 const MDString *S = cast<MDString>(N->getOperand(0));
1449 OutStreamer.EmitIdent(S->getString());
1454 //===--------------------------------------------------------------------===//
1455 // Emission and print routines
1458 /// EmitInt8 - Emit a byte directive and value.
1460 void AsmPrinter::EmitInt8(int Value) const {
1461 OutStreamer.EmitIntValue(Value, 1);
1464 /// EmitInt16 - Emit a short directive and value.
1466 void AsmPrinter::EmitInt16(int Value) const {
1467 OutStreamer.EmitIntValue(Value, 2);
1470 /// EmitInt32 - Emit a long directive and value.
1472 void AsmPrinter::EmitInt32(int Value) const {
1473 OutStreamer.EmitIntValue(Value, 4);
1476 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1477 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1478 /// .set if it avoids relocations.
1479 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1480 unsigned Size) const {
1481 // Get the Hi-Lo expression.
1482 const MCExpr *Diff =
1483 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1484 MCSymbolRefExpr::Create(Lo, OutContext),
1487 if (!MAI->doesSetDirectiveSuppressesReloc()) {
1488 OutStreamer.EmitValue(Diff, Size);
1492 // Otherwise, emit with .set (aka assignment).
1493 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1494 OutStreamer.EmitAssignment(SetLabel, Diff);
1495 OutStreamer.EmitSymbolValue(SetLabel, Size);
1498 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1499 /// where the size in bytes of the directive is specified by Size and Label
1500 /// specifies the label. This implicitly uses .set if it is available.
1501 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1503 bool IsSectionRelative) const {
1504 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1505 OutStreamer.EmitCOFFSecRel32(Label);
1509 // Emit Label+Offset (or just Label if Offset is zero)
1510 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1512 Expr = MCBinaryExpr::CreateAdd(
1513 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1515 OutStreamer.EmitValue(Expr, Size);
1518 //===----------------------------------------------------------------------===//
1520 // EmitAlignment - Emit an alignment directive to the specified power of
1521 // two boundary. For example, if you pass in 3 here, you will get an 8
1522 // byte alignment. If a global value is specified, and if that global has
1523 // an explicit alignment requested, it will override the alignment request
1524 // if required for correctness.
1526 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1528 NumBits = getGVAlignmentLog2(GV, *TM.getSubtargetImpl()->getDataLayout(),
1531 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1534 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
1535 "undefined behavior");
1536 if (getCurrentSection()->getKind().isText())
1537 OutStreamer.EmitCodeAlignment(1u << NumBits);
1539 OutStreamer.EmitValueToAlignment(1u << NumBits);
1542 //===----------------------------------------------------------------------===//
1543 // Constant emission.
1544 //===----------------------------------------------------------------------===//
1546 const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1547 MCContext &Ctx = OutContext;
1549 if (CV->isNullValue() || isa<UndefValue>(CV))
1550 return MCConstantExpr::Create(0, Ctx);
1552 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1553 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1555 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1556 return MCSymbolRefExpr::Create(getSymbol(GV), Ctx);
1558 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1559 return MCSymbolRefExpr::Create(GetBlockAddressSymbol(BA), Ctx);
1561 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1563 llvm_unreachable("Unknown constant value to lower!");
1566 if (const MCExpr *RelocExpr
1567 = getObjFileLowering().getExecutableRelativeSymbol(CE, *Mang, TM))
1570 switch (CE->getOpcode()) {
1572 // If the code isn't optimized, there may be outstanding folding
1573 // opportunities. Attempt to fold the expression using DataLayout as a
1574 // last resort before giving up.
1575 if (Constant *C = ConstantFoldConstantExpression(
1576 CE, TM.getSubtargetImpl()->getDataLayout()))
1578 return lowerConstant(C);
1580 // Otherwise report the problem to the user.
1583 raw_string_ostream OS(S);
1584 OS << "Unsupported expression in static initializer: ";
1585 CE->printAsOperand(OS, /*PrintType=*/false,
1586 !MF ? nullptr : MF->getFunction()->getParent());
1587 report_fatal_error(OS.str());
1589 case Instruction::GetElementPtr: {
1590 const DataLayout &DL = *TM.getSubtargetImpl()->getDataLayout();
1591 // Generate a symbolic expression for the byte address
1592 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1593 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1595 const MCExpr *Base = lowerConstant(CE->getOperand(0));
1599 int64_t Offset = OffsetAI.getSExtValue();
1600 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1604 case Instruction::Trunc:
1605 // We emit the value and depend on the assembler to truncate the generated
1606 // expression properly. This is important for differences between
1607 // blockaddress labels. Since the two labels are in the same function, it
1608 // is reasonable to treat their delta as a 32-bit value.
1610 case Instruction::BitCast:
1611 return lowerConstant(CE->getOperand(0));
1613 case Instruction::IntToPtr: {
1614 const DataLayout &DL = *TM.getSubtargetImpl()->getDataLayout();
1615 // Handle casts to pointers by changing them into casts to the appropriate
1616 // integer type. This promotes constant folding and simplifies this code.
1617 Constant *Op = CE->getOperand(0);
1618 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1620 return lowerConstant(Op);
1623 case Instruction::PtrToInt: {
1624 const DataLayout &DL = *TM.getSubtargetImpl()->getDataLayout();
1625 // Support only foldable casts to/from pointers that can be eliminated by
1626 // changing the pointer to the appropriately sized integer type.
1627 Constant *Op = CE->getOperand(0);
1628 Type *Ty = CE->getType();
1630 const MCExpr *OpExpr = lowerConstant(Op);
1632 // We can emit the pointer value into this slot if the slot is an
1633 // integer slot equal to the size of the pointer.
1634 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1637 // Otherwise the pointer is smaller than the resultant integer, mask off
1638 // the high bits so we are sure to get a proper truncation if the input is
1640 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1641 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1642 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1645 // The MC library also has a right-shift operator, but it isn't consistently
1646 // signed or unsigned between different targets.
1647 case Instruction::Add:
1648 case Instruction::Sub:
1649 case Instruction::Mul:
1650 case Instruction::SDiv:
1651 case Instruction::SRem:
1652 case Instruction::Shl:
1653 case Instruction::And:
1654 case Instruction::Or:
1655 case Instruction::Xor: {
1656 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
1657 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
1658 switch (CE->getOpcode()) {
1659 default: llvm_unreachable("Unknown binary operator constant cast expr");
1660 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1661 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1662 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1663 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1664 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1665 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1666 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1667 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1668 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1674 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1676 /// isRepeatedByteSequence - Determine whether the given value is
1677 /// composed of a repeated sequence of identical bytes and return the
1678 /// byte value. If it is not a repeated sequence, return -1.
1679 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1680 StringRef Data = V->getRawDataValues();
1681 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1683 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1684 if (Data[i] != C) return -1;
1685 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1689 /// isRepeatedByteSequence - Determine whether the given value is
1690 /// composed of a repeated sequence of identical bytes and return the
1691 /// byte value. If it is not a repeated sequence, return -1.
1692 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1694 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1695 if (CI->getBitWidth() > 64) return -1;
1698 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(V->getType());
1699 uint64_t Value = CI->getZExtValue();
1701 // Make sure the constant is at least 8 bits long and has a power
1702 // of 2 bit width. This guarantees the constant bit width is
1703 // always a multiple of 8 bits, avoiding issues with padding out
1704 // to Size and other such corner cases.
1705 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1707 uint8_t Byte = static_cast<uint8_t>(Value);
1709 for (unsigned i = 1; i < Size; ++i) {
1711 if (static_cast<uint8_t>(Value) != Byte) return -1;
1715 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1716 // Make sure all array elements are sequences of the same repeated
1718 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1719 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1720 if (Byte == -1) return -1;
1722 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1723 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1724 if (ThisByte == -1) return -1;
1725 if (Byte != ThisByte) return -1;
1730 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1731 return isRepeatedByteSequence(CDS);
1736 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1739 // See if we can aggregate this into a .fill, if so, emit it as such.
1740 int Value = isRepeatedByteSequence(CDS, AP.TM);
1743 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1745 // Don't emit a 1-byte object as a .fill.
1747 return AP.OutStreamer.EmitFill(Bytes, Value);
1750 // If this can be emitted with .ascii/.asciz, emit it as such.
1751 if (CDS->isString())
1752 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1754 // Otherwise, emit the values in successive locations.
1755 unsigned ElementByteSize = CDS->getElementByteSize();
1756 if (isa<IntegerType>(CDS->getElementType())) {
1757 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1759 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1760 CDS->getElementAsInteger(i));
1761 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1764 } else if (ElementByteSize == 4) {
1765 // FP Constants are printed as integer constants to avoid losing
1767 assert(CDS->getElementType()->isFloatTy());
1768 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1774 F = CDS->getElementAsFloat(i);
1776 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1777 AP.OutStreamer.EmitIntValue(I, 4);
1780 assert(CDS->getElementType()->isDoubleTy());
1781 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1787 F = CDS->getElementAsDouble(i);
1789 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1790 AP.OutStreamer.EmitIntValue(I, 8);
1794 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1795 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1796 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1797 CDS->getNumElements();
1798 if (unsigned Padding = Size - EmittedSize)
1799 AP.OutStreamer.EmitZeros(Padding);
1803 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1804 // See if we can aggregate some values. Make sure it can be
1805 // represented as a series of bytes of the constant value.
1806 int Value = isRepeatedByteSequence(CA, AP.TM);
1810 AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1812 AP.OutStreamer.EmitFill(Bytes, Value);
1815 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1816 emitGlobalConstantImpl(CA->getOperand(i), AP);
1820 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1821 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1822 emitGlobalConstantImpl(CV->getOperand(i), AP);
1824 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1825 unsigned Size = DL.getTypeAllocSize(CV->getType());
1826 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1827 CV->getType()->getNumElements();
1828 if (unsigned Padding = Size - EmittedSize)
1829 AP.OutStreamer.EmitZeros(Padding);
1832 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1833 // Print the fields in successive locations. Pad to align if needed!
1834 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1835 unsigned Size = DL->getTypeAllocSize(CS->getType());
1836 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1837 uint64_t SizeSoFar = 0;
1838 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1839 const Constant *Field = CS->getOperand(i);
1841 // Check if padding is needed and insert one or more 0s.
1842 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1843 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1844 - Layout->getElementOffset(i)) - FieldSize;
1845 SizeSoFar += FieldSize + PadSize;
1847 // Now print the actual field value.
1848 emitGlobalConstantImpl(Field, AP);
1850 // Insert padding - this may include padding to increase the size of the
1851 // current field up to the ABI size (if the struct is not packed) as well
1852 // as padding to ensure that the next field starts at the right offset.
1853 AP.OutStreamer.EmitZeros(PadSize);
1855 assert(SizeSoFar == Layout->getSizeInBytes() &&
1856 "Layout of constant struct may be incorrect!");
1859 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1860 APInt API = CFP->getValueAPF().bitcastToAPInt();
1862 // First print a comment with what we think the original floating-point value
1863 // should have been.
1864 if (AP.isVerbose()) {
1865 SmallString<8> StrVal;
1866 CFP->getValueAPF().toString(StrVal);
1869 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1871 AP.OutStreamer.GetCommentOS() << "Printing <null> Type";
1872 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1875 // Now iterate through the APInt chunks, emitting them in endian-correct
1876 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1878 unsigned NumBytes = API.getBitWidth() / 8;
1879 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1880 const uint64_t *p = API.getRawData();
1882 // PPC's long double has odd notions of endianness compared to how LLVM
1883 // handles it: p[0] goes first for *big* endian on PPC.
1884 if (AP.TM.getSubtargetImpl()->getDataLayout()->isBigEndian() &&
1885 !CFP->getType()->isPPC_FP128Ty()) {
1886 int Chunk = API.getNumWords() - 1;
1889 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1891 for (; Chunk >= 0; --Chunk)
1892 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1895 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1896 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1899 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1902 // Emit the tail padding for the long double.
1903 const DataLayout &DL = *AP.TM.getSubtargetImpl()->getDataLayout();
1904 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1905 DL.getTypeStoreSize(CFP->getType()));
1908 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1909 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1910 unsigned BitWidth = CI->getBitWidth();
1912 // Copy the value as we may massage the layout for constants whose bit width
1913 // is not a multiple of 64-bits.
1914 APInt Realigned(CI->getValue());
1915 uint64_t ExtraBits = 0;
1916 unsigned ExtraBitsSize = BitWidth & 63;
1918 if (ExtraBitsSize) {
1919 // The bit width of the data is not a multiple of 64-bits.
1920 // The extra bits are expected to be at the end of the chunk of the memory.
1922 // * Nothing to be done, just record the extra bits to emit.
1924 // * Record the extra bits to emit.
1925 // * Realign the raw data to emit the chunks of 64-bits.
1926 if (DL->isBigEndian()) {
1927 // Basically the structure of the raw data is a chunk of 64-bits cells:
1928 // 0 1 BitWidth / 64
1929 // [chunk1][chunk2] ... [chunkN].
1930 // The most significant chunk is chunkN and it should be emitted first.
1931 // However, due to the alignment issue chunkN contains useless bits.
1932 // Realign the chunks so that they contain only useless information:
1933 // ExtraBits 0 1 (BitWidth / 64) - 1
1934 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1935 ExtraBits = Realigned.getRawData()[0] &
1936 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1937 Realigned = Realigned.lshr(ExtraBitsSize);
1939 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1942 // We don't expect assemblers to support integer data directives
1943 // for more than 64 bits, so we emit the data in at most 64-bit
1944 // quantities at a time.
1945 const uint64_t *RawData = Realigned.getRawData();
1946 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1947 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1948 AP.OutStreamer.EmitIntValue(Val, 8);
1951 if (ExtraBitsSize) {
1952 // Emit the extra bits after the 64-bits chunks.
1954 // Emit a directive that fills the expected size.
1955 uint64_t Size = AP.TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(
1957 Size -= (BitWidth / 64) * 8;
1958 assert(Size && Size * 8 >= ExtraBitsSize &&
1959 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1960 == ExtraBits && "Directive too small for extra bits.");
1961 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1965 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1966 const DataLayout *DL = AP.TM.getSubtargetImpl()->getDataLayout();
1967 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1968 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1969 return AP.OutStreamer.EmitZeros(Size);
1971 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1978 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1979 CI->getZExtValue());
1980 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1983 emitGlobalConstantLargeInt(CI, AP);
1988 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1989 return emitGlobalConstantFP(CFP, AP);
1991 if (isa<ConstantPointerNull>(CV)) {
1992 AP.OutStreamer.EmitIntValue(0, Size);
1996 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1997 return emitGlobalConstantDataSequential(CDS, AP);
1999 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2000 return emitGlobalConstantArray(CVA, AP);
2002 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2003 return emitGlobalConstantStruct(CVS, AP);
2005 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2006 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2008 if (CE->getOpcode() == Instruction::BitCast)
2009 return emitGlobalConstantImpl(CE->getOperand(0), AP);
2012 // If the constant expression's size is greater than 64-bits, then we have
2013 // to emit the value in chunks. Try to constant fold the value and emit it
2015 Constant *New = ConstantFoldConstantExpression(CE, DL);
2016 if (New && New != CE)
2017 return emitGlobalConstantImpl(New, AP);
2021 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2022 return emitGlobalConstantVector(V, AP);
2024 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2025 // thread the streamer with EmitValue.
2026 AP.OutStreamer.EmitValue(AP.lowerConstant(CV), Size);
2029 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2030 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2032 TM.getSubtargetImpl()->getDataLayout()->getTypeAllocSize(CV->getType());
2034 emitGlobalConstantImpl(CV, *this);
2035 else if (MAI->hasSubsectionsViaSymbols()) {
2036 // If the global has zero size, emit a single byte so that two labels don't
2037 // look like they are at the same location.
2038 OutStreamer.EmitIntValue(0, 1);
2042 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2043 // Target doesn't support this yet!
2044 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2047 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2049 OS << '+' << Offset;
2050 else if (Offset < 0)
2054 //===----------------------------------------------------------------------===//
2055 // Symbol Lowering Routines.
2056 //===----------------------------------------------------------------------===//
2058 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2059 /// temporary label with the specified stem and unique ID.
2060 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const {
2061 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2062 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2066 /// GetTempSymbol - Return an assembler temporary label with the specified
2068 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const {
2069 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2070 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2075 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2076 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2079 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2080 return MMI->getAddrLabelSymbol(BB);
2083 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2084 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2085 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2086 return OutContext.GetOrCreateSymbol
2087 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2088 + "_" + Twine(CPID));
2091 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2092 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2093 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2096 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2097 /// FIXME: privatize to AsmPrinter.
2098 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2099 const DataLayout *DL = TM.getSubtargetImpl()->getDataLayout();
2100 return OutContext.GetOrCreateSymbol
2101 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2102 Twine(UID) + "_set_" + Twine(MBBID));
2105 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2106 StringRef Suffix) const {
2107 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2111 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2113 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2114 SmallString<60> NameStr;
2115 Mang->getNameWithPrefix(NameStr, Sym);
2116 return OutContext.GetOrCreateSymbol(NameStr.str());
2121 /// PrintParentLoopComment - Print comments about parent loops of this one.
2122 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2123 unsigned FunctionNumber) {
2125 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2126 OS.indent(Loop->getLoopDepth()*2)
2127 << "Parent Loop BB" << FunctionNumber << "_"
2128 << Loop->getHeader()->getNumber()
2129 << " Depth=" << Loop->getLoopDepth() << '\n';
2133 /// PrintChildLoopComment - Print comments about child loops within
2134 /// the loop for this basic block, with nesting.
2135 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2136 unsigned FunctionNumber) {
2137 // Add child loop information
2138 for (const MachineLoop *CL : *Loop) {
2139 OS.indent(CL->getLoopDepth()*2)
2140 << "Child Loop BB" << FunctionNumber << "_"
2141 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2143 PrintChildLoopComment(OS, CL, FunctionNumber);
2147 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2148 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2149 const MachineLoopInfo *LI,
2150 const AsmPrinter &AP) {
2151 // Add loop depth information
2152 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2155 MachineBasicBlock *Header = Loop->getHeader();
2156 assert(Header && "No header for loop");
2158 // If this block is not a loop header, just print out what is the loop header
2160 if (Header != &MBB) {
2161 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2162 Twine(AP.getFunctionNumber())+"_" +
2163 Twine(Loop->getHeader()->getNumber())+
2164 " Depth="+Twine(Loop->getLoopDepth()));
2168 // Otherwise, it is a loop header. Print out information about child and
2170 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2172 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2175 OS.indent(Loop->getLoopDepth()*2-2);
2180 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2182 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2186 /// EmitBasicBlockStart - This method prints the label for the specified
2187 /// MachineBasicBlock, an alignment (if present) and a comment describing
2188 /// it if appropriate.
2189 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2190 // Emit an alignment directive for this block, if needed.
2191 if (unsigned Align = MBB.getAlignment())
2192 EmitAlignment(Align);
2194 // If the block has its address taken, emit any labels that were used to
2195 // reference the block. It is possible that there is more than one label
2196 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2197 // the references were generated.
2198 if (MBB.hasAddressTaken()) {
2199 const BasicBlock *BB = MBB.getBasicBlock();
2201 OutStreamer.AddComment("Block address taken");
2203 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2204 for (auto *Sym : Symbols)
2205 OutStreamer.EmitLabel(Sym);
2208 // Print some verbose block comments.
2210 if (const BasicBlock *BB = MBB.getBasicBlock())
2212 OutStreamer.AddComment("%" + BB->getName());
2213 emitBasicBlockLoopComments(MBB, LI, *this);
2216 // Print the main label for the block.
2217 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2219 // NOTE: Want this comment at start of line, don't emit with AddComment.
2220 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2223 OutStreamer.EmitLabel(MBB.getSymbol());
2227 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2228 bool IsDefinition) const {
2229 MCSymbolAttr Attr = MCSA_Invalid;
2231 switch (Visibility) {
2233 case GlobalValue::HiddenVisibility:
2235 Attr = MAI->getHiddenVisibilityAttr();
2237 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2239 case GlobalValue::ProtectedVisibility:
2240 Attr = MAI->getProtectedVisibilityAttr();
2244 if (Attr != MCSA_Invalid)
2245 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2248 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2249 /// exactly one predecessor and the control transfer mechanism between
2250 /// the predecessor and this block is a fall-through.
2252 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2253 // If this is a landing pad, it isn't a fall through. If it has no preds,
2254 // then nothing falls through to it.
2255 if (MBB->isLandingPad() || MBB->pred_empty())
2258 // If there isn't exactly one predecessor, it can't be a fall through.
2259 if (MBB->pred_size() > 1)
2262 // The predecessor has to be immediately before this block.
2263 MachineBasicBlock *Pred = *MBB->pred_begin();
2264 if (!Pred->isLayoutSuccessor(MBB))
2267 // If the block is completely empty, then it definitely does fall through.
2271 // Check the terminators in the previous blocks
2272 for (const auto &MI : Pred->terminators()) {
2273 // If it is not a simple branch, we are in a table somewhere.
2274 if (!MI.isBranch() || MI.isIndirectBranch())
2277 // If we are the operands of one of the branches, this is not a fall
2278 // through. Note that targets with delay slots will usually bundle
2279 // terminators with the delay slot instruction.
2280 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2283 if (OP->isMBB() && OP->getMBB() == MBB)
2293 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2294 if (!S.usesMetadata())
2297 assert(!S.useStatepoints() && "statepoints do not currently support custom"
2298 " stackmap formats, please see the documentation for a description of"
2299 " the default format. If you really need a custom serialized format,"
2300 " please file a bug");
2302 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2303 gcp_map_type::iterator GCPI = GCMap.find(&S);
2304 if (GCPI != GCMap.end())
2305 return GCPI->second.get();
2307 const char *Name = S.getName().c_str();
2309 for (GCMetadataPrinterRegistry::iterator
2310 I = GCMetadataPrinterRegistry::begin(),
2311 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2312 if (strcmp(Name, I->getName()) == 0) {
2313 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2315 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2316 return IterBool.first->second.get();
2319 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2322 /// Pin vtable to this file.
2323 AsmPrinterHandler::~AsmPrinterHandler() {}