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 // If there is init value, use .data.rel.local section;
359 // otherwise use the .data section.
360 MCSection *TLSVarSection = const_cast<MCSection*>(
361 (GV->hasInitializer() && !AllZeroInitValue)
362 ? getObjFileLowering().getDataRelLocalSection()
363 : getObjFileLowering().getDataSection());
364 OutStreamer->SwitchSection(TLSVarSection);
365 MCSymbol *GVSym = getSymbol(GV);
366 EmitLinkage(GV, EmittedSym); // same linkage as GV
367 const DataLayout &DL = GV->getParent()->getDataLayout();
368 uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
369 unsigned AlignLog = getGVAlignmentLog2(GV, DL);
370 unsigned WordSize = DL.getPointerSize();
371 unsigned Alignment = DL.getPointerABIAlignment();
372 EmitAlignment(Log2_32(Alignment));
373 OutStreamer->EmitLabel(EmittedSym);
374 OutStreamer->EmitIntValue(Size, WordSize);
375 OutStreamer->EmitIntValue((1 << AlignLog), WordSize);
376 OutStreamer->EmitIntValue(0, WordSize);
377 if (GV->hasInitializer() && !AllZeroInitValue) {
378 OutStreamer->EmitSymbolValue(
379 getOrCreateEmuTLSInitSym(GVSym, OutContext), WordSize);
381 OutStreamer->EmitIntValue(0, WordSize);
382 if (MAI->hasDotTypeDotSizeDirective())
383 OutStreamer->emitELFSize(cast<MCSymbolELF>(EmittedSym),
384 MCConstantExpr::create(4 * WordSize, OutContext));
385 OutStreamer->AddBlankLine(); // End of the __emutls_v.* variable.
388 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
389 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
391 GV->getThreadLocalMode() != llvm::GlobalVariable::NotThreadLocal &&
392 TM.Options.EmulatedTLS;
393 assert((!IsEmuTLSVar || getObjFileLowering().getDataRelLocalSection()) &&
394 "Need relocatable local section for emulated TLS variables");
395 assert(!(IsEmuTLSVar && GV->hasCommonLinkage()) &&
396 "No emulated TLS variables in the common section");
398 if (GV->hasInitializer()) {
399 // Check to see if this is a special global used by LLVM, if so, emit it.
400 if (EmitSpecialLLVMGlobal(GV))
403 // Skip the emission of global equivalents. The symbol can be emitted later
404 // on by emitGlobalGOTEquivs in case it turns out to be needed.
405 if (GlobalGOTEquivs.count(getSymbol(GV)))
408 if (isVerbose() && !IsEmuTLSVar) {
409 // When printing the control variable __emutls_v.*,
410 // we don't need to print the original TLS variable name.
411 GV->printAsOperand(OutStreamer->GetCommentOS(),
412 /*PrintType=*/false, GV->getParent());
413 OutStreamer->GetCommentOS() << '\n';
417 MCSymbol *GVSym = getSymbol(GV);
418 MCSymbol *EmittedSym = IsEmuTLSVar ?
419 getOrCreateEmuTLSControlSym(GVSym, OutContext) : GVSym;
420 // getOrCreateEmuTLSControlSym only creates the symbol with name and default attributes.
421 // GV's or GVSym's attributes will be used for the EmittedSym.
423 EmitVisibility(EmittedSym, GV->getVisibility(), !GV->isDeclaration());
425 if (!GV->hasInitializer()) // External globals require no extra code.
428 GVSym->redefineIfPossible();
429 if (GVSym->isDefined() || GVSym->isVariable())
430 report_fatal_error("symbol '" + Twine(GVSym->getName()) +
431 "' is already defined");
433 if (MAI->hasDotTypeDotSizeDirective())
434 OutStreamer->EmitSymbolAttribute(EmittedSym, MCSA_ELF_TypeObject);
436 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
438 const DataLayout &DL = GV->getParent()->getDataLayout();
439 uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
441 // If the alignment is specified, we *must* obey it. Overaligning a global
442 // with a specified alignment is a prompt way to break globals emitted to
443 // sections and expected to be contiguous (e.g. ObjC metadata).
444 unsigned AlignLog = getGVAlignmentLog2(GV, DL);
446 bool AllZeroInitValue = false;
447 const Constant *InitValue = GV->getInitializer();
448 if (isa<ConstantAggregateZero>(InitValue))
449 AllZeroInitValue = true;
451 const ConstantInt *InitIntValue = dyn_cast<ConstantInt>(InitValue);
452 if (InitIntValue && InitIntValue->isZero())
453 AllZeroInitValue = true;
456 EmitEmulatedTLSControlVariable(GV, EmittedSym, AllZeroInitValue);
458 for (const HandlerInfo &HI : Handlers) {
459 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
460 HI.Handler->setSymbolSize(GVSym, Size);
463 // Handle common and BSS local symbols (.lcomm).
464 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
465 assert(!(IsEmuTLSVar && GVKind.isCommon()) &&
466 "No emulated TLS variables in the common section");
467 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
468 unsigned Align = 1 << AlignLog;
470 // Handle common symbols.
471 if (GVKind.isCommon()) {
472 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
476 OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
480 // Handle local BSS symbols.
481 if (MAI->hasMachoZeroFillDirective()) {
482 MCSection *TheSection =
483 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
484 // .zerofill __DATA, __bss, _foo, 400, 5
485 OutStreamer->EmitZerofill(TheSection, GVSym, Size, Align);
489 // Use .lcomm only if it supports user-specified alignment.
490 // Otherwise, while it would still be correct to use .lcomm in some
491 // cases (e.g. when Align == 1), the external assembler might enfore
492 // some -unknown- default alignment behavior, which could cause
493 // spurious differences between external and integrated assembler.
494 // Prefer to simply fall back to .local / .comm in this case.
495 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
497 OutStreamer->EmitLocalCommonSymbol(GVSym, Size, Align);
501 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
505 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Local);
507 OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
511 if (IsEmuTLSVar && AllZeroInitValue)
512 return; // No need of initialization values.
514 MCSymbol *EmittedInitSym = IsEmuTLSVar ?
515 getOrCreateEmuTLSInitSym(GVSym, OutContext) : GVSym;
516 // getOrCreateEmuTLSInitSym only creates the symbol with name and default attributes.
517 // GV's or GVSym's attributes will be used for the EmittedInitSym.
519 MCSection *TheSection = IsEmuTLSVar ?
520 getObjFileLowering().getReadOnlySection() :
521 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
523 // Handle the zerofill directive on darwin, which is a special form of BSS
525 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective() && !IsEmuTLSVar) {
526 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
529 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
530 // .zerofill __DATA, __common, _foo, 400, 5
531 OutStreamer->EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
535 // Handle thread local data for mach-o which requires us to output an
536 // additional structure of data and mangle the original symbol so that we
537 // can reference it later.
539 // TODO: This should become an "emit thread local global" method on TLOF.
540 // All of this macho specific stuff should be sunk down into TLOFMachO and
541 // stuff like "TLSExtraDataSection" should no longer be part of the parent
542 // TLOF class. This will also make it more obvious that stuff like
543 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
545 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective() && !IsEmuTLSVar) {
546 // Emit the .tbss symbol
548 OutContext.getOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
550 if (GVKind.isThreadBSS()) {
551 TheSection = getObjFileLowering().getTLSBSSSection();
552 OutStreamer->EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
553 } else if (GVKind.isThreadData()) {
554 OutStreamer->SwitchSection(TheSection);
556 EmitAlignment(AlignLog, GV);
557 OutStreamer->EmitLabel(MangSym);
559 EmitGlobalConstant(GV->getParent()->getDataLayout(),
560 GV->getInitializer());
563 OutStreamer->AddBlankLine();
565 // Emit the variable struct for the runtime.
566 MCSection *TLVSect = getObjFileLowering().getTLSExtraDataSection();
568 OutStreamer->SwitchSection(TLVSect);
569 // Emit the linkage here.
570 EmitLinkage(GV, GVSym);
571 OutStreamer->EmitLabel(GVSym);
573 // Three pointers in size:
574 // - __tlv_bootstrap - used to make sure support exists
575 // - spare pointer, used when mapped by the runtime
576 // - pointer to mangled symbol above with initializer
577 unsigned PtrSize = DL.getPointerTypeSize(GV->getType());
578 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
580 OutStreamer->EmitIntValue(0, PtrSize);
581 OutStreamer->EmitSymbolValue(MangSym, PtrSize);
583 OutStreamer->AddBlankLine();
587 OutStreamer->SwitchSection(TheSection);
589 // emutls_t.* symbols are only used in the current compilation unit.
591 EmitLinkage(GV, EmittedInitSym);
592 EmitAlignment(AlignLog, GV);
594 OutStreamer->EmitLabel(EmittedInitSym);
596 EmitGlobalConstant(GV->getParent()->getDataLayout(), GV->getInitializer());
598 if (MAI->hasDotTypeDotSizeDirective())
600 OutStreamer->emitELFSize(cast<MCSymbolELF>(EmittedInitSym),
601 MCConstantExpr::create(Size, OutContext));
603 OutStreamer->AddBlankLine();
606 /// EmitFunctionHeader - This method emits the header for the current
608 void AsmPrinter::EmitFunctionHeader() {
609 // Print out constants referenced by the function
612 // Print the 'header' of function.
613 const Function *F = MF->getFunction();
615 OutStreamer->SwitchSection(
616 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
617 EmitVisibility(CurrentFnSym, F->getVisibility());
619 EmitLinkage(F, CurrentFnSym);
620 if (MAI->hasFunctionAlignment())
621 EmitAlignment(MF->getAlignment(), F);
623 if (MAI->hasDotTypeDotSizeDirective())
624 OutStreamer->EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
627 F->printAsOperand(OutStreamer->GetCommentOS(),
628 /*PrintType=*/false, F->getParent());
629 OutStreamer->GetCommentOS() << '\n';
632 // Emit the prefix data.
633 if (F->hasPrefixData())
634 EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrefixData());
636 // Emit the CurrentFnSym. This is a virtual function to allow targets to
637 // do their wild and crazy things as required.
638 EmitFunctionEntryLabel();
640 // If the function had address-taken blocks that got deleted, then we have
641 // references to the dangling symbols. Emit them at the start of the function
642 // so that we don't get references to undefined symbols.
643 std::vector<MCSymbol*> DeadBlockSyms;
644 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
645 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
646 OutStreamer->AddComment("Address taken block that was later removed");
647 OutStreamer->EmitLabel(DeadBlockSyms[i]);
650 if (CurrentFnBegin) {
651 if (MAI->useAssignmentForEHBegin()) {
652 MCSymbol *CurPos = OutContext.createTempSymbol();
653 OutStreamer->EmitLabel(CurPos);
654 OutStreamer->EmitAssignment(CurrentFnBegin,
655 MCSymbolRefExpr::create(CurPos, OutContext));
657 OutStreamer->EmitLabel(CurrentFnBegin);
661 // Emit pre-function debug and/or EH information.
662 for (const HandlerInfo &HI : Handlers) {
663 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
664 HI.Handler->beginFunction(MF);
667 // Emit the prologue data.
668 if (F->hasPrologueData())
669 EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrologueData());
672 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
673 /// function. This can be overridden by targets as required to do custom stuff.
674 void AsmPrinter::EmitFunctionEntryLabel() {
675 CurrentFnSym->redefineIfPossible();
677 // The function label could have already been emitted if two symbols end up
678 // conflicting due to asm renaming. Detect this and emit an error.
679 if (CurrentFnSym->isVariable())
680 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
681 "' is a protected alias");
682 if (CurrentFnSym->isDefined())
683 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
684 "' label emitted multiple times to assembly file");
686 return OutStreamer->EmitLabel(CurrentFnSym);
689 /// emitComments - Pretty-print comments for instructions.
690 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
691 const MachineFunction *MF = MI.getParent()->getParent();
692 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
694 // Check for spills and reloads
697 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
699 // We assume a single instruction only has a spill or reload, not
701 const MachineMemOperand *MMO;
702 if (TII->isLoadFromStackSlotPostFE(&MI, FI)) {
703 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
704 MMO = *MI.memoperands_begin();
705 CommentOS << MMO->getSize() << "-byte Reload\n";
707 } else if (TII->hasLoadFromStackSlot(&MI, MMO, FI)) {
708 if (FrameInfo->isSpillSlotObjectIndex(FI))
709 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
710 } else if (TII->isStoreToStackSlotPostFE(&MI, FI)) {
711 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
712 MMO = *MI.memoperands_begin();
713 CommentOS << MMO->getSize() << "-byte Spill\n";
715 } else if (TII->hasStoreToStackSlot(&MI, MMO, FI)) {
716 if (FrameInfo->isSpillSlotObjectIndex(FI))
717 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
720 // Check for spill-induced copies
721 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
722 CommentOS << " Reload Reuse\n";
725 /// emitImplicitDef - This method emits the specified machine instruction
726 /// that is an implicit def.
727 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
728 unsigned RegNo = MI->getOperand(0).getReg();
729 OutStreamer->AddComment(Twine("implicit-def: ") +
730 MMI->getContext().getRegisterInfo()->getName(RegNo));
731 OutStreamer->AddBlankLine();
734 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
735 std::string Str = "kill:";
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 Str += AP.MMI->getContext().getRegisterInfo()->getName(Op.getReg());
741 Str += (Op.isDef() ? "<def>" : "<kill>");
743 AP.OutStreamer->AddComment(Str);
744 AP.OutStreamer->AddBlankLine();
747 /// emitDebugValueComment - This method handles the target-independent form
748 /// of DBG_VALUE, returning true if it was able to do so. A false return
749 /// means the target will need to handle MI in EmitInstruction.
750 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
751 // This code handles only the 4-operand target-independent form.
752 if (MI->getNumOperands() != 4)
755 SmallString<128> Str;
756 raw_svector_ostream OS(Str);
757 OS << "DEBUG_VALUE: ";
759 const DILocalVariable *V = MI->getDebugVariable();
760 if (auto *SP = dyn_cast<DISubprogram>(V->getScope())) {
761 StringRef Name = SP->getDisplayName();
767 const DIExpression *Expr = MI->getDebugExpression();
768 if (Expr->isBitPiece())
769 OS << " [bit_piece offset=" << Expr->getBitPieceOffset()
770 << " size=" << Expr->getBitPieceSize() << "]";
773 // The second operand is only an offset if it's an immediate.
774 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
775 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
777 // Register or immediate value. Register 0 means undef.
778 if (MI->getOperand(0).isFPImm()) {
779 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
780 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
781 OS << (double)APF.convertToFloat();
782 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
783 OS << APF.convertToDouble();
785 // There is no good way to print long double. Convert a copy to
786 // double. Ah well, it's only a comment.
788 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
790 OS << "(long double) " << APF.convertToDouble();
792 } else if (MI->getOperand(0).isImm()) {
793 OS << MI->getOperand(0).getImm();
794 } else if (MI->getOperand(0).isCImm()) {
795 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
798 if (MI->getOperand(0).isReg()) {
799 Reg = MI->getOperand(0).getReg();
801 assert(MI->getOperand(0).isFI() && "Unknown operand type");
802 const TargetFrameLowering *TFI = AP.MF->getSubtarget().getFrameLowering();
803 Offset += TFI->getFrameIndexReference(*AP.MF,
804 MI->getOperand(0).getIndex(), Reg);
808 // Suppress offset, it is not meaningful here.
810 // NOTE: Want this comment at start of line, don't emit with AddComment.
811 AP.OutStreamer->emitRawComment(OS.str());
816 OS << AP.MMI->getContext().getRegisterInfo()->getName(Reg);
820 OS << '+' << Offset << ']';
822 // NOTE: Want this comment at start of line, don't emit with AddComment.
823 AP.OutStreamer->emitRawComment(OS.str());
827 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
828 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
829 MF->getFunction()->needsUnwindTableEntry())
832 if (MMI->hasDebugInfo())
838 bool AsmPrinter::needsSEHMoves() {
839 return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
842 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
843 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
844 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
845 ExceptionHandlingType != ExceptionHandling::ARM)
848 if (needsCFIMoves() == CFI_M_None)
851 const MachineModuleInfo &MMI = MF->getMMI();
852 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
853 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
854 const MCCFIInstruction &CFI = Instrs[CFIIndex];
855 emitCFIInstruction(CFI);
858 void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
859 // The operands are the MCSymbol and the frame offset of the allocation.
860 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
861 int FrameOffset = MI.getOperand(1).getImm();
863 // Emit a symbol assignment.
864 OutStreamer->EmitAssignment(FrameAllocSym,
865 MCConstantExpr::create(FrameOffset, OutContext));
868 /// EmitFunctionBody - This method emits the body and trailer for a
870 void AsmPrinter::EmitFunctionBody() {
871 EmitFunctionHeader();
873 // Emit target-specific gunk before the function body.
874 EmitFunctionBodyStart();
876 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
878 // Print out code for the function.
879 bool HasAnyRealCode = false;
880 for (auto &MBB : *MF) {
881 // Print a label for the basic block.
882 EmitBasicBlockStart(MBB);
883 for (auto &MI : MBB) {
885 // Print the assembly for the instruction.
886 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
887 !MI.isDebugValue()) {
888 HasAnyRealCode = true;
892 if (ShouldPrintDebugScopes) {
893 for (const HandlerInfo &HI : Handlers) {
894 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
895 TimePassesIsEnabled);
896 HI.Handler->beginInstruction(&MI);
901 emitComments(MI, OutStreamer->GetCommentOS());
903 switch (MI.getOpcode()) {
904 case TargetOpcode::CFI_INSTRUCTION:
905 emitCFIInstruction(MI);
908 case TargetOpcode::LOCAL_ESCAPE:
912 case TargetOpcode::EH_LABEL:
913 case TargetOpcode::GC_LABEL:
914 OutStreamer->EmitLabel(MI.getOperand(0).getMCSymbol());
916 case TargetOpcode::INLINEASM:
919 case TargetOpcode::DBG_VALUE:
921 if (!emitDebugValueComment(&MI, *this))
922 EmitInstruction(&MI);
925 case TargetOpcode::IMPLICIT_DEF:
926 if (isVerbose()) emitImplicitDef(&MI);
928 case TargetOpcode::KILL:
929 if (isVerbose()) emitKill(&MI, *this);
932 EmitInstruction(&MI);
936 if (ShouldPrintDebugScopes) {
937 for (const HandlerInfo &HI : Handlers) {
938 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
939 TimePassesIsEnabled);
940 HI.Handler->endInstruction();
945 EmitBasicBlockEnd(MBB);
948 // If the function is empty and the object file uses .subsections_via_symbols,
949 // then we need to emit *something* to the function body to prevent the
950 // labels from collapsing together. Just emit a noop.
951 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
953 MF->getSubtarget().getInstrInfo()->getNoopForMachoTarget(Noop);
954 OutStreamer->AddComment("avoids zero-length function");
956 // Targets can opt-out of emitting the noop here by leaving the opcode
958 if (Noop.getOpcode())
959 OutStreamer->EmitInstruction(Noop, getSubtargetInfo());
962 const Function *F = MF->getFunction();
963 for (const auto &BB : *F) {
964 if (!BB.hasAddressTaken())
966 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
967 if (Sym->isDefined())
969 OutStreamer->AddComment("Address of block that was removed by CodeGen");
970 OutStreamer->EmitLabel(Sym);
973 // Emit target-specific gunk after the function body.
974 EmitFunctionBodyEnd();
976 if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
977 MMI->hasEHFunclets() || MAI->hasDotTypeDotSizeDirective()) {
978 // Create a symbol for the end of function.
979 CurrentFnEnd = createTempSymbol("func_end");
980 OutStreamer->EmitLabel(CurrentFnEnd);
983 // If the target wants a .size directive for the size of the function, emit
985 if (MAI->hasDotTypeDotSizeDirective()) {
986 // We can get the size as difference between the function label and the
988 const MCExpr *SizeExp = MCBinaryExpr::createSub(
989 MCSymbolRefExpr::create(CurrentFnEnd, OutContext),
990 MCSymbolRefExpr::create(CurrentFnSymForSize, OutContext), OutContext);
991 if (auto Sym = dyn_cast<MCSymbolELF>(CurrentFnSym))
992 OutStreamer->emitELFSize(Sym, SizeExp);
995 for (const HandlerInfo &HI : Handlers) {
996 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
997 HI.Handler->markFunctionEnd();
1000 // Print out jump tables referenced by the function.
1001 EmitJumpTableInfo();
1003 // Emit post-function debug and/or EH information.
1004 for (const HandlerInfo &HI : Handlers) {
1005 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
1006 HI.Handler->endFunction(MF);
1010 OutStreamer->AddBlankLine();
1013 /// \brief Compute the number of Global Variables that uses a Constant.
1014 static unsigned getNumGlobalVariableUses(const Constant *C) {
1018 if (isa<GlobalVariable>(C))
1021 unsigned NumUses = 0;
1022 for (auto *CU : C->users())
1023 NumUses += getNumGlobalVariableUses(dyn_cast<Constant>(CU));
1028 /// \brief Only consider global GOT equivalents if at least one user is a
1029 /// cstexpr inside an initializer of another global variables. Also, don't
1030 /// handle cstexpr inside instructions. During global variable emission,
1031 /// candidates are skipped and are emitted later in case at least one cstexpr
1032 /// isn't replaced by a PC relative GOT entry access.
1033 static bool isGOTEquivalentCandidate(const GlobalVariable *GV,
1034 unsigned &NumGOTEquivUsers) {
1035 // Global GOT equivalents are unnamed private globals with a constant
1036 // pointer initializer to another global symbol. They must point to a
1037 // GlobalVariable or Function, i.e., as GlobalValue.
1038 if (!GV->hasUnnamedAddr() || !GV->hasInitializer() || !GV->isConstant() ||
1039 !GV->isDiscardableIfUnused() || !dyn_cast<GlobalValue>(GV->getOperand(0)))
1042 // To be a got equivalent, at least one of its users need to be a constant
1043 // expression used by another global variable.
1044 for (auto *U : GV->users())
1045 NumGOTEquivUsers += getNumGlobalVariableUses(dyn_cast<Constant>(U));
1047 return NumGOTEquivUsers > 0;
1050 /// \brief Unnamed constant global variables solely contaning a pointer to
1051 /// another globals variable is equivalent to a GOT table entry; it contains the
1052 /// the address of another symbol. Optimize it and replace accesses to these
1053 /// "GOT equivalents" by using the GOT entry for the final global instead.
1054 /// Compute GOT equivalent candidates among all global variables to avoid
1055 /// emitting them if possible later on, after it use is replaced by a GOT entry
1057 void AsmPrinter::computeGlobalGOTEquivs(Module &M) {
1058 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
1061 for (const auto &G : M.globals()) {
1062 unsigned NumGOTEquivUsers = 0;
1063 if (!isGOTEquivalentCandidate(&G, NumGOTEquivUsers))
1066 const MCSymbol *GOTEquivSym = getSymbol(&G);
1067 GlobalGOTEquivs[GOTEquivSym] = std::make_pair(&G, NumGOTEquivUsers);
1071 /// \brief Constant expressions using GOT equivalent globals may not be eligible
1072 /// for PC relative GOT entry conversion, in such cases we need to emit such
1073 /// globals we previously omitted in EmitGlobalVariable.
1074 void AsmPrinter::emitGlobalGOTEquivs() {
1075 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
1078 SmallVector<const GlobalVariable *, 8> FailedCandidates;
1079 for (auto &I : GlobalGOTEquivs) {
1080 const GlobalVariable *GV = I.second.first;
1081 unsigned Cnt = I.second.second;
1083 FailedCandidates.push_back(GV);
1085 GlobalGOTEquivs.clear();
1087 for (auto *GV : FailedCandidates)
1088 EmitGlobalVariable(GV);
1091 bool AsmPrinter::doFinalization(Module &M) {
1092 // Set the MachineFunction to nullptr so that we can catch attempted
1093 // accesses to MF specific features at the module level and so that
1094 // we can conditionalize accesses based on whether or not it is nullptr.
1097 // Gather all GOT equivalent globals in the module. We really need two
1098 // passes over the globals: one to compute and another to avoid its emission
1099 // in EmitGlobalVariable, otherwise we would not be able to handle cases
1100 // where the got equivalent shows up before its use.
1101 computeGlobalGOTEquivs(M);
1103 // Emit global variables.
1104 for (const auto &G : M.globals())
1105 EmitGlobalVariable(&G);
1107 // Emit remaining GOT equivalent globals.
1108 emitGlobalGOTEquivs();
1110 // Emit visibility info for declarations
1111 for (const Function &F : M) {
1112 if (!F.isDeclarationForLinker())
1114 GlobalValue::VisibilityTypes V = F.getVisibility();
1115 if (V == GlobalValue::DefaultVisibility)
1118 MCSymbol *Name = getSymbol(&F);
1119 EmitVisibility(Name, V, false);
1122 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1124 // Emit module flags.
1125 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
1126 M.getModuleFlagsMetadata(ModuleFlags);
1127 if (!ModuleFlags.empty())
1128 TLOF.emitModuleFlags(*OutStreamer, ModuleFlags, *Mang, TM);
1130 if (TM.getTargetTriple().isOSBinFormatELF()) {
1131 MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
1133 // Output stubs for external and common global variables.
1134 MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
1135 if (!Stubs.empty()) {
1136 OutStreamer->SwitchSection(TLOF.getDataRelSection());
1137 const DataLayout &DL = M.getDataLayout();
1139 for (const auto &Stub : Stubs) {
1140 OutStreamer->EmitLabel(Stub.first);
1141 OutStreamer->EmitSymbolValue(Stub.second.getPointer(),
1142 DL.getPointerSize());
1147 // Finalize debug and EH information.
1148 for (const HandlerInfo &HI : Handlers) {
1149 NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
1150 TimePassesIsEnabled);
1151 HI.Handler->endModule();
1157 // If the target wants to know about weak references, print them all.
1158 if (MAI->getWeakRefDirective()) {
1159 // FIXME: This is not lazy, it would be nice to only print weak references
1160 // to stuff that is actually used. Note that doing so would require targets
1161 // to notice uses in operands (due to constant exprs etc). This should
1162 // happen with the MC stuff eventually.
1164 // Print out module-level global variables here.
1165 for (const auto &G : M.globals()) {
1166 if (!G.hasExternalWeakLinkage())
1168 OutStreamer->EmitSymbolAttribute(getSymbol(&G), MCSA_WeakReference);
1171 for (const auto &F : M) {
1172 if (!F.hasExternalWeakLinkage())
1174 OutStreamer->EmitSymbolAttribute(getSymbol(&F), MCSA_WeakReference);
1178 OutStreamer->AddBlankLine();
1179 for (const auto &Alias : M.aliases()) {
1180 MCSymbol *Name = getSymbol(&Alias);
1182 if (Alias.hasExternalLinkage() || !MAI->getWeakRefDirective())
1183 OutStreamer->EmitSymbolAttribute(Name, MCSA_Global);
1184 else if (Alias.hasWeakLinkage() || Alias.hasLinkOnceLinkage())
1185 OutStreamer->EmitSymbolAttribute(Name, MCSA_WeakReference);
1187 assert(Alias.hasLocalLinkage() && "Invalid alias linkage");
1189 EmitVisibility(Name, Alias.getVisibility());
1191 // Emit the directives as assignments aka .set:
1192 OutStreamer->EmitAssignment(Name, lowerConstant(Alias.getAliasee()));
1194 // If the aliasee does not correspond to a symbol in the output, i.e. the
1195 // alias is not of an object or the aliased object is private, then set the
1196 // size of the alias symbol from the type of the alias. We don't do this in
1197 // other situations as the alias and aliasee having differing types but same
1198 // size may be intentional.
1199 const GlobalObject *BaseObject = Alias.getBaseObject();
1200 if (MAI->hasDotTypeDotSizeDirective() && Alias.getValueType()->isSized() &&
1201 (!BaseObject || BaseObject->hasPrivateLinkage())) {
1202 const DataLayout &DL = M.getDataLayout();
1203 uint64_t Size = DL.getTypeAllocSize(Alias.getValueType());
1204 OutStreamer->emitELFSize(cast<MCSymbolELF>(Name),
1205 MCConstantExpr::create(Size, OutContext));
1209 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1210 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1211 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1212 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1213 MP->finishAssembly(M, *MI, *this);
1215 // Emit llvm.ident metadata in an '.ident' directive.
1216 EmitModuleIdents(M);
1218 // Emit __morestack address if needed for indirect calls.
1219 if (MMI->usesMorestackAddr()) {
1220 MCSection *ReadOnlySection = getObjFileLowering().getSectionForConstant(
1221 getDataLayout(), SectionKind::getReadOnly(),
1223 OutStreamer->SwitchSection(ReadOnlySection);
1225 MCSymbol *AddrSymbol =
1226 OutContext.getOrCreateSymbol(StringRef("__morestack_addr"));
1227 OutStreamer->EmitLabel(AddrSymbol);
1229 unsigned PtrSize = M.getDataLayout().getPointerSize(0);
1230 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("__morestack"),
1234 // If we don't have any trampolines, then we don't require stack memory
1235 // to be executable. Some targets have a directive to declare this.
1236 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1237 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1238 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1239 OutStreamer->SwitchSection(S);
1241 // Allow the target to emit any magic that it wants at the end of the file,
1242 // after everything else has gone out.
1243 EmitEndOfAsmFile(M);
1245 delete Mang; Mang = nullptr;
1248 OutStreamer->Finish();
1249 OutStreamer->reset();
1254 MCSymbol *AsmPrinter::getCurExceptionSym() {
1255 if (!CurExceptionSym)
1256 CurExceptionSym = createTempSymbol("exception");
1257 return CurExceptionSym;
1260 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1262 // Get the function symbol.
1263 CurrentFnSym = getSymbol(MF.getFunction());
1264 CurrentFnSymForSize = CurrentFnSym;
1265 CurrentFnBegin = nullptr;
1266 CurExceptionSym = nullptr;
1267 bool NeedsLocalForSize = MAI->needsLocalForSize();
1268 if (!MMI->getLandingPads().empty() || MMI->hasDebugInfo() ||
1269 MMI->hasEHFunclets() || NeedsLocalForSize) {
1270 CurrentFnBegin = createTempSymbol("func_begin");
1271 if (NeedsLocalForSize)
1272 CurrentFnSymForSize = CurrentFnBegin;
1276 LI = &getAnalysis<MachineLoopInfo>();
1280 // Keep track the alignment, constpool entries per Section.
1284 SmallVector<unsigned, 4> CPEs;
1285 SectionCPs(MCSection *s, unsigned a) : S(s), Alignment(a) {}
1289 /// EmitConstantPool - Print to the current output stream assembly
1290 /// representations of the constants in the constant pool MCP. This is
1291 /// used to print out constants which have been "spilled to memory" by
1292 /// the code generator.
1294 void AsmPrinter::EmitConstantPool() {
1295 const MachineConstantPool *MCP = MF->getConstantPool();
1296 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1297 if (CP.empty()) return;
1299 // Calculate sections for constant pool entries. We collect entries to go into
1300 // the same section together to reduce amount of section switch statements.
1301 SmallVector<SectionCPs, 4> CPSections;
1302 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1303 const MachineConstantPoolEntry &CPE = CP[i];
1304 unsigned Align = CPE.getAlignment();
1306 SectionKind Kind = CPE.getSectionKind(&getDataLayout());
1308 const Constant *C = nullptr;
1309 if (!CPE.isMachineConstantPoolEntry())
1310 C = CPE.Val.ConstVal;
1313 getObjFileLowering().getSectionForConstant(getDataLayout(), Kind, C);
1315 // The number of sections are small, just do a linear search from the
1316 // last section to the first.
1318 unsigned SecIdx = CPSections.size();
1319 while (SecIdx != 0) {
1320 if (CPSections[--SecIdx].S == S) {
1326 SecIdx = CPSections.size();
1327 CPSections.push_back(SectionCPs(S, Align));
1330 if (Align > CPSections[SecIdx].Alignment)
1331 CPSections[SecIdx].Alignment = Align;
1332 CPSections[SecIdx].CPEs.push_back(i);
1335 // Now print stuff into the calculated sections.
1336 const MCSection *CurSection = nullptr;
1337 unsigned Offset = 0;
1338 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1339 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1340 unsigned CPI = CPSections[i].CPEs[j];
1341 MCSymbol *Sym = GetCPISymbol(CPI);
1342 if (!Sym->isUndefined())
1345 if (CurSection != CPSections[i].S) {
1346 OutStreamer->SwitchSection(CPSections[i].S);
1347 EmitAlignment(Log2_32(CPSections[i].Alignment));
1348 CurSection = CPSections[i].S;
1352 MachineConstantPoolEntry CPE = CP[CPI];
1354 // Emit inter-object padding for alignment.
1355 unsigned AlignMask = CPE.getAlignment() - 1;
1356 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1357 OutStreamer->EmitZeros(NewOffset - Offset);
1359 Type *Ty = CPE.getType();
1360 Offset = NewOffset + getDataLayout().getTypeAllocSize(Ty);
1362 OutStreamer->EmitLabel(Sym);
1363 if (CPE.isMachineConstantPoolEntry())
1364 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1366 EmitGlobalConstant(getDataLayout(), CPE.Val.ConstVal);
1371 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1372 /// by the current function to the current output stream.
1374 void AsmPrinter::EmitJumpTableInfo() {
1375 const DataLayout &DL = MF->getDataLayout();
1376 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1378 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1379 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1380 if (JT.empty()) return;
1382 // Pick the directive to use to print the jump table entries, and switch to
1383 // the appropriate section.
1384 const Function *F = MF->getFunction();
1385 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1386 bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
1387 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
1389 if (JTInDiffSection) {
1390 // Drop it in the readonly section.
1391 MCSection *ReadOnlySection = TLOF.getSectionForJumpTable(*F, *Mang, TM);
1392 OutStreamer->SwitchSection(ReadOnlySection);
1395 EmitAlignment(Log2_32(MJTI->getEntryAlignment(DL)));
1397 // Jump tables in code sections are marked with a data_region directive
1398 // where that's supported.
1399 if (!JTInDiffSection)
1400 OutStreamer->EmitDataRegion(MCDR_DataRegionJT32);
1402 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1403 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1405 // If this jump table was deleted, ignore it.
1406 if (JTBBs.empty()) continue;
1408 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1409 /// emit a .set directive for each unique entry.
1410 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1411 MAI->doesSetDirectiveSuppressesReloc()) {
1412 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1413 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1414 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1415 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1416 const MachineBasicBlock *MBB = JTBBs[ii];
1417 if (!EmittedSets.insert(MBB).second)
1420 // .set LJTSet, LBB32-base
1422 MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1423 OutStreamer->EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1424 MCBinaryExpr::createSub(LHS, Base,
1429 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1430 // before each jump table. The first label is never referenced, but tells
1431 // the assembler and linker the extents of the jump table object. The
1432 // second label is actually referenced by the code.
1433 if (JTInDiffSection && DL.hasLinkerPrivateGlobalPrefix())
1434 // FIXME: This doesn't have to have any specific name, just any randomly
1435 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1436 OutStreamer->EmitLabel(GetJTISymbol(JTI, true));
1438 OutStreamer->EmitLabel(GetJTISymbol(JTI));
1440 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1441 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1443 if (!JTInDiffSection)
1444 OutStreamer->EmitDataRegion(MCDR_DataRegionEnd);
1447 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1449 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1450 const MachineBasicBlock *MBB,
1451 unsigned UID) const {
1452 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1453 const MCExpr *Value = nullptr;
1454 switch (MJTI->getEntryKind()) {
1455 case MachineJumpTableInfo::EK_Inline:
1456 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1457 case MachineJumpTableInfo::EK_Custom32:
1458 Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
1459 MJTI, MBB, UID, OutContext);
1461 case MachineJumpTableInfo::EK_BlockAddress:
1462 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1464 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1466 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1467 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1468 // with a relocation as gp-relative, e.g.:
1470 MCSymbol *MBBSym = MBB->getSymbol();
1471 OutStreamer->EmitGPRel32Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1475 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1476 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1477 // with a relocation as gp-relative, e.g.:
1479 MCSymbol *MBBSym = MBB->getSymbol();
1480 OutStreamer->EmitGPRel64Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1484 case MachineJumpTableInfo::EK_LabelDifference32: {
1485 // Each entry is the address of the block minus the address of the jump
1486 // table. This is used for PIC jump tables where gprel32 is not supported.
1488 // .word LBB123 - LJTI1_2
1489 // If the .set directive avoids relocations, this is emitted as:
1490 // .set L4_5_set_123, LBB123 - LJTI1_2
1491 // .word L4_5_set_123
1492 if (MAI->doesSetDirectiveSuppressesReloc()) {
1493 Value = MCSymbolRefExpr::create(GetJTSetSymbol(UID, MBB->getNumber()),
1497 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1498 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1499 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1500 Value = MCBinaryExpr::createSub(Value, Base, OutContext);
1505 assert(Value && "Unknown entry kind!");
1507 unsigned EntrySize = MJTI->getEntrySize(getDataLayout());
1508 OutStreamer->EmitValue(Value, EntrySize);
1512 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1513 /// special global used by LLVM. If so, emit it and return true, otherwise
1514 /// do nothing and return false.
1515 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1516 if (GV->getName() == "llvm.used") {
1517 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1518 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1522 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1523 if (StringRef(GV->getSection()) == "llvm.metadata" ||
1524 GV->hasAvailableExternallyLinkage())
1527 if (!GV->hasAppendingLinkage()) return false;
1529 assert(GV->hasInitializer() && "Not a special LLVM global!");
1531 if (GV->getName() == "llvm.global_ctors") {
1532 EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
1535 if (TM.getRelocationModel() == Reloc::Static &&
1536 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1537 StringRef Sym(".constructors_used");
1538 OutStreamer->EmitSymbolAttribute(OutContext.getOrCreateSymbol(Sym),
1544 if (GV->getName() == "llvm.global_dtors") {
1545 EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
1546 /* isCtor */ false);
1548 if (TM.getRelocationModel() == Reloc::Static &&
1549 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1550 StringRef Sym(".destructors_used");
1551 OutStreamer->EmitSymbolAttribute(OutContext.getOrCreateSymbol(Sym),
1560 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1561 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1562 /// is true, as being used with this directive.
1563 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1564 // Should be an array of 'i8*'.
1565 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1566 const GlobalValue *GV =
1567 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1569 OutStreamer->EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1575 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1577 llvm::Constant *Func;
1578 llvm::GlobalValue *ComdatKey;
1582 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1584 void AsmPrinter::EmitXXStructorList(const DataLayout &DL, const Constant *List,
1586 // Should be an array of '{ int, void ()* }' structs. The first value is the
1588 if (!isa<ConstantArray>(List)) return;
1590 // Sanity check the structors list.
1591 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1592 if (!InitList) return; // Not an array!
1593 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1594 // FIXME: Only allow the 3-field form in LLVM 4.0.
1595 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1596 return; // Not an array of two or three elements!
1597 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1598 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1599 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1600 return; // Not (int, ptr, ptr).
1602 // Gather the structors in a form that's convenient for sorting by priority.
1603 SmallVector<Structor, 8> Structors;
1604 for (Value *O : InitList->operands()) {
1605 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1606 if (!CS) continue; // Malformed.
1607 if (CS->getOperand(1)->isNullValue())
1608 break; // Found a null terminator, skip the rest.
1609 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1610 if (!Priority) continue; // Malformed.
1611 Structors.push_back(Structor());
1612 Structor &S = Structors.back();
1613 S.Priority = Priority->getLimitedValue(65535);
1614 S.Func = CS->getOperand(1);
1615 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1616 S.ComdatKey = dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1619 // Emit the function pointers in the target-specific order
1620 unsigned Align = Log2_32(DL.getPointerPrefAlignment());
1621 std::stable_sort(Structors.begin(), Structors.end(),
1622 [](const Structor &L,
1623 const Structor &R) { return L.Priority < R.Priority; });
1624 for (Structor &S : Structors) {
1625 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1626 const MCSymbol *KeySym = nullptr;
1627 if (GlobalValue *GV = S.ComdatKey) {
1628 if (GV->hasAvailableExternallyLinkage())
1629 // If the associated variable is available_externally, some other TU
1630 // will provide its dynamic initializer.
1633 KeySym = getSymbol(GV);
1635 MCSection *OutputSection =
1636 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1637 : Obj.getStaticDtorSection(S.Priority, KeySym));
1638 OutStreamer->SwitchSection(OutputSection);
1639 if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
1640 EmitAlignment(Align);
1641 EmitXXStructor(DL, S.Func);
1645 void AsmPrinter::EmitModuleIdents(Module &M) {
1646 if (!MAI->hasIdentDirective())
1649 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1650 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1651 const MDNode *N = NMD->getOperand(i);
1652 assert(N->getNumOperands() == 1 &&
1653 "llvm.ident metadata entry can have only one operand");
1654 const MDString *S = cast<MDString>(N->getOperand(0));
1655 OutStreamer->EmitIdent(S->getString());
1660 //===--------------------------------------------------------------------===//
1661 // Emission and print routines
1664 /// EmitInt8 - Emit a byte directive and value.
1666 void AsmPrinter::EmitInt8(int Value) const {
1667 OutStreamer->EmitIntValue(Value, 1);
1670 /// EmitInt16 - Emit a short directive and value.
1672 void AsmPrinter::EmitInt16(int Value) const {
1673 OutStreamer->EmitIntValue(Value, 2);
1676 /// EmitInt32 - Emit a long directive and value.
1678 void AsmPrinter::EmitInt32(int Value) const {
1679 OutStreamer->EmitIntValue(Value, 4);
1682 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1683 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1684 /// .set if it avoids relocations.
1685 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1686 unsigned Size) const {
1687 OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
1690 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1691 /// where the size in bytes of the directive is specified by Size and Label
1692 /// specifies the label. This implicitly uses .set if it is available.
1693 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1695 bool IsSectionRelative) const {
1696 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1697 OutStreamer->EmitCOFFSecRel32(Label);
1701 // Emit Label+Offset (or just Label if Offset is zero)
1702 const MCExpr *Expr = MCSymbolRefExpr::create(Label, OutContext);
1704 Expr = MCBinaryExpr::createAdd(
1705 Expr, MCConstantExpr::create(Offset, OutContext), OutContext);
1707 OutStreamer->EmitValue(Expr, Size);
1710 //===----------------------------------------------------------------------===//
1712 // EmitAlignment - Emit an alignment directive to the specified power of
1713 // two boundary. For example, if you pass in 3 here, you will get an 8
1714 // byte alignment. If a global value is specified, and if that global has
1715 // an explicit alignment requested, it will override the alignment request
1716 // if required for correctness.
1718 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1720 NumBits = getGVAlignmentLog2(GV, GV->getParent()->getDataLayout(), NumBits);
1722 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1725 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
1726 "undefined behavior");
1727 if (getCurrentSection()->getKind().isText())
1728 OutStreamer->EmitCodeAlignment(1u << NumBits);
1730 OutStreamer->EmitValueToAlignment(1u << NumBits);
1733 //===----------------------------------------------------------------------===//
1734 // Constant emission.
1735 //===----------------------------------------------------------------------===//
1737 const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1738 MCContext &Ctx = OutContext;
1740 if (CV->isNullValue() || isa<UndefValue>(CV))
1741 return MCConstantExpr::create(0, Ctx);
1743 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1744 return MCConstantExpr::create(CI->getZExtValue(), Ctx);
1746 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1747 return MCSymbolRefExpr::create(getSymbol(GV), Ctx);
1749 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1750 return MCSymbolRefExpr::create(GetBlockAddressSymbol(BA), Ctx);
1752 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1754 llvm_unreachable("Unknown constant value to lower!");
1757 if (const MCExpr *RelocExpr
1758 = getObjFileLowering().getExecutableRelativeSymbol(CE, *Mang, TM))
1761 switch (CE->getOpcode()) {
1763 // If the code isn't optimized, there may be outstanding folding
1764 // opportunities. Attempt to fold the expression using DataLayout as a
1765 // last resort before giving up.
1766 if (Constant *C = ConstantFoldConstantExpression(CE, getDataLayout()))
1768 return lowerConstant(C);
1770 // Otherwise report the problem to the user.
1773 raw_string_ostream OS(S);
1774 OS << "Unsupported expression in static initializer: ";
1775 CE->printAsOperand(OS, /*PrintType=*/false,
1776 !MF ? nullptr : MF->getFunction()->getParent());
1777 report_fatal_error(OS.str());
1779 case Instruction::GetElementPtr: {
1780 // Generate a symbolic expression for the byte address
1781 APInt OffsetAI(getDataLayout().getPointerTypeSizeInBits(CE->getType()), 0);
1782 cast<GEPOperator>(CE)->accumulateConstantOffset(getDataLayout(), OffsetAI);
1784 const MCExpr *Base = lowerConstant(CE->getOperand(0));
1788 int64_t Offset = OffsetAI.getSExtValue();
1789 return MCBinaryExpr::createAdd(Base, MCConstantExpr::create(Offset, Ctx),
1793 case Instruction::Trunc:
1794 // We emit the value and depend on the assembler to truncate the generated
1795 // expression properly. This is important for differences between
1796 // blockaddress labels. Since the two labels are in the same function, it
1797 // is reasonable to treat their delta as a 32-bit value.
1799 case Instruction::BitCast:
1800 return lowerConstant(CE->getOperand(0));
1802 case Instruction::IntToPtr: {
1803 const DataLayout &DL = getDataLayout();
1805 // Handle casts to pointers by changing them into casts to the appropriate
1806 // integer type. This promotes constant folding and simplifies this code.
1807 Constant *Op = CE->getOperand(0);
1808 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1810 return lowerConstant(Op);
1813 case Instruction::PtrToInt: {
1814 const DataLayout &DL = getDataLayout();
1816 // Support only foldable casts to/from pointers that can be eliminated by
1817 // changing the pointer to the appropriately sized integer type.
1818 Constant *Op = CE->getOperand(0);
1819 Type *Ty = CE->getType();
1821 const MCExpr *OpExpr = lowerConstant(Op);
1823 // We can emit the pointer value into this slot if the slot is an
1824 // integer slot equal to the size of the pointer.
1825 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1828 // Otherwise the pointer is smaller than the resultant integer, mask off
1829 // the high bits so we are sure to get a proper truncation if the input is
1831 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1832 const MCExpr *MaskExpr = MCConstantExpr::create(~0ULL >> (64-InBits), Ctx);
1833 return MCBinaryExpr::createAnd(OpExpr, MaskExpr, Ctx);
1836 // The MC library also has a right-shift operator, but it isn't consistently
1837 // signed or unsigned between different targets.
1838 case Instruction::Add:
1839 case Instruction::Sub:
1840 case Instruction::Mul:
1841 case Instruction::SDiv:
1842 case Instruction::SRem:
1843 case Instruction::Shl:
1844 case Instruction::And:
1845 case Instruction::Or:
1846 case Instruction::Xor: {
1847 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
1848 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
1849 switch (CE->getOpcode()) {
1850 default: llvm_unreachable("Unknown binary operator constant cast expr");
1851 case Instruction::Add: return MCBinaryExpr::createAdd(LHS, RHS, Ctx);
1852 case Instruction::Sub: return MCBinaryExpr::createSub(LHS, RHS, Ctx);
1853 case Instruction::Mul: return MCBinaryExpr::createMul(LHS, RHS, Ctx);
1854 case Instruction::SDiv: return MCBinaryExpr::createDiv(LHS, RHS, Ctx);
1855 case Instruction::SRem: return MCBinaryExpr::createMod(LHS, RHS, Ctx);
1856 case Instruction::Shl: return MCBinaryExpr::createShl(LHS, RHS, Ctx);
1857 case Instruction::And: return MCBinaryExpr::createAnd(LHS, RHS, Ctx);
1858 case Instruction::Or: return MCBinaryExpr::createOr (LHS, RHS, Ctx);
1859 case Instruction::Xor: return MCBinaryExpr::createXor(LHS, RHS, Ctx);
1865 static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *C,
1867 const Constant *BaseCV = nullptr,
1868 uint64_t Offset = 0);
1870 /// isRepeatedByteSequence - Determine whether the given value is
1871 /// composed of a repeated sequence of identical bytes and return the
1872 /// byte value. If it is not a repeated sequence, return -1.
1873 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1874 StringRef Data = V->getRawDataValues();
1875 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1877 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1878 if (Data[i] != C) return -1;
1879 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1883 /// isRepeatedByteSequence - Determine whether the given value is
1884 /// composed of a repeated sequence of identical bytes and return the
1885 /// byte value. If it is not a repeated sequence, return -1.
1886 static int isRepeatedByteSequence(const Value *V, const DataLayout &DL) {
1887 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1888 uint64_t Size = DL.getTypeAllocSizeInBits(V->getType());
1889 assert(Size % 8 == 0);
1891 // Extend the element to take zero padding into account.
1892 APInt Value = CI->getValue().zextOrSelf(Size);
1893 if (!Value.isSplat(8))
1896 return Value.zextOrTrunc(8).getZExtValue();
1898 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1899 // Make sure all array elements are sequences of the same repeated
1901 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1902 Constant *Op0 = CA->getOperand(0);
1903 int Byte = isRepeatedByteSequence(Op0, DL);
1907 // All array elements must be equal.
1908 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i)
1909 if (CA->getOperand(i) != Op0)
1914 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1915 return isRepeatedByteSequence(CDS);
1920 static void emitGlobalConstantDataSequential(const DataLayout &DL,
1921 const ConstantDataSequential *CDS,
1924 // See if we can aggregate this into a .fill, if so, emit it as such.
1925 int Value = isRepeatedByteSequence(CDS, DL);
1927 uint64_t Bytes = DL.getTypeAllocSize(CDS->getType());
1928 // Don't emit a 1-byte object as a .fill.
1930 return AP.OutStreamer->EmitFill(Bytes, Value);
1933 // If this can be emitted with .ascii/.asciz, emit it as such.
1934 if (CDS->isString())
1935 return AP.OutStreamer->EmitBytes(CDS->getAsString());
1937 // Otherwise, emit the values in successive locations.
1938 unsigned ElementByteSize = CDS->getElementByteSize();
1939 if (isa<IntegerType>(CDS->getElementType())) {
1940 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1942 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
1943 CDS->getElementAsInteger(i));
1944 AP.OutStreamer->EmitIntValue(CDS->getElementAsInteger(i),
1947 } else if (ElementByteSize == 4) {
1948 // FP Constants are printed as integer constants to avoid losing
1950 assert(CDS->getElementType()->isFloatTy());
1951 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1957 F = CDS->getElementAsFloat(i);
1959 AP.OutStreamer->GetCommentOS() << "float " << F << '\n';
1960 AP.OutStreamer->EmitIntValue(I, 4);
1963 assert(CDS->getElementType()->isDoubleTy());
1964 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1970 F = CDS->getElementAsDouble(i);
1972 AP.OutStreamer->GetCommentOS() << "double " << F << '\n';
1973 AP.OutStreamer->EmitIntValue(I, 8);
1977 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1978 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1979 CDS->getNumElements();
1980 if (unsigned Padding = Size - EmittedSize)
1981 AP.OutStreamer->EmitZeros(Padding);
1985 static void emitGlobalConstantArray(const DataLayout &DL,
1986 const ConstantArray *CA, AsmPrinter &AP,
1987 const Constant *BaseCV, uint64_t Offset) {
1988 // See if we can aggregate some values. Make sure it can be
1989 // represented as a series of bytes of the constant value.
1990 int Value = isRepeatedByteSequence(CA, DL);
1993 uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
1994 AP.OutStreamer->EmitFill(Bytes, Value);
1997 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
1998 emitGlobalConstantImpl(DL, CA->getOperand(i), AP, BaseCV, Offset);
1999 Offset += DL.getTypeAllocSize(CA->getOperand(i)->getType());
2004 static void emitGlobalConstantVector(const DataLayout &DL,
2005 const ConstantVector *CV, AsmPrinter &AP) {
2006 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
2007 emitGlobalConstantImpl(DL, CV->getOperand(i), AP);
2009 unsigned Size = DL.getTypeAllocSize(CV->getType());
2010 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
2011 CV->getType()->getNumElements();
2012 if (unsigned Padding = Size - EmittedSize)
2013 AP.OutStreamer->EmitZeros(Padding);
2016 static void emitGlobalConstantStruct(const DataLayout &DL,
2017 const ConstantStruct *CS, AsmPrinter &AP,
2018 const Constant *BaseCV, uint64_t Offset) {
2019 // Print the fields in successive locations. Pad to align if needed!
2020 unsigned Size = DL.getTypeAllocSize(CS->getType());
2021 const StructLayout *Layout = DL.getStructLayout(CS->getType());
2022 uint64_t SizeSoFar = 0;
2023 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
2024 const Constant *Field = CS->getOperand(i);
2026 // Print the actual field value.
2027 emitGlobalConstantImpl(DL, Field, AP, BaseCV, Offset + SizeSoFar);
2029 // Check if padding is needed and insert one or more 0s.
2030 uint64_t FieldSize = DL.getTypeAllocSize(Field->getType());
2031 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
2032 - Layout->getElementOffset(i)) - FieldSize;
2033 SizeSoFar += FieldSize + PadSize;
2035 // Insert padding - this may include padding to increase the size of the
2036 // current field up to the ABI size (if the struct is not packed) as well
2037 // as padding to ensure that the next field starts at the right offset.
2038 AP.OutStreamer->EmitZeros(PadSize);
2040 assert(SizeSoFar == Layout->getSizeInBytes() &&
2041 "Layout of constant struct may be incorrect!");
2044 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
2045 APInt API = CFP->getValueAPF().bitcastToAPInt();
2047 // First print a comment with what we think the original floating-point value
2048 // should have been.
2049 if (AP.isVerbose()) {
2050 SmallString<8> StrVal;
2051 CFP->getValueAPF().toString(StrVal);
2054 CFP->getType()->print(AP.OutStreamer->GetCommentOS());
2056 AP.OutStreamer->GetCommentOS() << "Printing <null> Type";
2057 AP.OutStreamer->GetCommentOS() << ' ' << StrVal << '\n';
2060 // Now iterate through the APInt chunks, emitting them in endian-correct
2061 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
2063 unsigned NumBytes = API.getBitWidth() / 8;
2064 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
2065 const uint64_t *p = API.getRawData();
2067 // PPC's long double has odd notions of endianness compared to how LLVM
2068 // handles it: p[0] goes first for *big* endian on PPC.
2069 if (AP.getDataLayout().isBigEndian() && !CFP->getType()->isPPC_FP128Ty()) {
2070 int Chunk = API.getNumWords() - 1;
2073 AP.OutStreamer->EmitIntValue(p[Chunk--], TrailingBytes);
2075 for (; Chunk >= 0; --Chunk)
2076 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
2079 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
2080 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
2083 AP.OutStreamer->EmitIntValue(p[Chunk], TrailingBytes);
2086 // Emit the tail padding for the long double.
2087 const DataLayout &DL = AP.getDataLayout();
2088 AP.OutStreamer->EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
2089 DL.getTypeStoreSize(CFP->getType()));
2092 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
2093 const DataLayout &DL = AP.getDataLayout();
2094 unsigned BitWidth = CI->getBitWidth();
2096 // Copy the value as we may massage the layout for constants whose bit width
2097 // is not a multiple of 64-bits.
2098 APInt Realigned(CI->getValue());
2099 uint64_t ExtraBits = 0;
2100 unsigned ExtraBitsSize = BitWidth & 63;
2102 if (ExtraBitsSize) {
2103 // The bit width of the data is not a multiple of 64-bits.
2104 // The extra bits are expected to be at the end of the chunk of the memory.
2106 // * Nothing to be done, just record the extra bits to emit.
2108 // * Record the extra bits to emit.
2109 // * Realign the raw data to emit the chunks of 64-bits.
2110 if (DL.isBigEndian()) {
2111 // Basically the structure of the raw data is a chunk of 64-bits cells:
2112 // 0 1 BitWidth / 64
2113 // [chunk1][chunk2] ... [chunkN].
2114 // The most significant chunk is chunkN and it should be emitted first.
2115 // However, due to the alignment issue chunkN contains useless bits.
2116 // Realign the chunks so that they contain only useless information:
2117 // ExtraBits 0 1 (BitWidth / 64) - 1
2118 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
2119 ExtraBits = Realigned.getRawData()[0] &
2120 (((uint64_t)-1) >> (64 - ExtraBitsSize));
2121 Realigned = Realigned.lshr(ExtraBitsSize);
2123 ExtraBits = Realigned.getRawData()[BitWidth / 64];
2126 // We don't expect assemblers to support integer data directives
2127 // for more than 64 bits, so we emit the data in at most 64-bit
2128 // quantities at a time.
2129 const uint64_t *RawData = Realigned.getRawData();
2130 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
2131 uint64_t Val = DL.isBigEndian() ? RawData[e - i - 1] : RawData[i];
2132 AP.OutStreamer->EmitIntValue(Val, 8);
2135 if (ExtraBitsSize) {
2136 // Emit the extra bits after the 64-bits chunks.
2138 // Emit a directive that fills the expected size.
2139 uint64_t Size = AP.getDataLayout().getTypeAllocSize(CI->getType());
2140 Size -= (BitWidth / 64) * 8;
2141 assert(Size && Size * 8 >= ExtraBitsSize &&
2142 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
2143 == ExtraBits && "Directive too small for extra bits.");
2144 AP.OutStreamer->EmitIntValue(ExtraBits, Size);
2148 /// \brief Transform a not absolute MCExpr containing a reference to a GOT
2149 /// equivalent global, by a target specific GOT pc relative access to the
2151 static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
2152 const Constant *BaseCst,
2154 // The global @foo below illustrates a global that uses a got equivalent.
2156 // @bar = global i32 42
2157 // @gotequiv = private unnamed_addr constant i32* @bar
2158 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
2159 // i64 ptrtoint (i32* @foo to i64))
2162 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
2163 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
2166 // foo = cstexpr, where
2167 // cstexpr := <gotequiv> - "." + <cst>
2168 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
2170 // After canonicalization by evaluateAsRelocatable `ME` turns into:
2172 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
2173 // gotpcrelcst := <offset from @foo base> + <cst>
2176 if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
2178 const MCSymbolRefExpr *SymA = MV.getSymA();
2182 // Check that GOT equivalent symbol is cached.
2183 const MCSymbol *GOTEquivSym = &SymA->getSymbol();
2184 if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
2187 const GlobalValue *BaseGV = dyn_cast_or_null<GlobalValue>(BaseCst);
2191 // Check for a valid base symbol
2192 const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
2193 const MCSymbolRefExpr *SymB = MV.getSymB();
2195 if (!SymB || BaseSym != &SymB->getSymbol())
2198 // Make sure to match:
2200 // gotpcrelcst := <offset from @foo base> + <cst>
2202 // If gotpcrelcst is positive it means that we can safely fold the pc rel
2203 // displacement into the GOTPCREL. We can also can have an extra offset <cst>
2204 // if the target knows how to encode it.
2206 int64_t GOTPCRelCst = Offset + MV.getConstant();
2207 if (GOTPCRelCst < 0)
2209 if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
2212 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
2219 // .long gotequiv - "." + <cst>
2221 // is replaced by the target specific equivalent to:
2226 // .long bar@GOTPCREL+<gotpcrelcst>
2228 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
2229 const GlobalVariable *GV = Result.first;
2230 int NumUses = (int)Result.second;
2231 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
2232 const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
2233 *ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(
2234 FinalSym, MV, Offset, AP.MMI, *AP.OutStreamer);
2236 // Update GOT equivalent usage information
2239 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
2242 static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *CV,
2243 AsmPrinter &AP, const Constant *BaseCV,
2245 uint64_t Size = DL.getTypeAllocSize(CV->getType());
2247 // Globals with sub-elements such as combinations of arrays and structs
2248 // are handled recursively by emitGlobalConstantImpl. Keep track of the
2249 // constant symbol base and the current position with BaseCV and Offset.
2250 if (!BaseCV && CV->hasOneUse())
2251 BaseCV = dyn_cast<Constant>(CV->user_back());
2253 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
2254 return AP.OutStreamer->EmitZeros(Size);
2256 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
2263 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
2264 CI->getZExtValue());
2265 AP.OutStreamer->EmitIntValue(CI->getZExtValue(), Size);
2268 emitGlobalConstantLargeInt(CI, AP);
2273 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
2274 return emitGlobalConstantFP(CFP, AP);
2276 if (isa<ConstantPointerNull>(CV)) {
2277 AP.OutStreamer->EmitIntValue(0, Size);
2281 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
2282 return emitGlobalConstantDataSequential(DL, CDS, AP);
2284 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2285 return emitGlobalConstantArray(DL, CVA, AP, BaseCV, Offset);
2287 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2288 return emitGlobalConstantStruct(DL, CVS, AP, BaseCV, Offset);
2290 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2291 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2293 if (CE->getOpcode() == Instruction::BitCast)
2294 return emitGlobalConstantImpl(DL, CE->getOperand(0), AP);
2297 // If the constant expression's size is greater than 64-bits, then we have
2298 // to emit the value in chunks. Try to constant fold the value and emit it
2300 Constant *New = ConstantFoldConstantExpression(CE, DL);
2301 if (New && New != CE)
2302 return emitGlobalConstantImpl(DL, New, AP);
2306 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2307 return emitGlobalConstantVector(DL, V, AP);
2309 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2310 // thread the streamer with EmitValue.
2311 const MCExpr *ME = AP.lowerConstant(CV);
2313 // Since lowerConstant already folded and got rid of all IR pointer and
2314 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
2316 if (AP.getObjFileLowering().supportIndirectSymViaGOTPCRel())
2317 handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
2319 AP.OutStreamer->EmitValue(ME, Size);
2322 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2323 void AsmPrinter::EmitGlobalConstant(const DataLayout &DL, const Constant *CV) {
2324 uint64_t Size = DL.getTypeAllocSize(CV->getType());
2326 emitGlobalConstantImpl(DL, CV, *this);
2327 else if (MAI->hasSubsectionsViaSymbols()) {
2328 // If the global has zero size, emit a single byte so that two labels don't
2329 // look like they are at the same location.
2330 OutStreamer->EmitIntValue(0, 1);
2334 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2335 // Target doesn't support this yet!
2336 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2339 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2341 OS << '+' << Offset;
2342 else if (Offset < 0)
2346 //===----------------------------------------------------------------------===//
2347 // Symbol Lowering Routines.
2348 //===----------------------------------------------------------------------===//
2350 MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name) const {
2351 return OutContext.createTempSymbol(Name, true);
2354 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2355 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2358 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2359 return MMI->getAddrLabelSymbol(BB);
2362 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2363 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2364 const DataLayout &DL = getDataLayout();
2365 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
2366 "CPI" + Twine(getFunctionNumber()) + "_" +
2370 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2371 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2372 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2375 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2376 /// FIXME: privatize to AsmPrinter.
2377 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2378 const DataLayout &DL = getDataLayout();
2379 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
2380 Twine(getFunctionNumber()) + "_" +
2381 Twine(UID) + "_set_" + Twine(MBBID));
2384 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2385 StringRef Suffix) const {
2386 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2390 /// Return the MCSymbol for the specified ExternalSymbol.
2391 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2392 SmallString<60> NameStr;
2393 Mangler::getNameWithPrefix(NameStr, Sym, getDataLayout());
2394 return OutContext.getOrCreateSymbol(NameStr);
2399 /// PrintParentLoopComment - Print comments about parent loops of this one.
2400 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2401 unsigned FunctionNumber) {
2403 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2404 OS.indent(Loop->getLoopDepth()*2)
2405 << "Parent Loop BB" << FunctionNumber << "_"
2406 << Loop->getHeader()->getNumber()
2407 << " Depth=" << Loop->getLoopDepth() << '\n';
2411 /// PrintChildLoopComment - Print comments about child loops within
2412 /// the loop for this basic block, with nesting.
2413 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2414 unsigned FunctionNumber) {
2415 // Add child loop information
2416 for (const MachineLoop *CL : *Loop) {
2417 OS.indent(CL->getLoopDepth()*2)
2418 << "Child Loop BB" << FunctionNumber << "_"
2419 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2421 PrintChildLoopComment(OS, CL, FunctionNumber);
2425 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2426 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2427 const MachineLoopInfo *LI,
2428 const AsmPrinter &AP) {
2429 // Add loop depth information
2430 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2433 MachineBasicBlock *Header = Loop->getHeader();
2434 assert(Header && "No header for loop");
2436 // If this block is not a loop header, just print out what is the loop header
2438 if (Header != &MBB) {
2439 AP.OutStreamer->AddComment(" in Loop: Header=BB" +
2440 Twine(AP.getFunctionNumber())+"_" +
2441 Twine(Loop->getHeader()->getNumber())+
2442 " Depth="+Twine(Loop->getLoopDepth()));
2446 // Otherwise, it is a loop header. Print out information about child and
2448 raw_ostream &OS = AP.OutStreamer->GetCommentOS();
2450 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2453 OS.indent(Loop->getLoopDepth()*2-2);
2458 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2460 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2464 /// EmitBasicBlockStart - This method prints the label for the specified
2465 /// MachineBasicBlock, an alignment (if present) and a comment describing
2466 /// it if appropriate.
2467 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2468 // End the previous funclet and start a new one.
2469 if (MBB.isEHFuncletEntry()) {
2470 for (const HandlerInfo &HI : Handlers) {
2471 HI.Handler->endFunclet();
2472 HI.Handler->beginFunclet(MBB);
2476 // Emit an alignment directive for this block, if needed.
2477 if (unsigned Align = MBB.getAlignment())
2478 EmitAlignment(Align);
2480 // If the block has its address taken, emit any labels that were used to
2481 // reference the block. It is possible that there is more than one label
2482 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2483 // the references were generated.
2484 if (MBB.hasAddressTaken()) {
2485 const BasicBlock *BB = MBB.getBasicBlock();
2487 OutStreamer->AddComment("Block address taken");
2489 // MBBs can have their address taken as part of CodeGen without having
2490 // their corresponding BB's address taken in IR
2491 if (BB->hasAddressTaken())
2492 for (MCSymbol *Sym : MMI->getAddrLabelSymbolToEmit(BB))
2493 OutStreamer->EmitLabel(Sym);
2496 // Print some verbose block comments.
2498 if (const BasicBlock *BB = MBB.getBasicBlock())
2500 OutStreamer->AddComment("%" + BB->getName());
2501 emitBasicBlockLoopComments(MBB, LI, *this);
2504 // Print the main label for the block.
2505 if (MBB.pred_empty() ||
2506 (isBlockOnlyReachableByFallthrough(&MBB) && !MBB.isEHFuncletEntry())) {
2508 // NOTE: Want this comment at start of line, don't emit with AddComment.
2509 OutStreamer->emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2512 OutStreamer->EmitLabel(MBB.getSymbol());
2516 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2517 bool IsDefinition) const {
2518 MCSymbolAttr Attr = MCSA_Invalid;
2520 switch (Visibility) {
2522 case GlobalValue::HiddenVisibility:
2524 Attr = MAI->getHiddenVisibilityAttr();
2526 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2528 case GlobalValue::ProtectedVisibility:
2529 Attr = MAI->getProtectedVisibilityAttr();
2533 if (Attr != MCSA_Invalid)
2534 OutStreamer->EmitSymbolAttribute(Sym, Attr);
2537 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2538 /// exactly one predecessor and the control transfer mechanism between
2539 /// the predecessor and this block is a fall-through.
2541 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2542 // If this is a landing pad, it isn't a fall through. If it has no preds,
2543 // then nothing falls through to it.
2544 if (MBB->isEHPad() || MBB->pred_empty())
2547 // If there isn't exactly one predecessor, it can't be a fall through.
2548 if (MBB->pred_size() > 1)
2551 // The predecessor has to be immediately before this block.
2552 MachineBasicBlock *Pred = *MBB->pred_begin();
2553 if (!Pred->isLayoutSuccessor(MBB))
2556 // If the block is completely empty, then it definitely does fall through.
2560 // Check the terminators in the previous blocks
2561 for (const auto &MI : Pred->terminators()) {
2562 // If it is not a simple branch, we are in a table somewhere.
2563 if (!MI.isBranch() || MI.isIndirectBranch())
2566 // If we are the operands of one of the branches, this is not a fall
2567 // through. Note that targets with delay slots will usually bundle
2568 // terminators with the delay slot instruction.
2569 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2572 if (OP->isMBB() && OP->getMBB() == MBB)
2582 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2583 if (!S.usesMetadata())
2586 assert(!S.useStatepoints() && "statepoints do not currently support custom"
2587 " stackmap formats, please see the documentation for a description of"
2588 " the default format. If you really need a custom serialized format,"
2589 " please file a bug");
2591 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2592 gcp_map_type::iterator GCPI = GCMap.find(&S);
2593 if (GCPI != GCMap.end())
2594 return GCPI->second.get();
2596 const char *Name = S.getName().c_str();
2598 for (GCMetadataPrinterRegistry::iterator
2599 I = GCMetadataPrinterRegistry::begin(),
2600 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2601 if (strcmp(Name, I->getName()) == 0) {
2602 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2604 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2605 return IterBool.first->second.get();
2608 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2611 /// Pin vtable to this file.
2612 AsmPrinterHandler::~AsmPrinterHandler() {}
2614 void AsmPrinterHandler::markFunctionEnd() {}