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 "WinException.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/Analysis.h"
23 #include "llvm/CodeGen/GCMetadataPrinter.h"
24 #include "llvm/CodeGen/MachineConstantPool.h"
25 #include "llvm/CodeGen/MachineFrameInfo.h"
26 #include "llvm/CodeGen/MachineFunction.h"
27 #include "llvm/CodeGen/MachineInstrBundle.h"
28 #include "llvm/CodeGen/MachineJumpTableInfo.h"
29 #include "llvm/CodeGen/MachineLoopInfo.h"
30 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
31 #include "llvm/IR/DataLayout.h"
32 #include "llvm/IR/DebugInfo.h"
33 #include "llvm/IR/Mangler.h"
34 #include "llvm/IR/Module.h"
35 #include "llvm/IR/Operator.h"
36 #include "llvm/MC/MCAsmInfo.h"
37 #include "llvm/MC/MCContext.h"
38 #include "llvm/MC/MCExpr.h"
39 #include "llvm/MC/MCInst.h"
40 #include "llvm/MC/MCSection.h"
41 #include "llvm/MC/MCStreamer.h"
42 #include "llvm/MC/MCSymbolELF.h"
43 #include "llvm/MC/MCValue.h"
44 #include "llvm/Support/ErrorHandling.h"
45 #include "llvm/Support/Format.h"
46 #include "llvm/Support/MathExtras.h"
47 #include "llvm/Support/TargetRegistry.h"
48 #include "llvm/Support/Timer.h"
49 #include "llvm/Target/TargetFrameLowering.h"
50 #include "llvm/Target/TargetInstrInfo.h"
51 #include "llvm/Target/TargetLowering.h"
52 #include "llvm/Target/TargetLoweringObjectFile.h"
53 #include "llvm/Target/TargetRegisterInfo.h"
54 #include "llvm/Target/TargetSubtargetInfo.h"
57 #define DEBUG_TYPE "asm-printer"
59 static const char *const DWARFGroupName = "DWARF Emission";
60 static const char *const DbgTimerName = "Debug Info Emission";
61 static const char *const EHTimerName = "DWARF Exception Writer";
62 static const char *const CodeViewLineTablesGroupName = "CodeView Line Tables";
64 STATISTIC(EmittedInsts, "Number of machine instrs printed");
66 char AsmPrinter::ID = 0;
68 typedef DenseMap<GCStrategy*, std::unique_ptr<GCMetadataPrinter>> gcp_map_type;
69 static gcp_map_type &getGCMap(void *&P) {
71 P = new gcp_map_type();
72 return *(gcp_map_type*)P;
76 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
77 /// value in log2 form. This rounds up to the preferred alignment if possible
79 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &DL,
80 unsigned InBits = 0) {
82 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
83 NumBits = DL.getPreferredAlignmentLog(GVar);
85 // If InBits is specified, round it to it.
89 // If the GV has a specified alignment, take it into account.
90 if (GV->getAlignment() == 0)
93 unsigned GVAlign = Log2_32(GV->getAlignment());
95 // If the GVAlign is larger than NumBits, or if we are required to obey
96 // NumBits because the GV has an assigned section, obey it.
97 if (GVAlign > NumBits || GV->hasSection())
102 AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
103 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
104 OutContext(Streamer->getContext()), OutStreamer(std::move(Streamer)),
105 LastMI(nullptr), LastFn(0), Counter(~0U) {
110 CurExceptionSym = CurrentFnSym = CurrentFnSymForSize = nullptr;
111 CurrentFnBegin = nullptr;
112 CurrentFnEnd = nullptr;
113 GCMetadataPrinters = nullptr;
114 VerboseAsm = OutStreamer->isVerboseAsm();
117 AsmPrinter::~AsmPrinter() {
118 assert(!DD && Handlers.empty() && "Debug/EH info didn't get finalized");
120 if (GCMetadataPrinters) {
121 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
124 GCMetadataPrinters = nullptr;
128 /// getFunctionNumber - Return a unique ID for the current function.
130 unsigned AsmPrinter::getFunctionNumber() const {
131 return MF->getFunctionNumber();
134 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
135 return *TM.getObjFileLowering();
138 const DataLayout &AsmPrinter::getDataLayout() const {
139 return MMI->getModule()->getDataLayout();
142 // Do not use the cached DataLayout because some client use it without a Module
143 // (llmv-dsymutil, llvm-dwarfdump).
144 unsigned AsmPrinter::getPointerSize() const { return TM.getPointerSize(); }
146 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
147 assert(MF && "getSubtargetInfo requires a valid MachineFunction!");
148 return MF->getSubtarget<MCSubtargetInfo>();
151 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
152 S.EmitInstruction(Inst, getSubtargetInfo());
155 StringRef AsmPrinter::getTargetTriple() const {
156 return TM.getTargetTriple().str();
159 /// getCurrentSection() - Return the current section we are emitting to.
160 const MCSection *AsmPrinter::getCurrentSection() const {
161 return OutStreamer->getCurrentSection().first;
166 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
167 AU.setPreservesAll();
168 MachineFunctionPass::getAnalysisUsage(AU);
169 AU.addRequired<MachineModuleInfo>();
170 AU.addRequired<GCModuleInfo>();
172 AU.addRequired<MachineLoopInfo>();
175 bool AsmPrinter::doInitialization(Module &M) {
176 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
178 // Initialize TargetLoweringObjectFile.
179 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
180 .Initialize(OutContext, TM);
182 OutStreamer->InitSections(false);
184 Mang = new Mangler();
186 // Emit the version-min deplyment target directive if needed.
188 // FIXME: If we end up with a collection of these sorts of Darwin-specific
189 // or ELF-specific things, it may make sense to have a platform helper class
190 // that will work with the target helper class. For now keep it here, as the
191 // alternative is duplicated code in each of the target asm printers that
192 // use the directive, where it would need the same conditionalization
194 Triple TT(getTargetTriple());
195 if (TT.isOSDarwin()) {
196 unsigned Major, Minor, Update;
197 TT.getOSVersion(Major, Minor, Update);
198 // If there is a version specified, Major will be non-zero.
200 MCVersionMinType VersionType;
202 VersionType = MCVM_WatchOSVersionMin;
203 else if (TT.isTvOS())
204 VersionType = MCVM_TvOSVersionMin;
205 else if (TT.isMacOSX())
206 VersionType = MCVM_OSXVersionMin;
208 VersionType = MCVM_IOSVersionMin;
209 OutStreamer->EmitVersionMin(VersionType, Major, Minor, Update);
213 // Allow the target to emit any magic that it wants at the start of the file.
214 EmitStartOfAsmFile(M);
216 // Very minimal debug info. It is ignored if we emit actual debug info. If we
217 // don't, this at least helps the user find where a global came from.
218 if (MAI->hasSingleParameterDotFile()) {
220 OutStreamer->EmitFileDirective(M.getModuleIdentifier());
223 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
224 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
226 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
227 MP->beginAssembly(M, *MI, *this);
229 // Emit module-level inline asm if it exists.
230 if (!M.getModuleInlineAsm().empty()) {
231 // We're at the module level. Construct MCSubtarget from the default CPU
232 // and target triple.
233 std::unique_ptr<MCSubtargetInfo> STI(TM.getTarget().createMCSubtargetInfo(
234 TM.getTargetTriple().str(), TM.getTargetCPU(),
235 TM.getTargetFeatureString()));
236 OutStreamer->AddComment("Start of file scope inline assembly");
237 OutStreamer->AddBlankLine();
238 EmitInlineAsm(M.getModuleInlineAsm()+"\n",
239 OutContext.getSubtargetCopy(*STI), TM.Options.MCOptions);
240 OutStreamer->AddComment("End of file scope inline assembly");
241 OutStreamer->AddBlankLine();
244 if (MAI->doesSupportDebugInformation()) {
245 bool EmitCodeView = MMI->getModule()->getCodeViewFlag();
246 if (EmitCodeView && TM.getTargetTriple().isKnownWindowsMSVCEnvironment()) {
247 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this),
249 CodeViewLineTablesGroupName));
251 if (!EmitCodeView || MMI->getModule()->getDwarfVersion()) {
252 DD = new DwarfDebug(this, &M);
253 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
257 EHStreamer *ES = nullptr;
258 switch (MAI->getExceptionHandlingType()) {
259 case ExceptionHandling::None:
261 case ExceptionHandling::SjLj:
262 case ExceptionHandling::DwarfCFI:
263 ES = new DwarfCFIException(this);
265 case ExceptionHandling::ARM:
266 ES = new ARMException(this);
268 case ExceptionHandling::WinEH:
269 switch (MAI->getWinEHEncodingType()) {
270 default: llvm_unreachable("unsupported unwinding information encoding");
271 case WinEH::EncodingType::Invalid:
273 case WinEH::EncodingType::X86:
274 case WinEH::EncodingType::Itanium:
275 ES = new WinException(this);
281 Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
285 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
286 if (!MAI.hasWeakDefCanBeHiddenDirective())
289 return canBeOmittedFromSymbolTable(GV);
292 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
293 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
295 case GlobalValue::CommonLinkage:
296 case GlobalValue::LinkOnceAnyLinkage:
297 case GlobalValue::LinkOnceODRLinkage:
298 case GlobalValue::WeakAnyLinkage:
299 case GlobalValue::WeakODRLinkage:
300 if (MAI->hasWeakDefDirective()) {
302 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
304 if (!canBeHidden(GV, *MAI))
305 // .weak_definition _foo
306 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
308 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
309 } else if (MAI->hasLinkOnceDirective()) {
311 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
312 //NOTE: linkonce is handled by the section the symbol was assigned to.
315 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Weak);
318 case GlobalValue::AppendingLinkage:
319 // FIXME: appending linkage variables should go into a section of
320 // their name or something. For now, just emit them as external.
321 case GlobalValue::ExternalLinkage:
322 // If external or appending, declare as a global symbol.
324 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
326 case GlobalValue::PrivateLinkage:
327 case GlobalValue::InternalLinkage:
329 case GlobalValue::AvailableExternallyLinkage:
330 llvm_unreachable("Should never emit this");
331 case GlobalValue::ExternalWeakLinkage:
332 llvm_unreachable("Don't know how to emit these");
334 llvm_unreachable("Unknown linkage type!");
337 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
338 const GlobalValue *GV) const {
339 TM.getNameWithPrefix(Name, GV, *Mang);
342 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
343 return TM.getSymbol(GV, *Mang);
346 static MCSymbol *getOrCreateEmuTLSControlSym(MCSymbol *GVSym, MCContext &C) {
347 return C.getOrCreateSymbol(Twine("__emutls_v.") + GVSym->getName());
350 static MCSymbol *getOrCreateEmuTLSInitSym(MCSymbol *GVSym, MCContext &C) {
351 return C.getOrCreateSymbol(Twine("__emutls_t.") + GVSym->getName());
354 /// EmitEmulatedTLSControlVariable - Emit the control variable for an emulated TLS variable.
355 void AsmPrinter::EmitEmulatedTLSControlVariable(const GlobalVariable *GV,
356 MCSymbol *EmittedSym,
357 bool AllZeroInitValue) {
358 MCSection *TLSVarSection = getObjFileLowering().getDataSection();
359 OutStreamer->SwitchSection(TLSVarSection);
360 MCSymbol *GVSym = getSymbol(GV);
361 EmitLinkage(GV, EmittedSym); // same linkage as GV
362 const DataLayout &DL = GV->getParent()->getDataLayout();
363 uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
364 unsigned AlignLog = getGVAlignmentLog2(GV, DL);
365 unsigned WordSize = DL.getPointerSize();
366 unsigned Alignment = DL.getPointerABIAlignment();
367 EmitAlignment(Log2_32(Alignment));
368 OutStreamer->EmitLabel(EmittedSym);
369 OutStreamer->EmitIntValue(Size, WordSize);
370 OutStreamer->EmitIntValue((1 << AlignLog), WordSize);
371 OutStreamer->EmitIntValue(0, WordSize);
372 if (GV->hasInitializer() && !AllZeroInitValue) {
373 OutStreamer->EmitSymbolValue(
374 getOrCreateEmuTLSInitSym(GVSym, OutContext), WordSize);
376 OutStreamer->EmitIntValue(0, WordSize);
377 if (MAI->hasDotTypeDotSizeDirective())
378 OutStreamer->emitELFSize(cast<MCSymbolELF>(EmittedSym),
379 MCConstantExpr::create(4 * WordSize, OutContext));
380 OutStreamer->AddBlankLine(); // End of the __emutls_v.* variable.
383 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
384 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
386 GV->getThreadLocalMode() != llvm::GlobalVariable::NotThreadLocal &&
387 TM.Options.EmulatedTLS;
388 assert(!(IsEmuTLSVar && GV->hasCommonLinkage()) &&
389 "No emulated TLS variables in the common section");
391 if (GV->hasInitializer()) {
392 // Check to see if this is a special global used by LLVM, if so, emit it.
393 if (EmitSpecialLLVMGlobal(GV))
396 // Skip the emission of global equivalents. The symbol can be emitted later
397 // on by emitGlobalGOTEquivs in case it turns out to be needed.
398 if (GlobalGOTEquivs.count(getSymbol(GV)))
401 if (isVerbose() && !IsEmuTLSVar) {
402 // When printing the control variable __emutls_v.*,
403 // we don't need to print the original TLS variable name.
404 GV->printAsOperand(OutStreamer->GetCommentOS(),
405 /*PrintType=*/false, GV->getParent());
406 OutStreamer->GetCommentOS() << '\n';
410 MCSymbol *GVSym = getSymbol(GV);
411 MCSymbol *EmittedSym = IsEmuTLSVar ?
412 getOrCreateEmuTLSControlSym(GVSym, OutContext) : GVSym;
413 // getOrCreateEmuTLSControlSym only creates the symbol with name and default attributes.
414 // GV's or GVSym's attributes will be used for the EmittedSym.
416 EmitVisibility(EmittedSym, GV->getVisibility(), !GV->isDeclaration());
418 if (!GV->hasInitializer()) // External globals require no extra code.
421 GVSym->redefineIfPossible();
422 if (GVSym->isDefined() || GVSym->isVariable())
423 report_fatal_error("symbol '" + Twine(GVSym->getName()) +
424 "' is already defined");
426 if (MAI->hasDotTypeDotSizeDirective())
427 OutStreamer->EmitSymbolAttribute(EmittedSym, MCSA_ELF_TypeObject);
429 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
431 const DataLayout &DL = GV->getParent()->getDataLayout();
432 uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
434 // If the alignment is specified, we *must* obey it. Overaligning a global
435 // with a specified alignment is a prompt way to break globals emitted to
436 // sections and expected to be contiguous (e.g. ObjC metadata).
437 unsigned AlignLog = getGVAlignmentLog2(GV, DL);
439 bool AllZeroInitValue = false;
440 const Constant *InitValue = GV->getInitializer();
441 if (isa<ConstantAggregateZero>(InitValue))
442 AllZeroInitValue = true;
444 const ConstantInt *InitIntValue = dyn_cast<ConstantInt>(InitValue);
445 if (InitIntValue && InitIntValue->isZero())
446 AllZeroInitValue = true;
449 EmitEmulatedTLSControlVariable(GV, EmittedSym, AllZeroInitValue);
451 for (const HandlerInfo &HI : Handlers) {
452 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
453 HI.Handler->setSymbolSize(GVSym, Size);
456 // Handle common and BSS local symbols (.lcomm).
457 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
458 assert(!(IsEmuTLSVar && GVKind.isCommon()) &&
459 "No emulated TLS variables in the common section");
460 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
461 unsigned Align = 1 << AlignLog;
463 // Handle common symbols.
464 if (GVKind.isCommon()) {
465 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
469 OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
473 // Handle local BSS symbols.
474 if (MAI->hasMachoZeroFillDirective()) {
475 MCSection *TheSection =
476 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
477 // .zerofill __DATA, __bss, _foo, 400, 5
478 OutStreamer->EmitZerofill(TheSection, GVSym, Size, Align);
482 // Use .lcomm only if it supports user-specified alignment.
483 // Otherwise, while it would still be correct to use .lcomm in some
484 // cases (e.g. when Align == 1), the external assembler might enfore
485 // some -unknown- default alignment behavior, which could cause
486 // spurious differences between external and integrated assembler.
487 // Prefer to simply fall back to .local / .comm in this case.
488 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
490 OutStreamer->EmitLocalCommonSymbol(GVSym, Size, Align);
494 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
498 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Local);
500 OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
504 if (IsEmuTLSVar && AllZeroInitValue)
505 return; // No need of initialization values.
507 MCSymbol *EmittedInitSym = IsEmuTLSVar ?
508 getOrCreateEmuTLSInitSym(GVSym, OutContext) : GVSym;
509 // getOrCreateEmuTLSInitSym only creates the symbol with name and default attributes.
510 // GV's or GVSym's attributes will be used for the EmittedInitSym.
512 MCSection *TheSection = IsEmuTLSVar ?
513 getObjFileLowering().getReadOnlySection() :
514 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
516 // Handle the zerofill directive on darwin, which is a special form of BSS
518 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective() && !IsEmuTLSVar) {
519 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
522 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
523 // .zerofill __DATA, __common, _foo, 400, 5
524 OutStreamer->EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
528 // Handle thread local data for mach-o which requires us to output an
529 // additional structure of data and mangle the original symbol so that we
530 // can reference it later.
532 // TODO: This should become an "emit thread local global" method on TLOF.
533 // All of this macho specific stuff should be sunk down into TLOFMachO and
534 // stuff like "TLSExtraDataSection" should no longer be part of the parent
535 // TLOF class. This will also make it more obvious that stuff like
536 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
538 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective() && !IsEmuTLSVar) {
539 // Emit the .tbss symbol
541 OutContext.getOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
543 if (GVKind.isThreadBSS()) {
544 TheSection = getObjFileLowering().getTLSBSSSection();
545 OutStreamer->EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
546 } else if (GVKind.isThreadData()) {
547 OutStreamer->SwitchSection(TheSection);
549 EmitAlignment(AlignLog, GV);
550 OutStreamer->EmitLabel(MangSym);
552 EmitGlobalConstant(GV->getParent()->getDataLayout(),
553 GV->getInitializer());
556 OutStreamer->AddBlankLine();
558 // Emit the variable struct for the runtime.
559 MCSection *TLVSect = getObjFileLowering().getTLSExtraDataSection();
561 OutStreamer->SwitchSection(TLVSect);
562 // Emit the linkage here.
563 EmitLinkage(GV, GVSym);
564 OutStreamer->EmitLabel(GVSym);
566 // Three pointers in size:
567 // - __tlv_bootstrap - used to make sure support exists
568 // - spare pointer, used when mapped by the runtime
569 // - pointer to mangled symbol above with initializer
570 unsigned PtrSize = DL.getPointerTypeSize(GV->getType());
571 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
573 OutStreamer->EmitIntValue(0, PtrSize);
574 OutStreamer->EmitSymbolValue(MangSym, PtrSize);
576 OutStreamer->AddBlankLine();
580 OutStreamer->SwitchSection(TheSection);
582 // emutls_t.* symbols are only used in the current compilation unit.
584 EmitLinkage(GV, EmittedInitSym);
585 EmitAlignment(AlignLog, GV);
587 OutStreamer->EmitLabel(EmittedInitSym);
589 EmitGlobalConstant(GV->getParent()->getDataLayout(), GV->getInitializer());
591 if (MAI->hasDotTypeDotSizeDirective())
593 OutStreamer->emitELFSize(cast<MCSymbolELF>(EmittedInitSym),
594 MCConstantExpr::create(Size, OutContext));
596 OutStreamer->AddBlankLine();
599 /// EmitFunctionHeader - This method emits the header for the current
601 void AsmPrinter::EmitFunctionHeader() {
602 // Print out constants referenced by the function
605 // Print the 'header' of function.
606 const Function *F = MF->getFunction();
608 OutStreamer->SwitchSection(
609 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
610 EmitVisibility(CurrentFnSym, F->getVisibility());
612 EmitLinkage(F, CurrentFnSym);
613 if (MAI->hasFunctionAlignment())
614 EmitAlignment(MF->getAlignment(), F);
616 if (MAI->hasDotTypeDotSizeDirective())
617 OutStreamer->EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
620 F->printAsOperand(OutStreamer->GetCommentOS(),
621 /*PrintType=*/false, F->getParent());
622 OutStreamer->GetCommentOS() << '\n';
625 // Emit the prefix data.
626 if (F->hasPrefixData())
627 EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrefixData());
629 // Emit the CurrentFnSym. This is a virtual function to allow targets to
630 // do their wild and crazy things as required.
631 EmitFunctionEntryLabel();
633 // If the function had address-taken blocks that got deleted, then we have
634 // references to the dangling symbols. Emit them at the start of the function
635 // so that we don't get references to undefined symbols.
636 std::vector<MCSymbol*> DeadBlockSyms;
637 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
638 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
639 OutStreamer->AddComment("Address taken block that was later removed");
640 OutStreamer->EmitLabel(DeadBlockSyms[i]);
643 if (CurrentFnBegin) {
644 if (MAI->useAssignmentForEHBegin()) {
645 MCSymbol *CurPos = OutContext.createTempSymbol();
646 OutStreamer->EmitLabel(CurPos);
647 OutStreamer->EmitAssignment(CurrentFnBegin,
648 MCSymbolRefExpr::create(CurPos, OutContext));
650 OutStreamer->EmitLabel(CurrentFnBegin);
654 // Emit pre-function debug and/or EH information.
655 for (const HandlerInfo &HI : Handlers) {
656 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
657 HI.Handler->beginFunction(MF);
660 // Emit the prologue data.
661 if (F->hasPrologueData())
662 EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrologueData());
665 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
666 /// function. This can be overridden by targets as required to do custom stuff.
667 void AsmPrinter::EmitFunctionEntryLabel() {
668 CurrentFnSym->redefineIfPossible();
670 // The function label could have already been emitted if two symbols end up
671 // conflicting due to asm renaming. Detect this and emit an error.
672 if (CurrentFnSym->isVariable())
673 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
674 "' is a protected alias");
675 if (CurrentFnSym->isDefined())
676 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
677 "' label emitted multiple times to assembly file");
679 return OutStreamer->EmitLabel(CurrentFnSym);
682 /// emitComments - Pretty-print comments for instructions.
683 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
684 const MachineFunction *MF = MI.getParent()->getParent();
685 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
687 // Check for spills and reloads
690 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
692 // We assume a single instruction only has a spill or reload, not
694 const MachineMemOperand *MMO;
695 if (TII->isLoadFromStackSlotPostFE(&MI, FI)) {
696 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
697 MMO = *MI.memoperands_begin();
698 CommentOS << MMO->getSize() << "-byte Reload\n";
700 } else if (TII->hasLoadFromStackSlot(&MI, MMO, FI)) {
701 if (FrameInfo->isSpillSlotObjectIndex(FI))
702 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
703 } else if (TII->isStoreToStackSlotPostFE(&MI, FI)) {
704 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
705 MMO = *MI.memoperands_begin();
706 CommentOS << MMO->getSize() << "-byte Spill\n";
708 } else if (TII->hasStoreToStackSlot(&MI, MMO, FI)) {
709 if (FrameInfo->isSpillSlotObjectIndex(FI))
710 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
713 // Check for spill-induced copies
714 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
715 CommentOS << " Reload Reuse\n";
718 /// emitImplicitDef - This method emits the specified machine instruction
719 /// that is an implicit def.
720 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
721 unsigned RegNo = MI->getOperand(0).getReg();
723 SmallString<128> Str;
724 raw_svector_ostream OS(Str);
725 OS << "implicit-def: "
726 << PrintReg(RegNo, MF->getSubtarget().getRegisterInfo());
728 OutStreamer->AddComment(OS.str());
729 OutStreamer->AddBlankLine();
732 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
734 raw_string_ostream OS(Str);
736 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
737 const MachineOperand &Op = MI->getOperand(i);
738 assert(Op.isReg() && "KILL instruction must have only register operands");
740 << PrintReg(Op.getReg(),
741 AP.MF->getSubtarget().getRegisterInfo())
742 << (Op.isDef() ? "<def>" : "<kill>");
744 AP.OutStreamer->AddComment(Str);
745 AP.OutStreamer->AddBlankLine();
748 /// emitDebugValueComment - This method handles the target-independent form
749 /// of DBG_VALUE, returning true if it was able to do so. A false return
750 /// means the target will need to handle MI in EmitInstruction.
751 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
752 // This code handles only the 4-operand target-independent form.
753 if (MI->getNumOperands() != 4)
756 SmallString<128> Str;
757 raw_svector_ostream OS(Str);
758 OS << "DEBUG_VALUE: ";
760 const DILocalVariable *V = MI->getDebugVariable();
761 if (auto *SP = dyn_cast<DISubprogram>(V->getScope())) {
762 StringRef Name = SP->getDisplayName();
768 const DIExpression *Expr = MI->getDebugExpression();
769 if (Expr->isBitPiece())
770 OS << " [bit_piece offset=" << Expr->getBitPieceOffset()
771 << " size=" << Expr->getBitPieceSize() << "]";
774 // The second operand is only an offset if it's an immediate.
775 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
776 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
778 for (unsigned i = 0; i < Expr->getNumElements(); ++i) {
780 // We currently don't support extra Offsets or derefs after the first
781 // one. Bail out early instead of emitting an incorrect comment
782 OS << " [complex expression]";
783 AP.OutStreamer->emitRawComment(OS.str());
786 uint64_t Op = Expr->getElement(i);
787 if (Op == dwarf::DW_OP_deref) {
791 uint64_t ExtraOffset = Expr->getElement(i++);
792 if (Op == dwarf::DW_OP_plus)
793 Offset += ExtraOffset;
795 assert(Op == dwarf::DW_OP_minus);
796 Offset -= ExtraOffset;
800 // Register or immediate value. Register 0 means undef.
801 if (MI->getOperand(0).isFPImm()) {
802 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
803 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
804 OS << (double)APF.convertToFloat();
805 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
806 OS << APF.convertToDouble();
808 // There is no good way to print long double. Convert a copy to
809 // double. Ah well, it's only a comment.
811 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
813 OS << "(long double) " << APF.convertToDouble();
815 } else if (MI->getOperand(0).isImm()) {
816 OS << MI->getOperand(0).getImm();
817 } else if (MI->getOperand(0).isCImm()) {
818 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
821 if (MI->getOperand(0).isReg()) {
822 Reg = MI->getOperand(0).getReg();
824 assert(MI->getOperand(0).isFI() && "Unknown operand type");
825 const TargetFrameLowering *TFI = AP.MF->getSubtarget().getFrameLowering();
826 Offset += TFI->getFrameIndexReference(*AP.MF,
827 MI->getOperand(0).getIndex(), Reg);
831 // Suppress offset, it is not meaningful here.
833 // NOTE: Want this comment at start of line, don't emit with AddComment.
834 AP.OutStreamer->emitRawComment(OS.str());
839 OS << PrintReg(Reg, AP.MF->getSubtarget().getRegisterInfo());
843 OS << '+' << Offset << ']';
845 // NOTE: Want this comment at start of line, don't emit with AddComment.
846 AP.OutStreamer->emitRawComment(OS.str());
850 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
851 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
852 MF->getFunction()->needsUnwindTableEntry())
855 if (MMI->hasDebugInfo())
861 bool AsmPrinter::needsSEHMoves() {
862 return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
865 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
866 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
867 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
868 ExceptionHandlingType != ExceptionHandling::ARM)
871 if (needsCFIMoves() == CFI_M_None)
874 const MachineModuleInfo &MMI = MF->getMMI();
875 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
876 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
877 const MCCFIInstruction &CFI = Instrs[CFIIndex];
878 emitCFIInstruction(CFI);
881 void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
882 // The operands are the MCSymbol and the frame offset of the allocation.
883 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
884 int FrameOffset = MI.getOperand(1).getImm();
886 // Emit a symbol assignment.
887 OutStreamer->EmitAssignment(FrameAllocSym,
888 MCConstantExpr::create(FrameOffset, OutContext));
891 /// EmitFunctionBody - This method emits the body and trailer for a
893 void AsmPrinter::EmitFunctionBody() {
894 EmitFunctionHeader();
896 // Emit target-specific gunk before the function body.
897 EmitFunctionBodyStart();
899 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
901 // Print out code for the function.
902 bool HasAnyRealCode = false;
903 for (auto &MBB : *MF) {
904 // Print a label for the basic block.
905 EmitBasicBlockStart(MBB);
906 for (auto &MI : MBB) {
908 // Print the assembly for the instruction.
909 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
910 !MI.isDebugValue()) {
911 HasAnyRealCode = true;
915 if (ShouldPrintDebugScopes) {
916 for (const HandlerInfo &HI : Handlers) {
917 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
918 TimePassesIsEnabled);
919 HI.Handler->beginInstruction(&MI);
924 emitComments(MI, OutStreamer->GetCommentOS());
926 switch (MI.getOpcode()) {
927 case TargetOpcode::CFI_INSTRUCTION:
928 emitCFIInstruction(MI);
931 case TargetOpcode::LOCAL_ESCAPE:
935 case TargetOpcode::EH_LABEL:
936 case TargetOpcode::GC_LABEL:
937 OutStreamer->EmitLabel(MI.getOperand(0).getMCSymbol());
939 case TargetOpcode::INLINEASM:
942 case TargetOpcode::DBG_VALUE:
944 if (!emitDebugValueComment(&MI, *this))
945 EmitInstruction(&MI);
948 case TargetOpcode::IMPLICIT_DEF:
949 if (isVerbose()) emitImplicitDef(&MI);
951 case TargetOpcode::KILL:
952 if (isVerbose()) emitKill(&MI, *this);
955 EmitInstruction(&MI);
959 if (ShouldPrintDebugScopes) {
960 for (const HandlerInfo &HI : Handlers) {
961 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
962 TimePassesIsEnabled);
963 HI.Handler->endInstruction();
968 EmitBasicBlockEnd(MBB);
971 // If the function is empty and the object file uses .subsections_via_symbols,
972 // then we need to emit *something* to the function body to prevent the
973 // labels from collapsing together. Just emit a noop.
974 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
976 MF->getSubtarget().getInstrInfo()->getNoopForMachoTarget(Noop);
977 OutStreamer->AddComment("avoids zero-length function");
979 // Targets can opt-out of emitting the noop here by leaving the opcode
981 if (Noop.getOpcode())
982 OutStreamer->EmitInstruction(Noop, getSubtargetInfo());
985 const Function *F = MF->getFunction();
986 for (const auto &BB : *F) {
987 if (!BB.hasAddressTaken())
989 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
990 if (Sym->isDefined())
992 OutStreamer->AddComment("Address of block that was removed by CodeGen");
993 OutStreamer->EmitLabel(Sym);
996 // Emit target-specific gunk after the function body.
997 EmitFunctionBodyEnd();
999 if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
1000 MMI->hasEHFunclets() || MAI->hasDotTypeDotSizeDirective()) {
1001 // Create a symbol for the end of function.
1002 CurrentFnEnd = createTempSymbol("func_end");
1003 OutStreamer->EmitLabel(CurrentFnEnd);
1006 // If the target wants a .size directive for the size of the function, emit
1008 if (MAI->hasDotTypeDotSizeDirective()) {
1009 // We can get the size as difference between the function label and the
1011 const MCExpr *SizeExp = MCBinaryExpr::createSub(
1012 MCSymbolRefExpr::create(CurrentFnEnd, OutContext),
1013 MCSymbolRefExpr::create(CurrentFnSymForSize, OutContext), OutContext);
1014 if (auto Sym = dyn_cast<MCSymbolELF>(CurrentFnSym))
1015 OutStreamer->emitELFSize(Sym, SizeExp);
1018 for (const HandlerInfo &HI : Handlers) {
1019 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
1020 HI.Handler->markFunctionEnd();
1023 // Print out jump tables referenced by the function.
1024 EmitJumpTableInfo();
1026 // Emit post-function debug and/or EH information.
1027 for (const HandlerInfo &HI : Handlers) {
1028 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
1029 HI.Handler->endFunction(MF);
1033 OutStreamer->AddBlankLine();
1036 /// \brief Compute the number of Global Variables that uses a Constant.
1037 static unsigned getNumGlobalVariableUses(const Constant *C) {
1041 if (isa<GlobalVariable>(C))
1044 unsigned NumUses = 0;
1045 for (auto *CU : C->users())
1046 NumUses += getNumGlobalVariableUses(dyn_cast<Constant>(CU));
1051 /// \brief Only consider global GOT equivalents if at least one user is a
1052 /// cstexpr inside an initializer of another global variables. Also, don't
1053 /// handle cstexpr inside instructions. During global variable emission,
1054 /// candidates are skipped and are emitted later in case at least one cstexpr
1055 /// isn't replaced by a PC relative GOT entry access.
1056 static bool isGOTEquivalentCandidate(const GlobalVariable *GV,
1057 unsigned &NumGOTEquivUsers) {
1058 // Global GOT equivalents are unnamed private globals with a constant
1059 // pointer initializer to another global symbol. They must point to a
1060 // GlobalVariable or Function, i.e., as GlobalValue.
1061 if (!GV->hasUnnamedAddr() || !GV->hasInitializer() || !GV->isConstant() ||
1062 !GV->isDiscardableIfUnused() || !dyn_cast<GlobalValue>(GV->getOperand(0)))
1065 // To be a got equivalent, at least one of its users need to be a constant
1066 // expression used by another global variable.
1067 for (auto *U : GV->users())
1068 NumGOTEquivUsers += getNumGlobalVariableUses(dyn_cast<Constant>(U));
1070 return NumGOTEquivUsers > 0;
1073 /// \brief Unnamed constant global variables solely contaning a pointer to
1074 /// another globals variable is equivalent to a GOT table entry; it contains the
1075 /// the address of another symbol. Optimize it and replace accesses to these
1076 /// "GOT equivalents" by using the GOT entry for the final global instead.
1077 /// Compute GOT equivalent candidates among all global variables to avoid
1078 /// emitting them if possible later on, after it use is replaced by a GOT entry
1080 void AsmPrinter::computeGlobalGOTEquivs(Module &M) {
1081 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
1084 for (const auto &G : M.globals()) {
1085 unsigned NumGOTEquivUsers = 0;
1086 if (!isGOTEquivalentCandidate(&G, NumGOTEquivUsers))
1089 const MCSymbol *GOTEquivSym = getSymbol(&G);
1090 GlobalGOTEquivs[GOTEquivSym] = std::make_pair(&G, NumGOTEquivUsers);
1094 /// \brief Constant expressions using GOT equivalent globals may not be eligible
1095 /// for PC relative GOT entry conversion, in such cases we need to emit such
1096 /// globals we previously omitted in EmitGlobalVariable.
1097 void AsmPrinter::emitGlobalGOTEquivs() {
1098 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
1101 SmallVector<const GlobalVariable *, 8> FailedCandidates;
1102 for (auto &I : GlobalGOTEquivs) {
1103 const GlobalVariable *GV = I.second.first;
1104 unsigned Cnt = I.second.second;
1106 FailedCandidates.push_back(GV);
1108 GlobalGOTEquivs.clear();
1110 for (auto *GV : FailedCandidates)
1111 EmitGlobalVariable(GV);
1114 bool AsmPrinter::doFinalization(Module &M) {
1115 // Set the MachineFunction to nullptr so that we can catch attempted
1116 // accesses to MF specific features at the module level and so that
1117 // we can conditionalize accesses based on whether or not it is nullptr.
1120 // Gather all GOT equivalent globals in the module. We really need two
1121 // passes over the globals: one to compute and another to avoid its emission
1122 // in EmitGlobalVariable, otherwise we would not be able to handle cases
1123 // where the got equivalent shows up before its use.
1124 computeGlobalGOTEquivs(M);
1126 // Emit global variables.
1127 for (const auto &G : M.globals())
1128 EmitGlobalVariable(&G);
1130 // Emit remaining GOT equivalent globals.
1131 emitGlobalGOTEquivs();
1133 // Emit visibility info for declarations
1134 for (const Function &F : M) {
1135 if (!F.isDeclarationForLinker())
1137 GlobalValue::VisibilityTypes V = F.getVisibility();
1138 if (V == GlobalValue::DefaultVisibility)
1141 MCSymbol *Name = getSymbol(&F);
1142 EmitVisibility(Name, V, false);
1145 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1147 // Emit module flags.
1148 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
1149 M.getModuleFlagsMetadata(ModuleFlags);
1150 if (!ModuleFlags.empty())
1151 TLOF.emitModuleFlags(*OutStreamer, ModuleFlags, *Mang, TM);
1153 if (TM.getTargetTriple().isOSBinFormatELF()) {
1154 MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
1156 // Output stubs for external and common global variables.
1157 MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
1158 if (!Stubs.empty()) {
1159 OutStreamer->SwitchSection(TLOF.getDataSection());
1160 const DataLayout &DL = M.getDataLayout();
1162 for (const auto &Stub : Stubs) {
1163 OutStreamer->EmitLabel(Stub.first);
1164 OutStreamer->EmitSymbolValue(Stub.second.getPointer(),
1165 DL.getPointerSize());
1170 // Finalize debug and EH information.
1171 for (const HandlerInfo &HI : Handlers) {
1172 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
1173 TimePassesIsEnabled);
1174 HI.Handler->endModule();
1180 // If the target wants to know about weak references, print them all.
1181 if (MAI->getWeakRefDirective()) {
1182 // FIXME: This is not lazy, it would be nice to only print weak references
1183 // to stuff that is actually used. Note that doing so would require targets
1184 // to notice uses in operands (due to constant exprs etc). This should
1185 // happen with the MC stuff eventually.
1187 // Print out module-level global variables here.
1188 for (const auto &G : M.globals()) {
1189 if (!G.hasExternalWeakLinkage())
1191 OutStreamer->EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
1194 for (const auto &F : M) {
1195 if (!F.hasExternalWeakLinkage())
1197 OutStreamer->EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
1201 OutStreamer->AddBlankLine();
1202 for (const auto &Alias : M.aliases()) {
1203 MCSymbol *Name = getSymbol(&Alias);
1205 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
1206 OutStreamer->EmitSymbolAttribute(Name, MCSA_Global);
1207 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
1208 OutStreamer->EmitSymbolAttribute(Name, MCSA_WeakReference);
1210 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
1212 // Set the symbol type to function if the alias has a function type.
1213 // This affects codegen when the aliasee is not a function.
1214 if (Alias.getType()->getPointerElementType()->isFunctionTy())
1215 OutStreamer->EmitSymbolAttribute(Name, MCSA_ELF_TypeFunction);
1217 EmitVisibility(Name, Alias.getVisibility());
1219 // Emit the directives as assignments aka .set:
1220 OutStreamer->EmitAssignment(Name, lowerConstant(Alias.getAliasee()));
1222 // If the aliasee does not correspond to a symbol in the output, i.e. the
1223 // alias is not of an object or the aliased object is private, then set the
1224 // size of the alias symbol from the type of the alias. We don't do this in
1225 // other situations as the alias and aliasee having differing types but same
1226 // size may be intentional.
1227 const GlobalObject *BaseObject = Alias.getBaseObject();
1228 if (MAI->hasDotTypeDotSizeDirective() && Alias.getValueType()->isSized() &&
1229 (!BaseObject || BaseObject->hasPrivateLinkage())) {
1230 const DataLayout &DL = M.getDataLayout();
1231 uint64_t Size = DL.getTypeAllocSize(Alias.getValueType());
1232 OutStreamer->emitELFSize(cast<MCSymbolELF>(Name),
1233 MCConstantExpr::create(Size, OutContext));
1237 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1238 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1239 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1240 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1241 MP->finishAssembly(M, *MI, *this);
1243 // Emit llvm.ident metadata in an '.ident' directive.
1244 EmitModuleIdents(M);
1246 // Emit __morestack address if needed for indirect calls.
1247 if (MMI->usesMorestackAddr()) {
1248 MCSection *ReadOnlySection = getObjFileLowering().getSectionForConstant(
1249 getDataLayout(), SectionKind::getReadOnly(),
1251 OutStreamer->SwitchSection(ReadOnlySection);
1253 MCSymbol *AddrSymbol =
1254 OutContext.getOrCreateSymbol(StringRef("__morestack_addr"));
1255 OutStreamer->EmitLabel(AddrSymbol);
1257 unsigned PtrSize = M.getDataLayout().getPointerSize(0);
1258 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("__morestack"),
1262 // If we don't have any trampolines, then we don't require stack memory
1263 // to be executable. Some targets have a directive to declare this.
1264 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1265 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1266 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1267 OutStreamer->SwitchSection(S);
1269 // Allow the target to emit any magic that it wants at the end of the file,
1270 // after everything else has gone out.
1271 EmitEndOfAsmFile(M);
1273 delete Mang; Mang = nullptr;
1276 OutStreamer->Finish();
1277 OutStreamer->reset();
1282 MCSymbol *AsmPrinter::getCurExceptionSym() {
1283 if (!CurExceptionSym)
1284 CurExceptionSym = createTempSymbol("exception");
1285 return CurExceptionSym;
1288 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1290 // Get the function symbol.
1291 CurrentFnSym = getSymbol(MF.getFunction());
1292 CurrentFnSymForSize = CurrentFnSym;
1293 CurrentFnBegin = nullptr;
1294 CurExceptionSym = nullptr;
1295 bool NeedsLocalForSize = MAI->needsLocalForSize();
1296 if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
1297 MMI->hasEHFunclets() || NeedsLocalForSize) {
1298 CurrentFnBegin = createTempSymbol("func_begin");
1299 if (NeedsLocalForSize)
1300 CurrentFnSymForSize = CurrentFnBegin;
1304 LI = &getAnalysis<MachineLoopInfo>();
1308 // Keep track the alignment, constpool entries per Section.
1312 SmallVector<unsigned, 4> CPEs;
1313 SectionCPs(MCSection *s, unsigned a) : S(s), Alignment(a) {}
1317 /// EmitConstantPool - Print to the current output stream assembly
1318 /// representations of the constants in the constant pool MCP. This is
1319 /// used to print out constants which have been "spilled to memory" by
1320 /// the code generator.
1322 void AsmPrinter::EmitConstantPool() {
1323 const MachineConstantPool *MCP = MF->getConstantPool();
1324 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1325 if (CP.empty()) return;
1327 // Calculate sections for constant pool entries. We collect entries to go into
1328 // the same section together to reduce amount of section switch statements.
1329 SmallVector<SectionCPs, 4> CPSections;
1330 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1331 const MachineConstantPoolEntry &CPE = CP[i];
1332 unsigned Align = CPE.getAlignment();
1334 SectionKind Kind = CPE.getSectionKind(&getDataLayout());
1336 const Constant *C = nullptr;
1337 if (!CPE.isMachineConstantPoolEntry())
1338 C = CPE.Val.ConstVal;
1341 getObjFileLowering().getSectionForConstant(getDataLayout(), Kind, C);
1343 // The number of sections are small, just do a linear search from the
1344 // last section to the first.
1346 unsigned SecIdx = CPSections.size();
1347 while (SecIdx != 0) {
1348 if (CPSections[--SecIdx].S == S) {
1354 SecIdx = CPSections.size();
1355 CPSections.push_back(SectionCPs(S, Align));
1358 if (Align > CPSections[SecIdx].Alignment)
1359 CPSections[SecIdx].Alignment = Align;
1360 CPSections[SecIdx].CPEs.push_back(i);
1363 // Now print stuff into the calculated sections.
1364 const MCSection *CurSection = nullptr;
1365 unsigned Offset = 0;
1366 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1367 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1368 unsigned CPI = CPSections[i].CPEs[j];
1369 MCSymbol *Sym = GetCPISymbol(CPI);
1370 if (!Sym->isUndefined())
1373 if (CurSection != CPSections[i].S) {
1374 OutStreamer->SwitchSection(CPSections[i].S);
1375 EmitAlignment(Log2_32(CPSections[i].Alignment));
1376 CurSection = CPSections[i].S;
1380 MachineConstantPoolEntry CPE = CP[CPI];
1382 // Emit inter-object padding for alignment.
1383 unsigned AlignMask = CPE.getAlignment() - 1;
1384 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1385 OutStreamer->EmitZeros(NewOffset - Offset);
1387 Type *Ty = CPE.getType();
1388 Offset = NewOffset + getDataLayout().getTypeAllocSize(Ty);
1390 OutStreamer->EmitLabel(Sym);
1391 if (CPE.isMachineConstantPoolEntry())
1392 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1394 EmitGlobalConstant(getDataLayout(), CPE.Val.ConstVal);
1399 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1400 /// by the current function to the current output stream.
1402 void AsmPrinter::EmitJumpTableInfo() {
1403 const DataLayout &DL = MF->getDataLayout();
1404 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1406 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1407 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1408 if (JT.empty()) return;
1410 // Pick the directive to use to print the jump table entries, and switch to
1411 // the appropriate section.
1412 const Function *F = MF->getFunction();
1413 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1414 bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
1415 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
1417 if (JTInDiffSection) {
1418 // Drop it in the readonly section.
1419 MCSection *ReadOnlySection = TLOF.getSectionForJumpTable(*F, *Mang, TM);
1420 OutStreamer->SwitchSection(ReadOnlySection);
1423 EmitAlignment(Log2_32(MJTI->getEntryAlignment(DL)));
1425 // Jump tables in code sections are marked with a data_region directive
1426 // where that's supported.
1427 if (!JTInDiffSection)
1428 OutStreamer->EmitDataRegion(MCDR_DataRegionJT32);
1430 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1431 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1433 // If this jump table was deleted, ignore it.
1434 if (JTBBs.empty()) continue;
1436 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1437 /// emit a .set directive for each unique entry.
1438 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1439 MAI->doesSetDirectiveSuppressesReloc()) {
1440 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1441 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1442 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1443 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1444 const MachineBasicBlock *MBB = JTBBs[ii];
1445 if (!EmittedSets.insert(MBB).second)
1448 // .set LJTSet, LBB32-base
1450 MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1451 OutStreamer->EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1452 MCBinaryExpr::createSub(LHS, Base,
1457 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1458 // before each jump table. The first label is never referenced, but tells
1459 // the assembler and linker the extents of the jump table object. The
1460 // second label is actually referenced by the code.
1461 if (JTInDiffSection && DL.hasLinkerPrivateGlobalPrefix())
1462 // FIXME: This doesn't have to have any specific name, just any randomly
1463 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1464 OutStreamer->EmitLabel(GetJTISymbol(JTI, true));
1466 OutStreamer->EmitLabel(GetJTISymbol(JTI));
1468 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1469 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1471 if (!JTInDiffSection)
1472 OutStreamer->EmitDataRegion(MCDR_DataRegionEnd);
1475 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1477 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1478 const MachineBasicBlock *MBB,
1479 unsigned UID) const {
1480 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1481 const MCExpr *Value = nullptr;
1482 switch (MJTI->getEntryKind()) {
1483 case MachineJumpTableInfo::EK_Inline:
1484 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1485 case MachineJumpTableInfo::EK_Custom32:
1486 Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
1487 MJTI, MBB, UID, OutContext);
1489 case MachineJumpTableInfo::EK_BlockAddress:
1490 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1492 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1494 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1495 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1496 // with a relocation as gp-relative, e.g.:
1498 MCSymbol *MBBSym = MBB->getSymbol();
1499 OutStreamer->EmitGPRel32Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1503 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1504 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1505 // with a relocation as gp-relative, e.g.:
1507 MCSymbol *MBBSym = MBB->getSymbol();
1508 OutStreamer->EmitGPRel64Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1512 case MachineJumpTableInfo::EK_LabelDifference32: {
1513 // Each entry is the address of the block minus the address of the jump
1514 // table. This is used for PIC jump tables where gprel32 is not supported.
1516 // .word LBB123 - LJTI1_2
1517 // If the .set directive avoids relocations, this is emitted as:
1518 // .set L4_5_set_123, LBB123 - LJTI1_2
1519 // .word L4_5_set_123
1520 if (MAI->doesSetDirectiveSuppressesReloc()) {
1521 Value = MCSymbolRefExpr::create(GetJTSetSymbol(UID, MBB->getNumber()),
1525 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1526 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1527 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1528 Value = MCBinaryExpr::createSub(Value, Base, OutContext);
1533 assert(Value && "Unknown entry kind!");
1535 unsigned EntrySize = MJTI->getEntrySize(getDataLayout());
1536 OutStreamer->EmitValue(Value, EntrySize);
1540 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1541 /// special global used by LLVM. If so, emit it and return true, otherwise
1542 /// do nothing and return false.
1543 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1544 if (GV->getName() == "llvm.used") {
1545 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1546 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1550 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1551 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1552 GV->hasAvailableExternallyLinkage())
1555 if (!GV->hasAppendingLinkage()) return false;
1557 assert(GV->hasInitializer() && "Not a special LLVM global!");
1559 if (GV->getName() == "llvm.global_ctors") {
1560 EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
1563 if (TM.getRelocationModel() == Reloc::Static &&
1564 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1565 StringRef Sym(".constructors_used");
1566 OutStreamer->EmitSymbolAttribute(OutContext.getOrCreateSymbol(Sym),
1572 if (GV->getName() == "llvm.global_dtors") {
1573 EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
1574 /* isCtor */ false);
1576 if (TM.getRelocationModel() == Reloc::Static &&
1577 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1578 StringRef Sym(".destructors_used");
1579 OutStreamer->EmitSymbolAttribute(OutContext.getOrCreateSymbol(Sym),
1588 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1589 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1590 /// is true, as being used with this directive.
1591 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1592 // Should be an array of 'i8*'.
1593 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1594 const GlobalValue *GV =
1595 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1597 OutStreamer->EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1603 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1605 llvm::Constant *Func;
1606 llvm::GlobalValue *ComdatKey;
1610 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1612 void AsmPrinter::EmitXXStructorList(const DataLayout &DL, const Constant *List,
1614 // Should be an array of '{ int, void ()* }' structs. The first value is the
1616 if (!isa<ConstantArray>(List)) return;
1618 // Sanity check the structors list.
1619 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1620 if (!InitList) return; // Not an array!
1621 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1622 // FIXME: Only allow the 3-field form in LLVM 4.0.
1623 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1624 return; // Not an array of two or three elements!
1625 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1626 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1627 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1628 return; // Not (int, ptr, ptr).
1630 // Gather the structors in a form that's convenient for sorting by priority.
1631 SmallVector<Structor, 8> Structors;
1632 for (Value *O : InitList->operands()) {
1633 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1634 if (!CS) continue; // Malformed.
1635 if (CS->getOperand(1)->isNullValue())
1636 break; // Found a null terminator, skip the rest.
1637 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1638 if (!Priority) continue; // Malformed.
1639 Structors.push_back(Structor());
1640 Structor &S = Structors.back();
1641 S.Priority = Priority->getLimitedValue(65535);
1642 S.Func = CS->getOperand(1);
1643 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1644 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1647 // Emit the function pointers in the target-specific order
1648 unsigned Align = Log2_32(DL.getPointerPrefAlignment());
1649 std::stable_sort(Structors.begin(), Structors.end(),
1650 [](const Structor &L,
1651 const Structor &R) { return L.Priority < R.Priority; });
1652 for (Structor &S : Structors) {
1653 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1654 const MCSymbol *KeySym = nullptr;
1655 if (GlobalValue *GV = S.ComdatKey) {
1656 if (GV->hasAvailableExternallyLinkage())
1657 // If the associated variable is available_externally, some other TU
1658 // will provide its dynamic initializer.
1661 KeySym = getSymbol(GV);
1663 MCSection *OutputSection =
1664 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1665 : Obj.getStaticDtorSection(S.Priority, KeySym));
1666 OutStreamer->SwitchSection(OutputSection);
1667 if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
1668 EmitAlignment(Align);
1669 EmitXXStructor(DL, S.Func);
1673 void AsmPrinter::EmitModuleIdents(Module &M) {
1674 if (!MAI->hasIdentDirective())
1677 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1678 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1679 const MDNode *N = NMD->getOperand(i);
1680 assert(N->getNumOperands() == 1 &&
1681 "llvm.ident metadata entry can have only one operand");
1682 const MDString *S = cast<MDString>(N->getOperand(0));
1683 OutStreamer->EmitIdent(S->getString());
1688 //===--------------------------------------------------------------------===//
1689 // Emission and print routines
1692 /// EmitInt8 - Emit a byte directive and value.
1694 void AsmPrinter::EmitInt8(int Value) const {
1695 OutStreamer->EmitIntValue(Value, 1);
1698 /// EmitInt16 - Emit a short directive and value.
1700 void AsmPrinter::EmitInt16(int Value) const {
1701 OutStreamer->EmitIntValue(Value, 2);
1704 /// EmitInt32 - Emit a long directive and value.
1706 void AsmPrinter::EmitInt32(int Value) const {
1707 OutStreamer->EmitIntValue(Value, 4);
1710 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1711 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1712 /// .set if it avoids relocations.
1713 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1714 unsigned Size) const {
1715 OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
1718 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1719 /// where the size in bytes of the directive is specified by Size and Label
1720 /// specifies the label. This implicitly uses .set if it is available.
1721 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1723 bool IsSectionRelative) const {
1724 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1725 OutStreamer->EmitCOFFSecRel32(Label);
1729 // Emit Label+Offset (or just Label if Offset is zero)
1730 const MCExpr *Expr = MCSymbolRefExpr::create(Label, OutContext);
1732 Expr = MCBinaryExpr::createAdd(
1733 Expr, MCConstantExpr::create(Offset, OutContext), OutContext);
1735 OutStreamer->EmitValue(Expr, Size);
1738 //===----------------------------------------------------------------------===//
1740 // EmitAlignment - Emit an alignment directive to the specified power of
1741 // two boundary. For example, if you pass in 3 here, you will get an 8
1742 // byte alignment. If a global value is specified, and if that global has
1743 // an explicit alignment requested, it will override the alignment request
1744 // if required for correctness.
1746 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1748 NumBits = getGVAlignmentLog2(GV, GV->getParent()->getDataLayout(), NumBits);
1750 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1753 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
1754 "undefined behavior");
1755 if (getCurrentSection()->getKind().isText())
1756 OutStreamer->EmitCodeAlignment(1u << NumBits);
1758 OutStreamer->EmitValueToAlignment(1u << NumBits);
1761 //===----------------------------------------------------------------------===//
1762 // Constant emission.
1763 //===----------------------------------------------------------------------===//
1765 const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1766 MCContext &Ctx = OutContext;
1768 if (CV->isNullValue() || isa<UndefValue>(CV))
1769 return MCConstantExpr::create(0, Ctx);
1771 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1772 return MCConstantExpr::create(CI->getZExtValue(), Ctx);
1774 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1775 return MCSymbolRefExpr::create(getSymbol(GV), Ctx);
1777 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1778 return MCSymbolRefExpr::create(GetBlockAddressSymbol(BA), Ctx);
1780 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1782 llvm_unreachable("Unknown constant value to lower!");
1785 if (const MCExpr *RelocExpr
1786 = getObjFileLowering().getExecutableRelativeSymbol(CE, *Mang, TM))
1789 switch (CE->getOpcode()) {
1791 // If the code isn't optimized, there may be outstanding folding
1792 // opportunities. Attempt to fold the expression using DataLayout as a
1793 // last resort before giving up.
1794 if (Constant *C = ConstantFoldConstantExpression(CE, getDataLayout()))
1796 return lowerConstant(C);
1798 // Otherwise report the problem to the user.
1801 raw_string_ostream OS(S);
1802 OS << "Unsupported expression in static initializer: ";
1803 CE->printAsOperand(OS, /*PrintType=*/false,
1804 !MF ? nullptr : MF->getFunction()->getParent());
1805 report_fatal_error(OS.str());
1807 case Instruction::GetElementPtr: {
1808 // Generate a symbolic expression for the byte address
1809 APInt OffsetAI(getDataLayout().getPointerTypeSizeInBits(CE->getType()), 0);
1810 cast<GEPOperator>(CE)->accumulateConstantOffset(getDataLayout(), OffsetAI);
1812 const MCExpr *Base = lowerConstant(CE->getOperand(0));
1816 int64_t Offset = OffsetAI.getSExtValue();
1817 return MCBinaryExpr::createAdd(Base, MCConstantExpr::create(Offset, Ctx),
1821 case Instruction::Trunc:
1822 // We emit the value and depend on the assembler to truncate the generated
1823 // expression properly. This is important for differences between
1824 // blockaddress labels. Since the two labels are in the same function, it
1825 // is reasonable to treat their delta as a 32-bit value.
1827 case Instruction::BitCast:
1828 return lowerConstant(CE->getOperand(0));
1830 case Instruction::IntToPtr: {
1831 const DataLayout &DL = getDataLayout();
1833 // Handle casts to pointers by changing them into casts to the appropriate
1834 // integer type. This promotes constant folding and simplifies this code.
1835 Constant *Op = CE->getOperand(0);
1836 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1838 return lowerConstant(Op);
1841 case Instruction::PtrToInt: {
1842 const DataLayout &DL = getDataLayout();
1844 // Support only foldable casts to/from pointers that can be eliminated by
1845 // changing the pointer to the appropriately sized integer type.
1846 Constant *Op = CE->getOperand(0);
1847 Type *Ty = CE->getType();
1849 const MCExpr *OpExpr = lowerConstant(Op);
1851 // We can emit the pointer value into this slot if the slot is an
1852 // integer slot equal to the size of the pointer.
1853 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1856 // Otherwise the pointer is smaller than the resultant integer, mask off
1857 // the high bits so we are sure to get a proper truncation if the input is
1859 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1860 const MCExpr *MaskExpr = MCConstantExpr::create(~0ULL >> (64-InBits), Ctx);
1861 return MCBinaryExpr::createAnd(OpExpr, MaskExpr, Ctx);
1864 // The MC library also has a right-shift operator, but it isn't consistently
1865 // signed or unsigned between different targets.
1866 case Instruction::Add:
1867 case Instruction::Sub:
1868 case Instruction::Mul:
1869 case Instruction::SDiv:
1870 case Instruction::SRem:
1871 case Instruction::Shl:
1872 case Instruction::And:
1873 case Instruction::Or:
1874 case Instruction::Xor: {
1875 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
1876 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
1877 switch (CE->getOpcode()) {
1878 default: llvm_unreachable("Unknown binary operator constant cast expr");
1879 case Instruction::Add: return MCBinaryExpr::createAdd(LHS, RHS, Ctx);
1880 case Instruction::Sub: return MCBinaryExpr::createSub(LHS, RHS, Ctx);
1881 case Instruction::Mul: return MCBinaryExpr::createMul(LHS, RHS, Ctx);
1882 case Instruction::SDiv: return MCBinaryExpr::createDiv(LHS, RHS, Ctx);
1883 case Instruction::SRem: return MCBinaryExpr::createMod(LHS, RHS, Ctx);
1884 case Instruction::Shl: return MCBinaryExpr::createShl(LHS, RHS, Ctx);
1885 case Instruction::And: return MCBinaryExpr::createAnd(LHS, RHS, Ctx);
1886 case Instruction::Or: return MCBinaryExpr::createOr (LHS, RHS, Ctx);
1887 case Instruction::Xor: return MCBinaryExpr::createXor(LHS, RHS, Ctx);
1893 static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *C,
1895 const Constant *BaseCV = nullptr,
1896 uint64_t Offset = 0);
1898 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP);
1900 /// isRepeatedByteSequence - Determine whether the given value is
1901 /// composed of a repeated sequence of identical bytes and return the
1902 /// byte value. If it is not a repeated sequence, return -1.
1903 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1904 StringRef Data = V->getRawDataValues();
1905 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1907 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1908 if (Data[i] != C) return -1;
1909 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1913 /// isRepeatedByteSequence - Determine whether the given value is
1914 /// composed of a repeated sequence of identical bytes and return the
1915 /// byte value. If it is not a repeated sequence, return -1.
1916 static int isRepeatedByteSequence(const Value *V, const DataLayout &DL) {
1917 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1918 uint64_t Size = DL.getTypeAllocSizeInBits(V->getType());
1919 assert(Size % 8 == 0);
1921 // Extend the element to take zero padding into account.
1922 APInt Value = CI->getValue().zextOrSelf(Size);
1923 if (!Value.isSplat(8))
1926 return Value.zextOrTrunc(8).getZExtValue();
1928 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1929 // Make sure all array elements are sequences of the same repeated
1931 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1932 Constant *Op0 = CA->getOperand(0);
1933 int Byte = isRepeatedByteSequence(Op0, DL);
1937 // All array elements must be equal.
1938 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i)
1939 if (CA->getOperand(i) != Op0)
1944 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1945 return isRepeatedByteSequence(CDS);
1950 static void emitGlobalConstantDataSequential(const DataLayout &DL,
1951 const ConstantDataSequential *CDS,
1954 // See if we can aggregate this into a .fill, if so, emit it as such.
1955 int Value = isRepeatedByteSequence(CDS, DL);
1957 uint64_t Bytes = DL.getTypeAllocSize(CDS->getType());
1958 // Don't emit a 1-byte object as a .fill.
1960 return AP.OutStreamer->EmitFill(Bytes, Value);
1963 // If this can be emitted with .ascii/.asciz, emit it as such.
1964 if (CDS->isString())
1965 return AP.OutStreamer->EmitBytes(CDS->getAsString());
1967 // Otherwise, emit the values in successive locations.
1968 unsigned ElementByteSize = CDS->getElementByteSize();
1969 if (isa<IntegerType>(CDS->getElementType())) {
1970 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1972 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
1973 CDS->getElementAsInteger(i));
1974 AP.OutStreamer->EmitIntValue(CDS->getElementAsInteger(i),
1978 for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I)
1979 emitGlobalConstantFP(cast<ConstantFP>(CDS->getElementAsConstant(I)), AP);
1982 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1983 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1984 CDS->getNumElements();
1985 if (unsigned Padding = Size - EmittedSize)
1986 AP.OutStreamer->EmitZeros(Padding);
1990 static void emitGlobalConstantArray(const DataLayout &DL,
1991 const ConstantArray *CA, AsmPrinter &AP,
1992 const Constant *BaseCV, uint64_t Offset) {
1993 // See if we can aggregate some values. Make sure it can be
1994 // represented as a series of bytes of the constant value.
1995 int Value = isRepeatedByteSequence(CA, DL);
1998 uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
1999 AP.OutStreamer->EmitFill(Bytes, Value);
2002 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
2003 emitGlobalConstantImpl(DL, CA->getOperand(i), AP, BaseCV, Offset);
2004 Offset += DL.getTypeAllocSize(CA->getOperand(i)->getType());
2009 static void emitGlobalConstantVector(const DataLayout &DL,
2010 const ConstantVector *CV, AsmPrinter &AP) {
2011 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
2012 emitGlobalConstantImpl(DL, CV->getOperand(i), AP);
2014 unsigned Size = DL.getTypeAllocSize(CV->getType());
2015 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
2016 CV->getType()->getNumElements();
2017 if (unsigned Padding = Size - EmittedSize)
2018 AP.OutStreamer->EmitZeros(Padding);
2021 static void emitGlobalConstantStruct(const DataLayout &DL,
2022 const ConstantStruct *CS, AsmPrinter &AP,
2023 const Constant *BaseCV, uint64_t Offset) {
2024 // Print the fields in successive locations. Pad to align if needed!
2025 unsigned Size = DL.getTypeAllocSize(CS->getType());
2026 const StructLayout *Layout = DL.getStructLayout(CS->getType());
2027 uint64_t SizeSoFar = 0;
2028 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
2029 const Constant *Field = CS->getOperand(i);
2031 // Print the actual field value.
2032 emitGlobalConstantImpl(DL, Field, AP, BaseCV, Offset + SizeSoFar);
2034 // Check if padding is needed and insert one or more 0s.
2035 uint64_t FieldSize = DL.getTypeAllocSize(Field->getType());
2036 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
2037 - Layout->getElementOffset(i)) - FieldSize;
2038 SizeSoFar += FieldSize + PadSize;
2040 // Insert padding - this may include padding to increase the size of the
2041 // current field up to the ABI size (if the struct is not packed) as well
2042 // as padding to ensure that the next field starts at the right offset.
2043 AP.OutStreamer->EmitZeros(PadSize);
2045 assert(SizeSoFar == Layout->getSizeInBytes() &&
2046 "Layout of constant struct may be incorrect!");
2049 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
2050 APInt API = CFP->getValueAPF().bitcastToAPInt();
2052 // First print a comment with what we think the original floating-point value
2053 // should have been.
2054 if (AP.isVerbose()) {
2055 SmallString<8> StrVal;
2056 CFP->getValueAPF().toString(StrVal);
2059 CFP->getType()->print(AP.OutStreamer->GetCommentOS());
2061 AP.OutStreamer->GetCommentOS() << "Printing <null> Type";
2062 AP.OutStreamer->GetCommentOS() << ' ' << StrVal << '\n';
2065 // Now iterate through the APInt chunks, emitting them in endian-correct
2066 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
2068 unsigned NumBytes = API.getBitWidth() / 8;
2069 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
2070 const uint64_t *p = API.getRawData();
2072 // PPC's long double has odd notions of endianness compared to how LLVM
2073 // handles it: p[0] goes first for *big* endian on PPC.
2074 if (AP.getDataLayout().isBigEndian() && !CFP->getType()->isPPC_FP128Ty()) {
2075 int Chunk = API.getNumWords() - 1;
2078 AP.OutStreamer->EmitIntValue(p[Chunk--], TrailingBytes);
2080 for (; Chunk >= 0; --Chunk)
2081 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
2084 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
2085 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
2088 AP.OutStreamer->EmitIntValue(p[Chunk], TrailingBytes);
2091 // Emit the tail padding for the long double.
2092 const DataLayout &DL = AP.getDataLayout();
2093 AP.OutStreamer->EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
2094 DL.getTypeStoreSize(CFP->getType()));
2097 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
2098 const DataLayout &DL = AP.getDataLayout();
2099 unsigned BitWidth = CI->getBitWidth();
2101 // Copy the value as we may massage the layout for constants whose bit width
2102 // is not a multiple of 64-bits.
2103 APInt Realigned(CI->getValue());
2104 uint64_t ExtraBits = 0;
2105 unsigned ExtraBitsSize = BitWidth & 63;
2107 if (ExtraBitsSize) {
2108 // The bit width of the data is not a multiple of 64-bits.
2109 // The extra bits are expected to be at the end of the chunk of the memory.
2111 // * Nothing to be done, just record the extra bits to emit.
2113 // * Record the extra bits to emit.
2114 // * Realign the raw data to emit the chunks of 64-bits.
2115 if (DL.isBigEndian()) {
2116 // Basically the structure of the raw data is a chunk of 64-bits cells:
2117 // 0 1 BitWidth / 64
2118 // [chunk1][chunk2] ... [chunkN].
2119 // The most significant chunk is chunkN and it should be emitted first.
2120 // However, due to the alignment issue chunkN contains useless bits.
2121 // Realign the chunks so that they contain only useless information:
2122 // ExtraBits 0 1 (BitWidth / 64) - 1
2123 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
2124 ExtraBits = Realigned.getRawData()[0] &
2125 (((uint64_t)-1) >> (64 - ExtraBitsSize));
2126 Realigned = Realigned.lshr(ExtraBitsSize);
2128 ExtraBits = Realigned.getRawData()[BitWidth / 64];
2131 // We don't expect assemblers to support integer data directives
2132 // for more than 64 bits, so we emit the data in at most 64-bit
2133 // quantities at a time.
2134 const uint64_t *RawData = Realigned.getRawData();
2135 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
2136 uint64_t Val = DL.isBigEndian() ? RawData[e - i - 1] : RawData[i];
2137 AP.OutStreamer->EmitIntValue(Val, 8);
2140 if (ExtraBitsSize) {
2141 // Emit the extra bits after the 64-bits chunks.
2143 // Emit a directive that fills the expected size.
2144 uint64_t Size = AP.getDataLayout().getTypeAllocSize(CI->getType());
2145 Size -= (BitWidth / 64) * 8;
2146 assert(Size && Size * 8 >= ExtraBitsSize &&
2147 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
2148 == ExtraBits && "Directive too small for extra bits.");
2149 AP.OutStreamer->EmitIntValue(ExtraBits, Size);
2153 /// \brief Transform a not absolute MCExpr containing a reference to a GOT
2154 /// equivalent global, by a target specific GOT pc relative access to the
2156 static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
2157 const Constant *BaseCst,
2159 // The global @foo below illustrates a global that uses a got equivalent.
2161 // @bar = global i32 42
2162 // @gotequiv = private unnamed_addr constant i32* @bar
2163 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
2164 // i64 ptrtoint (i32* @foo to i64))
2167 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
2168 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
2171 // foo = cstexpr, where
2172 // cstexpr := <gotequiv> - "." + <cst>
2173 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
2175 // After canonicalization by evaluateAsRelocatable `ME` turns into:
2177 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
2178 // gotpcrelcst := <offset from @foo base> + <cst>
2181 if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
2183 const MCSymbolRefExpr *SymA = MV.getSymA();
2187 // Check that GOT equivalent symbol is cached.
2188 const MCSymbol *GOTEquivSym = &SymA->getSymbol();
2189 if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
2192 const GlobalValue *BaseGV = dyn_cast_or_null<GlobalValue>(BaseCst);
2196 // Check for a valid base symbol
2197 const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
2198 const MCSymbolRefExpr *SymB = MV.getSymB();
2200 if (!SymB || BaseSym != &SymB->getSymbol())
2203 // Make sure to match:
2205 // gotpcrelcst := <offset from @foo base> + <cst>
2207 // If gotpcrelcst is positive it means that we can safely fold the pc rel
2208 // displacement into the GOTPCREL. We can also can have an extra offset <cst>
2209 // if the target knows how to encode it.
2211 int64_t GOTPCRelCst = Offset + MV.getConstant();
2212 if (GOTPCRelCst < 0)
2214 if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
2217 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
2224 // .long gotequiv - "." + <cst>
2226 // is replaced by the target specific equivalent to:
2231 // .long bar@GOTPCREL+<gotpcrelcst>
2233 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
2234 const GlobalVariable *GV = Result.first;
2235 int NumUses = (int)Result.second;
2236 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
2237 const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
2238 *ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(
2239 FinalSym, MV, Offset, AP.MMI, *AP.OutStreamer);
2241 // Update GOT equivalent usage information
2244 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
2247 static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *CV,
2248 AsmPrinter &AP, const Constant *BaseCV,
2250 uint64_t Size = DL.getTypeAllocSize(CV->getType());
2252 // Globals with sub-elements such as combinations of arrays and structs
2253 // are handled recursively by emitGlobalConstantImpl. Keep track of the
2254 // constant symbol base and the current position with BaseCV and Offset.
2255 if (!BaseCV && CV->hasOneUse())
2256 BaseCV = dyn_cast<Constant>(CV->user_back());
2258 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
2259 return AP.OutStreamer->EmitZeros(Size);
2261 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
2268 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
2269 CI->getZExtValue());
2270 AP.OutStreamer->EmitIntValue(CI->getZExtValue(), Size);
2273 emitGlobalConstantLargeInt(CI, AP);
2278 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
2279 return emitGlobalConstantFP(CFP, AP);
2281 if (isa<ConstantPointerNull>(CV)) {
2282 AP.OutStreamer->EmitIntValue(0, Size);
2286 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
2287 return emitGlobalConstantDataSequential(DL, CDS, AP);
2289 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2290 return emitGlobalConstantArray(DL, CVA, AP, BaseCV, Offset);
2292 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2293 return emitGlobalConstantStruct(DL, CVS, AP, BaseCV, Offset);
2295 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2296 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2298 if (CE->getOpcode() == Instruction::BitCast)
2299 return emitGlobalConstantImpl(DL, CE->getOperand(0), AP);
2302 // If the constant expression's size is greater than 64-bits, then we have
2303 // to emit the value in chunks. Try to constant fold the value and emit it
2305 Constant *New = ConstantFoldConstantExpression(CE, DL);
2306 if (New && New != CE)
2307 return emitGlobalConstantImpl(DL, New, AP);
2311 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2312 return emitGlobalConstantVector(DL, V, AP);
2314 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2315 // thread the streamer with EmitValue.
2316 const MCExpr *ME = AP.lowerConstant(CV);
2318 // Since lowerConstant already folded and got rid of all IR pointer and
2319 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
2321 if (AP.getObjFileLowering().supportIndirectSymViaGOTPCRel())
2322 handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
2324 AP.OutStreamer->EmitValue(ME, Size);
2327 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2328 void AsmPrinter::EmitGlobalConstant(const DataLayout &DL, const Constant *CV) {
2329 uint64_t Size = DL.getTypeAllocSize(CV->getType());
2331 emitGlobalConstantImpl(DL, CV, *this);
2332 else if (MAI->hasSubsectionsViaSymbols()) {
2333 // If the global has zero size, emit a single byte so that two labels don't
2334 // look like they are at the same location.
2335 OutStreamer->EmitIntValue(0, 1);
2339 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2340 // Target doesn't support this yet!
2341 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2344 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2346 OS << '+' << Offset;
2347 else if (Offset < 0)
2351 //===----------------------------------------------------------------------===//
2352 // Symbol Lowering Routines.
2353 //===----------------------------------------------------------------------===//
2355 MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name) const {
2356 return OutContext.createTempSymbol(Name, true);
2359 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2360 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2363 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2364 return MMI->getAddrLabelSymbol(BB);
2367 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2368 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2369 const DataLayout &DL = getDataLayout();
2370 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
2371 "CPI" + Twine(getFunctionNumber()) + "_" +
2375 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2376 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2377 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2380 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2381 /// FIXME: privatize to AsmPrinter.
2382 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2383 const DataLayout &DL = getDataLayout();
2384 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
2385 Twine(getFunctionNumber()) + "_" +
2386 Twine(UID) + "_set_" + Twine(MBBID));
2389 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2390 StringRef Suffix) const {
2391 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2395 /// Return the MCSymbol for the specified ExternalSymbol.
2396 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2397 SmallString<60> NameStr;
2398 Mangler::getNameWithPrefix(NameStr, Sym, getDataLayout());
2399 return OutContext.getOrCreateSymbol(NameStr);
2404 /// PrintParentLoopComment - Print comments about parent loops of this one.
2405 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2406 unsigned FunctionNumber) {
2408 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2409 OS.indent(Loop->getLoopDepth()*2)
2410 << "Parent Loop BB" << FunctionNumber << "_"
2411 << Loop->getHeader()->getNumber()
2412 << " Depth=" << Loop->getLoopDepth() << '\n';
2416 /// PrintChildLoopComment - Print comments about child loops within
2417 /// the loop for this basic block, with nesting.
2418 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2419 unsigned FunctionNumber) {
2420 // Add child loop information
2421 for (const MachineLoop *CL : *Loop) {
2422 OS.indent(CL->getLoopDepth()*2)
2423 << "Child Loop BB" << FunctionNumber << "_"
2424 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2426 PrintChildLoopComment(OS, CL, FunctionNumber);
2430 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2431 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2432 const MachineLoopInfo *LI,
2433 const AsmPrinter &AP) {
2434 // Add loop depth information
2435 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2438 MachineBasicBlock *Header = Loop->getHeader();
2439 assert(Header && "No header for loop");
2441 // If this block is not a loop header, just print out what is the loop header
2443 if (Header != &MBB) {
2444 AP.OutStreamer->AddComment(" in Loop: Header=BB" +
2445 Twine(AP.getFunctionNumber())+"_" +
2446 Twine(Loop->getHeader()->getNumber())+
2447 " Depth="+Twine(Loop->getLoopDepth()));
2451 // Otherwise, it is a loop header. Print out information about child and
2453 raw_ostream &OS = AP.OutStreamer->GetCommentOS();
2455 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2458 OS.indent(Loop->getLoopDepth()*2-2);
2463 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2465 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2469 /// EmitBasicBlockStart - This method prints the label for the specified
2470 /// MachineBasicBlock, an alignment (if present) and a comment describing
2471 /// it if appropriate.
2472 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2473 // End the previous funclet and start a new one.
2474 if (MBB.isEHFuncletEntry()) {
2475 for (const HandlerInfo &HI : Handlers) {
2476 HI.Handler->endFunclet();
2477 HI.Handler->beginFunclet(MBB);
2481 // Emit an alignment directive for this block, if needed.
2482 if (unsigned Align = MBB.getAlignment())
2483 EmitAlignment(Align);
2485 // If the block has its address taken, emit any labels that were used to
2486 // reference the block. It is possible that there is more than one label
2487 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2488 // the references were generated.
2489 if (MBB.hasAddressTaken()) {
2490 const BasicBlock *BB = MBB.getBasicBlock();
2492 OutStreamer->AddComment("Block address taken");
2494 // MBBs can have their address taken as part of CodeGen without having
2495 // their corresponding BB's address taken in IR
2496 if (BB->hasAddressTaken())
2497 for (MCSymbol *Sym : MMI->getAddrLabelSymbolToEmit(BB))
2498 OutStreamer->EmitLabel(Sym);
2501 // Print some verbose block comments.
2503 if (const BasicBlock *BB = MBB.getBasicBlock())
2505 OutStreamer->AddComment("%" + BB->getName());
2506 emitBasicBlockLoopComments(MBB, LI, *this);
2509 // Print the main label for the block.
2510 if (MBB.pred_empty() ||
2511 (isBlockOnlyReachableByFallthrough(&MBB) && !MBB.isEHFuncletEntry())) {
2513 // NOTE: Want this comment at start of line, don't emit with AddComment.
2514 OutStreamer->emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2517 OutStreamer->EmitLabel(MBB.getSymbol());
2521 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2522 bool IsDefinition) const {
2523 MCSymbolAttr Attr = MCSA_Invalid;
2525 switch (Visibility) {
2527 case GlobalValue::HiddenVisibility:
2529 Attr = MAI->getHiddenVisibilityAttr();
2531 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2533 case GlobalValue::ProtectedVisibility:
2534 Attr = MAI->getProtectedVisibilityAttr();
2538 if (Attr != MCSA_Invalid)
2539 OutStreamer->EmitSymbolAttribute(Sym, Attr);
2542 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2543 /// exactly one predecessor and the control transfer mechanism between
2544 /// the predecessor and this block is a fall-through.
2546 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2547 // If this is a landing pad, it isn't a fall through. If it has no preds,
2548 // then nothing falls through to it.
2549 if (MBB->isEHPad() || MBB->pred_empty())
2552 // If there isn't exactly one predecessor, it can't be a fall through.
2553 if (MBB->pred_size() > 1)
2556 // The predecessor has to be immediately before this block.
2557 MachineBasicBlock *Pred = *MBB->pred_begin();
2558 if (!Pred->isLayoutSuccessor(MBB))
2561 // If the block is completely empty, then it definitely does fall through.
2565 // Check the terminators in the previous blocks
2566 for (const auto &MI : Pred->terminators()) {
2567 // If it is not a simple branch, we are in a table somewhere.
2568 if (!MI.isBranch() || MI.isIndirectBranch())
2571 // If we are the operands of one of the branches, this is not a fall
2572 // through. Note that targets with delay slots will usually bundle
2573 // terminators with the delay slot instruction.
2574 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2577 if (OP->isMBB() && OP->getMBB() == MBB)
2587 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2588 if (!S.usesMetadata())
2591 assert(!S.useStatepoints() && "statepoints do not currently support custom"
2592 " stackmap formats, please see the documentation for a description of"
2593 " the default format. If you really need a custom serialized format,"
2594 " please file a bug");
2596 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2597 gcp_map_type::iterator GCPI = GCMap.find(&S);
2598 if (GCPI != GCMap.end())
2599 return GCPI->second.get();
2601 const char *Name = S.getName().c_str();
2603 for (GCMetadataPrinterRegistry::iterator
2604 I = GCMetadataPrinterRegistry::begin(),
2605 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2606 if (strcmp(Name, I->getName()) == 0) {
2607 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2609 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2610 return IterBool.first->second.get();
2613 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2616 /// Pin vtable to this file.
2617 AsmPrinterHandler::~AsmPrinterHandler() {}
2619 void AsmPrinterHandler::markFunctionEnd() {}