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 #define DEBUG_TYPE "asm-printer"
15 #include "llvm/CodeGen/AsmPrinter.h"
16 #include "DwarfDebug.h"
17 #include "DwarfException.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/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 static const char *const DWARFGroupName = "DWARF Emission";
57 static const char *const DbgTimerName = "Debug Info Emission";
58 static const char *const EHTimerName = "DWARF Exception Writer";
59 static const char *const CodeViewLineTablesGroupName = "CodeView Line Tables";
61 STATISTIC(EmittedInsts, "Number of machine instrs printed");
63 char AsmPrinter::ID = 0;
65 typedef DenseMap<GCStrategy*, std::unique_ptr<GCMetadataPrinter>> gcp_map_type;
66 static gcp_map_type &getGCMap(void *&P) {
68 P = new gcp_map_type();
69 return *(gcp_map_type*)P;
73 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
74 /// value in log2 form. This rounds up to the preferred alignment if possible
76 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD,
77 unsigned InBits = 0) {
79 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
80 NumBits = TD.getPreferredAlignmentLog(GVar);
82 // If InBits is specified, round it to it.
86 // If the GV has a specified alignment, take it into account.
87 if (GV->getAlignment() == 0)
90 unsigned GVAlign = Log2_32(GV->getAlignment());
92 // If the GVAlign is larger than NumBits, or if we are required to obey
93 // NumBits because the GV has an assigned section, obey it.
94 if (GVAlign > NumBits || GV->hasSection())
99 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
100 : MachineFunctionPass(ID),
101 TM(tm), MAI(tm.getMCAsmInfo()), MII(tm.getInstrInfo()),
102 OutContext(Streamer.getContext()),
103 OutStreamer(Streamer),
104 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
105 DD = 0; MMI = 0; LI = 0; MF = 0;
106 CurrentFnSym = CurrentFnSymForSize = 0;
107 GCMetadataPrinters = 0;
108 VerboseAsm = Streamer.isVerboseAsm();
111 AsmPrinter::~AsmPrinter() {
112 assert(DD == 0 && Handlers.empty() && "Debug/EH info didn't get finalized");
114 if (GCMetadataPrinters != 0) {
115 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
118 GCMetadataPrinters = 0;
124 /// getFunctionNumber - Return a unique ID for the current function.
126 unsigned AsmPrinter::getFunctionNumber() const {
127 return MF->getFunctionNumber();
130 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
131 return TM.getTargetLowering()->getObjFileLowering();
134 /// getDataLayout - Return information about data layout.
135 const DataLayout &AsmPrinter::getDataLayout() const {
136 return *TM.getDataLayout();
139 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
140 return TM.getSubtarget<MCSubtargetInfo>();
143 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
144 S.EmitInstruction(Inst, getSubtargetInfo());
147 StringRef AsmPrinter::getTargetTriple() const {
148 return TM.getTargetTriple();
151 /// getCurrentSection() - Return the current section we are emitting to.
152 const MCSection *AsmPrinter::getCurrentSection() const {
153 return OutStreamer.getCurrentSection().first;
158 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
159 AU.setPreservesAll();
160 MachineFunctionPass::getAnalysisUsage(AU);
161 AU.addRequired<MachineModuleInfo>();
162 AU.addRequired<GCModuleInfo>();
164 AU.addRequired<MachineLoopInfo>();
167 bool AsmPrinter::doInitialization(Module &M) {
168 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
169 MMI->AnalyzeModule(M);
171 // Initialize TargetLoweringObjectFile.
172 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
173 .Initialize(OutContext, TM);
175 OutStreamer.InitSections();
177 Mang = new Mangler(TM.getDataLayout());
179 // Emit the version-min deplyment target directive if needed.
181 // FIXME: If we end up with a collection of these sorts of Darwin-specific
182 // or ELF-specific things, it may make sense to have a platform helper class
183 // that will work with the target helper class. For now keep it here, as the
184 // alternative is duplicated code in each of the target asm printers that
185 // use the directive, where it would need the same conditionalization
187 Triple TT(getTargetTriple());
188 if (TT.isOSDarwin()) {
189 unsigned Major, Minor, Update;
190 TT.getOSVersion(Major, Minor, Update);
191 // If there is a version specified, Major will be non-zero.
193 OutStreamer.EmitVersionMin((TT.isMacOSX() ?
194 MCVM_OSXVersionMin : MCVM_IOSVersionMin),
195 Major, Minor, Update);
198 // Allow the target to emit any magic that it wants at the start of the file.
199 EmitStartOfAsmFile(M);
201 // Very minimal debug info. It is ignored if we emit actual debug info. If we
202 // don't, this at least helps the user find where a global came from.
203 if (MAI->hasSingleParameterDotFile()) {
205 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
208 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
209 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
211 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
212 MP->beginAssembly(*this);
214 // Emit module-level inline asm if it exists.
215 if (!M.getModuleInlineAsm().empty()) {
216 OutStreamer.AddComment("Start of file scope inline assembly");
217 OutStreamer.AddBlankLine();
218 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
219 OutStreamer.AddComment("End of file scope inline assembly");
220 OutStreamer.AddBlankLine();
223 if (MAI->doesSupportDebugInformation()) {
224 if (Triple(TM.getTargetTriple()).isKnownWindowsMSVCEnvironment()) {
225 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this),
227 CodeViewLineTablesGroupName));
229 DD = new DwarfDebug(this, &M);
230 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
234 DwarfException *DE = 0;
235 switch (MAI->getExceptionHandlingType()) {
236 case ExceptionHandling::None:
238 case ExceptionHandling::SjLj:
239 case ExceptionHandling::DwarfCFI:
240 DE = new DwarfCFIException(this);
242 case ExceptionHandling::ARM:
243 DE = new ARMException(this);
245 case ExceptionHandling::Win64:
246 DE = new Win64Exception(this);
250 Handlers.push_back(HandlerInfo(DE, EHTimerName, DWARFGroupName));
254 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
255 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
256 if (Linkage != GlobalValue::LinkOnceODRLinkage)
259 if (!MAI.hasWeakDefCanBeHiddenDirective())
262 if (GV->hasUnnamedAddr())
265 // This is only used for MachO, so right now it doesn't really matter how
266 // we handle alias. Revisit this once the MachO linker implements aliases.
267 if (isa<GlobalAlias>(GV))
270 // If it is a non constant variable, it needs to be uniqued across shared
272 if (const GlobalVariable *Var = dyn_cast<GlobalVariable>(GV)) {
273 if (!Var->isConstant())
278 if (!GlobalStatus::analyzeGlobal(GV, GS) && !GS.IsCompared)
284 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
285 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
287 case GlobalValue::CommonLinkage:
288 case GlobalValue::LinkOnceAnyLinkage:
289 case GlobalValue::LinkOnceODRLinkage:
290 case GlobalValue::WeakAnyLinkage:
291 case GlobalValue::WeakODRLinkage:
292 if (MAI->hasWeakDefDirective()) {
294 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
296 if (!canBeHidden(GV, *MAI))
297 // .weak_definition _foo
298 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
300 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
301 } else if (MAI->hasLinkOnceDirective()) {
303 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
304 //NOTE: linkonce is handled by the section the symbol was assigned to.
307 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
310 case GlobalValue::AppendingLinkage:
311 // FIXME: appending linkage variables should go into a section of
312 // their name or something. For now, just emit them as external.
313 case GlobalValue::ExternalLinkage:
314 // If external or appending, declare as a global symbol.
316 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
318 case GlobalValue::PrivateLinkage:
319 case GlobalValue::InternalLinkage:
321 case GlobalValue::AvailableExternallyLinkage:
322 llvm_unreachable("Should never emit this");
323 case GlobalValue::ExternalWeakLinkage:
324 llvm_unreachable("Don't know how to emit these");
326 llvm_unreachable("Unknown linkage type!");
329 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
330 const GlobalValue *GV) const {
331 TM.getNameWithPrefix(Name, GV, *Mang);
334 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
335 return TM.getSymbol(GV, *Mang);
338 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
339 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
340 if (GV->hasInitializer()) {
341 // Check to see if this is a special global used by LLVM, if so, emit it.
342 if (EmitSpecialLLVMGlobal(GV))
346 GV->printAsOperand(OutStreamer.GetCommentOS(),
347 /*PrintType=*/false, GV->getParent());
348 OutStreamer.GetCommentOS() << '\n';
352 MCSymbol *GVSym = getSymbol(GV);
353 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
355 if (!GV->hasInitializer()) // External globals require no extra code.
358 if (MAI->hasDotTypeDotSizeDirective())
359 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
361 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
363 const DataLayout *DL = TM.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 CurrentFnSym. This is a virtual function to allow targets to
531 // do their wild and crazy things as required.
532 EmitFunctionEntryLabel();
534 // If the function had address-taken blocks that got deleted, then we have
535 // references to the dangling symbols. Emit them at the start of the function
536 // so that we don't get references to undefined symbols.
537 std::vector<MCSymbol*> DeadBlockSyms;
538 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
539 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
540 OutStreamer.AddComment("Address taken block that was later removed");
541 OutStreamer.EmitLabel(DeadBlockSyms[i]);
544 // Emit pre-function debug and/or EH information.
545 for (const HandlerInfo &HI : Handlers) {
546 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
547 HI.Handler->beginFunction(MF);
550 // Emit the prefix data.
551 if (F->hasPrefixData())
552 EmitGlobalConstant(F->getPrefixData());
555 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
556 /// function. This can be overridden by targets as required to do custom stuff.
557 void AsmPrinter::EmitFunctionEntryLabel() {
558 // The function label could have already been emitted if two symbols end up
559 // conflicting due to asm renaming. Detect this and emit an error.
560 if (CurrentFnSym->isUndefined())
561 return OutStreamer.EmitLabel(CurrentFnSym);
563 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
564 "' label emitted multiple times to assembly file");
567 /// emitComments - Pretty-print comments for instructions.
568 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
569 const MachineFunction *MF = MI.getParent()->getParent();
570 const TargetMachine &TM = MF->getTarget();
572 // Check for spills and reloads
575 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
577 // We assume a single instruction only has a spill or reload, not
579 const MachineMemOperand *MMO;
580 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
581 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
582 MMO = *MI.memoperands_begin();
583 CommentOS << MMO->getSize() << "-byte Reload\n";
585 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
586 if (FrameInfo->isSpillSlotObjectIndex(FI))
587 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
588 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
589 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
590 MMO = *MI.memoperands_begin();
591 CommentOS << MMO->getSize() << "-byte Spill\n";
593 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
594 if (FrameInfo->isSpillSlotObjectIndex(FI))
595 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
598 // Check for spill-induced copies
599 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
600 CommentOS << " Reload Reuse\n";
603 /// emitImplicitDef - This method emits the specified machine instruction
604 /// that is an implicit def.
605 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
606 unsigned RegNo = MI->getOperand(0).getReg();
607 OutStreamer.AddComment(Twine("implicit-def: ") +
608 TM.getRegisterInfo()->getName(RegNo));
609 OutStreamer.AddBlankLine();
612 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
613 std::string Str = "kill:";
614 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
615 const MachineOperand &Op = MI->getOperand(i);
616 assert(Op.isReg() && "KILL instruction must have only register operands");
618 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
619 Str += (Op.isDef() ? "<def>" : "<kill>");
621 AP.OutStreamer.AddComment(Str);
622 AP.OutStreamer.AddBlankLine();
625 /// emitDebugValueComment - This method handles the target-independent form
626 /// of DBG_VALUE, returning true if it was able to do so. A false return
627 /// means the target will need to handle MI in EmitInstruction.
628 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
629 // This code handles only the 3-operand target-independent form.
630 if (MI->getNumOperands() != 3)
633 SmallString<128> Str;
634 raw_svector_ostream OS(Str);
635 OS << "DEBUG_VALUE: ";
637 DIVariable V(MI->getOperand(2).getMetadata());
638 if (V.getContext().isSubprogram()) {
639 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
643 OS << V.getName() << " <- ";
645 // The second operand is only an offset if it's an immediate.
646 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
647 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
649 // Register or immediate value. Register 0 means undef.
650 if (MI->getOperand(0).isFPImm()) {
651 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
652 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
653 OS << (double)APF.convertToFloat();
654 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
655 OS << APF.convertToDouble();
657 // There is no good way to print long double. Convert a copy to
658 // double. Ah well, it's only a comment.
660 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
662 OS << "(long double) " << APF.convertToDouble();
664 } else if (MI->getOperand(0).isImm()) {
665 OS << MI->getOperand(0).getImm();
666 } else if (MI->getOperand(0).isCImm()) {
667 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
670 if (MI->getOperand(0).isReg()) {
671 Reg = MI->getOperand(0).getReg();
673 assert(MI->getOperand(0).isFI() && "Unknown operand type");
674 const TargetFrameLowering *TFI = AP.TM.getFrameLowering();
675 Offset += TFI->getFrameIndexReference(*AP.MF,
676 MI->getOperand(0).getIndex(), Reg);
680 // Suppress offset, it is not meaningful here.
682 // NOTE: Want this comment at start of line, don't emit with AddComment.
683 AP.OutStreamer.emitRawComment(OS.str());
688 OS << AP.TM.getRegisterInfo()->getName(Reg);
692 OS << '+' << Offset << ']';
694 // NOTE: Want this comment at start of line, don't emit with AddComment.
695 AP.OutStreamer.emitRawComment(OS.str());
699 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
700 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
701 MF->getFunction()->needsUnwindTableEntry())
704 if (MMI->hasDebugInfo())
710 bool AsmPrinter::needsSEHMoves() {
711 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 &&
712 MF->getFunction()->needsUnwindTableEntry();
715 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
716 ExceptionHandling::ExceptionsType ExceptionHandlingType =
717 MAI->getExceptionHandlingType();
718 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
719 ExceptionHandlingType != ExceptionHandling::ARM)
722 if (needsCFIMoves() == CFI_M_None)
725 if (MMI->getCompactUnwindEncoding() != 0)
726 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding());
728 const MachineModuleInfo &MMI = MF->getMMI();
729 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
730 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
731 const MCCFIInstruction &CFI = Instrs[CFIIndex];
732 emitCFIInstruction(CFI);
735 /// EmitFunctionBody - This method emits the body and trailer for a
737 void AsmPrinter::EmitFunctionBody() {
738 // Emit target-specific gunk before the function body.
739 EmitFunctionBodyStart();
741 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
743 // Print out code for the function.
744 bool HasAnyRealCode = false;
745 const MachineInstr *LastMI = 0;
746 for (auto &MBB : *MF) {
747 // Print a label for the basic block.
748 EmitBasicBlockStart(MBB);
749 for (auto &MI : MBB) {
752 // Print the assembly for the instruction.
753 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
754 !MI.isDebugValue()) {
755 HasAnyRealCode = true;
759 if (ShouldPrintDebugScopes) {
760 for (const HandlerInfo &HI : Handlers) {
761 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
762 TimePassesIsEnabled);
763 HI.Handler->beginInstruction(&MI);
768 emitComments(MI, OutStreamer.GetCommentOS());
770 switch (MI.getOpcode()) {
771 case TargetOpcode::CFI_INSTRUCTION:
772 emitCFIInstruction(MI);
775 case TargetOpcode::EH_LABEL:
776 case TargetOpcode::GC_LABEL:
777 OutStreamer.EmitLabel(MI.getOperand(0).getMCSymbol());
779 case TargetOpcode::INLINEASM:
782 case TargetOpcode::DBG_VALUE:
784 if (!emitDebugValueComment(&MI, *this))
785 EmitInstruction(&MI);
788 case TargetOpcode::IMPLICIT_DEF:
789 if (isVerbose()) emitImplicitDef(&MI);
791 case TargetOpcode::KILL:
792 if (isVerbose()) emitKill(&MI, *this);
795 EmitInstruction(&MI);
799 if (ShouldPrintDebugScopes) {
800 for (const HandlerInfo &HI : Handlers) {
801 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
802 TimePassesIsEnabled);
803 HI.Handler->endInstruction();
809 // If the last instruction was a prolog label, then we have a situation where
810 // we emitted a prolog but no function body. This results in the ending prolog
811 // label equaling the end of function label and an invalid "row" in the
812 // FDE. We need to emit a noop in this situation so that the FDE's rows are
814 bool RequiresNoop = LastMI && LastMI->isCFIInstruction();
816 // If the function is empty and the object file uses .subsections_via_symbols,
817 // then we need to emit *something* to the function body to prevent the
818 // labels from collapsing together. Just emit a noop.
819 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
821 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
822 if (Noop.getOpcode()) {
823 OutStreamer.AddComment("avoids zero-length function");
824 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
825 } else // Target not mc-ized yet.
826 OutStreamer.EmitRawText(StringRef("\tnop\n"));
829 const Function *F = MF->getFunction();
830 for (const auto &BB : *F) {
831 if (!BB.hasAddressTaken())
833 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
834 if (Sym->isDefined())
836 OutStreamer.AddComment("Address of block that was removed by CodeGen");
837 OutStreamer.EmitLabel(Sym);
840 // Emit target-specific gunk after the function body.
841 EmitFunctionBodyEnd();
843 // If the target wants a .size directive for the size of the function, emit
845 if (MAI->hasDotTypeDotSizeDirective()) {
846 // Create a symbol for the end of function, so we can get the size as
847 // difference between the function label and the temp label.
848 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
849 OutStreamer.EmitLabel(FnEndLabel);
851 const MCExpr *SizeExp =
852 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
853 MCSymbolRefExpr::Create(CurrentFnSymForSize,
856 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
859 // Emit post-function debug and/or EH information.
860 for (const HandlerInfo &HI : Handlers) {
861 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
862 HI.Handler->endFunction(MF);
866 // Print out jump tables referenced by the function.
869 OutStreamer.AddBlankLine();
872 bool AsmPrinter::doFinalization(Module &M) {
873 // Emit global variables.
874 for (const auto &G : M.globals())
875 EmitGlobalVariable(&G);
877 // Emit visibility info for declarations
878 for (const Function &F : M) {
879 if (!F.isDeclaration())
881 GlobalValue::VisibilityTypes V = F.getVisibility();
882 if (V == GlobalValue::DefaultVisibility)
885 MCSymbol *Name = getSymbol(&F);
886 EmitVisibility(Name, V, false);
889 // Emit module flags.
890 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
891 M.getModuleFlagsMetadata(ModuleFlags);
892 if (!ModuleFlags.empty())
893 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
895 // Make sure we wrote out everything we need.
898 // Finalize debug and EH information.
899 for (const HandlerInfo &HI : Handlers) {
900 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
901 TimePassesIsEnabled);
902 HI.Handler->endModule();
908 // If the target wants to know about weak references, print them all.
909 if (MAI->getWeakRefDirective()) {
910 // FIXME: This is not lazy, it would be nice to only print weak references
911 // to stuff that is actually used. Note that doing so would require targets
912 // to notice uses in operands (due to constant exprs etc). This should
913 // happen with the MC stuff eventually.
915 // Print out module-level global variables here.
916 for (const auto &G : M.globals()) {
917 if (!G.hasExternalWeakLinkage())
919 OutStreamer.EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
922 for (const auto &F : M) {
923 if (!F.hasExternalWeakLinkage())
925 OutStreamer.EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
929 if (MAI->hasSetDirective()) {
930 OutStreamer.AddBlankLine();
931 for (const auto &Alias : M.aliases()) {
932 MCSymbol *Name = getSymbol(&Alias);
934 const GlobalValue *GV = Alias.getAliasedGlobal();
935 assert(!GV->isDeclaration());
936 MCSymbol *Target = getSymbol(GV);
938 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
939 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
940 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
941 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
943 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
945 EmitVisibility(Name, Alias.getVisibility());
947 // Emit the directives as assignments aka .set:
948 OutStreamer.EmitAssignment(Name,
949 MCSymbolRefExpr::Create(Target, OutContext));
953 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
954 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
955 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
956 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
957 MP->finishAssembly(*this);
959 // Emit llvm.ident metadata in an '.ident' directive.
962 // If we don't have any trampolines, then we don't require stack memory
963 // to be executable. Some targets have a directive to declare this.
964 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
965 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
966 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
967 OutStreamer.SwitchSection(S);
969 // Allow the target to emit any magic that it wants at the end of the file,
970 // after everything else has gone out.
973 delete Mang; Mang = 0;
976 OutStreamer.Finish();
982 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
984 // Get the function symbol.
985 CurrentFnSym = getSymbol(MF.getFunction());
986 CurrentFnSymForSize = CurrentFnSym;
989 LI = &getAnalysis<MachineLoopInfo>();
993 // SectionCPs - Keep track the alignment, constpool entries per Section.
997 SmallVector<unsigned, 4> CPEs;
998 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1002 /// EmitConstantPool - Print to the current output stream assembly
1003 /// representations of the constants in the constant pool MCP. This is
1004 /// used to print out constants which have been "spilled to memory" by
1005 /// the code generator.
1007 void AsmPrinter::EmitConstantPool() {
1008 const MachineConstantPool *MCP = MF->getConstantPool();
1009 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1010 if (CP.empty()) return;
1012 // Calculate sections for constant pool entries. We collect entries to go into
1013 // the same section together to reduce amount of section switch statements.
1014 SmallVector<SectionCPs, 4> CPSections;
1015 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1016 const MachineConstantPoolEntry &CPE = CP[i];
1017 unsigned Align = CPE.getAlignment();
1020 switch (CPE.getRelocationInfo()) {
1021 default: llvm_unreachable("Unknown section kind");
1022 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
1024 Kind = SectionKind::getReadOnlyWithRelLocal();
1027 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) {
1028 case 4: Kind = SectionKind::getMergeableConst4(); break;
1029 case 8: Kind = SectionKind::getMergeableConst8(); break;
1030 case 16: Kind = SectionKind::getMergeableConst16();break;
1031 default: Kind = SectionKind::getMergeableConst(); break;
1035 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
1037 // The number of sections are small, just do a linear search from the
1038 // last section to the first.
1040 unsigned SecIdx = CPSections.size();
1041 while (SecIdx != 0) {
1042 if (CPSections[--SecIdx].S == S) {
1048 SecIdx = CPSections.size();
1049 CPSections.push_back(SectionCPs(S, Align));
1052 if (Align > CPSections[SecIdx].Alignment)
1053 CPSections[SecIdx].Alignment = Align;
1054 CPSections[SecIdx].CPEs.push_back(i);
1057 // Now print stuff into the calculated sections.
1058 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1059 OutStreamer.SwitchSection(CPSections[i].S);
1060 EmitAlignment(Log2_32(CPSections[i].Alignment));
1062 unsigned Offset = 0;
1063 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1064 unsigned CPI = CPSections[i].CPEs[j];
1065 MachineConstantPoolEntry CPE = CP[CPI];
1067 // Emit inter-object padding for alignment.
1068 unsigned AlignMask = CPE.getAlignment() - 1;
1069 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1070 OutStreamer.EmitZeros(NewOffset - Offset);
1072 Type *Ty = CPE.getType();
1073 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty);
1074 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1076 if (CPE.isMachineConstantPoolEntry())
1077 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1079 EmitGlobalConstant(CPE.Val.ConstVal);
1084 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1085 /// by the current function to the current output stream.
1087 void AsmPrinter::EmitJumpTableInfo() {
1088 const DataLayout *DL = MF->getTarget().getDataLayout();
1089 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1090 if (MJTI == 0) return;
1091 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1092 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1093 if (JT.empty()) return;
1095 // Pick the directive to use to print the jump table entries, and switch to
1096 // the appropriate section.
1097 const Function *F = MF->getFunction();
1098 bool JTInDiffSection = false;
1099 if (// In PIC mode, we need to emit the jump table to the same section as the
1100 // function body itself, otherwise the label differences won't make sense.
1101 // FIXME: Need a better predicate for this: what about custom entries?
1102 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1103 // We should also do if the section name is NULL or function is declared
1104 // in discardable section
1105 // FIXME: this isn't the right predicate, should be based on the MCSection
1106 // for the function.
1107 F->isWeakForLinker()) {
1108 OutStreamer.SwitchSection(
1109 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1111 // Otherwise, drop it in the readonly section.
1112 const MCSection *ReadOnlySection =
1113 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1114 OutStreamer.SwitchSection(ReadOnlySection);
1115 JTInDiffSection = true;
1118 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout())));
1120 // Jump tables in code sections are marked with a data_region directive
1121 // where that's supported.
1122 if (!JTInDiffSection)
1123 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1125 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1126 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1128 // If this jump table was deleted, ignore it.
1129 if (JTBBs.empty()) continue;
1131 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1132 // .set directive for each unique entry. This reduces the number of
1133 // relocations the assembler will generate for the jump table.
1134 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1135 MAI->hasSetDirective()) {
1136 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1137 const TargetLowering *TLI = TM.getTargetLowering();
1138 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1139 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1140 const MachineBasicBlock *MBB = JTBBs[ii];
1141 if (!EmittedSets.insert(MBB)) continue;
1143 // .set LJTSet, LBB32-base
1145 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1146 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1147 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1151 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1152 // before each jump table. The first label is never referenced, but tells
1153 // the assembler and linker the extents of the jump table object. The
1154 // second label is actually referenced by the code.
1155 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1156 // FIXME: This doesn't have to have any specific name, just any randomly
1157 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1158 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1160 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1162 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1163 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1165 if (!JTInDiffSection)
1166 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1169 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1171 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1172 const MachineBasicBlock *MBB,
1173 unsigned UID) const {
1174 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1175 const MCExpr *Value = 0;
1176 switch (MJTI->getEntryKind()) {
1177 case MachineJumpTableInfo::EK_Inline:
1178 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1179 case MachineJumpTableInfo::EK_Custom32:
1180 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1183 case MachineJumpTableInfo::EK_BlockAddress:
1184 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1186 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1188 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1189 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1190 // with a relocation as gp-relative, e.g.:
1192 MCSymbol *MBBSym = MBB->getSymbol();
1193 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1197 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1198 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1199 // with a relocation as gp-relative, e.g.:
1201 MCSymbol *MBBSym = MBB->getSymbol();
1202 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1206 case MachineJumpTableInfo::EK_LabelDifference32: {
1207 // EK_LabelDifference32 - Each entry is the address of the block minus
1208 // the address of the jump table. This is used for PIC jump tables where
1209 // gprel32 is not supported. e.g.:
1210 // .word LBB123 - LJTI1_2
1211 // If the .set directive is supported, this is emitted as:
1212 // .set L4_5_set_123, LBB123 - LJTI1_2
1213 // .word L4_5_set_123
1215 // If we have emitted set directives for the jump table entries, print
1216 // them rather than the entries themselves. If we're emitting PIC, then
1217 // emit the table entries as differences between two text section labels.
1218 if (MAI->hasSetDirective()) {
1219 // If we used .set, reference the .set's symbol.
1220 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1224 // Otherwise, use the difference as the jump table entry.
1225 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1226 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1227 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1232 assert(Value && "Unknown entry kind!");
1234 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout());
1235 OutStreamer.EmitValue(Value, EntrySize);
1239 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1240 /// special global used by LLVM. If so, emit it and return true, otherwise
1241 /// do nothing and return false.
1242 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1243 if (GV->getName() == "llvm.used") {
1244 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1245 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1249 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1250 if (GV->getSection() == "llvm.metadata" ||
1251 GV->hasAvailableExternallyLinkage())
1254 if (!GV->hasAppendingLinkage()) return false;
1256 assert(GV->hasInitializer() && "Not a special LLVM global!");
1258 if (GV->getName() == "llvm.global_ctors") {
1259 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1261 if (TM.getRelocationModel() == Reloc::Static &&
1262 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1263 StringRef Sym(".constructors_used");
1264 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1270 if (GV->getName() == "llvm.global_dtors") {
1271 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1273 if (TM.getRelocationModel() == Reloc::Static &&
1274 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1275 StringRef Sym(".destructors_used");
1276 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1285 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1286 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1287 /// is true, as being used with this directive.
1288 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1289 // Should be an array of 'i8*'.
1290 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1291 const GlobalValue *GV =
1292 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1294 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1298 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1300 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1301 // Should be an array of '{ int, void ()* }' structs. The first value is the
1303 if (!isa<ConstantArray>(List)) return;
1305 // Sanity check the structors list.
1306 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1307 if (!InitList) return; // Not an array!
1308 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1309 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs!
1310 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1311 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1313 // Gather the structors in a form that's convenient for sorting by priority.
1314 typedef std::pair<unsigned, Constant *> Structor;
1315 SmallVector<Structor, 8> Structors;
1316 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1317 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i));
1318 if (!CS) continue; // Malformed.
1319 if (CS->getOperand(1)->isNullValue())
1320 break; // Found a null terminator, skip the rest.
1321 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1322 if (!Priority) continue; // Malformed.
1323 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535),
1324 CS->getOperand(1)));
1327 // Emit the function pointers in the target-specific order
1328 const DataLayout *DL = TM.getDataLayout();
1329 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1330 std::stable_sort(Structors.begin(), Structors.end(), less_first());
1331 for (unsigned i = 0, e = Structors.size(); i != e; ++i) {
1332 const MCSection *OutputSection =
1334 getObjFileLowering().getStaticCtorSection(Structors[i].first) :
1335 getObjFileLowering().getStaticDtorSection(Structors[i].first));
1336 OutStreamer.SwitchSection(OutputSection);
1337 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1338 EmitAlignment(Align);
1339 EmitXXStructor(Structors[i].second);
1343 void AsmPrinter::EmitModuleIdents(Module &M) {
1344 if (!MAI->hasIdentDirective())
1347 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1348 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1349 const MDNode *N = NMD->getOperand(i);
1350 assert(N->getNumOperands() == 1 &&
1351 "llvm.ident metadata entry can have only one operand");
1352 const MDString *S = cast<MDString>(N->getOperand(0));
1353 OutStreamer.EmitIdent(S->getString());
1358 //===--------------------------------------------------------------------===//
1359 // Emission and print routines
1362 /// EmitInt8 - Emit a byte directive and value.
1364 void AsmPrinter::EmitInt8(int Value) const {
1365 OutStreamer.EmitIntValue(Value, 1);
1368 /// EmitInt16 - Emit a short directive and value.
1370 void AsmPrinter::EmitInt16(int Value) const {
1371 OutStreamer.EmitIntValue(Value, 2);
1374 /// EmitInt32 - Emit a long directive and value.
1376 void AsmPrinter::EmitInt32(int Value) const {
1377 OutStreamer.EmitIntValue(Value, 4);
1380 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1381 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1382 /// labels. This implicitly uses .set if it is available.
1383 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1384 unsigned Size) const {
1385 // Get the Hi-Lo expression.
1386 const MCExpr *Diff =
1387 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1388 MCSymbolRefExpr::Create(Lo, OutContext),
1391 if (!MAI->hasSetDirective()) {
1392 OutStreamer.EmitValue(Diff, Size);
1396 // Otherwise, emit with .set (aka assignment).
1397 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1398 OutStreamer.EmitAssignment(SetLabel, Diff);
1399 OutStreamer.EmitSymbolValue(SetLabel, Size);
1402 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1403 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1404 /// specify the labels. This implicitly uses .set if it is available.
1405 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1407 unsigned Size) const {
1409 // Emit Hi+Offset - Lo
1410 // Get the Hi+Offset expression.
1411 const MCExpr *Plus =
1412 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1413 MCConstantExpr::Create(Offset, OutContext),
1416 // Get the Hi+Offset-Lo expression.
1417 const MCExpr *Diff =
1418 MCBinaryExpr::CreateSub(Plus,
1419 MCSymbolRefExpr::Create(Lo, OutContext),
1422 if (!MAI->hasSetDirective())
1423 OutStreamer.EmitValue(Diff, Size);
1425 // Otherwise, emit with .set (aka assignment).
1426 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1427 OutStreamer.EmitAssignment(SetLabel, Diff);
1428 OutStreamer.EmitSymbolValue(SetLabel, Size);
1432 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1433 /// where the size in bytes of the directive is specified by Size and Label
1434 /// specifies the label. This implicitly uses .set if it is available.
1435 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1437 bool IsSectionRelative) const {
1438 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1439 OutStreamer.EmitCOFFSecRel32(Label);
1443 // Emit Label+Offset (or just Label if Offset is zero)
1444 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1446 Expr = MCBinaryExpr::CreateAdd(
1447 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1449 OutStreamer.EmitValue(Expr, Size);
1452 //===----------------------------------------------------------------------===//
1454 // EmitAlignment - Emit an alignment directive to the specified power of
1455 // two boundary. For example, if you pass in 3 here, you will get an 8
1456 // byte alignment. If a global value is specified, and if that global has
1457 // an explicit alignment requested, it will override the alignment request
1458 // if required for correctness.
1460 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1461 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits);
1463 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1465 if (getCurrentSection()->getKind().isText())
1466 OutStreamer.EmitCodeAlignment(1 << NumBits);
1468 OutStreamer.EmitValueToAlignment(1 << NumBits);
1471 //===----------------------------------------------------------------------===//
1472 // Constant emission.
1473 //===----------------------------------------------------------------------===//
1475 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1477 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1478 MCContext &Ctx = AP.OutContext;
1480 if (CV->isNullValue() || isa<UndefValue>(CV))
1481 return MCConstantExpr::Create(0, Ctx);
1483 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1484 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1486 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1487 return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx);
1489 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1490 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1492 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1494 llvm_unreachable("Unknown constant value to lower!");
1497 if (const MCExpr *RelocExpr =
1498 AP.getObjFileLowering().getExecutableRelativeSymbol(CE, *AP.Mang,
1502 switch (CE->getOpcode()) {
1504 // If the code isn't optimized, there may be outstanding folding
1505 // opportunities. Attempt to fold the expression using DataLayout as a
1506 // last resort before giving up.
1508 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout()))
1510 return lowerConstant(C, AP);
1512 // Otherwise report the problem to the user.
1515 raw_string_ostream OS(S);
1516 OS << "Unsupported expression in static initializer: ";
1517 CE->printAsOperand(OS, /*PrintType=*/false,
1518 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1519 report_fatal_error(OS.str());
1521 case Instruction::GetElementPtr: {
1522 const DataLayout &DL = *AP.TM.getDataLayout();
1523 // Generate a symbolic expression for the byte address
1524 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1525 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1527 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1531 int64_t Offset = OffsetAI.getSExtValue();
1532 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1536 case Instruction::Trunc:
1537 // We emit the value and depend on the assembler to truncate the generated
1538 // expression properly. This is important for differences between
1539 // blockaddress labels. Since the two labels are in the same function, it
1540 // is reasonable to treat their delta as a 32-bit value.
1542 case Instruction::BitCast:
1543 return lowerConstant(CE->getOperand(0), AP);
1545 case Instruction::IntToPtr: {
1546 const DataLayout &DL = *AP.TM.getDataLayout();
1547 // Handle casts to pointers by changing them into casts to the appropriate
1548 // integer type. This promotes constant folding and simplifies this code.
1549 Constant *Op = CE->getOperand(0);
1550 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1552 return lowerConstant(Op, AP);
1555 case Instruction::PtrToInt: {
1556 const DataLayout &DL = *AP.TM.getDataLayout();
1557 // Support only foldable casts to/from pointers that can be eliminated by
1558 // changing the pointer to the appropriately sized integer type.
1559 Constant *Op = CE->getOperand(0);
1560 Type *Ty = CE->getType();
1562 const MCExpr *OpExpr = lowerConstant(Op, AP);
1564 // We can emit the pointer value into this slot if the slot is an
1565 // integer slot equal to the size of the pointer.
1566 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1569 // Otherwise the pointer is smaller than the resultant integer, mask off
1570 // the high bits so we are sure to get a proper truncation if the input is
1572 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1573 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1574 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1577 // The MC library also has a right-shift operator, but it isn't consistently
1578 // signed or unsigned between different targets.
1579 case Instruction::Add:
1580 case Instruction::Sub:
1581 case Instruction::Mul:
1582 case Instruction::SDiv:
1583 case Instruction::SRem:
1584 case Instruction::Shl:
1585 case Instruction::And:
1586 case Instruction::Or:
1587 case Instruction::Xor: {
1588 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1589 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1590 switch (CE->getOpcode()) {
1591 default: llvm_unreachable("Unknown binary operator constant cast expr");
1592 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1593 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1594 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1595 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1596 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1597 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1598 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1599 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1600 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1606 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1608 /// isRepeatedByteSequence - Determine whether the given value is
1609 /// composed of a repeated sequence of identical bytes and return the
1610 /// byte value. If it is not a repeated sequence, return -1.
1611 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1612 StringRef Data = V->getRawDataValues();
1613 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1615 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1616 if (Data[i] != C) return -1;
1617 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1621 /// isRepeatedByteSequence - Determine whether the given value is
1622 /// composed of a repeated sequence of identical bytes and return the
1623 /// byte value. If it is not a repeated sequence, return -1.
1624 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1626 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1627 if (CI->getBitWidth() > 64) return -1;
1629 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType());
1630 uint64_t Value = CI->getZExtValue();
1632 // Make sure the constant is at least 8 bits long and has a power
1633 // of 2 bit width. This guarantees the constant bit width is
1634 // always a multiple of 8 bits, avoiding issues with padding out
1635 // to Size and other such corner cases.
1636 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1638 uint8_t Byte = static_cast<uint8_t>(Value);
1640 for (unsigned i = 1; i < Size; ++i) {
1642 if (static_cast<uint8_t>(Value) != Byte) return -1;
1646 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1647 // Make sure all array elements are sequences of the same repeated
1649 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1650 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1651 if (Byte == -1) return -1;
1653 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1654 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1655 if (ThisByte == -1) return -1;
1656 if (Byte != ThisByte) return -1;
1661 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1662 return isRepeatedByteSequence(CDS);
1667 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1670 // See if we can aggregate this into a .fill, if so, emit it as such.
1671 int Value = isRepeatedByteSequence(CDS, AP.TM);
1673 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType());
1674 // Don't emit a 1-byte object as a .fill.
1676 return AP.OutStreamer.EmitFill(Bytes, Value);
1679 // If this can be emitted with .ascii/.asciz, emit it as such.
1680 if (CDS->isString())
1681 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1683 // Otherwise, emit the values in successive locations.
1684 unsigned ElementByteSize = CDS->getElementByteSize();
1685 if (isa<IntegerType>(CDS->getElementType())) {
1686 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1688 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1689 CDS->getElementAsInteger(i));
1690 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1693 } else if (ElementByteSize == 4) {
1694 // FP Constants are printed as integer constants to avoid losing
1696 assert(CDS->getElementType()->isFloatTy());
1697 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1703 F = CDS->getElementAsFloat(i);
1705 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1706 AP.OutStreamer.EmitIntValue(I, 4);
1709 assert(CDS->getElementType()->isDoubleTy());
1710 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1716 F = CDS->getElementAsDouble(i);
1718 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1719 AP.OutStreamer.EmitIntValue(I, 8);
1723 const DataLayout &DL = *AP.TM.getDataLayout();
1724 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1725 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1726 CDS->getNumElements();
1727 if (unsigned Padding = Size - EmittedSize)
1728 AP.OutStreamer.EmitZeros(Padding);
1732 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1733 // See if we can aggregate some values. Make sure it can be
1734 // represented as a series of bytes of the constant value.
1735 int Value = isRepeatedByteSequence(CA, AP.TM);
1738 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType());
1739 AP.OutStreamer.EmitFill(Bytes, Value);
1742 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1743 emitGlobalConstantImpl(CA->getOperand(i), AP);
1747 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1748 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1749 emitGlobalConstantImpl(CV->getOperand(i), AP);
1751 const DataLayout &DL = *AP.TM.getDataLayout();
1752 unsigned Size = DL.getTypeAllocSize(CV->getType());
1753 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1754 CV->getType()->getNumElements();
1755 if (unsigned Padding = Size - EmittedSize)
1756 AP.OutStreamer.EmitZeros(Padding);
1759 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1760 // Print the fields in successive locations. Pad to align if needed!
1761 const DataLayout *DL = AP.TM.getDataLayout();
1762 unsigned Size = DL->getTypeAllocSize(CS->getType());
1763 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1764 uint64_t SizeSoFar = 0;
1765 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1766 const Constant *Field = CS->getOperand(i);
1768 // Check if padding is needed and insert one or more 0s.
1769 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1770 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1771 - Layout->getElementOffset(i)) - FieldSize;
1772 SizeSoFar += FieldSize + PadSize;
1774 // Now print the actual field value.
1775 emitGlobalConstantImpl(Field, AP);
1777 // Insert padding - this may include padding to increase the size of the
1778 // current field up to the ABI size (if the struct is not packed) as well
1779 // as padding to ensure that the next field starts at the right offset.
1780 AP.OutStreamer.EmitZeros(PadSize);
1782 assert(SizeSoFar == Layout->getSizeInBytes() &&
1783 "Layout of constant struct may be incorrect!");
1786 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1787 APInt API = CFP->getValueAPF().bitcastToAPInt();
1789 // First print a comment with what we think the original floating-point value
1790 // should have been.
1791 if (AP.isVerbose()) {
1792 SmallString<8> StrVal;
1793 CFP->getValueAPF().toString(StrVal);
1795 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1796 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1799 // Now iterate through the APInt chunks, emitting them in endian-correct
1800 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1802 unsigned NumBytes = API.getBitWidth() / 8;
1803 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1804 const uint64_t *p = API.getRawData();
1806 // PPC's long double has odd notions of endianness compared to how LLVM
1807 // handles it: p[0] goes first for *big* endian on PPC.
1808 if (AP.TM.getDataLayout()->isBigEndian() != CFP->getType()->isPPC_FP128Ty()) {
1809 int Chunk = API.getNumWords() - 1;
1812 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1814 for (; Chunk >= 0; --Chunk)
1815 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1818 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1819 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1822 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1825 // Emit the tail padding for the long double.
1826 const DataLayout &DL = *AP.TM.getDataLayout();
1827 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1828 DL.getTypeStoreSize(CFP->getType()));
1831 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1832 const DataLayout *DL = AP.TM.getDataLayout();
1833 unsigned BitWidth = CI->getBitWidth();
1835 // Copy the value as we may massage the layout for constants whose bit width
1836 // is not a multiple of 64-bits.
1837 APInt Realigned(CI->getValue());
1838 uint64_t ExtraBits = 0;
1839 unsigned ExtraBitsSize = BitWidth & 63;
1841 if (ExtraBitsSize) {
1842 // The bit width of the data is not a multiple of 64-bits.
1843 // The extra bits are expected to be at the end of the chunk of the memory.
1845 // * Nothing to be done, just record the extra bits to emit.
1847 // * Record the extra bits to emit.
1848 // * Realign the raw data to emit the chunks of 64-bits.
1849 if (DL->isBigEndian()) {
1850 // Basically the structure of the raw data is a chunk of 64-bits cells:
1851 // 0 1 BitWidth / 64
1852 // [chunk1][chunk2] ... [chunkN].
1853 // The most significant chunk is chunkN and it should be emitted first.
1854 // However, due to the alignment issue chunkN contains useless bits.
1855 // Realign the chunks so that they contain only useless information:
1856 // ExtraBits 0 1 (BitWidth / 64) - 1
1857 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1858 ExtraBits = Realigned.getRawData()[0] &
1859 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1860 Realigned = Realigned.lshr(ExtraBitsSize);
1862 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1865 // We don't expect assemblers to support integer data directives
1866 // for more than 64 bits, so we emit the data in at most 64-bit
1867 // quantities at a time.
1868 const uint64_t *RawData = Realigned.getRawData();
1869 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1870 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1871 AP.OutStreamer.EmitIntValue(Val, 8);
1874 if (ExtraBitsSize) {
1875 // Emit the extra bits after the 64-bits chunks.
1877 // Emit a directive that fills the expected size.
1878 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(CI->getType());
1879 Size -= (BitWidth / 64) * 8;
1880 assert(Size && Size * 8 >= ExtraBitsSize &&
1881 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1882 == ExtraBits && "Directive too small for extra bits.");
1883 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1887 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1888 const DataLayout *DL = AP.TM.getDataLayout();
1889 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1890 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1891 return AP.OutStreamer.EmitZeros(Size);
1893 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1900 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1901 CI->getZExtValue());
1902 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1905 emitGlobalConstantLargeInt(CI, AP);
1910 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1911 return emitGlobalConstantFP(CFP, AP);
1913 if (isa<ConstantPointerNull>(CV)) {
1914 AP.OutStreamer.EmitIntValue(0, Size);
1918 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1919 return emitGlobalConstantDataSequential(CDS, AP);
1921 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1922 return emitGlobalConstantArray(CVA, AP);
1924 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1925 return emitGlobalConstantStruct(CVS, AP);
1927 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
1928 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
1930 if (CE->getOpcode() == Instruction::BitCast)
1931 return emitGlobalConstantImpl(CE->getOperand(0), AP);
1934 // If the constant expression's size is greater than 64-bits, then we have
1935 // to emit the value in chunks. Try to constant fold the value and emit it
1937 Constant *New = ConstantFoldConstantExpression(CE, DL);
1938 if (New && New != CE)
1939 return emitGlobalConstantImpl(New, AP);
1943 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1944 return emitGlobalConstantVector(V, AP);
1946 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1947 // thread the streamer with EmitValue.
1948 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
1951 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1952 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
1953 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType());
1955 emitGlobalConstantImpl(CV, *this);
1956 else if (MAI->hasSubsectionsViaSymbols()) {
1957 // If the global has zero size, emit a single byte so that two labels don't
1958 // look like they are at the same location.
1959 OutStreamer.EmitIntValue(0, 1);
1963 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1964 // Target doesn't support this yet!
1965 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1968 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1970 OS << '+' << Offset;
1971 else if (Offset < 0)
1975 //===----------------------------------------------------------------------===//
1976 // Symbol Lowering Routines.
1977 //===----------------------------------------------------------------------===//
1979 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1980 /// temporary label with the specified stem and unique ID.
1981 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const {
1982 const DataLayout *DL = TM.getDataLayout();
1983 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
1987 /// GetTempSymbol - Return an assembler temporary label with the specified
1989 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const {
1990 const DataLayout *DL = TM.getDataLayout();
1991 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
1996 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1997 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2000 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2001 return MMI->getAddrLabelSymbol(BB);
2004 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2005 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2006 const DataLayout *DL = TM.getDataLayout();
2007 return OutContext.GetOrCreateSymbol
2008 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2009 + "_" + Twine(CPID));
2012 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2013 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2014 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2017 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2018 /// FIXME: privatize to AsmPrinter.
2019 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2020 const DataLayout *DL = TM.getDataLayout();
2021 return OutContext.GetOrCreateSymbol
2022 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2023 Twine(UID) + "_set_" + Twine(MBBID));
2026 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2027 StringRef Suffix) const {
2028 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2032 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2034 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2035 SmallString<60> NameStr;
2036 Mang->getNameWithPrefix(NameStr, Sym);
2037 return OutContext.GetOrCreateSymbol(NameStr.str());
2042 /// PrintParentLoopComment - Print comments about parent loops of this one.
2043 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2044 unsigned FunctionNumber) {
2045 if (Loop == 0) return;
2046 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2047 OS.indent(Loop->getLoopDepth()*2)
2048 << "Parent Loop BB" << FunctionNumber << "_"
2049 << Loop->getHeader()->getNumber()
2050 << " Depth=" << Loop->getLoopDepth() << '\n';
2054 /// PrintChildLoopComment - Print comments about child loops within
2055 /// the loop for this basic block, with nesting.
2056 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2057 unsigned FunctionNumber) {
2058 // Add child loop information
2059 for (const MachineLoop *CL : *Loop) {
2060 OS.indent(CL->getLoopDepth()*2)
2061 << "Child Loop BB" << FunctionNumber << "_"
2062 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2064 PrintChildLoopComment(OS, CL, FunctionNumber);
2068 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2069 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2070 const MachineLoopInfo *LI,
2071 const AsmPrinter &AP) {
2072 // Add loop depth information
2073 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2074 if (Loop == 0) return;
2076 MachineBasicBlock *Header = Loop->getHeader();
2077 assert(Header && "No header for loop");
2079 // If this block is not a loop header, just print out what is the loop header
2081 if (Header != &MBB) {
2082 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2083 Twine(AP.getFunctionNumber())+"_" +
2084 Twine(Loop->getHeader()->getNumber())+
2085 " Depth="+Twine(Loop->getLoopDepth()));
2089 // Otherwise, it is a loop header. Print out information about child and
2091 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2093 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2096 OS.indent(Loop->getLoopDepth()*2-2);
2101 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2103 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2107 /// EmitBasicBlockStart - This method prints the label for the specified
2108 /// MachineBasicBlock, an alignment (if present) and a comment describing
2109 /// it if appropriate.
2110 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2111 // Emit an alignment directive for this block, if needed.
2112 if (unsigned Align = MBB.getAlignment())
2113 EmitAlignment(Align);
2115 // If the block has its address taken, emit any labels that were used to
2116 // reference the block. It is possible that there is more than one label
2117 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2118 // the references were generated.
2119 if (MBB.hasAddressTaken()) {
2120 const BasicBlock *BB = MBB.getBasicBlock();
2122 OutStreamer.AddComment("Block address taken");
2124 std::vector<MCSymbol*> Symbols = MMI->getAddrLabelSymbolToEmit(BB);
2125 for (auto *Sym : Symbols)
2126 OutStreamer.EmitLabel(Sym);
2129 // Print some verbose block comments.
2131 if (const BasicBlock *BB = MBB.getBasicBlock())
2133 OutStreamer.AddComment("%" + BB->getName());
2134 emitBasicBlockLoopComments(MBB, LI, *this);
2137 // Print the main label for the block.
2138 if (MBB.pred_empty() || isBlockOnlyReachableByFallthrough(&MBB)) {
2140 // NOTE: Want this comment at start of line, don't emit with AddComment.
2141 OutStreamer.emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2144 OutStreamer.EmitLabel(MBB.getSymbol());
2148 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2149 bool IsDefinition) const {
2150 MCSymbolAttr Attr = MCSA_Invalid;
2152 switch (Visibility) {
2154 case GlobalValue::HiddenVisibility:
2156 Attr = MAI->getHiddenVisibilityAttr();
2158 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2160 case GlobalValue::ProtectedVisibility:
2161 Attr = MAI->getProtectedVisibilityAttr();
2165 if (Attr != MCSA_Invalid)
2166 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2169 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2170 /// exactly one predecessor and the control transfer mechanism between
2171 /// the predecessor and this block is a fall-through.
2173 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2174 // If this is a landing pad, it isn't a fall through. If it has no preds,
2175 // then nothing falls through to it.
2176 if (MBB->isLandingPad() || MBB->pred_empty())
2179 // If there isn't exactly one predecessor, it can't be a fall through.
2180 if (MBB->pred_size() > 1)
2183 // The predecessor has to be immediately before this block.
2184 MachineBasicBlock *Pred = *MBB->pred_begin();
2185 if (!Pred->isLayoutSuccessor(MBB))
2188 // If the block is completely empty, then it definitely does fall through.
2192 // Check the terminators in the previous blocks
2193 for (const auto &MI : Pred->terminators()) {
2194 // If it is not a simple branch, we are in a table somewhere.
2195 if (!MI.isBranch() || MI.isIndirectBranch())
2198 // If we are the operands of one of the branches, this is not a fall
2199 // through. Note that targets with delay slots will usually bundle
2200 // terminators with the delay slot instruction.
2201 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2204 if (OP->isMBB() && OP->getMBB() == MBB)
2214 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2215 if (!S.usesMetadata())
2218 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2219 gcp_map_type::iterator GCPI = GCMap.find(&S);
2220 if (GCPI != GCMap.end())
2221 return GCPI->second.get();
2223 const char *Name = S.getName().c_str();
2225 for (GCMetadataPrinterRegistry::iterator
2226 I = GCMetadataPrinterRegistry::begin(),
2227 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2228 if (strcmp(Name, I->getName()) == 0) {
2229 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2231 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2232 return IterBool.first->second.get();
2235 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2238 /// Pin vtable to this file.
2239 AsmPrinterHandler::~AsmPrinterHandler() {}