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", *STI, TM.Options.MCOptions);
239 OutStreamer->AddComment("End of file scope inline assembly");
240 OutStreamer->AddBlankLine();
243 if (MAI->doesSupportDebugInformation()) {
244 bool EmitCodeView = MMI->getModule()->getCodeViewFlag();
245 if (EmitCodeView && TM.getTargetTriple().isKnownWindowsMSVCEnvironment()) {
246 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this),
248 CodeViewLineTablesGroupName));
250 if (!EmitCodeView || MMI->getModule()->getDwarfVersion()) {
251 DD = new DwarfDebug(this, &M);
252 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
256 EHStreamer *ES = nullptr;
257 switch (MAI->getExceptionHandlingType()) {
258 case ExceptionHandling::None:
260 case ExceptionHandling::SjLj:
261 case ExceptionHandling::DwarfCFI:
262 ES = new DwarfCFIException(this);
264 case ExceptionHandling::ARM:
265 ES = new ARMException(this);
267 case ExceptionHandling::WinEH:
268 switch (MAI->getWinEHEncodingType()) {
269 default: llvm_unreachable("unsupported unwinding information encoding");
270 case WinEH::EncodingType::Invalid:
272 case WinEH::EncodingType::X86:
273 case WinEH::EncodingType::Itanium:
274 ES = new WinException(this);
280 Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
284 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
285 if (!MAI.hasWeakDefCanBeHiddenDirective())
288 return canBeOmittedFromSymbolTable(GV);
291 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
292 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
294 case GlobalValue::CommonLinkage:
295 case GlobalValue::LinkOnceAnyLinkage:
296 case GlobalValue::LinkOnceODRLinkage:
297 case GlobalValue::WeakAnyLinkage:
298 case GlobalValue::WeakODRLinkage:
299 if (MAI->hasWeakDefDirective()) {
301 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
303 if (!canBeHidden(GV, *MAI))
304 // .weak_definition _foo
305 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
307 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
308 } else if (MAI->hasLinkOnceDirective()) {
310 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
311 //NOTE: linkonce is handled by the section the symbol was assigned to.
314 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Weak);
317 case GlobalValue::AppendingLinkage:
318 // FIXME: appending linkage variables should go into a section of
319 // their name or something. For now, just emit them as external.
320 case GlobalValue::ExternalLinkage:
321 // If external or appending, declare as a global symbol.
323 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
325 case GlobalValue::PrivateLinkage:
326 case GlobalValue::InternalLinkage:
328 case GlobalValue::AvailableExternallyLinkage:
329 llvm_unreachable("Should never emit this");
330 case GlobalValue::ExternalWeakLinkage:
331 llvm_unreachable("Don't know how to emit these");
333 llvm_unreachable("Unknown linkage type!");
336 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
337 const GlobalValue *GV) const {
338 TM.getNameWithPrefix(Name, GV, *Mang);
341 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
342 return TM.getSymbol(GV, *Mang);
345 static MCSymbol *getOrCreateEmuTLSControlSym(MCSymbol *GVSym, MCContext &C) {
346 return C.getOrCreateSymbol(Twine("__emutls_v.") + GVSym->getName());
349 static MCSymbol *getOrCreateEmuTLSInitSym(MCSymbol *GVSym, MCContext &C) {
350 return C.getOrCreateSymbol(Twine("__emutls_t.") + GVSym->getName());
353 /// EmitEmulatedTLSControlVariable - Emit the control variable for an emulated TLS variable.
354 void AsmPrinter::EmitEmulatedTLSControlVariable(const GlobalVariable *GV,
355 MCSymbol *EmittedSym,
356 bool AllZeroInitValue) {
357 // If there is init value, use .data.rel.local section;
358 // otherwise use the .data section.
359 MCSection *TLSVarSection = const_cast<MCSection*>(
360 (GV->hasInitializer() && !AllZeroInitValue)
361 ? getObjFileLowering().getDataRelLocalSection()
362 : getObjFileLowering().getDataSection());
363 OutStreamer->SwitchSection(TLSVarSection);
364 MCSymbol *GVSym = getSymbol(GV);
365 EmitLinkage(GV, EmittedSym); // same linkage as GV
366 const DataLayout &DL = GV->getParent()->getDataLayout();
367 uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
368 unsigned AlignLog = getGVAlignmentLog2(GV, DL);
369 unsigned WordSize = DL.getPointerSize();
370 unsigned Alignment = DL.getPointerABIAlignment();
371 EmitAlignment(Log2_32(Alignment));
372 OutStreamer->EmitLabel(EmittedSym);
373 OutStreamer->EmitIntValue(Size, WordSize);
374 OutStreamer->EmitIntValue((1 << AlignLog), WordSize);
375 OutStreamer->EmitIntValue(0, WordSize);
376 if (GV->hasInitializer() && !AllZeroInitValue) {
377 OutStreamer->EmitSymbolValue(
378 getOrCreateEmuTLSInitSym(GVSym, OutContext), WordSize);
380 OutStreamer->EmitIntValue(0, WordSize);
381 if (MAI->hasDotTypeDotSizeDirective())
382 OutStreamer->emitELFSize(cast<MCSymbolELF>(EmittedSym),
383 MCConstantExpr::create(4 * WordSize, OutContext));
384 OutStreamer->AddBlankLine(); // End of the __emutls_v.* variable.
387 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
388 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
390 GV->getThreadLocalMode() != llvm::GlobalVariable::NotThreadLocal &&
391 TM.Options.EmulatedTLS;
392 assert((!IsEmuTLSVar || getObjFileLowering().getDataRelLocalSection()) &&
393 "Need relocatable local section for emulated TLS variables");
394 assert(!(IsEmuTLSVar && GV->hasCommonLinkage()) &&
395 "No emulated TLS variables in the common section");
397 if (GV->hasInitializer()) {
398 // Check to see if this is a special global used by LLVM, if so, emit it.
399 if (EmitSpecialLLVMGlobal(GV))
402 // Skip the emission of global equivalents. The symbol can be emitted later
403 // on by emitGlobalGOTEquivs in case it turns out to be needed.
404 if (GlobalGOTEquivs.count(getSymbol(GV)))
407 if (isVerbose() && !IsEmuTLSVar) {
408 // When printing the control variable __emutls_v.*,
409 // we don't need to print the original TLS variable name.
410 GV->printAsOperand(OutStreamer->GetCommentOS(),
411 /*PrintType=*/false, GV->getParent());
412 OutStreamer->GetCommentOS() << '\n';
416 MCSymbol *GVSym = getSymbol(GV);
417 MCSymbol *EmittedSym = IsEmuTLSVar ?
418 getOrCreateEmuTLSControlSym(GVSym, OutContext) : GVSym;
419 // getOrCreateEmuTLSControlSym only creates the symbol with name and default attributes.
420 // GV's or GVSym's attributes will be used for the EmittedSym.
422 EmitVisibility(EmittedSym, GV->getVisibility(), !GV->isDeclaration());
424 if (!GV->hasInitializer()) // External globals require no extra code.
427 GVSym->redefineIfPossible();
428 if (GVSym->isDefined() || GVSym->isVariable())
429 report_fatal_error("symbol '" + Twine(GVSym->getName()) +
430 "' is already defined");
432 if (MAI->hasDotTypeDotSizeDirective())
433 OutStreamer->EmitSymbolAttribute(EmittedSym, MCSA_ELF_TypeObject);
435 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
437 const DataLayout &DL = GV->getParent()->getDataLayout();
438 uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
440 // If the alignment is specified, we *must* obey it. Overaligning a global
441 // with a specified alignment is a prompt way to break globals emitted to
442 // sections and expected to be contiguous (e.g. ObjC metadata).
443 unsigned AlignLog = getGVAlignmentLog2(GV, DL);
445 bool AllZeroInitValue = false;
446 const Constant *InitValue = GV->getInitializer();
447 if (isa<ConstantAggregateZero>(InitValue))
448 AllZeroInitValue = true;
450 const ConstantInt *InitIntValue = dyn_cast<ConstantInt>(InitValue);
451 if (InitIntValue && InitIntValue->isZero())
452 AllZeroInitValue = true;
455 EmitEmulatedTLSControlVariable(GV, EmittedSym, AllZeroInitValue);
457 for (const HandlerInfo &HI : Handlers) {
458 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
459 HI.Handler->setSymbolSize(GVSym, Size);
462 // Handle common and BSS local symbols (.lcomm).
463 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
464 assert(!(IsEmuTLSVar && GVKind.isCommon()) &&
465 "No emulated TLS variables in the common section");
466 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
467 unsigned Align = 1 << AlignLog;
469 // Handle common symbols.
470 if (GVKind.isCommon()) {
471 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
475 OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
479 // Handle local BSS symbols.
480 if (MAI->hasMachoZeroFillDirective()) {
481 MCSection *TheSection =
482 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
483 // .zerofill __DATA, __bss, _foo, 400, 5
484 OutStreamer->EmitZerofill(TheSection, GVSym, Size, Align);
488 // Use .lcomm only if it supports user-specified alignment.
489 // Otherwise, while it would still be correct to use .lcomm in some
490 // cases (e.g. when Align == 1), the external assembler might enfore
491 // some -unknown- default alignment behavior, which could cause
492 // spurious differences between external and integrated assembler.
493 // Prefer to simply fall back to .local / .comm in this case.
494 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
496 OutStreamer->EmitLocalCommonSymbol(GVSym, Size, Align);
500 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
504 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Local);
506 OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
510 if (IsEmuTLSVar && AllZeroInitValue)
511 return; // No need of initialization values.
513 MCSymbol *EmittedInitSym = IsEmuTLSVar ?
514 getOrCreateEmuTLSInitSym(GVSym, OutContext) : GVSym;
515 // getOrCreateEmuTLSInitSym only creates the symbol with name and default attributes.
516 // GV's or GVSym's attributes will be used for the EmittedInitSym.
518 MCSection *TheSection = IsEmuTLSVar ?
519 getObjFileLowering().getReadOnlySection() :
520 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
522 // Handle the zerofill directive on darwin, which is a special form of BSS
524 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective() && !IsEmuTLSVar) {
525 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
528 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
529 // .zerofill __DATA, __common, _foo, 400, 5
530 OutStreamer->EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
534 // Handle thread local data for mach-o which requires us to output an
535 // additional structure of data and mangle the original symbol so that we
536 // can reference it later.
538 // TODO: This should become an "emit thread local global" method on TLOF.
539 // All of this macho specific stuff should be sunk down into TLOFMachO and
540 // stuff like "TLSExtraDataSection" should no longer be part of the parent
541 // TLOF class. This will also make it more obvious that stuff like
542 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
544 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective() && !IsEmuTLSVar) {
545 // Emit the .tbss symbol
547 OutContext.getOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
549 if (GVKind.isThreadBSS()) {
550 TheSection = getObjFileLowering().getTLSBSSSection();
551 OutStreamer->EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
552 } else if (GVKind.isThreadData()) {
553 OutStreamer->SwitchSection(TheSection);
555 EmitAlignment(AlignLog, GV);
556 OutStreamer->EmitLabel(MangSym);
558 EmitGlobalConstant(GV->getParent()->getDataLayout(),
559 GV->getInitializer());
562 OutStreamer->AddBlankLine();
564 // Emit the variable struct for the runtime.
565 MCSection *TLVSect = getObjFileLowering().getTLSExtraDataSection();
567 OutStreamer->SwitchSection(TLVSect);
568 // Emit the linkage here.
569 EmitLinkage(GV, GVSym);
570 OutStreamer->EmitLabel(GVSym);
572 // Three pointers in size:
573 // - __tlv_bootstrap - used to make sure support exists
574 // - spare pointer, used when mapped by the runtime
575 // - pointer to mangled symbol above with initializer
576 unsigned PtrSize = DL.getPointerTypeSize(GV->getType());
577 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
579 OutStreamer->EmitIntValue(0, PtrSize);
580 OutStreamer->EmitSymbolValue(MangSym, PtrSize);
582 OutStreamer->AddBlankLine();
586 OutStreamer->SwitchSection(TheSection);
588 // emutls_t.* symbols are only used in the current compilation unit.
590 EmitLinkage(GV, EmittedInitSym);
591 EmitAlignment(AlignLog, GV);
593 OutStreamer->EmitLabel(EmittedInitSym);
595 EmitGlobalConstant(GV->getParent()->getDataLayout(), GV->getInitializer());
597 if (MAI->hasDotTypeDotSizeDirective())
599 OutStreamer->emitELFSize(cast<MCSymbolELF>(EmittedInitSym),
600 MCConstantExpr::create(Size, OutContext));
602 OutStreamer->AddBlankLine();
605 /// EmitFunctionHeader - This method emits the header for the current
607 void AsmPrinter::EmitFunctionHeader() {
608 // Print out constants referenced by the function
611 // Print the 'header' of function.
612 const Function *F = MF->getFunction();
614 OutStreamer->SwitchSection(
615 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
616 EmitVisibility(CurrentFnSym, F->getVisibility());
618 EmitLinkage(F, CurrentFnSym);
619 if (MAI->hasFunctionAlignment())
620 EmitAlignment(MF->getAlignment(), F);
622 if (MAI->hasDotTypeDotSizeDirective())
623 OutStreamer->EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
626 F->printAsOperand(OutStreamer->GetCommentOS(),
627 /*PrintType=*/false, F->getParent());
628 OutStreamer->GetCommentOS() << '\n';
631 // Emit the prefix data.
632 if (F->hasPrefixData())
633 EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrefixData());
635 // Emit the CurrentFnSym. This is a virtual function to allow targets to
636 // do their wild and crazy things as required.
637 EmitFunctionEntryLabel();
639 // If the function had address-taken blocks that got deleted, then we have
640 // references to the dangling symbols. Emit them at the start of the function
641 // so that we don't get references to undefined symbols.
642 std::vector<MCSymbol*> DeadBlockSyms;
643 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
644 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
645 OutStreamer->AddComment("Address taken block that was later removed");
646 OutStreamer->EmitLabel(DeadBlockSyms[i]);
649 if (CurrentFnBegin) {
650 if (MAI->useAssignmentForEHBegin()) {
651 MCSymbol *CurPos = OutContext.createTempSymbol();
652 OutStreamer->EmitLabel(CurPos);
653 OutStreamer->EmitAssignment(CurrentFnBegin,
654 MCSymbolRefExpr::create(CurPos, OutContext));
656 OutStreamer->EmitLabel(CurrentFnBegin);
660 // Emit pre-function debug and/or EH information.
661 for (const HandlerInfo &HI : Handlers) {
662 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
663 HI.Handler->beginFunction(MF);
666 // Emit the prologue data.
667 if (F->hasPrologueData())
668 EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrologueData());
671 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
672 /// function. This can be overridden by targets as required to do custom stuff.
673 void AsmPrinter::EmitFunctionEntryLabel() {
674 CurrentFnSym->redefineIfPossible();
676 // The function label could have already been emitted if two symbols end up
677 // conflicting due to asm renaming. Detect this and emit an error.
678 if (CurrentFnSym->isVariable())
679 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
680 "' is a protected alias");
681 if (CurrentFnSym->isDefined())
682 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
683 "' label emitted multiple times to assembly file");
685 return OutStreamer->EmitLabel(CurrentFnSym);
688 /// emitComments - Pretty-print comments for instructions.
689 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
690 const MachineFunction *MF = MI.getParent()->getParent();
691 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
693 // Check for spills and reloads
696 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
698 // We assume a single instruction only has a spill or reload, not
700 const MachineMemOperand *MMO;
701 if (TII->isLoadFromStackSlotPostFE(&MI, FI)) {
702 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
703 MMO = *MI.memoperands_begin();
704 CommentOS << MMO->getSize() << "-byte Reload\n";
706 } else if (TII->hasLoadFromStackSlot(&MI, MMO, FI)) {
707 if (FrameInfo->isSpillSlotObjectIndex(FI))
708 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
709 } else if (TII->isStoreToStackSlotPostFE(&MI, FI)) {
710 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
711 MMO = *MI.memoperands_begin();
712 CommentOS << MMO->getSize() << "-byte Spill\n";
714 } else if (TII->hasStoreToStackSlot(&MI, MMO, FI)) {
715 if (FrameInfo->isSpillSlotObjectIndex(FI))
716 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
719 // Check for spill-induced copies
720 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
721 CommentOS << " Reload Reuse\n";
724 /// emitImplicitDef - This method emits the specified machine instruction
725 /// that is an implicit def.
726 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
727 unsigned RegNo = MI->getOperand(0).getReg();
728 OutStreamer->AddComment(Twine("implicit-def: ") +
729 MMI->getContext().getRegisterInfo()->getName(RegNo));
730 OutStreamer->AddBlankLine();
733 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
734 std::string Str = "kill:";
735 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
736 const MachineOperand &Op = MI->getOperand(i);
737 assert(Op.isReg() && "KILL instruction must have only register operands");
739 Str += AP.MMI->getContext().getRegisterInfo()->getName(Op.getReg());
740 Str += (Op.isDef() ? "<def>" : "<kill>");
742 AP.OutStreamer->AddComment(Str);
743 AP.OutStreamer->AddBlankLine();
746 /// emitDebugValueComment - This method handles the target-independent form
747 /// of DBG_VALUE, returning true if it was able to do so. A false return
748 /// means the target will need to handle MI in EmitInstruction.
749 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
750 // This code handles only the 4-operand target-independent form.
751 if (MI->getNumOperands() != 4)
754 SmallString<128> Str;
755 raw_svector_ostream OS(Str);
756 OS << "DEBUG_VALUE: ";
758 const DILocalVariable *V = MI->getDebugVariable();
759 if (auto *SP = dyn_cast<DISubprogram>(V->getScope())) {
760 StringRef Name = SP->getDisplayName();
766 const DIExpression *Expr = MI->getDebugExpression();
767 if (Expr->isBitPiece())
768 OS << " [bit_piece offset=" << Expr->getBitPieceOffset()
769 << " size=" << Expr->getBitPieceSize() << "]";
772 // The second operand is only an offset if it's an immediate.
773 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
774 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
776 // Register or immediate value. Register 0 means undef.
777 if (MI->getOperand(0).isFPImm()) {
778 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
779 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
780 OS << (double)APF.convertToFloat();
781 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
782 OS << APF.convertToDouble();
784 // There is no good way to print long double. Convert a copy to
785 // double. Ah well, it's only a comment.
787 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
789 OS << "(long double) " << APF.convertToDouble();
791 } else if (MI->getOperand(0).isImm()) {
792 OS << MI->getOperand(0).getImm();
793 } else if (MI->getOperand(0).isCImm()) {
794 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
797 if (MI->getOperand(0).isReg()) {
798 Reg = MI->getOperand(0).getReg();
800 assert(MI->getOperand(0).isFI() && "Unknown operand type");
801 const TargetFrameLowering *TFI = AP.MF->getSubtarget().getFrameLowering();
802 Offset += TFI->getFrameIndexReference(*AP.MF,
803 MI->getOperand(0).getIndex(), Reg);
807 // Suppress offset, it is not meaningful here.
809 // NOTE: Want this comment at start of line, don't emit with AddComment.
810 AP.OutStreamer->emitRawComment(OS.str());
815 OS << AP.MMI->getContext().getRegisterInfo()->getName(Reg);
819 OS << '+' << Offset << ']';
821 // NOTE: Want this comment at start of line, don't emit with AddComment.
822 AP.OutStreamer->emitRawComment(OS.str());
826 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
827 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
828 MF->getFunction()->needsUnwindTableEntry())
831 if (MMI->hasDebugInfo())
837 bool AsmPrinter::needsSEHMoves() {
838 return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
841 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
842 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
843 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
844 ExceptionHandlingType != ExceptionHandling::ARM)
847 if (needsCFIMoves() == CFI_M_None)
850 const MachineModuleInfo &MMI = MF->getMMI();
851 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
852 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
853 const MCCFIInstruction &CFI = Instrs[CFIIndex];
854 emitCFIInstruction(CFI);
857 void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
858 // The operands are the MCSymbol and the frame offset of the allocation.
859 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
860 int FrameOffset = MI.getOperand(1).getImm();
862 // Emit a symbol assignment.
863 OutStreamer->EmitAssignment(FrameAllocSym,
864 MCConstantExpr::create(FrameOffset, OutContext));
867 /// EmitFunctionBody - This method emits the body and trailer for a
869 void AsmPrinter::EmitFunctionBody() {
870 EmitFunctionHeader();
872 // Emit target-specific gunk before the function body.
873 EmitFunctionBodyStart();
875 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
877 // Print out code for the function.
878 bool HasAnyRealCode = false;
879 for (auto &MBB : *MF) {
880 // Print a label for the basic block.
881 EmitBasicBlockStart(MBB);
882 for (auto &MI : MBB) {
884 // Print the assembly for the instruction.
885 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
886 !MI.isDebugValue()) {
887 HasAnyRealCode = true;
891 if (ShouldPrintDebugScopes) {
892 for (const HandlerInfo &HI : Handlers) {
893 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
894 TimePassesIsEnabled);
895 HI.Handler->beginInstruction(&MI);
900 emitComments(MI, OutStreamer->GetCommentOS());
902 switch (MI.getOpcode()) {
903 case TargetOpcode::CFI_INSTRUCTION:
904 emitCFIInstruction(MI);
907 case TargetOpcode::LOCAL_ESCAPE:
911 case TargetOpcode::EH_LABEL:
912 case TargetOpcode::GC_LABEL:
913 OutStreamer->EmitLabel(MI.getOperand(0).getMCSymbol());
915 case TargetOpcode::INLINEASM:
918 case TargetOpcode::DBG_VALUE:
920 if (!emitDebugValueComment(&MI, *this))
921 EmitInstruction(&MI);
924 case TargetOpcode::IMPLICIT_DEF:
925 if (isVerbose()) emitImplicitDef(&MI);
927 case TargetOpcode::KILL:
928 if (isVerbose()) emitKill(&MI, *this);
931 EmitInstruction(&MI);
935 if (ShouldPrintDebugScopes) {
936 for (const HandlerInfo &HI : Handlers) {
937 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
938 TimePassesIsEnabled);
939 HI.Handler->endInstruction();
944 EmitBasicBlockEnd(MBB);
947 // If the function is empty and the object file uses .subsections_via_symbols,
948 // then we need to emit *something* to the function body to prevent the
949 // labels from collapsing together. Just emit a noop.
950 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
952 MF->getSubtarget().getInstrInfo()->getNoopForMachoTarget(Noop);
953 OutStreamer->AddComment("avoids zero-length function");
955 // Targets can opt-out of emitting the noop here by leaving the opcode
957 if (Noop.getOpcode())
958 OutStreamer->EmitInstruction(Noop, getSubtargetInfo());
961 const Function *F = MF->getFunction();
962 for (const auto &BB : *F) {
963 if (!BB.hasAddressTaken())
965 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
966 if (Sym->isDefined())
968 OutStreamer->AddComment("Address of block that was removed by CodeGen");
969 OutStreamer->EmitLabel(Sym);
972 // Emit target-specific gunk after the function body.
973 EmitFunctionBodyEnd();
975 if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
976 MMI->hasEHFunclets() || MAI->hasDotTypeDotSizeDirective()) {
977 // Create a symbol for the end of function.
978 CurrentFnEnd = createTempSymbol("func_end");
979 OutStreamer->EmitLabel(CurrentFnEnd);
982 // If the target wants a .size directive for the size of the function, emit
984 if (MAI->hasDotTypeDotSizeDirective()) {
985 // We can get the size as difference between the function label and the
987 const MCExpr *SizeExp = MCBinaryExpr::createSub(
988 MCSymbolRefExpr::create(CurrentFnEnd, OutContext),
989 MCSymbolRefExpr::create(CurrentFnSymForSize, OutContext), OutContext);
990 if (auto Sym = dyn_cast<MCSymbolELF>(CurrentFnSym))
991 OutStreamer->emitELFSize(Sym, SizeExp);
994 for (const HandlerInfo &HI : Handlers) {
995 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
996 HI.Handler->markFunctionEnd();
999 // Print out jump tables referenced by the function.
1000 EmitJumpTableInfo();
1002 // Emit post-function debug and/or EH information.
1003 for (const HandlerInfo &HI : Handlers) {
1004 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
1005 HI.Handler->endFunction(MF);
1009 OutStreamer->AddBlankLine();
1012 /// \brief Compute the number of Global Variables that uses a Constant.
1013 static unsigned getNumGlobalVariableUses(const Constant *C) {
1017 if (isa<GlobalVariable>(C))
1020 unsigned NumUses = 0;
1021 for (auto *CU : C->users())
1022 NumUses += getNumGlobalVariableUses(dyn_cast<Constant>(CU));
1027 /// \brief Only consider global GOT equivalents if at least one user is a
1028 /// cstexpr inside an initializer of another global variables. Also, don't
1029 /// handle cstexpr inside instructions. During global variable emission,
1030 /// candidates are skipped and are emitted later in case at least one cstexpr
1031 /// isn't replaced by a PC relative GOT entry access.
1032 static bool isGOTEquivalentCandidate(const GlobalVariable *GV,
1033 unsigned &NumGOTEquivUsers) {
1034 // Global GOT equivalents are unnamed private globals with a constant
1035 // pointer initializer to another global symbol. They must point to a
1036 // GlobalVariable or Function, i.e., as GlobalValue.
1037 if (!GV->hasUnnamedAddr() || !GV->hasInitializer() || !GV->isConstant() ||
1038 !GV->isDiscardableIfUnused() || !dyn_cast<GlobalValue>(GV->getOperand(0)))
1041 // To be a got equivalent, at least one of its users need to be a constant
1042 // expression used by another global variable.
1043 for (auto *U : GV->users())
1044 NumGOTEquivUsers += getNumGlobalVariableUses(dyn_cast<Constant>(U));
1046 return NumGOTEquivUsers > 0;
1049 /// \brief Unnamed constant global variables solely contaning a pointer to
1050 /// another globals variable is equivalent to a GOT table entry; it contains the
1051 /// the address of another symbol. Optimize it and replace accesses to these
1052 /// "GOT equivalents" by using the GOT entry for the final global instead.
1053 /// Compute GOT equivalent candidates among all global variables to avoid
1054 /// emitting them if possible later on, after it use is replaced by a GOT entry
1056 void AsmPrinter::computeGlobalGOTEquivs(Module &M) {
1057 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
1060 for (const auto &G : M.globals()) {
1061 unsigned NumGOTEquivUsers = 0;
1062 if (!isGOTEquivalentCandidate(&G, NumGOTEquivUsers))
1065 const MCSymbol *GOTEquivSym = getSymbol(&G);
1066 GlobalGOTEquivs[GOTEquivSym] = std::make_pair(&G, NumGOTEquivUsers);
1070 /// \brief Constant expressions using GOT equivalent globals may not be eligible
1071 /// for PC relative GOT entry conversion, in such cases we need to emit such
1072 /// globals we previously omitted in EmitGlobalVariable.
1073 void AsmPrinter::emitGlobalGOTEquivs() {
1074 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
1077 SmallVector<const GlobalVariable *, 8> FailedCandidates;
1078 for (auto &I : GlobalGOTEquivs) {
1079 const GlobalVariable *GV = I.second.first;
1080 unsigned Cnt = I.second.second;
1082 FailedCandidates.push_back(GV);
1084 GlobalGOTEquivs.clear();
1086 for (auto *GV : FailedCandidates)
1087 EmitGlobalVariable(GV);
1090 bool AsmPrinter::doFinalization(Module &M) {
1091 // Set the MachineFunction to nullptr so that we can catch attempted
1092 // accesses to MF specific features at the module level and so that
1093 // we can conditionalize accesses based on whether or not it is nullptr.
1096 // Gather all GOT equivalent globals in the module. We really need two
1097 // passes over the globals: one to compute and another to avoid its emission
1098 // in EmitGlobalVariable, otherwise we would not be able to handle cases
1099 // where the got equivalent shows up before its use.
1100 computeGlobalGOTEquivs(M);
1102 // Emit global variables.
1103 for (const auto &G : M.globals())
1104 EmitGlobalVariable(&G);
1106 // Emit remaining GOT equivalent globals.
1107 emitGlobalGOTEquivs();
1109 // Emit visibility info for declarations
1110 for (const Function &F : M) {
1111 if (!F.isDeclarationForLinker())
1113 GlobalValue::VisibilityTypes V = F.getVisibility();
1114 if (V == GlobalValue::DefaultVisibility)
1117 MCSymbol *Name = getSymbol(&F);
1118 EmitVisibility(Name, V, false);
1121 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1123 // Emit module flags.
1124 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
1125 M.getModuleFlagsMetadata(ModuleFlags);
1126 if (!ModuleFlags.empty())
1127 TLOF.emitModuleFlags(*OutStreamer, ModuleFlags, *Mang, TM);
1129 if (TM.getTargetTriple().isOSBinFormatELF()) {
1130 MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
1132 // Output stubs for external and common global variables.
1133 MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
1134 if (!Stubs.empty()) {
1135 OutStreamer->SwitchSection(TLOF.getDataRelSection());
1136 const DataLayout &DL = M.getDataLayout();
1138 for (const auto &Stub : Stubs) {
1139 OutStreamer->EmitLabel(Stub.first);
1140 OutStreamer->EmitSymbolValue(Stub.second.getPointer(),
1141 DL.getPointerSize());
1146 // Make sure we wrote out everything we need.
1147 OutStreamer->Flush();
1149 // Finalize debug and EH information.
1150 for (const HandlerInfo &HI : Handlers) {
1151 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
1152 TimePassesIsEnabled);
1153 HI.Handler->endModule();
1159 // If the target wants to know about weak references, print them all.
1160 if (MAI->getWeakRefDirective()) {
1161 // FIXME: This is not lazy, it would be nice to only print weak references
1162 // to stuff that is actually used. Note that doing so would require targets
1163 // to notice uses in operands (due to constant exprs etc). This should
1164 // happen with the MC stuff eventually.
1166 // Print out module-level global variables here.
1167 for (const auto &G : M.globals()) {
1168 if (!G.hasExternalWeakLinkage())
1170 OutStreamer->EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
1173 for (const auto &F : M) {
1174 if (!F.hasExternalWeakLinkage())
1176 OutStreamer->EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
1180 OutStreamer->AddBlankLine();
1181 for (const auto &Alias : M.aliases()) {
1182 MCSymbol *Name = getSymbol(&Alias);
1184 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
1185 OutStreamer->EmitSymbolAttribute(Name, MCSA_Global);
1186 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
1187 OutStreamer->EmitSymbolAttribute(Name, MCSA_WeakReference);
1189 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
1191 EmitVisibility(Name, Alias.getVisibility());
1193 // Emit the directives as assignments aka .set:
1194 OutStreamer->EmitAssignment(Name, lowerConstant(Alias.getAliasee()));
1196 // If the aliasee does not correspond to a symbol in the output, i.e. the
1197 // alias is not of an object or the aliased object is private, then set the
1198 // size of the alias symbol from the type of the alias. We don't do this in
1199 // other situations as the alias and aliasee having differing types but same
1200 // size may be intentional.
1201 const GlobalObject *BaseObject = Alias.getBaseObject();
1202 if (MAI->hasDotTypeDotSizeDirective() && Alias.getValueType()->isSized() &&
1203 (!BaseObject || BaseObject->hasPrivateLinkage())) {
1204 const DataLayout &DL = M.getDataLayout();
1205 uint64_t Size = DL.getTypeAllocSize(Alias.getValueType());
1206 OutStreamer->emitELFSize(cast<MCSymbolELF>(Name),
1207 MCConstantExpr::create(Size, OutContext));
1211 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1212 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1213 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1214 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1215 MP->finishAssembly(M, *MI, *this);
1217 // Emit llvm.ident metadata in an '.ident' directive.
1218 EmitModuleIdents(M);
1220 // Emit __morestack address if needed for indirect calls.
1221 if (MMI->usesMorestackAddr()) {
1222 MCSection *ReadOnlySection = getObjFileLowering().getSectionForConstant(
1223 getDataLayout(), SectionKind::getReadOnly(),
1225 OutStreamer->SwitchSection(ReadOnlySection);
1227 MCSymbol *AddrSymbol =
1228 OutContext.getOrCreateSymbol(StringRef("__morestack_addr"));
1229 OutStreamer->EmitLabel(AddrSymbol);
1231 unsigned PtrSize = M.getDataLayout().getPointerSize(0);
1232 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("__morestack"),
1236 // If we don't have any trampolines, then we don't require stack memory
1237 // to be executable. Some targets have a directive to declare this.
1238 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1239 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1240 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1241 OutStreamer->SwitchSection(S);
1243 // Allow the target to emit any magic that it wants at the end of the file,
1244 // after everything else has gone out.
1245 EmitEndOfAsmFile(M);
1247 delete Mang; Mang = nullptr;
1250 OutStreamer->Finish();
1251 OutStreamer->reset();
1256 MCSymbol *AsmPrinter::getCurExceptionSym() {
1257 if (!CurExceptionSym)
1258 CurExceptionSym = createTempSymbol("exception");
1259 return CurExceptionSym;
1262 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1264 // Get the function symbol.
1265 CurrentFnSym = getSymbol(MF.getFunction());
1266 CurrentFnSymForSize = CurrentFnSym;
1267 CurrentFnBegin = nullptr;
1268 CurExceptionSym = nullptr;
1269 bool NeedsLocalForSize = MAI->needsLocalForSize();
1270 if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
1271 MMI->hasEHFunclets() || NeedsLocalForSize) {
1272 CurrentFnBegin = createTempSymbol("func_begin");
1273 if (NeedsLocalForSize)
1274 CurrentFnSymForSize = CurrentFnBegin;
1278 LI = &getAnalysis<MachineLoopInfo>();
1282 // Keep track the alignment, constpool entries per Section.
1286 SmallVector<unsigned, 4> CPEs;
1287 SectionCPs(MCSection *s, unsigned a) : S(s), Alignment(a) {}
1291 /// EmitConstantPool - Print to the current output stream assembly
1292 /// representations of the constants in the constant pool MCP. This is
1293 /// used to print out constants which have been "spilled to memory" by
1294 /// the code generator.
1296 void AsmPrinter::EmitConstantPool() {
1297 const MachineConstantPool *MCP = MF->getConstantPool();
1298 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1299 if (CP.empty()) return;
1301 // Calculate sections for constant pool entries. We collect entries to go into
1302 // the same section together to reduce amount of section switch statements.
1303 SmallVector<SectionCPs, 4> CPSections;
1304 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1305 const MachineConstantPoolEntry &CPE = CP[i];
1306 unsigned Align = CPE.getAlignment();
1308 SectionKind Kind = CPE.getSectionKind(&getDataLayout());
1310 const Constant *C = nullptr;
1311 if (!CPE.isMachineConstantPoolEntry())
1312 C = CPE.Val.ConstVal;
1315 getObjFileLowering().getSectionForConstant(getDataLayout(), Kind, C);
1317 // The number of sections are small, just do a linear search from the
1318 // last section to the first.
1320 unsigned SecIdx = CPSections.size();
1321 while (SecIdx != 0) {
1322 if (CPSections[--SecIdx].S == S) {
1328 SecIdx = CPSections.size();
1329 CPSections.push_back(SectionCPs(S, Align));
1332 if (Align > CPSections[SecIdx].Alignment)
1333 CPSections[SecIdx].Alignment = Align;
1334 CPSections[SecIdx].CPEs.push_back(i);
1337 // Now print stuff into the calculated sections.
1338 const MCSection *CurSection = nullptr;
1339 unsigned Offset = 0;
1340 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1341 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1342 unsigned CPI = CPSections[i].CPEs[j];
1343 MCSymbol *Sym = GetCPISymbol(CPI);
1344 if (!Sym->isUndefined())
1347 if (CurSection != CPSections[i].S) {
1348 OutStreamer->SwitchSection(CPSections[i].S);
1349 EmitAlignment(Log2_32(CPSections[i].Alignment));
1350 CurSection = CPSections[i].S;
1354 MachineConstantPoolEntry CPE = CP[CPI];
1356 // Emit inter-object padding for alignment.
1357 unsigned AlignMask = CPE.getAlignment() - 1;
1358 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1359 OutStreamer->EmitZeros(NewOffset - Offset);
1361 Type *Ty = CPE.getType();
1362 Offset = NewOffset + getDataLayout().getTypeAllocSize(Ty);
1364 OutStreamer->EmitLabel(Sym);
1365 if (CPE.isMachineConstantPoolEntry())
1366 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1368 EmitGlobalConstant(getDataLayout(), CPE.Val.ConstVal);
1373 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1374 /// by the current function to the current output stream.
1376 void AsmPrinter::EmitJumpTableInfo() {
1377 const DataLayout &DL = MF->getDataLayout();
1378 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1380 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1381 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1382 if (JT.empty()) return;
1384 // Pick the directive to use to print the jump table entries, and switch to
1385 // the appropriate section.
1386 const Function *F = MF->getFunction();
1387 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1388 bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
1389 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
1391 if (JTInDiffSection) {
1392 // Drop it in the readonly section.
1393 MCSection *ReadOnlySection = TLOF.getSectionForJumpTable(*F, *Mang, TM);
1394 OutStreamer->SwitchSection(ReadOnlySection);
1397 EmitAlignment(Log2_32(MJTI->getEntryAlignment(DL)));
1399 // Jump tables in code sections are marked with a data_region directive
1400 // where that's supported.
1401 if (!JTInDiffSection)
1402 OutStreamer->EmitDataRegion(MCDR_DataRegionJT32);
1404 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1405 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1407 // If this jump table was deleted, ignore it.
1408 if (JTBBs.empty()) continue;
1410 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1411 /// emit a .set directive for each unique entry.
1412 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1413 MAI->doesSetDirectiveSuppressesReloc()) {
1414 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1415 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1416 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1417 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1418 const MachineBasicBlock *MBB = JTBBs[ii];
1419 if (!EmittedSets.insert(MBB).second)
1422 // .set LJTSet, LBB32-base
1424 MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1425 OutStreamer->EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1426 MCBinaryExpr::createSub(LHS, Base,
1431 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1432 // before each jump table. The first label is never referenced, but tells
1433 // the assembler and linker the extents of the jump table object. The
1434 // second label is actually referenced by the code.
1435 if (JTInDiffSection && DL.hasLinkerPrivateGlobalPrefix())
1436 // FIXME: This doesn't have to have any specific name, just any randomly
1437 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1438 OutStreamer->EmitLabel(GetJTISymbol(JTI, true));
1440 OutStreamer->EmitLabel(GetJTISymbol(JTI));
1442 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1443 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1445 if (!JTInDiffSection)
1446 OutStreamer->EmitDataRegion(MCDR_DataRegionEnd);
1449 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1451 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1452 const MachineBasicBlock *MBB,
1453 unsigned UID) const {
1454 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1455 const MCExpr *Value = nullptr;
1456 switch (MJTI->getEntryKind()) {
1457 case MachineJumpTableInfo::EK_Inline:
1458 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1459 case MachineJumpTableInfo::EK_Custom32:
1460 Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
1461 MJTI, MBB, UID, OutContext);
1463 case MachineJumpTableInfo::EK_BlockAddress:
1464 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1466 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1468 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1469 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1470 // with a relocation as gp-relative, e.g.:
1472 MCSymbol *MBBSym = MBB->getSymbol();
1473 OutStreamer->EmitGPRel32Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1477 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1478 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1479 // with a relocation as gp-relative, e.g.:
1481 MCSymbol *MBBSym = MBB->getSymbol();
1482 OutStreamer->EmitGPRel64Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1486 case MachineJumpTableInfo::EK_LabelDifference32: {
1487 // Each entry is the address of the block minus the address of the jump
1488 // table. This is used for PIC jump tables where gprel32 is not supported.
1490 // .word LBB123 - LJTI1_2
1491 // If the .set directive avoids relocations, this is emitted as:
1492 // .set L4_5_set_123, LBB123 - LJTI1_2
1493 // .word L4_5_set_123
1494 if (MAI->doesSetDirectiveSuppressesReloc()) {
1495 Value = MCSymbolRefExpr::create(GetJTSetSymbol(UID, MBB->getNumber()),
1499 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1500 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1501 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1502 Value = MCBinaryExpr::createSub(Value, Base, OutContext);
1507 assert(Value && "Unknown entry kind!");
1509 unsigned EntrySize = MJTI->getEntrySize(getDataLayout());
1510 OutStreamer->EmitValue(Value, EntrySize);
1514 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1515 /// special global used by LLVM. If so, emit it and return true, otherwise
1516 /// do nothing and return false.
1517 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1518 if (GV->getName() == "llvm.used") {
1519 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1520 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1524 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1525 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1526 GV->hasAvailableExternallyLinkage())
1529 if (!GV->hasAppendingLinkage()) return false;
1531 assert(GV->hasInitializer() && "Not a special LLVM global!");
1533 if (GV->getName() == "llvm.global_ctors") {
1534 EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
1537 if (TM.getRelocationModel() == Reloc::Static &&
1538 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1539 StringRef Sym(".constructors_used");
1540 OutStreamer->EmitSymbolAttribute(OutContext.getOrCreateSymbol(Sym),
1546 if (GV->getName() == "llvm.global_dtors") {
1547 EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
1548 /* isCtor */ false);
1550 if (TM.getRelocationModel() == Reloc::Static &&
1551 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1552 StringRef Sym(".destructors_used");
1553 OutStreamer->EmitSymbolAttribute(OutContext.getOrCreateSymbol(Sym),
1562 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1563 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1564 /// is true, as being used with this directive.
1565 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1566 // Should be an array of 'i8*'.
1567 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1568 const GlobalValue *GV =
1569 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1571 OutStreamer->EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1577 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1579 llvm::Constant *Func;
1580 llvm::GlobalValue *ComdatKey;
1584 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1586 void AsmPrinter::EmitXXStructorList(const DataLayout &DL, const Constant *List,
1588 // Should be an array of '{ int, void ()* }' structs. The first value is the
1590 if (!isa<ConstantArray>(List)) return;
1592 // Sanity check the structors list.
1593 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1594 if (!InitList) return; // Not an array!
1595 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1596 // FIXME: Only allow the 3-field form in LLVM 4.0.
1597 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1598 return; // Not an array of two or three elements!
1599 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1600 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1601 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1602 return; // Not (int, ptr, ptr).
1604 // Gather the structors in a form that's convenient for sorting by priority.
1605 SmallVector<Structor, 8> Structors;
1606 for (Value *O : InitList->operands()) {
1607 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1608 if (!CS) continue; // Malformed.
1609 if (CS->getOperand(1)->isNullValue())
1610 break; // Found a null terminator, skip the rest.
1611 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1612 if (!Priority) continue; // Malformed.
1613 Structors.push_back(Structor());
1614 Structor &S = Structors.back();
1615 S.Priority = Priority->getLimitedValue(65535);
1616 S.Func = CS->getOperand(1);
1617 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1618 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1621 // Emit the function pointers in the target-specific order
1622 unsigned Align = Log2_32(DL.getPointerPrefAlignment());
1623 std::stable_sort(Structors.begin(), Structors.end(),
1624 [](const Structor &L,
1625 const Structor &R) { return L.Priority < R.Priority; });
1626 for (Structor &S : Structors) {
1627 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1628 const MCSymbol *KeySym = nullptr;
1629 if (GlobalValue *GV = S.ComdatKey) {
1630 if (GV->hasAvailableExternallyLinkage())
1631 // If the associated variable is available_externally, some other TU
1632 // will provide its dynamic initializer.
1635 KeySym = getSymbol(GV);
1637 MCSection *OutputSection =
1638 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1639 : Obj.getStaticDtorSection(S.Priority, KeySym));
1640 OutStreamer->SwitchSection(OutputSection);
1641 if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
1642 EmitAlignment(Align);
1643 EmitXXStructor(DL, S.Func);
1647 void AsmPrinter::EmitModuleIdents(Module &M) {
1648 if (!MAI->hasIdentDirective())
1651 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1652 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1653 const MDNode *N = NMD->getOperand(i);
1654 assert(N->getNumOperands() == 1 &&
1655 "llvm.ident metadata entry can have only one operand");
1656 const MDString *S = cast<MDString>(N->getOperand(0));
1657 OutStreamer->EmitIdent(S->getString());
1662 //===--------------------------------------------------------------------===//
1663 // Emission and print routines
1666 /// EmitInt8 - Emit a byte directive and value.
1668 void AsmPrinter::EmitInt8(int Value) const {
1669 OutStreamer->EmitIntValue(Value, 1);
1672 /// EmitInt16 - Emit a short directive and value.
1674 void AsmPrinter::EmitInt16(int Value) const {
1675 OutStreamer->EmitIntValue(Value, 2);
1678 /// EmitInt32 - Emit a long directive and value.
1680 void AsmPrinter::EmitInt32(int Value) const {
1681 OutStreamer->EmitIntValue(Value, 4);
1684 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1685 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1686 /// .set if it avoids relocations.
1687 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1688 unsigned Size) const {
1689 OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
1692 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1693 /// where the size in bytes of the directive is specified by Size and Label
1694 /// specifies the label. This implicitly uses .set if it is available.
1695 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1697 bool IsSectionRelative) const {
1698 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1699 OutStreamer->EmitCOFFSecRel32(Label);
1703 // Emit Label+Offset (or just Label if Offset is zero)
1704 const MCExpr *Expr = MCSymbolRefExpr::create(Label, OutContext);
1706 Expr = MCBinaryExpr::createAdd(
1707 Expr, MCConstantExpr::create(Offset, OutContext), OutContext);
1709 OutStreamer->EmitValue(Expr, Size);
1712 //===----------------------------------------------------------------------===//
1714 // EmitAlignment - Emit an alignment directive to the specified power of
1715 // two boundary. For example, if you pass in 3 here, you will get an 8
1716 // byte alignment. If a global value is specified, and if that global has
1717 // an explicit alignment requested, it will override the alignment request
1718 // if required for correctness.
1720 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1722 NumBits = getGVAlignmentLog2(GV, GV->getParent()->getDataLayout(), NumBits);
1724 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1727 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
1728 "undefined behavior");
1729 if (getCurrentSection()->getKind().isText())
1730 OutStreamer->EmitCodeAlignment(1u << NumBits);
1732 OutStreamer->EmitValueToAlignment(1u << NumBits);
1735 //===----------------------------------------------------------------------===//
1736 // Constant emission.
1737 //===----------------------------------------------------------------------===//
1739 const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1740 MCContext &Ctx = OutContext;
1742 if (CV->isNullValue() || isa<UndefValue>(CV))
1743 return MCConstantExpr::create(0, Ctx);
1745 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1746 return MCConstantExpr::create(CI->getZExtValue(), Ctx);
1748 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1749 return MCSymbolRefExpr::create(getSymbol(GV), Ctx);
1751 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1752 return MCSymbolRefExpr::create(GetBlockAddressSymbol(BA), Ctx);
1754 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1756 llvm_unreachable("Unknown constant value to lower!");
1759 if (const MCExpr *RelocExpr
1760 = getObjFileLowering().getExecutableRelativeSymbol(CE, *Mang, TM))
1763 switch (CE->getOpcode()) {
1765 // If the code isn't optimized, there may be outstanding folding
1766 // opportunities. Attempt to fold the expression using DataLayout as a
1767 // last resort before giving up.
1768 if (Constant *C = ConstantFoldConstantExpression(CE, getDataLayout()))
1770 return lowerConstant(C);
1772 // Otherwise report the problem to the user.
1775 raw_string_ostream OS(S);
1776 OS << "Unsupported expression in static initializer: ";
1777 CE->printAsOperand(OS, /*PrintType=*/false,
1778 !MF ? nullptr : MF->getFunction()->getParent());
1779 report_fatal_error(OS.str());
1781 case Instruction::GetElementPtr: {
1782 // Generate a symbolic expression for the byte address
1783 APInt OffsetAI(getDataLayout().getPointerTypeSizeInBits(CE->getType()), 0);
1784 cast<GEPOperator>(CE)->accumulateConstantOffset(getDataLayout(), OffsetAI);
1786 const MCExpr *Base = lowerConstant(CE->getOperand(0));
1790 int64_t Offset = OffsetAI.getSExtValue();
1791 return MCBinaryExpr::createAdd(Base, MCConstantExpr::create(Offset, Ctx),
1795 case Instruction::Trunc:
1796 // We emit the value and depend on the assembler to truncate the generated
1797 // expression properly. This is important for differences between
1798 // blockaddress labels. Since the two labels are in the same function, it
1799 // is reasonable to treat their delta as a 32-bit value.
1801 case Instruction::BitCast:
1802 return lowerConstant(CE->getOperand(0));
1804 case Instruction::IntToPtr: {
1805 const DataLayout &DL = getDataLayout();
1807 // Handle casts to pointers by changing them into casts to the appropriate
1808 // integer type. This promotes constant folding and simplifies this code.
1809 Constant *Op = CE->getOperand(0);
1810 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1812 return lowerConstant(Op);
1815 case Instruction::PtrToInt: {
1816 const DataLayout &DL = getDataLayout();
1818 // Support only foldable casts to/from pointers that can be eliminated by
1819 // changing the pointer to the appropriately sized integer type.
1820 Constant *Op = CE->getOperand(0);
1821 Type *Ty = CE->getType();
1823 const MCExpr *OpExpr = lowerConstant(Op);
1825 // We can emit the pointer value into this slot if the slot is an
1826 // integer slot equal to the size of the pointer.
1827 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1830 // Otherwise the pointer is smaller than the resultant integer, mask off
1831 // the high bits so we are sure to get a proper truncation if the input is
1833 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1834 const MCExpr *MaskExpr = MCConstantExpr::create(~0ULL >> (64-InBits), Ctx);
1835 return MCBinaryExpr::createAnd(OpExpr, MaskExpr, Ctx);
1838 // The MC library also has a right-shift operator, but it isn't consistently
1839 // signed or unsigned between different targets.
1840 case Instruction::Add:
1841 case Instruction::Sub:
1842 case Instruction::Mul:
1843 case Instruction::SDiv:
1844 case Instruction::SRem:
1845 case Instruction::Shl:
1846 case Instruction::And:
1847 case Instruction::Or:
1848 case Instruction::Xor: {
1849 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
1850 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
1851 switch (CE->getOpcode()) {
1852 default: llvm_unreachable("Unknown binary operator constant cast expr");
1853 case Instruction::Add: return MCBinaryExpr::createAdd(LHS, RHS, Ctx);
1854 case Instruction::Sub: return MCBinaryExpr::createSub(LHS, RHS, Ctx);
1855 case Instruction::Mul: return MCBinaryExpr::createMul(LHS, RHS, Ctx);
1856 case Instruction::SDiv: return MCBinaryExpr::createDiv(LHS, RHS, Ctx);
1857 case Instruction::SRem: return MCBinaryExpr::createMod(LHS, RHS, Ctx);
1858 case Instruction::Shl: return MCBinaryExpr::createShl(LHS, RHS, Ctx);
1859 case Instruction::And: return MCBinaryExpr::createAnd(LHS, RHS, Ctx);
1860 case Instruction::Or: return MCBinaryExpr::createOr (LHS, RHS, Ctx);
1861 case Instruction::Xor: return MCBinaryExpr::createXor(LHS, RHS, Ctx);
1867 static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *C,
1869 const Constant *BaseCV = nullptr,
1870 uint64_t Offset = 0);
1872 /// isRepeatedByteSequence - Determine whether the given value is
1873 /// composed of a repeated sequence of identical bytes and return the
1874 /// byte value. If it is not a repeated sequence, return -1.
1875 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1876 StringRef Data = V->getRawDataValues();
1877 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1879 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1880 if (Data[i] != C) return -1;
1881 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1885 /// isRepeatedByteSequence - Determine whether the given value is
1886 /// composed of a repeated sequence of identical bytes and return the
1887 /// byte value. If it is not a repeated sequence, return -1.
1888 static int isRepeatedByteSequence(const Value *V, const DataLayout &DL) {
1889 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1890 uint64_t Size = DL.getTypeAllocSizeInBits(V->getType());
1891 assert(Size % 8 == 0);
1893 // Extend the element to take zero padding into account.
1894 APInt Value = CI->getValue().zextOrSelf(Size);
1895 if (!Value.isSplat(8))
1898 return Value.zextOrTrunc(8).getZExtValue();
1900 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1901 // Make sure all array elements are sequences of the same repeated
1903 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1904 Constant *Op0 = CA->getOperand(0);
1905 int Byte = isRepeatedByteSequence(Op0, DL);
1909 // All array elements must be equal.
1910 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i)
1911 if (CA->getOperand(i) != Op0)
1916 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1917 return isRepeatedByteSequence(CDS);
1922 static void emitGlobalConstantDataSequential(const DataLayout &DL,
1923 const ConstantDataSequential *CDS,
1926 // See if we can aggregate this into a .fill, if so, emit it as such.
1927 int Value = isRepeatedByteSequence(CDS, DL);
1929 uint64_t Bytes = DL.getTypeAllocSize(CDS->getType());
1930 // Don't emit a 1-byte object as a .fill.
1932 return AP.OutStreamer->EmitFill(Bytes, Value);
1935 // If this can be emitted with .ascii/.asciz, emit it as such.
1936 if (CDS->isString())
1937 return AP.OutStreamer->EmitBytes(CDS->getAsString());
1939 // Otherwise, emit the values in successive locations.
1940 unsigned ElementByteSize = CDS->getElementByteSize();
1941 if (isa<IntegerType>(CDS->getElementType())) {
1942 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1944 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
1945 CDS->getElementAsInteger(i));
1946 AP.OutStreamer->EmitIntValue(CDS->getElementAsInteger(i),
1949 } else if (ElementByteSize == 4) {
1950 // FP Constants are printed as integer constants to avoid losing
1952 assert(CDS->getElementType()->isFloatTy());
1953 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1959 F = CDS->getElementAsFloat(i);
1961 AP.OutStreamer->GetCommentOS() << "float " << F << '\n';
1962 AP.OutStreamer->EmitIntValue(I, 4);
1965 assert(CDS->getElementType()->isDoubleTy());
1966 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1972 F = CDS->getElementAsDouble(i);
1974 AP.OutStreamer->GetCommentOS() << "double " << F << '\n';
1975 AP.OutStreamer->EmitIntValue(I, 8);
1979 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1980 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1981 CDS->getNumElements();
1982 if (unsigned Padding = Size - EmittedSize)
1983 AP.OutStreamer->EmitZeros(Padding);
1987 static void emitGlobalConstantArray(const DataLayout &DL,
1988 const ConstantArray *CA, AsmPrinter &AP,
1989 const Constant *BaseCV, uint64_t Offset) {
1990 // See if we can aggregate some values. Make sure it can be
1991 // represented as a series of bytes of the constant value.
1992 int Value = isRepeatedByteSequence(CA, DL);
1995 uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
1996 AP.OutStreamer->EmitFill(Bytes, Value);
1999 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
2000 emitGlobalConstantImpl(DL, CA->getOperand(i), AP, BaseCV, Offset);
2001 Offset += DL.getTypeAllocSize(CA->getOperand(i)->getType());
2006 static void emitGlobalConstantVector(const DataLayout &DL,
2007 const ConstantVector *CV, AsmPrinter &AP) {
2008 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
2009 emitGlobalConstantImpl(DL, CV->getOperand(i), AP);
2011 unsigned Size = DL.getTypeAllocSize(CV->getType());
2012 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
2013 CV->getType()->getNumElements();
2014 if (unsigned Padding = Size - EmittedSize)
2015 AP.OutStreamer->EmitZeros(Padding);
2018 static void emitGlobalConstantStruct(const DataLayout &DL,
2019 const ConstantStruct *CS, AsmPrinter &AP,
2020 const Constant *BaseCV, uint64_t Offset) {
2021 // Print the fields in successive locations. Pad to align if needed!
2022 unsigned Size = DL.getTypeAllocSize(CS->getType());
2023 const StructLayout *Layout = DL.getStructLayout(CS->getType());
2024 uint64_t SizeSoFar = 0;
2025 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
2026 const Constant *Field = CS->getOperand(i);
2028 // Print the actual field value.
2029 emitGlobalConstantImpl(DL, Field, AP, BaseCV, Offset + SizeSoFar);
2031 // Check if padding is needed and insert one or more 0s.
2032 uint64_t FieldSize = DL.getTypeAllocSize(Field->getType());
2033 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
2034 - Layout->getElementOffset(i)) - FieldSize;
2035 SizeSoFar += FieldSize + PadSize;
2037 // Insert padding - this may include padding to increase the size of the
2038 // current field up to the ABI size (if the struct is not packed) as well
2039 // as padding to ensure that the next field starts at the right offset.
2040 AP.OutStreamer->EmitZeros(PadSize);
2042 assert(SizeSoFar == Layout->getSizeInBytes() &&
2043 "Layout of constant struct may be incorrect!");
2046 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
2047 APInt API = CFP->getValueAPF().bitcastToAPInt();
2049 // First print a comment with what we think the original floating-point value
2050 // should have been.
2051 if (AP.isVerbose()) {
2052 SmallString<8> StrVal;
2053 CFP->getValueAPF().toString(StrVal);
2056 CFP->getType()->print(AP.OutStreamer->GetCommentOS());
2058 AP.OutStreamer->GetCommentOS() << "Printing <null> Type";
2059 AP.OutStreamer->GetCommentOS() << ' ' << StrVal << '\n';
2062 // Now iterate through the APInt chunks, emitting them in endian-correct
2063 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
2065 unsigned NumBytes = API.getBitWidth() / 8;
2066 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
2067 const uint64_t *p = API.getRawData();
2069 // PPC's long double has odd notions of endianness compared to how LLVM
2070 // handles it: p[0] goes first for *big* endian on PPC.
2071 if (AP.getDataLayout().isBigEndian() && !CFP->getType()->isPPC_FP128Ty()) {
2072 int Chunk = API.getNumWords() - 1;
2075 AP.OutStreamer->EmitIntValue(p[Chunk--], TrailingBytes);
2077 for (; Chunk >= 0; --Chunk)
2078 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
2081 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
2082 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
2085 AP.OutStreamer->EmitIntValue(p[Chunk], TrailingBytes);
2088 // Emit the tail padding for the long double.
2089 const DataLayout &DL = AP.getDataLayout();
2090 AP.OutStreamer->EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
2091 DL.getTypeStoreSize(CFP->getType()));
2094 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
2095 const DataLayout &DL = AP.getDataLayout();
2096 unsigned BitWidth = CI->getBitWidth();
2098 // Copy the value as we may massage the layout for constants whose bit width
2099 // is not a multiple of 64-bits.
2100 APInt Realigned(CI->getValue());
2101 uint64_t ExtraBits = 0;
2102 unsigned ExtraBitsSize = BitWidth & 63;
2104 if (ExtraBitsSize) {
2105 // The bit width of the data is not a multiple of 64-bits.
2106 // The extra bits are expected to be at the end of the chunk of the memory.
2108 // * Nothing to be done, just record the extra bits to emit.
2110 // * Record the extra bits to emit.
2111 // * Realign the raw data to emit the chunks of 64-bits.
2112 if (DL.isBigEndian()) {
2113 // Basically the structure of the raw data is a chunk of 64-bits cells:
2114 // 0 1 BitWidth / 64
2115 // [chunk1][chunk2] ... [chunkN].
2116 // The most significant chunk is chunkN and it should be emitted first.
2117 // However, due to the alignment issue chunkN contains useless bits.
2118 // Realign the chunks so that they contain only useless information:
2119 // ExtraBits 0 1 (BitWidth / 64) - 1
2120 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
2121 ExtraBits = Realigned.getRawData()[0] &
2122 (((uint64_t)-1) >> (64 - ExtraBitsSize));
2123 Realigned = Realigned.lshr(ExtraBitsSize);
2125 ExtraBits = Realigned.getRawData()[BitWidth / 64];
2128 // We don't expect assemblers to support integer data directives
2129 // for more than 64 bits, so we emit the data in at most 64-bit
2130 // quantities at a time.
2131 const uint64_t *RawData = Realigned.getRawData();
2132 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
2133 uint64_t Val = DL.isBigEndian() ? RawData[e - i - 1] : RawData[i];
2134 AP.OutStreamer->EmitIntValue(Val, 8);
2137 if (ExtraBitsSize) {
2138 // Emit the extra bits after the 64-bits chunks.
2140 // Emit a directive that fills the expected size.
2141 uint64_t Size = AP.getDataLayout().getTypeAllocSize(CI->getType());
2142 Size -= (BitWidth / 64) * 8;
2143 assert(Size && Size * 8 >= ExtraBitsSize &&
2144 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
2145 == ExtraBits && "Directive too small for extra bits.");
2146 AP.OutStreamer->EmitIntValue(ExtraBits, Size);
2150 /// \brief Transform a not absolute MCExpr containing a reference to a GOT
2151 /// equivalent global, by a target specific GOT pc relative access to the
2153 static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
2154 const Constant *BaseCst,
2156 // The global @foo below illustrates a global that uses a got equivalent.
2158 // @bar = global i32 42
2159 // @gotequiv = private unnamed_addr constant i32* @bar
2160 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
2161 // i64 ptrtoint (i32* @foo to i64))
2164 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
2165 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
2168 // foo = cstexpr, where
2169 // cstexpr := <gotequiv> - "." + <cst>
2170 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
2172 // After canonicalization by evaluateAsRelocatable `ME` turns into:
2174 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
2175 // gotpcrelcst := <offset from @foo base> + <cst>
2178 if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
2180 const MCSymbolRefExpr *SymA = MV.getSymA();
2184 // Check that GOT equivalent symbol is cached.
2185 const MCSymbol *GOTEquivSym = &SymA->getSymbol();
2186 if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
2189 const GlobalValue *BaseGV = dyn_cast_or_null<GlobalValue>(BaseCst);
2193 // Check for a valid base symbol
2194 const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
2195 const MCSymbolRefExpr *SymB = MV.getSymB();
2197 if (!SymB || BaseSym != &SymB->getSymbol())
2200 // Make sure to match:
2202 // gotpcrelcst := <offset from @foo base> + <cst>
2204 // If gotpcrelcst is positive it means that we can safely fold the pc rel
2205 // displacement into the GOTPCREL. We can also can have an extra offset <cst>
2206 // if the target knows how to encode it.
2208 int64_t GOTPCRelCst = Offset + MV.getConstant();
2209 if (GOTPCRelCst < 0)
2211 if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
2214 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
2221 // .long gotequiv - "." + <cst>
2223 // is replaced by the target specific equivalent to:
2228 // .long bar@GOTPCREL+<gotpcrelcst>
2230 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
2231 const GlobalVariable *GV = Result.first;
2232 int NumUses = (int)Result.second;
2233 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
2234 const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
2235 *ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(
2236 FinalSym, MV, Offset, AP.MMI, *AP.OutStreamer);
2238 // Update GOT equivalent usage information
2241 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
2244 static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *CV,
2245 AsmPrinter &AP, const Constant *BaseCV,
2247 uint64_t Size = DL.getTypeAllocSize(CV->getType());
2249 // Globals with sub-elements such as combinations of arrays and structs
2250 // are handled recursively by emitGlobalConstantImpl. Keep track of the
2251 // constant symbol base and the current position with BaseCV and Offset.
2252 if (!BaseCV && CV->hasOneUse())
2253 BaseCV = dyn_cast<Constant>(CV->user_back());
2255 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
2256 return AP.OutStreamer->EmitZeros(Size);
2258 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
2265 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
2266 CI->getZExtValue());
2267 AP.OutStreamer->EmitIntValue(CI->getZExtValue(), Size);
2270 emitGlobalConstantLargeInt(CI, AP);
2275 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
2276 return emitGlobalConstantFP(CFP, AP);
2278 if (isa<ConstantPointerNull>(CV)) {
2279 AP.OutStreamer->EmitIntValue(0, Size);
2283 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
2284 return emitGlobalConstantDataSequential(DL, CDS, AP);
2286 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2287 return emitGlobalConstantArray(DL, CVA, AP, BaseCV, Offset);
2289 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2290 return emitGlobalConstantStruct(DL, CVS, AP, BaseCV, Offset);
2292 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2293 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2295 if (CE->getOpcode() == Instruction::BitCast)
2296 return emitGlobalConstantImpl(DL, CE->getOperand(0), AP);
2299 // If the constant expression's size is greater than 64-bits, then we have
2300 // to emit the value in chunks. Try to constant fold the value and emit it
2302 Constant *New = ConstantFoldConstantExpression(CE, DL);
2303 if (New && New != CE)
2304 return emitGlobalConstantImpl(DL, New, AP);
2308 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2309 return emitGlobalConstantVector(DL, V, AP);
2311 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2312 // thread the streamer with EmitValue.
2313 const MCExpr *ME = AP.lowerConstant(CV);
2315 // Since lowerConstant already folded and got rid of all IR pointer and
2316 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
2318 if (AP.getObjFileLowering().supportIndirectSymViaGOTPCRel())
2319 handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
2321 AP.OutStreamer->EmitValue(ME, Size);
2324 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2325 void AsmPrinter::EmitGlobalConstant(const DataLayout &DL, const Constant *CV) {
2326 uint64_t Size = DL.getTypeAllocSize(CV->getType());
2328 emitGlobalConstantImpl(DL, CV, *this);
2329 else if (MAI->hasSubsectionsViaSymbols()) {
2330 // If the global has zero size, emit a single byte so that two labels don't
2331 // look like they are at the same location.
2332 OutStreamer->EmitIntValue(0, 1);
2336 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2337 // Target doesn't support this yet!
2338 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2341 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2343 OS << '+' << Offset;
2344 else if (Offset < 0)
2348 //===----------------------------------------------------------------------===//
2349 // Symbol Lowering Routines.
2350 //===----------------------------------------------------------------------===//
2352 MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name) const {
2353 return OutContext.createTempSymbol(Name, true);
2356 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2357 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2360 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2361 return MMI->getAddrLabelSymbol(BB);
2364 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2365 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2366 const DataLayout &DL = getDataLayout();
2367 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
2368 "CPI" + Twine(getFunctionNumber()) + "_" +
2372 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2373 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2374 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2377 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2378 /// FIXME: privatize to AsmPrinter.
2379 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2380 const DataLayout &DL = getDataLayout();
2381 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
2382 Twine(getFunctionNumber()) + "_" +
2383 Twine(UID) + "_set_" + Twine(MBBID));
2386 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2387 StringRef Suffix) const {
2388 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2392 /// Return the MCSymbol for the specified ExternalSymbol.
2393 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2394 SmallString<60> NameStr;
2395 Mangler::getNameWithPrefix(NameStr, Sym, getDataLayout());
2396 return OutContext.getOrCreateSymbol(NameStr);
2401 /// PrintParentLoopComment - Print comments about parent loops of this one.
2402 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2403 unsigned FunctionNumber) {
2405 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2406 OS.indent(Loop->getLoopDepth()*2)
2407 << "Parent Loop BB" << FunctionNumber << "_"
2408 << Loop->getHeader()->getNumber()
2409 << " Depth=" << Loop->getLoopDepth() << '\n';
2413 /// PrintChildLoopComment - Print comments about child loops within
2414 /// the loop for this basic block, with nesting.
2415 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2416 unsigned FunctionNumber) {
2417 // Add child loop information
2418 for (const MachineLoop *CL : *Loop) {
2419 OS.indent(CL->getLoopDepth()*2)
2420 << "Child Loop BB" << FunctionNumber << "_"
2421 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2423 PrintChildLoopComment(OS, CL, FunctionNumber);
2427 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2428 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2429 const MachineLoopInfo *LI,
2430 const AsmPrinter &AP) {
2431 // Add loop depth information
2432 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2435 MachineBasicBlock *Header = Loop->getHeader();
2436 assert(Header && "No header for loop");
2438 // If this block is not a loop header, just print out what is the loop header
2440 if (Header != &MBB) {
2441 AP.OutStreamer->AddComment(" in Loop: Header=BB" +
2442 Twine(AP.getFunctionNumber())+"_" +
2443 Twine(Loop->getHeader()->getNumber())+
2444 " Depth="+Twine(Loop->getLoopDepth()));
2448 // Otherwise, it is a loop header. Print out information about child and
2450 raw_ostream &OS = AP.OutStreamer->GetCommentOS();
2452 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2455 OS.indent(Loop->getLoopDepth()*2-2);
2460 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2462 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2466 /// EmitBasicBlockStart - This method prints the label for the specified
2467 /// MachineBasicBlock, an alignment (if present) and a comment describing
2468 /// it if appropriate.
2469 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2470 // End the previous funclet and start a new one.
2471 if (MBB.isEHFuncletEntry()) {
2472 for (const HandlerInfo &HI : Handlers) {
2473 HI.Handler->endFunclet();
2474 HI.Handler->beginFunclet(MBB);
2478 // Emit an alignment directive for this block, if needed.
2479 if (unsigned Align = MBB.getAlignment())
2480 EmitAlignment(Align);
2482 // If the block has its address taken, emit any labels that were used to
2483 // reference the block. It is possible that there is more than one label
2484 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2485 // the references were generated.
2486 if (MBB.hasAddressTaken()) {
2487 const BasicBlock *BB = MBB.getBasicBlock();
2489 OutStreamer->AddComment("Block address taken");
2491 // MBBs can have their address taken as part of CodeGen without having
2492 // their corresponding BB's address taken in IR
2493 if (BB->hasAddressTaken())
2494 for (MCSymbol *Sym : MMI->getAddrLabelSymbolToEmit(BB))
2495 OutStreamer->EmitLabel(Sym);
2498 // Print some verbose block comments.
2500 if (const BasicBlock *BB = MBB.getBasicBlock())
2502 OutStreamer->AddComment("%" + BB->getName());
2503 emitBasicBlockLoopComments(MBB, LI, *this);
2506 // Print the main label for the block.
2507 if (MBB.pred_empty() ||
2508 (isBlockOnlyReachableByFallthrough(&MBB) && !MBB.isEHFuncletEntry())) {
2510 // NOTE: Want this comment at start of line, don't emit with AddComment.
2511 OutStreamer->emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2514 OutStreamer->EmitLabel(MBB.getSymbol());
2518 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2519 bool IsDefinition) const {
2520 MCSymbolAttr Attr = MCSA_Invalid;
2522 switch (Visibility) {
2524 case GlobalValue::HiddenVisibility:
2526 Attr = MAI->getHiddenVisibilityAttr();
2528 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2530 case GlobalValue::ProtectedVisibility:
2531 Attr = MAI->getProtectedVisibilityAttr();
2535 if (Attr != MCSA_Invalid)
2536 OutStreamer->EmitSymbolAttribute(Sym, Attr);
2539 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2540 /// exactly one predecessor and the control transfer mechanism between
2541 /// the predecessor and this block is a fall-through.
2543 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2544 // If this is a landing pad, it isn't a fall through. If it has no preds,
2545 // then nothing falls through to it.
2546 if (MBB->isEHPad() || MBB->pred_empty())
2549 // If there isn't exactly one predecessor, it can't be a fall through.
2550 if (MBB->pred_size() > 1)
2553 // The predecessor has to be immediately before this block.
2554 MachineBasicBlock *Pred = *MBB->pred_begin();
2555 if (!Pred->isLayoutSuccessor(MBB))
2558 // If the block is completely empty, then it definitely does fall through.
2562 // Check the terminators in the previous blocks
2563 for (const auto &MI : Pred->terminators()) {
2564 // If it is not a simple branch, we are in a table somewhere.
2565 if (!MI.isBranch() || MI.isIndirectBranch())
2568 // If we are the operands of one of the branches, this is not a fall
2569 // through. Note that targets with delay slots will usually bundle
2570 // terminators with the delay slot instruction.
2571 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2574 if (OP->isMBB() && OP->getMBB() == MBB)
2584 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2585 if (!S.usesMetadata())
2588 assert(!S.useStatepoints() && "statepoints do not currently support custom"
2589 " stackmap formats, please see the documentation for a description of"
2590 " the default format. If you really need a custom serialized format,"
2591 " please file a bug");
2593 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2594 gcp_map_type::iterator GCPI = GCMap.find(&S);
2595 if (GCPI != GCMap.end())
2596 return GCPI->second.get();
2598 const char *Name = S.getName().c_str();
2600 for (GCMetadataPrinterRegistry::iterator
2601 I = GCMetadataPrinterRegistry::begin(),
2602 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2603 if (strcmp(Name, I->getName()) == 0) {
2604 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2606 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2607 return IterBool.first->second.get();
2610 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2613 /// Pin vtable to this file.
2614 AsmPrinterHandler::~AsmPrinterHandler() {}
2616 void AsmPrinterHandler::markFunctionEnd() {}