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 "WinCodeViewLineTables.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/Statistic.h"
20 #include "llvm/Analysis/ConstantFolding.h"
21 #include "llvm/Analysis/JumpInstrTableInfo.h"
22 #include "llvm/CodeGen/GCMetadataPrinter.h"
23 #include "llvm/CodeGen/MachineConstantPool.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineInstrBundle.h"
27 #include "llvm/CodeGen/MachineJumpTableInfo.h"
28 #include "llvm/CodeGen/MachineLoopInfo.h"
29 #include "llvm/CodeGen/MachineModuleInfo.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/DebugInfo.h"
32 #include "llvm/IR/Mangler.h"
33 #include "llvm/IR/Module.h"
34 #include "llvm/IR/Operator.h"
35 #include "llvm/MC/MCAsmInfo.h"
36 #include "llvm/MC/MCContext.h"
37 #include "llvm/MC/MCExpr.h"
38 #include "llvm/MC/MCInst.h"
39 #include "llvm/MC/MCSection.h"
40 #include "llvm/MC/MCStreamer.h"
41 #include "llvm/MC/MCSymbol.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include "llvm/Support/Format.h"
44 #include "llvm/Support/MathExtras.h"
45 #include "llvm/Support/Timer.h"
46 #include "llvm/Target/TargetFrameLowering.h"
47 #include "llvm/Target/TargetInstrInfo.h"
48 #include "llvm/Target/TargetLowering.h"
49 #include "llvm/Target/TargetLoweringObjectFile.h"
50 #include "llvm/Target/TargetOptions.h"
51 #include "llvm/Target/TargetRegisterInfo.h"
52 #include "llvm/Target/TargetSubtargetInfo.h"
53 #include "llvm/Transforms/Utils/GlobalStatus.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),
103 TM(tm), MAI(tm.getMCAsmInfo()), MII(tm.getInstrInfo()),
104 OutContext(Streamer.getContext()),
105 OutStreamer(Streamer),
106 LastMI(nullptr), LastFn(0), Counter(~0U), SetCounter(0) {
107 DD = nullptr; MMI = nullptr; LI = nullptr; MF = nullptr;
108 CurrentFnSym = CurrentFnSymForSize = nullptr;
109 GCMetadataPrinters = nullptr;
110 VerboseAsm = Streamer.isVerboseAsm();
113 AsmPrinter::~AsmPrinter() {
114 assert(!DD && Handlers.empty() && "Debug/EH info didn't get finalized");
116 if (GCMetadataPrinters) {
117 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
120 GCMetadataPrinters = nullptr;
126 /// getFunctionNumber - Return a unique ID for the current function.
128 unsigned AsmPrinter::getFunctionNumber() const {
129 return MF->getFunctionNumber();
132 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
133 return TM.getTargetLowering()->getObjFileLowering();
136 /// getDataLayout - Return information about data layout.
137 const DataLayout &AsmPrinter::getDataLayout() const {
138 return *TM.getDataLayout();
141 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
142 return TM.getSubtarget<MCSubtargetInfo>();
145 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
146 S.EmitInstruction(Inst, getSubtargetInfo());
149 StringRef AsmPrinter::getTargetTriple() const {
150 return TM.getTargetTriple();
153 /// getCurrentSection() - Return the current section we are emitting to.
154 const MCSection *AsmPrinter::getCurrentSection() const {
155 return OutStreamer.getCurrentSection().first;
160 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
161 AU.setPreservesAll();
162 MachineFunctionPass::getAnalysisUsage(AU);
163 AU.addRequired<MachineModuleInfo>();
164 AU.addRequired<GCModuleInfo>();
166 AU.addRequired<MachineLoopInfo>();
169 bool AsmPrinter::doInitialization(Module &M) {
170 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
171 MMI->AnalyzeModule(M);
173 // Initialize TargetLoweringObjectFile.
174 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
175 .Initialize(OutContext, TM);
177 OutStreamer.InitSections();
179 Mang = new Mangler(TM.getDataLayout());
181 // Emit the version-min deplyment target directive if needed.
183 // FIXME: If we end up with a collection of these sorts of Darwin-specific
184 // or ELF-specific things, it may make sense to have a platform helper class
185 // that will work with the target helper class. For now keep it here, as the
186 // alternative is duplicated code in each of the target asm printers that
187 // use the directive, where it would need the same conditionalization
189 Triple TT(getTargetTriple());
190 if (TT.isOSDarwin()) {
191 unsigned Major, Minor, Update;
192 TT.getOSVersion(Major, Minor, Update);
193 // If there is a version specified, Major will be non-zero.
195 OutStreamer.EmitVersionMin((TT.isMacOSX() ?
196 MCVM_OSXVersionMin : MCVM_IOSVersionMin),
197 Major, Minor, Update);
200 // Allow the target to emit any magic that it wants at the start of the file.
201 EmitStartOfAsmFile(M);
203 // Very minimal debug info. It is ignored if we emit actual debug info. If we
204 // don't, this at least helps the user find where a global came from.
205 if (MAI->hasSingleParameterDotFile()) {
207 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
210 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
211 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
213 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
214 MP->beginAssembly(*this);
216 // Emit module-level inline asm if it exists.
217 if (!M.getModuleInlineAsm().empty()) {
218 OutStreamer.AddComment("Start of file scope inline assembly");
219 OutStreamer.AddBlankLine();
220 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
221 OutStreamer.AddComment("End of file scope inline assembly");
222 OutStreamer.AddBlankLine();
225 if (MAI->doesSupportDebugInformation()) {
226 if (Triple(TM.getTargetTriple()).isKnownWindowsMSVCEnvironment()) {
227 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this),
229 CodeViewLineTablesGroupName));
231 DD = new DwarfDebug(this, &M);
232 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
236 DwarfException *DE = nullptr;
237 switch (MAI->getExceptionHandlingType()) {
238 case ExceptionHandling::None:
240 case ExceptionHandling::SjLj:
241 case ExceptionHandling::DwarfCFI:
242 DE = new DwarfCFIException(this);
244 case ExceptionHandling::ARM:
245 DE = new ARMException(this);
247 case ExceptionHandling::Win64:
248 DE = new Win64Exception(this);
252 Handlers.push_back(HandlerInfo(DE, EHTimerName, DWARFGroupName));
256 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
257 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
258 if (Linkage != GlobalValue::LinkOnceODRLinkage)
261 if (!MAI.hasWeakDefCanBeHiddenDirective())
264 if (GV->hasUnnamedAddr())
267 // This is only used for MachO, so right now it doesn't really matter how
268 // we handle alias. Revisit this once the MachO linker implements aliases.
269 if (isa<GlobalAlias>(GV))
272 // If it is a non constant variable, it needs to be uniqued across shared
274 if (const GlobalVariable *Var = dyn_cast<GlobalVariable>(GV)) {
275 if (!Var->isConstant())
280 if (!GlobalStatus::analyzeGlobal(GV, GS) && !GS.IsCompared)
286 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
287 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
289 case GlobalValue::CommonLinkage:
290 case GlobalValue::LinkOnceAnyLinkage:
291 case GlobalValue::LinkOnceODRLinkage:
292 case GlobalValue::WeakAnyLinkage:
293 case GlobalValue::WeakODRLinkage:
294 if (MAI->hasWeakDefDirective()) {
296 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
298 if (!canBeHidden(GV, *MAI))
299 // .weak_definition _foo
300 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
302 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
303 } else if (MAI->hasLinkOnceDirective()) {
305 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
306 //NOTE: linkonce is handled by the section the symbol was assigned to.
309 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
312 case GlobalValue::AppendingLinkage:
313 // FIXME: appending linkage variables should go into a section of
314 // their name or something. For now, just emit them as external.
315 case GlobalValue::ExternalLinkage:
316 // If external or appending, declare as a global symbol.
318 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
320 case GlobalValue::PrivateLinkage:
321 case GlobalValue::InternalLinkage:
323 case GlobalValue::AvailableExternallyLinkage:
324 llvm_unreachable("Should never emit this");
325 case GlobalValue::ExternalWeakLinkage:
326 llvm_unreachable("Don't know how to emit these");
328 llvm_unreachable("Unknown linkage type!");
331 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
332 const GlobalValue *GV) const {
333 TM.getNameWithPrefix(Name, GV, *Mang);
336 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
337 return TM.getSymbol(GV, *Mang);
340 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
341 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
342 if (GV->hasInitializer()) {
343 // Check to see if this is a special global used by LLVM, if so, emit it.
344 if (EmitSpecialLLVMGlobal(GV))
348 GV->printAsOperand(OutStreamer.GetCommentOS(),
349 /*PrintType=*/false, GV->getParent());
350 OutStreamer.GetCommentOS() << '\n';
354 MCSymbol *GVSym = getSymbol(GV);
355 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
357 if (!GV->hasInitializer()) // External globals require no extra code.
360 if (MAI->hasDotTypeDotSizeDirective())
361 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
363 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
365 const DataLayout *DL = TM.getDataLayout();
366 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
368 // If the alignment is specified, we *must* obey it. Overaligning a global
369 // with a specified alignment is a prompt way to break globals emitted to
370 // sections and expected to be contiguous (e.g. ObjC metadata).
371 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
373 for (const HandlerInfo &HI : Handlers) {
374 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
375 HI.Handler->setSymbolSize(GVSym, Size);
378 // Handle common and BSS local symbols (.lcomm).
379 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
380 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
381 unsigned Align = 1 << AlignLog;
383 // Handle common symbols.
384 if (GVKind.isCommon()) {
385 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
389 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
393 // Handle local BSS symbols.
394 if (MAI->hasMachoZeroFillDirective()) {
395 const MCSection *TheSection =
396 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
397 // .zerofill __DATA, __bss, _foo, 400, 5
398 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
402 // Use .lcomm only if it supports user-specified alignment.
403 // Otherwise, while it would still be correct to use .lcomm in some
404 // cases (e.g. when Align == 1), the external assembler might enfore
405 // some -unknown- default alignment behavior, which could cause
406 // spurious differences between external and integrated assembler.
407 // Prefer to simply fall back to .local / .comm in this case.
408 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
410 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
414 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
418 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
420 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
424 const MCSection *TheSection =
425 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
427 // Handle the zerofill directive on darwin, which is a special form of BSS
429 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
430 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
433 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
434 // .zerofill __DATA, __common, _foo, 400, 5
435 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
439 // Handle thread local data for mach-o which requires us to output an
440 // additional structure of data and mangle the original symbol so that we
441 // can reference it later.
443 // TODO: This should become an "emit thread local global" method on TLOF.
444 // All of this macho specific stuff should be sunk down into TLOFMachO and
445 // stuff like "TLSExtraDataSection" should no longer be part of the parent
446 // TLOF class. This will also make it more obvious that stuff like
447 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
449 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
450 // Emit the .tbss symbol
452 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
454 if (GVKind.isThreadBSS()) {
455 TheSection = getObjFileLowering().getTLSBSSSection();
456 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
457 } else if (GVKind.isThreadData()) {
458 OutStreamer.SwitchSection(TheSection);
460 EmitAlignment(AlignLog, GV);
461 OutStreamer.EmitLabel(MangSym);
463 EmitGlobalConstant(GV->getInitializer());
466 OutStreamer.AddBlankLine();
468 // Emit the variable struct for the runtime.
469 const MCSection *TLVSect
470 = getObjFileLowering().getTLSExtraDataSection();
472 OutStreamer.SwitchSection(TLVSect);
473 // Emit the linkage here.
474 EmitLinkage(GV, GVSym);
475 OutStreamer.EmitLabel(GVSym);
477 // Three pointers in size:
478 // - __tlv_bootstrap - used to make sure support exists
479 // - spare pointer, used when mapped by the runtime
480 // - pointer to mangled symbol above with initializer
481 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
482 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
484 OutStreamer.EmitIntValue(0, PtrSize);
485 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
487 OutStreamer.AddBlankLine();
491 OutStreamer.SwitchSection(TheSection);
493 EmitLinkage(GV, GVSym);
494 EmitAlignment(AlignLog, GV);
496 OutStreamer.EmitLabel(GVSym);
498 EmitGlobalConstant(GV->getInitializer());
500 if (MAI->hasDotTypeDotSizeDirective())
502 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
504 OutStreamer.AddBlankLine();
507 /// EmitFunctionHeader - This method emits the header for the current
509 void AsmPrinter::EmitFunctionHeader() {
510 // Print out constants referenced by the function
513 // Print the 'header' of function.
514 const Function *F = MF->getFunction();
516 OutStreamer.SwitchSection(
517 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
518 EmitVisibility(CurrentFnSym, F->getVisibility());
520 EmitLinkage(F, CurrentFnSym);
521 EmitAlignment(MF->getAlignment(), F);
523 if (MAI->hasDotTypeDotSizeDirective())
524 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
527 F->printAsOperand(OutStreamer.GetCommentOS(),
528 /*PrintType=*/false, F->getParent());
529 OutStreamer.GetCommentOS() << '\n';
532 // Emit the CurrentFnSym. This is a virtual function to allow targets to
533 // do their wild and crazy things as required.
534 EmitFunctionEntryLabel();
536 // If the function had address-taken blocks that got deleted, then we have
537 // references to the dangling symbols. Emit them at the start of the function
538 // so that we don't get references to undefined symbols.
539 std::vector<MCSymbol*> DeadBlockSyms;
540 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
541 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
542 OutStreamer.AddComment("Address taken block that was later removed");
543 OutStreamer.EmitLabel(DeadBlockSyms[i]);
546 // Emit pre-function debug and/or EH information.
547 for (const HandlerInfo &HI : Handlers) {
548 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
549 HI.Handler->beginFunction(MF);
552 // Emit the prefix data.
553 if (F->hasPrefixData())
554 EmitGlobalConstant(F->getPrefixData());
557 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
558 /// function. This can be overridden by targets as required to do custom stuff.
559 void AsmPrinter::EmitFunctionEntryLabel() {
560 // The function label could have already been emitted if two symbols end up
561 // conflicting due to asm renaming. Detect this and emit an error.
562 if (CurrentFnSym->isUndefined())
563 return OutStreamer.EmitLabel(CurrentFnSym);
565 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
566 "' label emitted multiple times to assembly file");
569 /// emitComments - Pretty-print comments for instructions.
570 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
571 const MachineFunction *MF = MI.getParent()->getParent();
572 const TargetMachine &TM = MF->getTarget();
574 // Check for spills and reloads
577 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
579 // We assume a single instruction only has a spill or reload, not
581 const MachineMemOperand *MMO;
582 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
583 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
584 MMO = *MI.memoperands_begin();
585 CommentOS << MMO->getSize() << "-byte Reload\n";
587 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
588 if (FrameInfo->isSpillSlotObjectIndex(FI))
589 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
590 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
591 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
592 MMO = *MI.memoperands_begin();
593 CommentOS << MMO->getSize() << "-byte Spill\n";
595 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
596 if (FrameInfo->isSpillSlotObjectIndex(FI))
597 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
600 // Check for spill-induced copies
601 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
602 CommentOS << " Reload Reuse\n";
605 /// emitImplicitDef - This method emits the specified machine instruction
606 /// that is an implicit def.
607 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
608 unsigned RegNo = MI->getOperand(0).getReg();
609 OutStreamer.AddComment(Twine("implicit-def: ") +
610 TM.getRegisterInfo()->getName(RegNo));
611 OutStreamer.AddBlankLine();
614 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
615 std::string Str = "kill:";
616 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
617 const MachineOperand &Op = MI->getOperand(i);
618 assert(Op.isReg() && "KILL instruction must have only register operands");
620 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
621 Str += (Op.isDef() ? "<def>" : "<kill>");
623 AP.OutStreamer.AddComment(Str);
624 AP.OutStreamer.AddBlankLine();
627 /// emitDebugValueComment - This method handles the target-independent form
628 /// of DBG_VALUE, returning true if it was able to do so. A false return
629 /// means the target will need to handle MI in EmitInstruction.
630 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
631 // This code handles only the 3-operand target-independent form.
632 if (MI->getNumOperands() != 3)
635 SmallString<128> Str;
636 raw_svector_ostream OS(Str);
637 OS << "DEBUG_VALUE: ";
639 DIVariable V(MI->getOperand(2).getMetadata());
640 if (V.getContext().isSubprogram()) {
641 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
645 OS << V.getName() << " <- ";
647 // The second operand is only an offset if it's an immediate.
648 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
649 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
651 // Register or immediate value. Register 0 means undef.
652 if (MI->getOperand(0).isFPImm()) {
653 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
654 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
655 OS << (double)APF.convertToFloat();
656 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
657 OS << APF.convertToDouble();
659 // There is no good way to print long double. Convert a copy to
660 // double. Ah well, it's only a comment.
662 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
664 OS << "(long double) " << APF.convertToDouble();
666 } else if (MI->getOperand(0).isImm()) {
667 OS << MI->getOperand(0).getImm();
668 } else if (MI->getOperand(0).isCImm()) {
669 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
672 if (MI->getOperand(0).isReg()) {
673 Reg = MI->getOperand(0).getReg();
675 assert(MI->getOperand(0).isFI() && "Unknown operand type");
676 const TargetFrameLowering *TFI = AP.TM.getFrameLowering();
677 Offset += TFI->getFrameIndexReference(*AP.MF,
678 MI->getOperand(0).getIndex(), Reg);
682 // Suppress offset, it is not meaningful here.
684 // NOTE: Want this comment at start of line, don't emit with AddComment.
685 AP.OutStreamer.emitRawComment(OS.str());
690 OS << AP.TM.getRegisterInfo()->getName(Reg);
694 OS << '+' << Offset << ']';
696 // NOTE: Want this comment at start of line, don't emit with AddComment.
697 AP.OutStreamer.emitRawComment(OS.str());
701 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
702 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
703 MF->getFunction()->needsUnwindTableEntry())
706 if (MMI->hasDebugInfo())
712 bool AsmPrinter::needsSEHMoves() {
713 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 &&
714 MF->getFunction()->needsUnwindTableEntry();
717 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
718 ExceptionHandling::ExceptionsType ExceptionHandlingType =
719 MAI->getExceptionHandlingType();
720 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
721 ExceptionHandlingType != ExceptionHandling::ARM)
724 if (needsCFIMoves() == CFI_M_None)
727 if (MMI->getCompactUnwindEncoding() != 0)
728 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding());
730 const MachineModuleInfo &MMI = MF->getMMI();
731 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
732 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
733 const MCCFIInstruction &CFI = Instrs[CFIIndex];
734 emitCFIInstruction(CFI);
737 /// EmitFunctionBody - This method emits the body and trailer for a
739 void AsmPrinter::EmitFunctionBody() {
740 // Emit target-specific gunk before the function body.
741 EmitFunctionBodyStart();
743 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
745 // Print out code for the function.
746 bool HasAnyRealCode = false;
747 const MachineInstr *LastMI = nullptr;
748 for (auto &MBB : *MF) {
749 // Print a label for the basic block.
750 EmitBasicBlockStart(MBB);
751 for (auto &MI : MBB) {
754 // Print the assembly for the instruction.
755 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
756 !MI.isDebugValue()) {
757 HasAnyRealCode = true;
761 if (ShouldPrintDebugScopes) {
762 for (const HandlerInfo &HI : Handlers) {
763 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
764 TimePassesIsEnabled);
765 HI.Handler->beginInstruction(&MI);
770 emitComments(MI, OutStreamer.GetCommentOS());
772 switch (MI.getOpcode()) {
773 case TargetOpcode::CFI_INSTRUCTION:
774 emitCFIInstruction(MI);
777 case TargetOpcode::EH_LABEL:
778 case TargetOpcode::GC_LABEL:
779 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
781 case TargetOpcode::INLINEASM:
784 case TargetOpcode::DBG_VALUE:
786 if (!emitDebugValueComment(&MI, *this))
787 EmitInstruction(&MI);
790 case TargetOpcode::IMPLICIT_DEF:
791 if (isVerbose()) emitImplicitDef(&MI);
793 case TargetOpcode::KILL:
794 if (isVerbose()) emitKill(&MI, *this);
797 EmitInstruction(&MI);
801 if (ShouldPrintDebugScopes) {
802 for (const HandlerInfo &HI : Handlers) {
803 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
804 TimePassesIsEnabled);
805 HI.Handler->endInstruction();
811 // If the last instruction was a prolog label, then we have a situation where
812 // we emitted a prolog but no function body. This results in the ending prolog
813 // label equaling the end of function label and an invalid "row" in the
814 // FDE. We need to emit a noop in this situation so that the FDE's rows are
816 bool RequiresNoop = LastMI && LastMI->isCFIInstruction();
818 // If the function is empty and the object file uses .subsections_via_symbols,
819 // then we need to emit *something* to the function body to prevent the
820 // labels from collapsing together. Just emit a noop.
821 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
823 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
824 if (Noop.getOpcode()) {
825 OutStreamer.AddComment("avoids zero-length function");
826 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
827 } else // Target not mc-ized yet.
828 OutStreamer.EmitRawText(StringRef("\tnop\n"));
831 const Function *F = MF->getFunction();
832 for (const auto &BB : *F) {
833 if (!BB.hasAddressTaken())
835 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
836 if (Sym->isDefined())
838 OutStreamer.AddComment("Address of block that was removed by CodeGen");
839 OutStreamer.EmitLabel(Sym);
842 // Emit target-specific gunk after the function body.
843 EmitFunctionBodyEnd();
845 // If the target wants a .size directive for the size of the function, emit
847 if (MAI->hasDotTypeDotSizeDirective()) {
848 // Create a symbol for the end of function, so we can get the size as
849 // difference between the function label and the temp label.
850 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
851 OutStreamer.EmitLabel(FnEndLabel);
853 const MCExpr *SizeExp =
854 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
855 MCSymbolRefExpr::Create(CurrentFnSymForSize,
858 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
861 // Emit post-function debug and/or EH information.
862 for (const HandlerInfo &HI : Handlers) {
863 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
864 HI.Handler->endFunction(MF);
868 // Print out jump tables referenced by the function.
871 OutStreamer.AddBlankLine();
874 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP);
876 bool AsmPrinter::doFinalization(Module &M) {
877 // Emit global variables.
878 for (const auto &G : M.globals())
879 EmitGlobalVariable(&G);
881 // Emit visibility info for declarations
882 for (const Function &F : M) {
883 if (!F.isDeclaration())
885 GlobalValue::VisibilityTypes V = F.getVisibility();
886 if (V == GlobalValue::DefaultVisibility)
889 MCSymbol *Name = getSymbol(&F);
890 EmitVisibility(Name, V, false);
893 // Get information about jump-instruction tables to print.
894 JumpInstrTableInfo *JITI = getAnalysisIfAvailable<JumpInstrTableInfo>();
896 if (JITI && !JITI->getTables().empty()) {
897 unsigned Arch = Triple(getTargetTriple()).getArch();
898 bool IsThumb = (Arch == Triple::thumb || Arch == Triple::thumbeb);
900 TM.getInstrInfo()->getTrap(TrapInst);
901 for (const auto &KV : JITI->getTables()) {
903 for (const auto &FunPair : KV.second) {
904 // Emit the function labels to make this be a function entry point.
906 OutContext.GetOrCreateSymbol(FunPair.second->getName());
907 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_Global);
908 // FIXME: JumpTableInstrInfo should store information about the required
909 // alignment of table entries and the size of the padding instruction.
912 OutStreamer.EmitThumbFunc(FunSym);
913 if (MAI->hasDotTypeDotSizeDirective())
914 OutStreamer.EmitSymbolAttribute(FunSym, MCSA_ELF_TypeFunction);
915 OutStreamer.EmitLabel(FunSym);
917 // Emit the jump instruction to transfer control to the original
920 MCSymbol *TargetSymbol =
921 OutContext.GetOrCreateSymbol(FunPair.first->getName());
922 const MCSymbolRefExpr *TargetSymRef =
923 MCSymbolRefExpr::Create(TargetSymbol, MCSymbolRefExpr::VK_PLT,
925 TM.getInstrInfo()->getUnconditionalBranch(JumpToFun, TargetSymRef);
926 OutStreamer.EmitInstruction(JumpToFun, getSubtargetInfo());
930 // Emit enough padding instructions to fill up to the next power of two.
931 // This assumes that the trap instruction takes 8 bytes or fewer.
932 uint64_t Remaining = NextPowerOf2(Count) - Count;
933 for (uint64_t C = 0; C < Remaining; ++C) {
935 OutStreamer.EmitInstruction(TrapInst, getSubtargetInfo());
941 // Emit module flags.
942 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
943 M.getModuleFlagsMetadata(ModuleFlags);
944 if (!ModuleFlags.empty())
945 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
947 // Make sure we wrote out everything we need.
950 // Finalize debug and EH information.
951 for (const HandlerInfo &HI : Handlers) {
952 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
953 TimePassesIsEnabled);
954 HI.Handler->endModule();
960 // If the target wants to know about weak references, print them all.
961 if (MAI->getWeakRefDirective()) {
962 // FIXME: This is not lazy, it would be nice to only print weak references
963 // to stuff that is actually used. Note that doing so would require targets
964 // to notice uses in operands (due to constant exprs etc). This should
965 // happen with the MC stuff eventually.
967 // Print out module-level global variables here.
968 for (const auto &G : M.globals()) {
969 if (!G.hasExternalWeakLinkage())
971 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
974 for (const auto &F : M) {
975 if (!F.hasExternalWeakLinkage())
977 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
981 if (MAI->hasSetDirective()) {
982 OutStreamer.AddBlankLine();
983 for (const auto &Alias : M.aliases()) {
984 MCSymbol *Name = getSymbol(&Alias);
986 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
987 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
988 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
989 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
991 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
993 EmitVisibility(Name, Alias.getVisibility());
995 // Emit the directives as assignments aka .set:
996 OutStreamer.EmitAssignment(Name,
997 lowerConstant(Alias.getAliasee(), *this));
1001 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1002 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1003 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1004 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1005 MP->finishAssembly(*this);
1007 // Emit llvm.ident metadata in an '.ident' directive.
1008 EmitModuleIdents(M);
1010 // If we don't have any trampolines, then we don't require stack memory
1011 // to be executable. Some targets have a directive to declare this.
1012 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1013 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1014 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1015 OutStreamer.SwitchSection(S);
1017 // Allow the target to emit any magic that it wants at the end of the file,
1018 // after everything else has gone out.
1019 EmitEndOfAsmFile(M);
1021 delete Mang; Mang = nullptr;
1024 OutStreamer.Finish();
1025 OutStreamer.reset();
1030 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1032 // Get the function symbol.
1033 CurrentFnSym = getSymbol(MF.getFunction());
1034 CurrentFnSymForSize = CurrentFnSym;
1037 LI = &getAnalysis<MachineLoopInfo>();
1041 // SectionCPs - Keep track the alignment, constpool entries per Section.
1045 SmallVector<unsigned, 4> CPEs;
1046 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1050 /// EmitConstantPool - Print to the current output stream assembly
1051 /// representations of the constants in the constant pool MCP. This is
1052 /// used to print out constants which have been "spilled to memory" by
1053 /// the code generator.
1055 void AsmPrinter::EmitConstantPool() {
1056 const MachineConstantPool *MCP = MF->getConstantPool();
1057 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1058 if (CP.empty()) return;
1060 // Calculate sections for constant pool entries. We collect entries to go into
1061 // the same section together to reduce amount of section switch statements.
1062 SmallVector<SectionCPs, 4> CPSections;
1063 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1064 const MachineConstantPoolEntry &CPE = CP[i];
1065 unsigned Align = CPE.getAlignment();
1068 switch (CPE.getRelocationInfo()) {
1069 default: llvm_unreachable("Unknown section kind");
1070 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
1072 Kind = SectionKind::getReadOnlyWithRelLocal();
1075 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) {
1076 case 4: Kind = SectionKind::getMergeableConst4(); break;
1077 case 8: Kind = SectionKind::getMergeableConst8(); break;
1078 case 16: Kind = SectionKind::getMergeableConst16();break;
1079 default: Kind = SectionKind::getMergeableConst(); break;
1083 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
1085 // The number of sections are small, just do a linear search from the
1086 // last section to the first.
1088 unsigned SecIdx = CPSections.size();
1089 while (SecIdx != 0) {
1090 if (CPSections[--SecIdx].S == S) {
1096 SecIdx = CPSections.size();
1097 CPSections.push_back(SectionCPs(S, Align));
1100 if (Align > CPSections[SecIdx].Alignment)
1101 CPSections[SecIdx].Alignment = Align;
1102 CPSections[SecIdx].CPEs.push_back(i);
1105 // Now print stuff into the calculated sections.
1106 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1107 OutStreamer.SwitchSection(CPSections[i].S);
1108 EmitAlignment(Log2_32(CPSections[i].Alignment));
1110 unsigned Offset = 0;
1111 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1112 unsigned CPI = CPSections[i].CPEs[j];
1113 MachineConstantPoolEntry CPE = CP[CPI];
1115 // Emit inter-object padding for alignment.
1116 unsigned AlignMask = CPE.getAlignment() - 1;
1117 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1118 OutStreamer.EmitZeros(NewOffset - Offset);
1120 Type *Ty = CPE.getType();
1121 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty);
1122 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1124 if (CPE.isMachineConstantPoolEntry())
1125 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1127 EmitGlobalConstant(CPE.Val.ConstVal);
1132 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1133 /// by the current function to the current output stream.
1135 void AsmPrinter::EmitJumpTableInfo() {
1136 const DataLayout *DL = MF->getTarget().getDataLayout();
1137 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1139 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1140 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1141 if (JT.empty()) return;
1143 // Pick the directive to use to print the jump table entries, and switch to
1144 // the appropriate section.
1145 const Function *F = MF->getFunction();
1146 bool JTInDiffSection = false;
1147 if (// In PIC mode, we need to emit the jump table to the same section as the
1148 // function body itself, otherwise the label differences won't make sense.
1149 // FIXME: Need a better predicate for this: what about custom entries?
1150 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1151 // We should also do if the section name is NULL or function is declared
1152 // in discardable section
1153 // FIXME: this isn't the right predicate, should be based on the MCSection
1154 // for the function.
1155 F->isWeakForLinker()) {
1156 OutStreamer.SwitchSection(
1157 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1159 // Otherwise, drop it in the readonly section.
1160 const MCSection *ReadOnlySection =
1161 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1162 OutStreamer.SwitchSection(ReadOnlySection);
1163 JTInDiffSection = true;
1166 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout())));
1168 // Jump tables in code sections are marked with a data_region directive
1169 // where that's supported.
1170 if (!JTInDiffSection)
1171 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1173 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1174 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1176 // If this jump table was deleted, ignore it.
1177 if (JTBBs.empty()) continue;
1179 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1180 // .set directive for each unique entry. This reduces the number of
1181 // relocations the assembler will generate for the jump table.
1182 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1183 MAI->hasSetDirective()) {
1184 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1185 const TargetLowering *TLI = TM.getTargetLowering();
1186 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1187 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1188 const MachineBasicBlock *MBB = JTBBs[ii];
1189 if (!EmittedSets.insert(MBB)) continue;
1191 // .set LJTSet, LBB32-base
1193 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1194 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1195 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1199 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1200 // before each jump table. The first label is never referenced, but tells
1201 // the assembler and linker the extents of the jump table object. The
1202 // second label is actually referenced by the code.
1203 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1204 // FIXME: This doesn't have to have any specific name, just any randomly
1205 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1206 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1208 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1210 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1211 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1213 if (!JTInDiffSection)
1214 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1217 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1219 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1220 const MachineBasicBlock *MBB,
1221 unsigned UID) const {
1222 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1223 const MCExpr *Value = nullptr;
1224 switch (MJTI->getEntryKind()) {
1225 case MachineJumpTableInfo::EK_Inline:
1226 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1227 case MachineJumpTableInfo::EK_Custom32:
1228 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1231 case MachineJumpTableInfo::EK_BlockAddress:
1232 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1234 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1236 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1237 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1238 // with a relocation as gp-relative, e.g.:
1240 MCSymbol *MBBSym = MBB->getSymbol();
1241 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1245 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1246 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1247 // with a relocation as gp-relative, e.g.:
1249 MCSymbol *MBBSym = MBB->getSymbol();
1250 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1254 case MachineJumpTableInfo::EK_LabelDifference32: {
1255 // EK_LabelDifference32 - Each entry is the address of the block minus
1256 // the address of the jump table. This is used for PIC jump tables where
1257 // gprel32 is not supported. e.g.:
1258 // .word LBB123 - LJTI1_2
1259 // If the .set directive is supported, this is emitted as:
1260 // .set L4_5_set_123, LBB123 - LJTI1_2
1261 // .word L4_5_set_123
1263 // If we have emitted set directives for the jump table entries, print
1264 // them rather than the entries themselves. If we're emitting PIC, then
1265 // emit the table entries as differences between two text section labels.
1266 if (MAI->hasSetDirective()) {
1267 // If we used .set, reference the .set's symbol.
1268 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1272 // Otherwise, use the difference as the jump table entry.
1273 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1274 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1275 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1280 assert(Value && "Unknown entry kind!");
1282 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout());
1283 OutStreamer.EmitValue(Value, EntrySize);
1287 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1288 /// special global used by LLVM. If so, emit it and return true, otherwise
1289 /// do nothing and return false.
1290 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1291 if (GV->getName() == "llvm.used") {
1292 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1293 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1297 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1298 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1299 GV->hasAvailableExternallyLinkage())
1302 if (!GV->hasAppendingLinkage()) return false;
1304 assert(GV->hasInitializer() && "Not a special LLVM global!");
1306 if (GV->getName() == "llvm.global_ctors") {
1307 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1309 if (TM.getRelocationModel() == Reloc::Static &&
1310 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1311 StringRef Sym(".constructors_used");
1312 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1318 if (GV->getName() == "llvm.global_dtors") {
1319 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1321 if (TM.getRelocationModel() == Reloc::Static &&
1322 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1323 StringRef Sym(".destructors_used");
1324 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1333 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1334 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1335 /// is true, as being used with this directive.
1336 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1337 // Should be an array of 'i8*'.
1338 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1339 const GlobalValue *GV =
1340 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1342 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1348 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1350 llvm::Constant *Func;
1351 llvm::GlobalValue *ComdatKey;
1355 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1357 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1358 // Should be an array of '{ int, void ()* }' structs. The first value is the
1360 if (!isa<ConstantArray>(List)) return;
1362 // Sanity check the structors list.
1363 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1364 if (!InitList) return; // Not an array!
1365 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1366 // FIXME: Only allow the 3-field form in LLVM 4.0.
1367 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1368 return; // Not an array of two or three elements!
1369 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1370 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1371 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1372 return; // Not (int, ptr, ptr).
1374 // Gather the structors in a form that's convenient for sorting by priority.
1375 SmallVector<Structor, 8> Structors;
1376 for (Value *O : InitList->operands()) {
1377 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1378 if (!CS) continue; // Malformed.
1379 if (CS->getOperand(1)->isNullValue())
1380 break; // Found a null terminator, skip the rest.
1381 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1382 if (!Priority) continue; // Malformed.
1383 Structors.push_back(Structor());
1384 Structor &S = Structors.back();
1385 S.Priority = Priority->getLimitedValue(65535);
1386 S.Func = CS->getOperand(1);
1387 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1388 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1391 // Emit the function pointers in the target-specific order
1392 const DataLayout *DL = TM.getDataLayout();
1393 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1394 std::stable_sort(Structors.begin(), Structors.end(),
1395 [](const Structor &L,
1396 const Structor &R) { return L.Priority < R.Priority; });
1397 for (Structor &S : Structors) {
1398 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1399 const MCSymbol *KeySym = nullptr;
1400 const MCSection *KeySec = nullptr;
1401 if (GlobalValue *GV = S.ComdatKey) {
1402 if (GV->hasAvailableExternallyLinkage())
1403 // If the associated variable is available_externally, some other TU
1404 // will provide its dynamic initializer.
1407 KeySym = getSymbol(GV);
1408 KeySec = getObjFileLowering().SectionForGlobal(GV, *Mang, TM);
1410 const MCSection *OutputSection =
1411 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym, KeySec)
1412 : Obj.getStaticDtorSection(S.Priority, KeySym, KeySec));
1413 OutStreamer.SwitchSection(OutputSection);
1414 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1415 EmitAlignment(Align);
1416 EmitXXStructor(S.Func);
1420 void AsmPrinter::EmitModuleIdents(Module &M) {
1421 if (!MAI->hasIdentDirective())
1424 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1425 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1426 const MDNode *N = NMD->getOperand(i);
1427 assert(N->getNumOperands() == 1 &&
1428 "llvm.ident metadata entry can have only one operand");
1429 const MDString *S = cast<MDString>(N->getOperand(0));
1430 OutStreamer.EmitIdent(S->getString());
1435 //===--------------------------------------------------------------------===//
1436 // Emission and print routines
1439 /// EmitInt8 - Emit a byte directive and value.
1441 void AsmPrinter::EmitInt8(int Value) const {
1442 OutStreamer.EmitIntValue(Value, 1);
1445 /// EmitInt16 - Emit a short directive and value.
1447 void AsmPrinter::EmitInt16(int Value) const {
1448 OutStreamer.EmitIntValue(Value, 2);
1451 /// EmitInt32 - Emit a long directive and value.
1453 void AsmPrinter::EmitInt32(int Value) const {
1454 OutStreamer.EmitIntValue(Value, 4);
1457 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1458 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1459 /// labels. This implicitly uses .set if it is available.
1460 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1461 unsigned Size) const {
1462 // Get the Hi-Lo expression.
1463 const MCExpr *Diff =
1464 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1465 MCSymbolRefExpr::Create(Lo, OutContext),
1468 if (!MAI->hasSetDirective()) {
1469 OutStreamer.EmitValue(Diff, Size);
1473 // Otherwise, emit with .set (aka assignment).
1474 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1475 OutStreamer.EmitAssignment(SetLabel, Diff);
1476 OutStreamer.EmitSymbolValue(SetLabel, Size);
1479 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1480 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1481 /// specify the labels. This implicitly uses .set if it is available.
1482 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1484 unsigned Size) const {
1486 // Emit Hi+Offset - Lo
1487 // Get the Hi+Offset expression.
1488 const MCExpr *Plus =
1489 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1490 MCConstantExpr::Create(Offset, OutContext),
1493 // Get the Hi+Offset-Lo expression.
1494 const MCExpr *Diff =
1495 MCBinaryExpr::CreateSub(Plus,
1496 MCSymbolRefExpr::Create(Lo, OutContext),
1499 if (!MAI->hasSetDirective())
1500 OutStreamer.EmitValue(Diff, Size);
1502 // Otherwise, emit with .set (aka assignment).
1503 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1504 OutStreamer.EmitAssignment(SetLabel, Diff);
1505 OutStreamer.EmitSymbolValue(SetLabel, Size);
1509 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1510 /// where the size in bytes of the directive is specified by Size and Label
1511 /// specifies the label. This implicitly uses .set if it is available.
1512 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1514 bool IsSectionRelative) const {
1515 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1516 OutStreamer.EmitCOFFSecRel32(Label);
1520 // Emit Label+Offset (or just Label if Offset is zero)
1521 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1523 Expr = MCBinaryExpr::CreateAdd(
1524 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1526 OutStreamer.EmitValue(Expr, Size);
1529 //===----------------------------------------------------------------------===//
1531 // EmitAlignment - Emit an alignment directive to the specified power of
1532 // two boundary. For example, if you pass in 3 here, you will get an 8
1533 // byte alignment. If a global value is specified, and if that global has
1534 // an explicit alignment requested, it will override the alignment request
1535 // if required for correctness.
1537 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1538 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits);
1540 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1542 if (getCurrentSection()->getKind().isText())
1543 OutStreamer.EmitCodeAlignment(1 << NumBits);
1545 OutStreamer.EmitValueToAlignment(1 << NumBits);
1548 //===----------------------------------------------------------------------===//
1549 // Constant emission.
1550 //===----------------------------------------------------------------------===//
1552 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1554 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1555 MCContext &Ctx = AP.OutContext;
1557 if (CV->isNullValue() || isa<UndefValue>(CV))
1558 return MCConstantExpr::Create(0, Ctx);
1560 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1561 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1563 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1564 return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx);
1566 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1567 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1569 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1571 llvm_unreachable("Unknown constant value to lower!");
1574 if (const MCExpr *RelocExpr =
1575 AP.getObjFileLowering().getExecutableRelativeSymbol(CE, *AP.Mang,
1579 switch (CE->getOpcode()) {
1581 // If the code isn't optimized, there may be outstanding folding
1582 // opportunities. Attempt to fold the expression using DataLayout as a
1583 // last resort before giving up.
1585 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout()))
1587 return lowerConstant(C, AP);
1589 // Otherwise report the problem to the user.
1592 raw_string_ostream OS(S);
1593 OS << "Unsupported expression in static initializer: ";
1594 CE->printAsOperand(OS, /*PrintType=*/false,
1595 !AP.MF ? nullptr : AP.MF->getFunction()->getParent());
1596 report_fatal_error(OS.str());
1598 case Instruction::GetElementPtr: {
1599 const DataLayout &DL = *AP.TM.getDataLayout();
1600 // Generate a symbolic expression for the byte address
1601 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1602 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1604 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1608 int64_t Offset = OffsetAI.getSExtValue();
1609 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1613 case Instruction::Trunc:
1614 // We emit the value and depend on the assembler to truncate the generated
1615 // expression properly. This is important for differences between
1616 // blockaddress labels. Since the two labels are in the same function, it
1617 // is reasonable to treat their delta as a 32-bit value.
1619 case Instruction::BitCast:
1620 return lowerConstant(CE->getOperand(0), AP);
1622 case Instruction::IntToPtr: {
1623 const DataLayout &DL = *AP.TM.getDataLayout();
1624 // Handle casts to pointers by changing them into casts to the appropriate
1625 // integer type. This promotes constant folding and simplifies this code.
1626 Constant *Op = CE->getOperand(0);
1627 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1629 return lowerConstant(Op, AP);
1632 case Instruction::PtrToInt: {
1633 const DataLayout &DL = *AP.TM.getDataLayout();
1634 // Support only foldable casts to/from pointers that can be eliminated by
1635 // changing the pointer to the appropriately sized integer type.
1636 Constant *Op = CE->getOperand(0);
1637 Type *Ty = CE->getType();
1639 const MCExpr *OpExpr = lowerConstant(Op, AP);
1641 // We can emit the pointer value into this slot if the slot is an
1642 // integer slot equal to the size of the pointer.
1643 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1646 // Otherwise the pointer is smaller than the resultant integer, mask off
1647 // the high bits so we are sure to get a proper truncation if the input is
1649 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1650 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1651 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1654 // The MC library also has a right-shift operator, but it isn't consistently
1655 // signed or unsigned between different targets.
1656 case Instruction::Add:
1657 case Instruction::Sub:
1658 case Instruction::Mul:
1659 case Instruction::SDiv:
1660 case Instruction::SRem:
1661 case Instruction::Shl:
1662 case Instruction::And:
1663 case Instruction::Or:
1664 case Instruction::Xor: {
1665 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1666 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1667 switch (CE->getOpcode()) {
1668 default: llvm_unreachable("Unknown binary operator constant cast expr");
1669 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1670 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1671 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1672 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1673 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1674 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1675 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1676 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1677 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1683 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1685 /// isRepeatedByteSequence - Determine whether the given value is
1686 /// composed of a repeated sequence of identical bytes and return the
1687 /// byte value. If it is not a repeated sequence, return -1.
1688 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1689 StringRef Data = V->getRawDataValues();
1690 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1692 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1693 if (Data[i] != C) return -1;
1694 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1698 /// isRepeatedByteSequence - Determine whether the given value is
1699 /// composed of a repeated sequence of identical bytes and return the
1700 /// byte value. If it is not a repeated sequence, return -1.
1701 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1703 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1704 if (CI->getBitWidth() > 64) return -1;
1706 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType());
1707 uint64_t Value = CI->getZExtValue();
1709 // Make sure the constant is at least 8 bits long and has a power
1710 // of 2 bit width. This guarantees the constant bit width is
1711 // always a multiple of 8 bits, avoiding issues with padding out
1712 // to Size and other such corner cases.
1713 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1715 uint8_t Byte = static_cast<uint8_t>(Value);
1717 for (unsigned i = 1; i < Size; ++i) {
1719 if (static_cast<uint8_t>(Value) != Byte) return -1;
1723 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1724 // Make sure all array elements are sequences of the same repeated
1726 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1727 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1728 if (Byte == -1) return -1;
1730 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1731 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1732 if (ThisByte == -1) return -1;
1733 if (Byte != ThisByte) return -1;
1738 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1739 return isRepeatedByteSequence(CDS);
1744 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1747 // See if we can aggregate this into a .fill, if so, emit it as such.
1748 int Value = isRepeatedByteSequence(CDS, AP.TM);
1750 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType());
1751 // Don't emit a 1-byte object as a .fill.
1753 return AP.OutStreamer.EmitFill(Bytes, Value);
1756 // If this can be emitted with .ascii/.asciz, emit it as such.
1757 if (CDS->isString())
1758 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1760 // Otherwise, emit the values in successive locations.
1761 unsigned ElementByteSize = CDS->getElementByteSize();
1762 if (isa<IntegerType>(CDS->getElementType())) {
1763 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1765 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1766 CDS->getElementAsInteger(i));
1767 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1770 } else if (ElementByteSize == 4) {
1771 // FP Constants are printed as integer constants to avoid losing
1773 assert(CDS->getElementType()->isFloatTy());
1774 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1780 F = CDS->getElementAsFloat(i);
1782 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1783 AP.OutStreamer.EmitIntValue(I, 4);
1786 assert(CDS->getElementType()->isDoubleTy());
1787 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1793 F = CDS->getElementAsDouble(i);
1795 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1796 AP.OutStreamer.EmitIntValue(I, 8);
1800 const DataLayout &DL = *AP.TM.getDataLayout();
1801 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1802 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1803 CDS->getNumElements();
1804 if (unsigned Padding = Size - EmittedSize)
1805 AP.OutStreamer.EmitZeros(Padding);
1809 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1810 // See if we can aggregate some values. Make sure it can be
1811 // represented as a series of bytes of the constant value.
1812 int Value = isRepeatedByteSequence(CA, AP.TM);
1815 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType());
1816 AP.OutStreamer.EmitFill(Bytes, Value);
1819 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1820 emitGlobalConstantImpl(CA->getOperand(i), AP);
1824 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1825 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1826 emitGlobalConstantImpl(CV->getOperand(i), AP);
1828 const DataLayout &DL = *AP.TM.getDataLayout();
1829 unsigned Size = DL.getTypeAllocSize(CV->getType());
1830 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1831 CV->getType()->getNumElements();
1832 if (unsigned Padding = Size - EmittedSize)
1833 AP.OutStreamer.EmitZeros(Padding);
1836 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1837 // Print the fields in successive locations. Pad to align if needed!
1838 const DataLayout *DL = AP.TM.getDataLayout();
1839 unsigned Size = DL->getTypeAllocSize(CS->getType());
1840 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1841 uint64_t SizeSoFar = 0;
1842 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1843 const Constant *Field = CS->getOperand(i);
1845 // Check if padding is needed and insert one or more 0s.
1846 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1847 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1848 - Layout->getElementOffset(i)) - FieldSize;
1849 SizeSoFar += FieldSize + PadSize;
1851 // Now print the actual field value.
1852 emitGlobalConstantImpl(Field, AP);
1854 // Insert padding - this may include padding to increase the size of the
1855 // current field up to the ABI size (if the struct is not packed) as well
1856 // as padding to ensure that the next field starts at the right offset.
1857 AP.OutStreamer.EmitZeros(PadSize);
1859 assert(SizeSoFar == Layout->getSizeInBytes() &&
1860 "Layout of constant struct may be incorrect!");
1863 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1864 APInt API = CFP->getValueAPF().bitcastToAPInt();
1866 // First print a comment with what we think the original floating-point value
1867 // should have been.
1868 if (AP.isVerbose()) {
1869 SmallString<8> StrVal;
1870 CFP->getValueAPF().toString(StrVal);
1872 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1873 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1876 // Now iterate through the APInt chunks, emitting them in endian-correct
1877 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1879 unsigned NumBytes = API.getBitWidth() / 8;
1880 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1881 const uint64_t *p = API.getRawData();
1883 // PPC's long double has odd notions of endianness compared to how LLVM
1884 // handles it: p[0] goes first for *big* endian on PPC.
1885 if (AP.TM.getDataLayout()->isBigEndian() != 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.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.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.getDataLayout()->getTypeAllocSize(CI->getType());
1956 Size -= (BitWidth / 64) * 8;
1957 assert(Size && Size * 8 >= ExtraBitsSize &&
1958 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1959 == ExtraBits && "Directive too small for extra bits.");
1960 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1964 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1965 const DataLayout *DL = AP.TM.getDataLayout();
1966 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1967 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1968 return AP.OutStreamer.EmitZeros(Size);
1970 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1977 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1978 CI->getZExtValue());
1979 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1982 emitGlobalConstantLargeInt(CI, AP);
1987 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1988 return emitGlobalConstantFP(CFP, AP);
1990 if (isa<ConstantPointerNull>(CV)) {
1991 AP.OutStreamer.EmitIntValue(0, Size);
1995 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1996 return emitGlobalConstantDataSequential(CDS, AP);
1998 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1999 return emitGlobalConstantArray(CVA, AP);
2001 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2002 return emitGlobalConstantStruct(CVS, AP);
2004 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2005 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2007 if (CE->getOpcode() == Instruction::BitCast)
2008 return emitGlobalConstantImpl(CE->getOperand(0), AP);
2011 // If the constant expression's size is greater than 64-bits, then we have
2012 // to emit the value in chunks. Try to constant fold the value and emit it
2014 Constant *New = ConstantFoldConstantExpression(CE, DL);
2015 if (New && New != CE)
2016 return emitGlobalConstantImpl(New, AP);
2020 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2021 return emitGlobalConstantVector(V, AP);
2023 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2024 // thread the streamer with EmitValue.
2025 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
2028 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2029 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2030 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType());
2032 emitGlobalConstantImpl(CV, *this);
2033 else if (MAI->hasSubsectionsViaSymbols()) {
2034 // If the global has zero size, emit a single byte so that two labels don't
2035 // look like they are at the same location.
2036 OutStreamer.EmitIntValue(0, 1);
2040 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2041 // Target doesn't support this yet!
2042 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2045 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2047 OS << '+' << Offset;
2048 else if (Offset < 0)
2052 //===----------------------------------------------------------------------===//
2053 // Symbol Lowering Routines.
2054 //===----------------------------------------------------------------------===//
2056 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2057 /// temporary label with the specified stem and unique ID.
2058 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const {
2059 const DataLayout *DL = TM.getDataLayout();
2060 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2064 /// GetTempSymbol - Return an assembler temporary label with the specified
2066 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const {
2067 const DataLayout *DL = TM.getDataLayout();
2068 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2073 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2074 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2077 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2078 return MMI->getAddrLabelSymbol(BB);
2081 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2082 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2083 const DataLayout *DL = TM.getDataLayout();
2084 return OutContext.GetOrCreateSymbol
2085 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2086 + "_" + Twine(CPID));
2089 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2090 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2091 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2094 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2095 /// FIXME: privatize to AsmPrinter.
2096 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2097 const DataLayout *DL = TM.getDataLayout();
2098 return OutContext.GetOrCreateSymbol
2099 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2100 Twine(UID) + "_set_" + Twine(MBBID));
2103 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2104 StringRef Suffix) const {
2105 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2109 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2111 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2112 SmallString<60> NameStr;
2113 Mang->getNameWithPrefix(NameStr, Sym);
2114 return OutContext.GetOrCreateSymbol(NameStr.str());
2119 /// PrintParentLoopComment - Print comments about parent loops of this one.
2120 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2121 unsigned FunctionNumber) {
2123 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2124 OS.indent(Loop->getLoopDepth()*2)
2125 << "Parent Loop BB" << FunctionNumber << "_"
2126 << Loop->getHeader()->getNumber()
2127 << " Depth=" << Loop->getLoopDepth() << '\n';
2131 /// PrintChildLoopComment - Print comments about child loops within
2132 /// the loop for this basic block, with nesting.
2133 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2134 unsigned FunctionNumber) {
2135 // Add child loop information
2136 for (const MachineLoop *CL : *Loop) {
2137 OS.indent(CL->getLoopDepth()*2)
2138 << "Child Loop BB" << FunctionNumber << "_"
2139 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2141 PrintChildLoopComment(OS, CL, FunctionNumber);
2145 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2146 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2147 const MachineLoopInfo *LI,
2148 const AsmPrinter &AP) {
2149 // Add loop depth information
2150 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2153 MachineBasicBlock *Header = Loop->getHeader();
2154 assert(Header && "No header for loop");
2156 // If this block is not a loop header, just print out what is the loop header
2158 if (Header != &MBB) {
2159 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2160 Twine(AP.getFunctionNumber())+"_" +
2161 Twine(Loop->getHeader()->getNumber())+
2162 " Depth="+Twine(Loop->getLoopDepth()));
2166 // Otherwise, it is a loop header. Print out information about child and
2168 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2170 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2173 OS.indent(Loop->getLoopDepth()*2-2);
2178 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2180 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2184 /// EmitBasicBlockStart - This method prints the label for the specified
2185 /// MachineBasicBlock, an alignment (if present) and a comment describing
2186 /// it if appropriate.
2187 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2188 // Emit an alignment directive for this block, if needed.
2189 if (unsigned Align = MBB.getAlignment())
2190 EmitAlignment(Align);
2192 // If the block has its address taken, emit any labels that were used to
2193 // reference the block. It is possible that there is more than one label
2194 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2195 // the references were generated.
2196 if (MBB.hasAddressTaken()) {
2197 const BasicBlock *BB = MBB.getBasicBlock();
2199 OutStreamer.AddComment("Block address taken");
2201 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2202 for (auto *Sym : Symbols)
2203 OutStreamer.EmitLabel(Sym);
2206 // Print some verbose block comments.
2208 if (const BasicBlock *BB = MBB.getBasicBlock())
2210 OutStreamer.AddComment("%" + BB->getName());
2211 emitBasicBlockLoopComments(MBB, LI, *this);
2214 // Print the main label for the block.
2215 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2217 // NOTE: Want this comment at start of line, don't emit with AddComment.
2218 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2221 OutStreamer.EmitLabel(MBB.getSymbol());
2225 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2226 bool IsDefinition) const {
2227 MCSymbolAttr Attr = MCSA_Invalid;
2229 switch (Visibility) {
2231 case GlobalValue::HiddenVisibility:
2233 Attr = MAI->getHiddenVisibilityAttr();
2235 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2237 case GlobalValue::ProtectedVisibility:
2238 Attr = MAI->getProtectedVisibilityAttr();
2242 if (Attr != MCSA_Invalid)
2243 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2246 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2247 /// exactly one predecessor and the control transfer mechanism between
2248 /// the predecessor and this block is a fall-through.
2250 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2251 // If this is a landing pad, it isn't a fall through. If it has no preds,
2252 // then nothing falls through to it.
2253 if (MBB->isLandingPad() || MBB->pred_empty())
2256 // If there isn't exactly one predecessor, it can't be a fall through.
2257 if (MBB->pred_size() > 1)
2260 // The predecessor has to be immediately before this block.
2261 MachineBasicBlock *Pred = *MBB->pred_begin();
2262 if (!Pred->isLayoutSuccessor(MBB))
2265 // If the block is completely empty, then it definitely does fall through.
2269 // Check the terminators in the previous blocks
2270 for (const auto &MI : Pred->terminators()) {
2271 // If it is not a simple branch, we are in a table somewhere.
2272 if (!MI.isBranch() || MI.isIndirectBranch())
2275 // If we are the operands of one of the branches, this is not a fall
2276 // through. Note that targets with delay slots will usually bundle
2277 // terminators with the delay slot instruction.
2278 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2281 if (OP->isMBB() && OP->getMBB() == MBB)
2291 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2292 if (!S.usesMetadata())
2295 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2296 gcp_map_type::iterator GCPI = GCMap.find(&S);
2297 if (GCPI != GCMap.end())
2298 return GCPI->second.get();
2300 const char *Name = S.getName().c_str();
2302 for (GCMetadataPrinterRegistry::iterator
2303 I = GCMetadataPrinterRegistry::begin(),
2304 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2305 if (strcmp(Name, I->getName()) == 0) {
2306 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2308 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2309 return IterBool.first->second.get();
2312 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2315 /// Pin vtable to this file.
2316 AsmPrinterHandler::~AsmPrinterHandler() {}