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 "CodeViewDebug.h"
16 #include "DwarfDebug.h"
17 #include "DwarfException.h"
18 #include "WinException.h"
19 #include "llvm/ADT/Statistic.h"
20 #include "llvm/Analysis/ConstantFolding.h"
21 #include "llvm/CodeGen/Analysis.h"
22 #include "llvm/CodeGen/GCMetadataPrinter.h"
23 #include "llvm/CodeGen/MachineConstantPool.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineInstrBundle.h"
27 #include "llvm/CodeGen/MachineJumpTableInfo.h"
28 #include "llvm/CodeGen/MachineLoopInfo.h"
29 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/DebugInfo.h"
32 #include "llvm/IR/Mangler.h"
33 #include "llvm/IR/Module.h"
34 #include "llvm/IR/Operator.h"
35 #include "llvm/MC/MCAsmInfo.h"
36 #include "llvm/MC/MCContext.h"
37 #include "llvm/MC/MCExpr.h"
38 #include "llvm/MC/MCInst.h"
39 #include "llvm/MC/MCSection.h"
40 #include "llvm/MC/MCSectionELF.h"
41 #include "llvm/MC/MCSectionMachO.h"
42 #include "llvm/MC/MCStreamer.h"
43 #include "llvm/MC/MCSymbolELF.h"
44 #include "llvm/MC/MCValue.h"
45 #include "llvm/Support/ErrorHandling.h"
46 #include "llvm/Support/Format.h"
47 #include "llvm/Support/MathExtras.h"
48 #include "llvm/Support/TargetRegistry.h"
49 #include "llvm/Support/Timer.h"
50 #include "llvm/Target/TargetFrameLowering.h"
51 #include "llvm/Target/TargetInstrInfo.h"
52 #include "llvm/Target/TargetLowering.h"
53 #include "llvm/Target/TargetLoweringObjectFile.h"
54 #include "llvm/Target/TargetRegisterInfo.h"
55 #include "llvm/Target/TargetSubtargetInfo.h"
58 #define DEBUG_TYPE "asm-printer"
60 static const char *const DWARFGroupName = "dwarf";
61 static const char *const DWARFGroupDescription = "DWARF Emission";
62 static const char *const DbgTimerName = "emit";
63 static const char *const DbgTimerDescription = "Debug Info Emission";
64 static const char *const EHTimerName = "write_exception";
65 static const char *const EHTimerDescription = "DWARF Exception Writer";
66 static const char *const CodeViewLineTablesGroupName = "linetables";
67 static const char *const CodeViewLineTablesGroupDescription =
68 "CodeView Line Tables";
70 STATISTIC(EmittedInsts, "Number of machine instrs printed");
72 char AsmPrinter::ID = 0;
74 typedef DenseMap<GCStrategy*, std::unique_ptr<GCMetadataPrinter>> gcp_map_type;
75 static gcp_map_type &getGCMap(void *&P) {
77 P = new gcp_map_type();
78 return *(gcp_map_type*)P;
82 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
83 /// value in log2 form. This rounds up to the preferred alignment if possible
85 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &DL,
86 unsigned InBits = 0) {
88 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
89 NumBits = DL.getPreferredAlignmentLog(GVar);
91 // If InBits is specified, round it to it.
95 // If the GV has a specified alignment, take it into account.
96 if (GV->getAlignment() == 0)
99 unsigned GVAlign = Log2_32(GV->getAlignment());
101 // If the GVAlign is larger than NumBits, or if we are required to obey
102 // NumBits because the GV has an assigned section, obey it.
103 if (GVAlign > NumBits || GV->hasSection())
108 AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
109 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
110 OutContext(Streamer->getContext()), OutStreamer(std::move(Streamer)),
111 isCFIMoveForDebugging(false), LastMI(nullptr), LastFn(0), Counter(~0U) {
116 CurExceptionSym = CurrentFnSym = CurrentFnSymForSize = nullptr;
117 CurrentFnBegin = nullptr;
118 CurrentFnEnd = nullptr;
119 GCMetadataPrinters = nullptr;
120 VerboseAsm = OutStreamer->isVerboseAsm();
123 AsmPrinter::~AsmPrinter() {
124 assert(!DD && Handlers.empty() && "Debug/EH info didn't get finalized");
126 if (GCMetadataPrinters) {
127 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
130 GCMetadataPrinters = nullptr;
134 bool AsmPrinter::isPositionIndependent() const {
135 return TM.isPositionIndependent();
138 /// getFunctionNumber - Return a unique ID for the current function.
140 unsigned AsmPrinter::getFunctionNumber() const {
141 return MF->getFunctionNumber();
144 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
145 return *TM.getObjFileLowering();
148 const DataLayout &AsmPrinter::getDataLayout() const {
149 return MMI->getModule()->getDataLayout();
152 // Do not use the cached DataLayout because some client use it without a Module
153 // (llvm-dsymutil, llvm-dwarfdump).
154 unsigned AsmPrinter::getPointerSize() const { return TM.getPointerSize(); }
156 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
157 assert(MF && "getSubtargetInfo requires a valid MachineFunction!");
158 return MF->getSubtarget<MCSubtargetInfo>();
161 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
162 S.EmitInstruction(Inst, getSubtargetInfo());
165 /// getCurrentSection() - Return the current section we are emitting to.
166 const MCSection *AsmPrinter::getCurrentSection() const {
167 return OutStreamer->getCurrentSectionOnly();
170 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
171 AU.setPreservesAll();
172 MachineFunctionPass::getAnalysisUsage(AU);
173 AU.addRequired<MachineModuleInfo>();
174 AU.addRequired<GCModuleInfo>();
176 AU.addRequired<MachineLoopInfo>();
179 bool AsmPrinter::doInitialization(Module &M) {
180 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
182 // Initialize TargetLoweringObjectFile.
183 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
184 .Initialize(OutContext, TM);
186 OutStreamer->InitSections(false);
188 // Emit the version-min deplyment target directive if needed.
190 // FIXME: If we end up with a collection of these sorts of Darwin-specific
191 // or ELF-specific things, it may make sense to have a platform helper class
192 // that will work with the target helper class. For now keep it here, as the
193 // alternative is duplicated code in each of the target asm printers that
194 // use the directive, where it would need the same conditionalization
196 const Triple &TT = TM.getTargetTriple();
197 // If there is a version specified, Major will be non-zero.
198 if (TT.isOSDarwin() && TT.getOSMajorVersion() != 0) {
199 unsigned Major, Minor, Update;
200 MCVersionMinType VersionType;
201 if (TT.isWatchOS()) {
202 VersionType = MCVM_WatchOSVersionMin;
203 TT.getWatchOSVersion(Major, Minor, Update);
204 } else if (TT.isTvOS()) {
205 VersionType = MCVM_TvOSVersionMin;
206 TT.getiOSVersion(Major, Minor, Update);
207 } else if (TT.isMacOSX()) {
208 VersionType = MCVM_OSXVersionMin;
209 if (!TT.getMacOSXVersion(Major, Minor, Update))
212 VersionType = MCVM_IOSVersionMin;
213 TT.getiOSVersion(Major, Minor, Update);
216 OutStreamer->EmitVersionMin(VersionType, Major, Minor, Update);
219 // Allow the target to emit any magic that it wants at the start of the file.
220 EmitStartOfAsmFile(M);
222 // Very minimal debug info. It is ignored if we emit actual debug info. If we
223 // don't, this at least helps the user find where a global came from.
224 if (MAI->hasSingleParameterDotFile()) {
226 OutStreamer->EmitFileDirective(M.getModuleIdentifier());
229 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
230 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
232 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
233 MP->beginAssembly(M, *MI, *this);
235 // Emit module-level inline asm if it exists.
236 if (!M.getModuleInlineAsm().empty()) {
237 // We're at the module level. Construct MCSubtarget from the default CPU
238 // and target triple.
239 std::unique_ptr<MCSubtargetInfo> STI(TM.getTarget().createMCSubtargetInfo(
240 TM.getTargetTriple().str(), TM.getTargetCPU(),
241 TM.getTargetFeatureString()));
242 OutStreamer->AddComment("Start of file scope inline assembly");
243 OutStreamer->AddBlankLine();
244 EmitInlineAsm(M.getModuleInlineAsm()+"\n",
245 OutContext.getSubtargetCopy(*STI), TM.Options.MCOptions);
246 OutStreamer->AddComment("End of file scope inline assembly");
247 OutStreamer->AddBlankLine();
250 if (MAI->doesSupportDebugInformation()) {
251 bool EmitCodeView = MMI->getModule()->getCodeViewFlag();
252 if (EmitCodeView && (TM.getTargetTriple().isKnownWindowsMSVCEnvironment() ||
253 TM.getTargetTriple().isWindowsItaniumEnvironment())) {
254 Handlers.push_back(HandlerInfo(new CodeViewDebug(this),
255 DbgTimerName, DbgTimerDescription,
256 CodeViewLineTablesGroupName,
257 CodeViewLineTablesGroupDescription));
259 if (!EmitCodeView || MMI->getModule()->getDwarfVersion()) {
260 DD = new DwarfDebug(this, &M);
262 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DbgTimerDescription,
263 DWARFGroupName, DWARFGroupDescription));
267 switch (MAI->getExceptionHandlingType()) {
268 case ExceptionHandling::SjLj:
269 case ExceptionHandling::DwarfCFI:
270 case ExceptionHandling::ARM:
271 isCFIMoveForDebugging = true;
272 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
274 for (auto &F: M.getFunctionList()) {
275 // If the module contains any function with unwind data,
276 // .eh_frame has to be emitted.
277 // Ignore functions that won't get emitted.
278 if (!F.isDeclarationForLinker() && F.needsUnwindTableEntry()) {
279 isCFIMoveForDebugging = false;
285 isCFIMoveForDebugging = false;
289 EHStreamer *ES = nullptr;
290 switch (MAI->getExceptionHandlingType()) {
291 case ExceptionHandling::None:
293 case ExceptionHandling::SjLj:
294 case ExceptionHandling::DwarfCFI:
295 ES = new DwarfCFIException(this);
297 case ExceptionHandling::ARM:
298 ES = new ARMException(this);
300 case ExceptionHandling::WinEH:
301 switch (MAI->getWinEHEncodingType()) {
302 default: llvm_unreachable("unsupported unwinding information encoding");
303 case WinEH::EncodingType::Invalid:
305 case WinEH::EncodingType::X86:
306 case WinEH::EncodingType::Itanium:
307 ES = new WinException(this);
313 Handlers.push_back(HandlerInfo(ES, EHTimerName, EHTimerDescription,
314 DWARFGroupName, DWARFGroupDescription));
318 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
319 if (!MAI.hasWeakDefCanBeHiddenDirective())
322 return canBeOmittedFromSymbolTable(GV);
325 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
326 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
328 case GlobalValue::CommonLinkage:
329 case GlobalValue::LinkOnceAnyLinkage:
330 case GlobalValue::LinkOnceODRLinkage:
331 case GlobalValue::WeakAnyLinkage:
332 case GlobalValue::WeakODRLinkage:
333 if (MAI->hasWeakDefDirective()) {
335 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
337 if (!canBeHidden(GV, *MAI))
338 // .weak_definition _foo
339 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
341 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
342 } else if (MAI->hasLinkOnceDirective()) {
344 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
345 //NOTE: linkonce is handled by the section the symbol was assigned to.
348 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Weak);
351 case GlobalValue::ExternalLinkage:
352 // If external, declare as a global symbol: .globl _foo
353 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
355 case GlobalValue::PrivateLinkage:
356 case GlobalValue::InternalLinkage:
358 case GlobalValue::AppendingLinkage:
359 case GlobalValue::AvailableExternallyLinkage:
360 case GlobalValue::ExternalWeakLinkage:
361 llvm_unreachable("Should never emit this");
363 llvm_unreachable("Unknown linkage type!");
366 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
367 const GlobalValue *GV) const {
368 TM.getNameWithPrefix(Name, GV, getObjFileLowering().getMangler());
371 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
372 return TM.getSymbol(GV);
375 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
376 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
377 bool IsEmuTLSVar = TM.Options.EmulatedTLS && GV->isThreadLocal();
378 assert(!(IsEmuTLSVar && GV->hasCommonLinkage()) &&
379 "No emulated TLS variables in the common section");
381 // Never emit TLS variable xyz in emulated TLS model.
382 // The initialization value is in __emutls_t.xyz instead of xyz.
386 if (GV->hasInitializer()) {
387 // Check to see if this is a special global used by LLVM, if so, emit it.
388 if (EmitSpecialLLVMGlobal(GV))
391 // Skip the emission of global equivalents. The symbol can be emitted later
392 // on by emitGlobalGOTEquivs in case it turns out to be needed.
393 if (GlobalGOTEquivs.count(getSymbol(GV)))
397 // When printing the control variable __emutls_v.*,
398 // we don't need to print the original TLS variable name.
399 GV->printAsOperand(OutStreamer->GetCommentOS(),
400 /*PrintType=*/false, GV->getParent());
401 OutStreamer->GetCommentOS() << '\n';
405 MCSymbol *GVSym = getSymbol(GV);
406 MCSymbol *EmittedSym = GVSym;
408 // getOrCreateEmuTLSControlSym only creates the symbol with name and default
410 // GV's or GVSym's attributes will be used for the EmittedSym.
411 EmitVisibility(EmittedSym, GV->getVisibility(), !GV->isDeclaration());
413 if (!GV->hasInitializer()) // External globals require no extra code.
416 GVSym->redefineIfPossible();
417 if (GVSym->isDefined() || GVSym->isVariable())
418 report_fatal_error("symbol '" + Twine(GVSym->getName()) +
419 "' is already defined");
421 if (MAI->hasDotTypeDotSizeDirective())
422 OutStreamer->EmitSymbolAttribute(EmittedSym, MCSA_ELF_TypeObject);
424 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
426 const DataLayout &DL = GV->getParent()->getDataLayout();
427 uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
429 // If the alignment is specified, we *must* obey it. Overaligning a global
430 // with a specified alignment is a prompt way to break globals emitted to
431 // sections and expected to be contiguous (e.g. ObjC metadata).
432 unsigned AlignLog = getGVAlignmentLog2(GV, DL);
434 for (const HandlerInfo &HI : Handlers) {
435 NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
436 HI.TimerGroupName, HI.TimerGroupDescription,
437 TimePassesIsEnabled);
438 HI.Handler->setSymbolSize(GVSym, Size);
441 // Handle common symbols
442 if (GVKind.isCommon()) {
443 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
444 unsigned Align = 1 << AlignLog;
445 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
449 OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
453 // Determine to which section this global should be emitted.
454 MCSection *TheSection = getObjFileLowering().SectionForGlobal(GV, GVKind, TM);
456 // If we have a bss global going to a section that supports the
457 // zerofill directive, do so here.
458 if (GVKind.isBSS() && MAI->hasMachoZeroFillDirective() &&
459 TheSection->isVirtualSection()) {
461 Size = 1; // zerofill of 0 bytes is undefined.
462 unsigned Align = 1 << AlignLog;
463 EmitLinkage(GV, GVSym);
464 // .zerofill __DATA, __bss, _foo, 400, 5
465 OutStreamer->EmitZerofill(TheSection, GVSym, Size, Align);
469 // If this is a BSS local symbol and we are emitting in the BSS
470 // section use .lcomm/.comm directive.
471 if (GVKind.isBSSLocal() &&
472 getObjFileLowering().getBSSSection() == TheSection) {
474 Size = 1; // .comm Foo, 0 is undefined, avoid it.
475 unsigned Align = 1 << AlignLog;
477 // Use .lcomm only if it supports user-specified alignment.
478 // Otherwise, while it would still be correct to use .lcomm in some
479 // cases (e.g. when Align == 1), the external assembler might enfore
480 // some -unknown- default alignment behavior, which could cause
481 // spurious differences between external and integrated assembler.
482 // Prefer to simply fall back to .local / .comm in this case.
483 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
485 OutStreamer->EmitLocalCommonSymbol(GVSym, Size, Align);
489 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
493 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Local);
495 OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
499 // Handle thread local data for mach-o which requires us to output an
500 // additional structure of data and mangle the original symbol so that we
501 // can reference it later.
503 // TODO: This should become an "emit thread local global" method on TLOF.
504 // All of this macho specific stuff should be sunk down into TLOFMachO and
505 // stuff like "TLSExtraDataSection" should no longer be part of the parent
506 // TLOF class. This will also make it more obvious that stuff like
507 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
509 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
510 // Emit the .tbss symbol
512 OutContext.getOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
514 if (GVKind.isThreadBSS()) {
515 TheSection = getObjFileLowering().getTLSBSSSection();
516 OutStreamer->EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
517 } else if (GVKind.isThreadData()) {
518 OutStreamer->SwitchSection(TheSection);
520 EmitAlignment(AlignLog, GV);
521 OutStreamer->EmitLabel(MangSym);
523 EmitGlobalConstant(GV->getParent()->getDataLayout(),
524 GV->getInitializer());
527 OutStreamer->AddBlankLine();
529 // Emit the variable struct for the runtime.
530 MCSection *TLVSect = getObjFileLowering().getTLSExtraDataSection();
532 OutStreamer->SwitchSection(TLVSect);
533 // Emit the linkage here.
534 EmitLinkage(GV, GVSym);
535 OutStreamer->EmitLabel(GVSym);
537 // Three pointers in size:
538 // - __tlv_bootstrap - used to make sure support exists
539 // - spare pointer, used when mapped by the runtime
540 // - pointer to mangled symbol above with initializer
541 unsigned PtrSize = DL.getPointerTypeSize(GV->getType());
542 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
544 OutStreamer->EmitIntValue(0, PtrSize);
545 OutStreamer->EmitSymbolValue(MangSym, PtrSize);
547 OutStreamer->AddBlankLine();
551 MCSymbol *EmittedInitSym = GVSym;
553 OutStreamer->SwitchSection(TheSection);
555 EmitLinkage(GV, EmittedInitSym);
556 EmitAlignment(AlignLog, GV);
558 OutStreamer->EmitLabel(EmittedInitSym);
560 EmitGlobalConstant(GV->getParent()->getDataLayout(), GV->getInitializer());
562 if (MAI->hasDotTypeDotSizeDirective())
564 OutStreamer->emitELFSize(EmittedInitSym,
565 MCConstantExpr::create(Size, OutContext));
567 OutStreamer->AddBlankLine();
570 /// EmitFunctionHeader - This method emits the header for the current
572 void AsmPrinter::EmitFunctionHeader() {
573 // Print out constants referenced by the function
576 // Print the 'header' of function.
577 const Function *F = MF->getFunction();
579 OutStreamer->SwitchSection(getObjFileLowering().SectionForGlobal(F, TM));
580 EmitVisibility(CurrentFnSym, F->getVisibility());
582 EmitLinkage(F, CurrentFnSym);
583 if (MAI->hasFunctionAlignment())
584 EmitAlignment(MF->getAlignment(), F);
586 if (MAI->hasDotTypeDotSizeDirective())
587 OutStreamer->EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
590 F->printAsOperand(OutStreamer->GetCommentOS(),
591 /*PrintType=*/false, F->getParent());
592 OutStreamer->GetCommentOS() << '\n';
595 // Emit the prefix data.
596 if (F->hasPrefixData())
597 EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrefixData());
599 // Emit the CurrentFnSym. This is a virtual function to allow targets to
600 // do their wild and crazy things as required.
601 EmitFunctionEntryLabel();
603 // If the function had address-taken blocks that got deleted, then we have
604 // references to the dangling symbols. Emit them at the start of the function
605 // so that we don't get references to undefined symbols.
606 std::vector<MCSymbol*> DeadBlockSyms;
607 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
608 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
609 OutStreamer->AddComment("Address taken block that was later removed");
610 OutStreamer->EmitLabel(DeadBlockSyms[i]);
613 if (CurrentFnBegin) {
614 if (MAI->useAssignmentForEHBegin()) {
615 MCSymbol *CurPos = OutContext.createTempSymbol();
616 OutStreamer->EmitLabel(CurPos);
617 OutStreamer->EmitAssignment(CurrentFnBegin,
618 MCSymbolRefExpr::create(CurPos, OutContext));
620 OutStreamer->EmitLabel(CurrentFnBegin);
624 // Emit pre-function debug and/or EH information.
625 for (const HandlerInfo &HI : Handlers) {
626 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
627 HI.TimerGroupDescription, TimePassesIsEnabled);
628 HI.Handler->beginFunction(MF);
631 // Emit the prologue data.
632 if (F->hasPrologueData())
633 EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrologueData());
636 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
637 /// function. This can be overridden by targets as required to do custom stuff.
638 void AsmPrinter::EmitFunctionEntryLabel() {
639 CurrentFnSym->redefineIfPossible();
641 // The function label could have already been emitted if two symbols end up
642 // conflicting due to asm renaming. Detect this and emit an error.
643 if (CurrentFnSym->isVariable())
644 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
645 "' is a protected alias");
646 if (CurrentFnSym->isDefined())
647 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
648 "' label emitted multiple times to assembly file");
650 return OutStreamer->EmitLabel(CurrentFnSym);
653 /// emitComments - Pretty-print comments for instructions.
654 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
655 const MachineFunction *MF = MI.getParent()->getParent();
656 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
658 // Check for spills and reloads
661 const MachineFrameInfo &MFI = MF->getFrameInfo();
663 // We assume a single instruction only has a spill or reload, not
665 const MachineMemOperand *MMO;
666 if (TII->isLoadFromStackSlotPostFE(MI, FI)) {
667 if (MFI.isSpillSlotObjectIndex(FI)) {
668 MMO = *MI.memoperands_begin();
669 CommentOS << MMO->getSize() << "-byte Reload\n";
671 } else if (TII->hasLoadFromStackSlot(MI, MMO, FI)) {
672 if (MFI.isSpillSlotObjectIndex(FI))
673 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
674 } else if (TII->isStoreToStackSlotPostFE(MI, FI)) {
675 if (MFI.isSpillSlotObjectIndex(FI)) {
676 MMO = *MI.memoperands_begin();
677 CommentOS << MMO->getSize() << "-byte Spill\n";
679 } else if (TII->hasStoreToStackSlot(MI, MMO, FI)) {
680 if (MFI.isSpillSlotObjectIndex(FI))
681 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
684 // Check for spill-induced copies
685 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
686 CommentOS << " Reload Reuse\n";
689 /// emitImplicitDef - This method emits the specified machine instruction
690 /// that is an implicit def.
691 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
692 unsigned RegNo = MI->getOperand(0).getReg();
694 SmallString<128> Str;
695 raw_svector_ostream OS(Str);
696 OS << "implicit-def: "
697 << PrintReg(RegNo, MF->getSubtarget().getRegisterInfo());
699 OutStreamer->AddComment(OS.str());
700 OutStreamer->AddBlankLine();
703 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
705 raw_string_ostream OS(Str);
707 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
708 const MachineOperand &Op = MI->getOperand(i);
709 assert(Op.isReg() && "KILL instruction must have only register operands");
711 << PrintReg(Op.getReg(),
712 AP.MF->getSubtarget().getRegisterInfo())
713 << (Op.isDef() ? "<def>" : "<kill>");
715 AP.OutStreamer->AddComment(OS.str());
716 AP.OutStreamer->AddBlankLine();
719 /// emitDebugValueComment - This method handles the target-independent form
720 /// of DBG_VALUE, returning true if it was able to do so. A false return
721 /// means the target will need to handle MI in EmitInstruction.
722 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
723 // This code handles only the 4-operand target-independent form.
724 if (MI->getNumOperands() != 4)
727 SmallString<128> Str;
728 raw_svector_ostream OS(Str);
729 OS << "DEBUG_VALUE: ";
731 const DILocalVariable *V = MI->getDebugVariable();
732 if (auto *SP = dyn_cast<DISubprogram>(V->getScope())) {
733 StringRef Name = SP->getDisplayName();
739 const DIExpression *Expr = MI->getDebugExpression();
740 auto Fragment = Expr->getFragmentInfo();
742 OS << " [fragment offset=" << Fragment->OffsetInBits
743 << " size=" << Fragment->SizeInBits << "]";
746 // The second operand is only an offset if it's an immediate.
747 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
748 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
750 for (unsigned i = 0; i < Expr->getNumElements(); ++i) {
751 uint64_t Op = Expr->getElement(i);
752 if (Op == dwarf::DW_OP_LLVM_fragment) {
753 // There can't be any operands after this in a valid expression
756 // We currently don't support extra Offsets or derefs after the first
757 // one. Bail out early instead of emitting an incorrect comment
758 OS << " [complex expression]";
759 AP.OutStreamer->emitRawComment(OS.str());
761 } else if (Op == dwarf::DW_OP_deref) {
766 uint64_t ExtraOffset = Expr->getElement(i++);
767 if (Op == dwarf::DW_OP_plus)
768 Offset += ExtraOffset;
770 assert(Op == dwarf::DW_OP_minus);
771 Offset -= ExtraOffset;
775 // Register or immediate value. Register 0 means undef.
776 if (MI->getOperand(0).isFPImm()) {
777 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
778 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
779 OS << (double)APF.convertToFloat();
780 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
781 OS << APF.convertToDouble();
783 // There is no good way to print long double. Convert a copy to
784 // double. Ah well, it's only a comment.
786 APF.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven,
788 OS << "(long double) " << APF.convertToDouble();
790 } else if (MI->getOperand(0).isImm()) {
791 OS << MI->getOperand(0).getImm();
792 } else if (MI->getOperand(0).isCImm()) {
793 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
796 if (MI->getOperand(0).isReg()) {
797 Reg = MI->getOperand(0).getReg();
799 assert(MI->getOperand(0).isFI() && "Unknown operand type");
800 const TargetFrameLowering *TFI = AP.MF->getSubtarget().getFrameLowering();
801 Offset += TFI->getFrameIndexReference(*AP.MF,
802 MI->getOperand(0).getIndex(), Reg);
806 // Suppress offset, it is not meaningful here.
808 // NOTE: Want this comment at start of line, don't emit with AddComment.
809 AP.OutStreamer->emitRawComment(OS.str());
814 OS << PrintReg(Reg, AP.MF->getSubtarget().getRegisterInfo());
818 OS << '+' << Offset << ']';
820 // NOTE: Want this comment at start of line, don't emit with AddComment.
821 AP.OutStreamer->emitRawComment(OS.str());
825 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
826 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
827 MF->getFunction()->needsUnwindTableEntry())
830 if (MMI->hasDebugInfo())
836 bool AsmPrinter::needsSEHMoves() {
837 return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
840 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
841 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
842 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
843 ExceptionHandlingType != ExceptionHandling::ARM)
846 if (needsCFIMoves() == CFI_M_None)
849 const std::vector<MCCFIInstruction> &Instrs = MF->getFrameInstructions();
850 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
851 const MCCFIInstruction &CFI = Instrs[CFIIndex];
852 emitCFIInstruction(CFI);
855 void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
856 // The operands are the MCSymbol and the frame offset of the allocation.
857 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
858 int FrameOffset = MI.getOperand(1).getImm();
860 // Emit a symbol assignment.
861 OutStreamer->EmitAssignment(FrameAllocSym,
862 MCConstantExpr::create(FrameOffset, OutContext));
865 /// EmitFunctionBody - This method emits the body and trailer for a
867 void AsmPrinter::EmitFunctionBody() {
868 EmitFunctionHeader();
870 // Emit target-specific gunk before the function body.
871 EmitFunctionBodyStart();
873 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
875 // Print out code for the function.
876 bool HasAnyRealCode = false;
877 for (auto &MBB : *MF) {
878 // Print a label for the basic block.
879 EmitBasicBlockStart(MBB);
880 for (auto &MI : MBB) {
882 // Print the assembly for the instruction.
883 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
884 !MI.isDebugValue()) {
885 HasAnyRealCode = true;
889 if (ShouldPrintDebugScopes) {
890 for (const HandlerInfo &HI : Handlers) {
891 NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
892 HI.TimerGroupName, HI.TimerGroupDescription,
893 TimePassesIsEnabled);
894 HI.Handler->beginInstruction(&MI);
899 emitComments(MI, OutStreamer->GetCommentOS());
901 switch (MI.getOpcode()) {
902 case TargetOpcode::CFI_INSTRUCTION:
903 emitCFIInstruction(MI);
906 case TargetOpcode::LOCAL_ESCAPE:
910 case TargetOpcode::EH_LABEL:
911 case TargetOpcode::GC_LABEL:
912 OutStreamer->EmitLabel(MI.getOperand(0).getMCSymbol());
914 case TargetOpcode::INLINEASM:
917 case TargetOpcode::DBG_VALUE:
919 if (!emitDebugValueComment(&MI, *this))
920 EmitInstruction(&MI);
923 case TargetOpcode::IMPLICIT_DEF:
924 if (isVerbose()) emitImplicitDef(&MI);
926 case TargetOpcode::KILL:
927 if (isVerbose()) emitKill(&MI, *this);
930 EmitInstruction(&MI);
934 if (ShouldPrintDebugScopes) {
935 for (const HandlerInfo &HI : Handlers) {
936 NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
937 HI.TimerGroupName, HI.TimerGroupDescription,
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 (!MF->getLandingPads().empty() || MMI->hasDebugInfo() ||
976 MF->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 OutStreamer->emitELFSize(CurrentFnSym, SizeExp);
993 for (const HandlerInfo &HI : Handlers) {
994 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
995 HI.TimerGroupDescription, 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.TimerDescription, HI.TimerGroupName,
1005 HI.TimerGroupDescription, TimePassesIsEnabled);
1006 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->hasGlobalUnnamedAddr() || !GV->hasInitializer() ||
1038 !GV->isConstant() || !GV->isDiscardableIfUnused() ||
1039 !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 void AsmPrinter::emitGlobalIndirectSymbol(Module &M,
1092 const GlobalIndirectSymbol& GIS) {
1093 MCSymbol *Name = getSymbol(&GIS);
1095 if (GIS.hasExternalLinkage() || !MAI->getWeakRefDirective())
1096 OutStreamer->EmitSymbolAttribute(Name, MCSA_Global);
1097 else if (GIS.hasWeakLinkage() || GIS.hasLinkOnceLinkage())
1098 OutStreamer->EmitSymbolAttribute(Name, MCSA_WeakReference);
1100 assert(GIS.hasLocalLinkage() && "Invalid alias or ifunc linkage");
1102 // Set the symbol type to function if the alias has a function type.
1103 // This affects codegen when the aliasee is not a function.
1104 if (GIS.getType()->getPointerElementType()->isFunctionTy()) {
1105 OutStreamer->EmitSymbolAttribute(Name, MCSA_ELF_TypeFunction);
1106 if (isa<GlobalIFunc>(GIS))
1107 OutStreamer->EmitSymbolAttribute(Name, MCSA_ELF_TypeIndFunction);
1110 EmitVisibility(Name, GIS.getVisibility());
1112 const MCExpr *Expr = lowerConstant(GIS.getIndirectSymbol());
1114 if (isa<GlobalAlias>(&GIS) && MAI->hasAltEntry() && isa<MCBinaryExpr>(Expr))
1115 OutStreamer->EmitSymbolAttribute(Name, MCSA_AltEntry);
1117 // Emit the directives as assignments aka .set:
1118 OutStreamer->EmitAssignment(Name, Expr);
1120 if (auto *GA = dyn_cast<GlobalAlias>(&GIS)) {
1121 // If the aliasee does not correspond to a symbol in the output, i.e. the
1122 // alias is not of an object or the aliased object is private, then set the
1123 // size of the alias symbol from the type of the alias. We don't do this in
1124 // other situations as the alias and aliasee having differing types but same
1125 // size may be intentional.
1126 const GlobalObject *BaseObject = GA->getBaseObject();
1127 if (MAI->hasDotTypeDotSizeDirective() && GA->getValueType()->isSized() &&
1128 (!BaseObject || BaseObject->hasPrivateLinkage())) {
1129 const DataLayout &DL = M.getDataLayout();
1130 uint64_t Size = DL.getTypeAllocSize(GA->getValueType());
1131 OutStreamer->emitELFSize(Name, MCConstantExpr::create(Size, OutContext));
1136 bool AsmPrinter::doFinalization(Module &M) {
1137 // Set the MachineFunction to nullptr so that we can catch attempted
1138 // accesses to MF specific features at the module level and so that
1139 // we can conditionalize accesses based on whether or not it is nullptr.
1142 // Gather all GOT equivalent globals in the module. We really need two
1143 // passes over the globals: one to compute and another to avoid its emission
1144 // in EmitGlobalVariable, otherwise we would not be able to handle cases
1145 // where the got equivalent shows up before its use.
1146 computeGlobalGOTEquivs(M);
1148 // Emit global variables.
1149 for (const auto &G : M.globals())
1150 EmitGlobalVariable(&G);
1152 // Emit remaining GOT equivalent globals.
1153 emitGlobalGOTEquivs();
1155 // Emit visibility info for declarations
1156 for (const Function &F : M) {
1157 if (!F.isDeclarationForLinker())
1159 GlobalValue::VisibilityTypes V = F.getVisibility();
1160 if (V == GlobalValue::DefaultVisibility)
1163 MCSymbol *Name = getSymbol(&F);
1164 EmitVisibility(Name, V, false);
1167 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1169 // Emit module flags.
1170 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
1171 M.getModuleFlagsMetadata(ModuleFlags);
1172 if (!ModuleFlags.empty())
1173 TLOF.emitModuleFlags(*OutStreamer, ModuleFlags, TM);
1175 if (TM.getTargetTriple().isOSBinFormatELF()) {
1176 MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
1178 // Output stubs for external and common global variables.
1179 MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
1180 if (!Stubs.empty()) {
1181 OutStreamer->SwitchSection(TLOF.getDataSection());
1182 const DataLayout &DL = M.getDataLayout();
1184 for (const auto &Stub : Stubs) {
1185 OutStreamer->EmitLabel(Stub.first);
1186 OutStreamer->EmitSymbolValue(Stub.second.getPointer(),
1187 DL.getPointerSize());
1192 // Finalize debug and EH information.
1193 for (const HandlerInfo &HI : Handlers) {
1194 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1195 HI.TimerGroupDescription, TimePassesIsEnabled);
1196 HI.Handler->endModule();
1202 // If the target wants to know about weak references, print them all.
1203 if (MAI->getWeakRefDirective()) {
1204 // FIXME: This is not lazy, it would be nice to only print weak references
1205 // to stuff that is actually used. Note that doing so would require targets
1206 // to notice uses in operands (due to constant exprs etc). This should
1207 // happen with the MC stuff eventually.
1209 // Print out module-level global objects here.
1210 for (const auto &GO : M.global_objects()) {
1211 if (!GO.hasExternalWeakLinkage())
1213 OutStreamer->EmitSymbolAttribute(getSymbol(&GO), MCSA_WeakReference);
1217 OutStreamer->AddBlankLine();
1219 // Print aliases in topological order, that is, for each alias a = b,
1220 // b must be printed before a.
1221 // This is because on some targets (e.g. PowerPC) linker expects aliases in
1222 // such an order to generate correct TOC information.
1223 SmallVector<const GlobalAlias *, 16> AliasStack;
1224 SmallPtrSet<const GlobalAlias *, 16> AliasVisited;
1225 for (const auto &Alias : M.aliases()) {
1226 for (const GlobalAlias *Cur = &Alias; Cur;
1227 Cur = dyn_cast<GlobalAlias>(Cur->getAliasee())) {
1228 if (!AliasVisited.insert(Cur).second)
1230 AliasStack.push_back(Cur);
1232 for (const GlobalAlias *AncestorAlias : reverse(AliasStack))
1233 emitGlobalIndirectSymbol(M, *AncestorAlias);
1236 for (const auto &IFunc : M.ifuncs())
1237 emitGlobalIndirectSymbol(M, IFunc);
1239 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1240 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1241 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1242 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1243 MP->finishAssembly(M, *MI, *this);
1245 // Emit llvm.ident metadata in an '.ident' directive.
1246 EmitModuleIdents(M);
1248 // Emit __morestack address if needed for indirect calls.
1249 if (MMI->usesMorestackAddr()) {
1251 MCSection *ReadOnlySection = getObjFileLowering().getSectionForConstant(
1252 getDataLayout(), SectionKind::getReadOnly(),
1253 /*C=*/nullptr, Align);
1254 OutStreamer->SwitchSection(ReadOnlySection);
1256 MCSymbol *AddrSymbol =
1257 OutContext.getOrCreateSymbol(StringRef("__morestack_addr"));
1258 OutStreamer->EmitLabel(AddrSymbol);
1260 unsigned PtrSize = M.getDataLayout().getPointerSize(0);
1261 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("__morestack"),
1265 // If we don't have any trampolines, then we don't require stack memory
1266 // to be executable. Some targets have a directive to declare this.
1267 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1268 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1269 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1270 OutStreamer->SwitchSection(S);
1272 // Allow the target to emit any magic that it wants at the end of the file,
1273 // after everything else has gone out.
1274 EmitEndOfAsmFile(M);
1278 OutStreamer->Finish();
1279 OutStreamer->reset();
1284 MCSymbol *AsmPrinter::getCurExceptionSym() {
1285 if (!CurExceptionSym)
1286 CurExceptionSym = createTempSymbol("exception");
1287 return CurExceptionSym;
1290 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1292 // Get the function symbol.
1293 CurrentFnSym = getSymbol(MF.getFunction());
1294 CurrentFnSymForSize = CurrentFnSym;
1295 CurrentFnBegin = nullptr;
1296 CurExceptionSym = nullptr;
1297 bool NeedsLocalForSize = MAI->needsLocalForSize();
1298 if (!MF.getLandingPads().empty() || MMI->hasDebugInfo() ||
1299 MF.hasEHFunclets() || NeedsLocalForSize) {
1300 CurrentFnBegin = createTempSymbol("func_begin");
1301 if (NeedsLocalForSize)
1302 CurrentFnSymForSize = CurrentFnBegin;
1306 LI = &getAnalysis<MachineLoopInfo>();
1310 // Keep track the alignment, constpool entries per Section.
1314 SmallVector<unsigned, 4> CPEs;
1315 SectionCPs(MCSection *s, unsigned a) : S(s), Alignment(a) {}
1319 /// EmitConstantPool - Print to the current output stream assembly
1320 /// representations of the constants in the constant pool MCP. This is
1321 /// used to print out constants which have been "spilled to memory" by
1322 /// the code generator.
1324 void AsmPrinter::EmitConstantPool() {
1325 const MachineConstantPool *MCP = MF->getConstantPool();
1326 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1327 if (CP.empty()) return;
1329 // Calculate sections for constant pool entries. We collect entries to go into
1330 // the same section together to reduce amount of section switch statements.
1331 SmallVector<SectionCPs, 4> CPSections;
1332 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1333 const MachineConstantPoolEntry &CPE = CP[i];
1334 unsigned Align = CPE.getAlignment();
1336 SectionKind Kind = CPE.getSectionKind(&getDataLayout());
1338 const Constant *C = nullptr;
1339 if (!CPE.isMachineConstantPoolEntry())
1340 C = CPE.Val.ConstVal;
1342 MCSection *S = getObjFileLowering().getSectionForConstant(getDataLayout(),
1345 // The number of sections are small, just do a linear search from the
1346 // last section to the first.
1348 unsigned SecIdx = CPSections.size();
1349 while (SecIdx != 0) {
1350 if (CPSections[--SecIdx].S == S) {
1356 SecIdx = CPSections.size();
1357 CPSections.push_back(SectionCPs(S, Align));
1360 if (Align > CPSections[SecIdx].Alignment)
1361 CPSections[SecIdx].Alignment = Align;
1362 CPSections[SecIdx].CPEs.push_back(i);
1365 // Now print stuff into the calculated sections.
1366 const MCSection *CurSection = nullptr;
1367 unsigned Offset = 0;
1368 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1369 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1370 unsigned CPI = CPSections[i].CPEs[j];
1371 MCSymbol *Sym = GetCPISymbol(CPI);
1372 if (!Sym->isUndefined())
1375 if (CurSection != CPSections[i].S) {
1376 OutStreamer->SwitchSection(CPSections[i].S);
1377 EmitAlignment(Log2_32(CPSections[i].Alignment));
1378 CurSection = CPSections[i].S;
1382 MachineConstantPoolEntry CPE = CP[CPI];
1384 // Emit inter-object padding for alignment.
1385 unsigned AlignMask = CPE.getAlignment() - 1;
1386 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1387 OutStreamer->EmitZeros(NewOffset - Offset);
1389 Type *Ty = CPE.getType();
1390 Offset = NewOffset + getDataLayout().getTypeAllocSize(Ty);
1392 OutStreamer->EmitLabel(Sym);
1393 if (CPE.isMachineConstantPoolEntry())
1394 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1396 EmitGlobalConstant(getDataLayout(), CPE.Val.ConstVal);
1401 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1402 /// by the current function to the current output stream.
1404 void AsmPrinter::EmitJumpTableInfo() {
1405 const DataLayout &DL = MF->getDataLayout();
1406 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1408 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1409 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1410 if (JT.empty()) return;
1412 // Pick the directive to use to print the jump table entries, and switch to
1413 // the appropriate section.
1414 const Function *F = MF->getFunction();
1415 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1416 bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
1417 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
1419 if (JTInDiffSection) {
1420 // Drop it in the readonly section.
1421 MCSection *ReadOnlySection = TLOF.getSectionForJumpTable(*F, TM);
1422 OutStreamer->SwitchSection(ReadOnlySection);
1425 EmitAlignment(Log2_32(MJTI->getEntryAlignment(DL)));
1427 // Jump tables in code sections are marked with a data_region directive
1428 // where that's supported.
1429 if (!JTInDiffSection)
1430 OutStreamer->EmitDataRegion(MCDR_DataRegionJT32);
1432 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1433 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1435 // If this jump table was deleted, ignore it.
1436 if (JTBBs.empty()) continue;
1438 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1439 /// emit a .set directive for each unique entry.
1440 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1441 MAI->doesSetDirectiveSuppressReloc()) {
1442 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1443 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1444 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1445 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1446 const MachineBasicBlock *MBB = JTBBs[ii];
1447 if (!EmittedSets.insert(MBB).second)
1450 // .set LJTSet, LBB32-base
1452 MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1453 OutStreamer->EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1454 MCBinaryExpr::createSub(LHS, Base,
1459 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1460 // before each jump table. The first label is never referenced, but tells
1461 // the assembler and linker the extents of the jump table object. The
1462 // second label is actually referenced by the code.
1463 if (JTInDiffSection && DL.hasLinkerPrivateGlobalPrefix())
1464 // FIXME: This doesn't have to have any specific name, just any randomly
1465 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1466 OutStreamer->EmitLabel(GetJTISymbol(JTI, true));
1468 OutStreamer->EmitLabel(GetJTISymbol(JTI));
1470 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1471 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1473 if (!JTInDiffSection)
1474 OutStreamer->EmitDataRegion(MCDR_DataRegionEnd);
1477 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1479 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1480 const MachineBasicBlock *MBB,
1481 unsigned UID) const {
1482 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1483 const MCExpr *Value = nullptr;
1484 switch (MJTI->getEntryKind()) {
1485 case MachineJumpTableInfo::EK_Inline:
1486 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1487 case MachineJumpTableInfo::EK_Custom32:
1488 Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
1489 MJTI, MBB, UID, OutContext);
1491 case MachineJumpTableInfo::EK_BlockAddress:
1492 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1494 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1496 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1497 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1498 // with a relocation as gp-relative, e.g.:
1500 MCSymbol *MBBSym = MBB->getSymbol();
1501 OutStreamer->EmitGPRel32Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1505 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1506 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1507 // with a relocation as gp-relative, e.g.:
1509 MCSymbol *MBBSym = MBB->getSymbol();
1510 OutStreamer->EmitGPRel64Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1514 case MachineJumpTableInfo::EK_LabelDifference32: {
1515 // Each entry is the address of the block minus the address of the jump
1516 // table. This is used for PIC jump tables where gprel32 is not supported.
1518 // .word LBB123 - LJTI1_2
1519 // If the .set directive avoids relocations, this is emitted as:
1520 // .set L4_5_set_123, LBB123 - LJTI1_2
1521 // .word L4_5_set_123
1522 if (MAI->doesSetDirectiveSuppressReloc()) {
1523 Value = MCSymbolRefExpr::create(GetJTSetSymbol(UID, MBB->getNumber()),
1527 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1528 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1529 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1530 Value = MCBinaryExpr::createSub(Value, Base, OutContext);
1535 assert(Value && "Unknown entry kind!");
1537 unsigned EntrySize = MJTI->getEntrySize(getDataLayout());
1538 OutStreamer->EmitValue(Value, EntrySize);
1542 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1543 /// special global used by LLVM. If so, emit it and return true, otherwise
1544 /// do nothing and return false.
1545 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1546 if (GV->getName() == "llvm.used") {
1547 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1548 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1552 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1553 if (GV->getSection() == "llvm.metadata" ||
1554 GV->hasAvailableExternallyLinkage())
1557 if (!GV->hasAppendingLinkage()) return false;
1559 assert(GV->hasInitializer() && "Not a special LLVM global!");
1561 if (GV->getName() == "llvm.global_ctors") {
1562 EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
1568 if (GV->getName() == "llvm.global_dtors") {
1569 EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
1570 /* isCtor */ false);
1575 report_fatal_error("unknown special variable");
1578 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1579 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1580 /// is true, as being used with this directive.
1581 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1582 // Should be an array of 'i8*'.
1583 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1584 const GlobalValue *GV =
1585 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1587 OutStreamer->EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1593 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1595 llvm::Constant *Func;
1596 llvm::GlobalValue *ComdatKey;
1600 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1602 void AsmPrinter::EmitXXStructorList(const DataLayout &DL, const Constant *List,
1604 // Should be an array of '{ int, void ()* }' structs. The first value is the
1606 if (!isa<ConstantArray>(List)) return;
1608 // Sanity check the structors list.
1609 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1610 if (!InitList) return; // Not an array!
1611 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1612 // FIXME: Only allow the 3-field form in LLVM 4.0.
1613 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1614 return; // Not an array of two or three elements!
1615 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1616 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1617 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1618 return; // Not (int, ptr, ptr).
1620 // Gather the structors in a form that's convenient for sorting by priority.
1621 SmallVector<Structor, 8> Structors;
1622 for (Value *O : InitList->operands()) {
1623 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1624 if (!CS) continue; // Malformed.
1625 if (CS->getOperand(1)->isNullValue())
1626 break; // Found a null terminator, skip the rest.
1627 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1628 if (!Priority) continue; // Malformed.
1629 Structors.push_back(Structor());
1630 Structor &S = Structors.back();
1631 S.Priority = Priority->getLimitedValue(65535);
1632 S.Func = CS->getOperand(1);
1633 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1635 dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1638 // Emit the function pointers in the target-specific order
1639 unsigned Align = Log2_32(DL.getPointerPrefAlignment());
1640 std::stable_sort(Structors.begin(), Structors.end(),
1641 [](const Structor &L,
1642 const Structor &R) { return L.Priority < R.Priority; });
1643 for (Structor &S : Structors) {
1644 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1645 const MCSymbol *KeySym = nullptr;
1646 if (GlobalValue *GV = S.ComdatKey) {
1647 if (GV->hasAvailableExternallyLinkage())
1648 // If the associated variable is available_externally, some other TU
1649 // will provide its dynamic initializer.
1652 KeySym = getSymbol(GV);
1654 MCSection *OutputSection =
1655 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1656 : Obj.getStaticDtorSection(S.Priority, KeySym));
1657 OutStreamer->SwitchSection(OutputSection);
1658 if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
1659 EmitAlignment(Align);
1660 EmitXXStructor(DL, S.Func);
1664 void AsmPrinter::EmitModuleIdents(Module &M) {
1665 if (!MAI->hasIdentDirective())
1668 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1669 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1670 const MDNode *N = NMD->getOperand(i);
1671 assert(N->getNumOperands() == 1 &&
1672 "llvm.ident metadata entry can have only one operand");
1673 const MDString *S = cast<MDString>(N->getOperand(0));
1674 OutStreamer->EmitIdent(S->getString());
1679 //===--------------------------------------------------------------------===//
1680 // Emission and print routines
1683 /// EmitInt8 - Emit a byte directive and value.
1685 void AsmPrinter::EmitInt8(int Value) const {
1686 OutStreamer->EmitIntValue(Value, 1);
1689 /// EmitInt16 - Emit a short directive and value.
1691 void AsmPrinter::EmitInt16(int Value) const {
1692 OutStreamer->EmitIntValue(Value, 2);
1695 /// EmitInt32 - Emit a long directive and value.
1697 void AsmPrinter::EmitInt32(int Value) const {
1698 OutStreamer->EmitIntValue(Value, 4);
1701 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1702 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1703 /// .set if it avoids relocations.
1704 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1705 unsigned Size) const {
1706 OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
1709 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1710 /// where the size in bytes of the directive is specified by Size and Label
1711 /// specifies the label. This implicitly uses .set if it is available.
1712 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1714 bool IsSectionRelative) const {
1715 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1716 OutStreamer->EmitCOFFSecRel32(Label, Offset);
1718 OutStreamer->EmitZeros(Size - 4);
1722 // Emit Label+Offset (or just Label if Offset is zero)
1723 const MCExpr *Expr = MCSymbolRefExpr::create(Label, OutContext);
1725 Expr = MCBinaryExpr::createAdd(
1726 Expr, MCConstantExpr::create(Offset, OutContext), OutContext);
1728 OutStreamer->EmitValue(Expr, Size);
1731 //===----------------------------------------------------------------------===//
1733 // EmitAlignment - Emit an alignment directive to the specified power of
1734 // two boundary. For example, if you pass in 3 here, you will get an 8
1735 // byte alignment. If a global value is specified, and if that global has
1736 // an explicit alignment requested, it will override the alignment request
1737 // if required for correctness.
1739 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1741 NumBits = getGVAlignmentLog2(GV, GV->getParent()->getDataLayout(), NumBits);
1743 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1746 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
1747 "undefined behavior");
1748 if (getCurrentSection()->getKind().isText())
1749 OutStreamer->EmitCodeAlignment(1u << NumBits);
1751 OutStreamer->EmitValueToAlignment(1u << NumBits);
1754 //===----------------------------------------------------------------------===//
1755 // Constant emission.
1756 //===----------------------------------------------------------------------===//
1758 const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1759 MCContext &Ctx = OutContext;
1761 if (CV->isNullValue() || isa<UndefValue>(CV))
1762 return MCConstantExpr::create(0, Ctx);
1764 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1765 return MCConstantExpr::create(CI->getZExtValue(), Ctx);
1767 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1768 return MCSymbolRefExpr::create(getSymbol(GV), Ctx);
1770 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1771 return MCSymbolRefExpr::create(GetBlockAddressSymbol(BA), Ctx);
1773 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1775 llvm_unreachable("Unknown constant value to lower!");
1778 switch (CE->getOpcode()) {
1780 // If the code isn't optimized, there may be outstanding folding
1781 // opportunities. Attempt to fold the expression using DataLayout as a
1782 // last resort before giving up.
1783 if (Constant *C = ConstantFoldConstant(CE, getDataLayout()))
1785 return lowerConstant(C);
1787 // Otherwise report the problem to the user.
1790 raw_string_ostream OS(S);
1791 OS << "Unsupported expression in static initializer: ";
1792 CE->printAsOperand(OS, /*PrintType=*/false,
1793 !MF ? nullptr : MF->getFunction()->getParent());
1794 report_fatal_error(OS.str());
1796 case Instruction::GetElementPtr: {
1797 // Generate a symbolic expression for the byte address
1798 APInt OffsetAI(getDataLayout().getPointerTypeSizeInBits(CE->getType()), 0);
1799 cast<GEPOperator>(CE)->accumulateConstantOffset(getDataLayout(), OffsetAI);
1801 const MCExpr *Base = lowerConstant(CE->getOperand(0));
1805 int64_t Offset = OffsetAI.getSExtValue();
1806 return MCBinaryExpr::createAdd(Base, MCConstantExpr::create(Offset, Ctx),
1810 case Instruction::Trunc:
1811 // We emit the value and depend on the assembler to truncate the generated
1812 // expression properly. This is important for differences between
1813 // blockaddress labels. Since the two labels are in the same function, it
1814 // is reasonable to treat their delta as a 32-bit value.
1816 case Instruction::BitCast:
1817 return lowerConstant(CE->getOperand(0));
1819 case Instruction::IntToPtr: {
1820 const DataLayout &DL = getDataLayout();
1822 // Handle casts to pointers by changing them into casts to the appropriate
1823 // integer type. This promotes constant folding and simplifies this code.
1824 Constant *Op = CE->getOperand(0);
1825 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1827 return lowerConstant(Op);
1830 case Instruction::PtrToInt: {
1831 const DataLayout &DL = getDataLayout();
1833 // Support only foldable casts to/from pointers that can be eliminated by
1834 // changing the pointer to the appropriately sized integer type.
1835 Constant *Op = CE->getOperand(0);
1836 Type *Ty = CE->getType();
1838 const MCExpr *OpExpr = lowerConstant(Op);
1840 // We can emit the pointer value into this slot if the slot is an
1841 // integer slot equal to the size of the pointer.
1842 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1845 // Otherwise the pointer is smaller than the resultant integer, mask off
1846 // the high bits so we are sure to get a proper truncation if the input is
1848 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1849 const MCExpr *MaskExpr = MCConstantExpr::create(~0ULL >> (64-InBits), Ctx);
1850 return MCBinaryExpr::createAnd(OpExpr, MaskExpr, Ctx);
1853 case Instruction::Sub: {
1856 if (IsConstantOffsetFromGlobal(CE->getOperand(0), LHSGV, LHSOffset,
1860 if (IsConstantOffsetFromGlobal(CE->getOperand(1), RHSGV, RHSOffset,
1862 const MCExpr *RelocExpr =
1863 getObjFileLowering().lowerRelativeReference(LHSGV, RHSGV, TM);
1865 RelocExpr = MCBinaryExpr::createSub(
1866 MCSymbolRefExpr::create(getSymbol(LHSGV), Ctx),
1867 MCSymbolRefExpr::create(getSymbol(RHSGV), Ctx), Ctx);
1868 int64_t Addend = (LHSOffset - RHSOffset).getSExtValue();
1870 RelocExpr = MCBinaryExpr::createAdd(
1871 RelocExpr, MCConstantExpr::create(Addend, Ctx), Ctx);
1878 // The MC library also has a right-shift operator, but it isn't consistently
1879 // signed or unsigned between different targets.
1880 case Instruction::Add:
1881 case Instruction::Mul:
1882 case Instruction::SDiv:
1883 case Instruction::SRem:
1884 case Instruction::Shl:
1885 case Instruction::And:
1886 case Instruction::Or:
1887 case Instruction::Xor: {
1888 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
1889 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
1890 switch (CE->getOpcode()) {
1891 default: llvm_unreachable("Unknown binary operator constant cast expr");
1892 case Instruction::Add: return MCBinaryExpr::createAdd(LHS, RHS, Ctx);
1893 case Instruction::Sub: return MCBinaryExpr::createSub(LHS, RHS, Ctx);
1894 case Instruction::Mul: return MCBinaryExpr::createMul(LHS, RHS, Ctx);
1895 case Instruction::SDiv: return MCBinaryExpr::createDiv(LHS, RHS, Ctx);
1896 case Instruction::SRem: return MCBinaryExpr::createMod(LHS, RHS, Ctx);
1897 case Instruction::Shl: return MCBinaryExpr::createShl(LHS, RHS, Ctx);
1898 case Instruction::And: return MCBinaryExpr::createAnd(LHS, RHS, Ctx);
1899 case Instruction::Or: return MCBinaryExpr::createOr (LHS, RHS, Ctx);
1900 case Instruction::Xor: return MCBinaryExpr::createXor(LHS, RHS, Ctx);
1906 static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *C,
1908 const Constant *BaseCV = nullptr,
1909 uint64_t Offset = 0);
1911 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP);
1913 /// isRepeatedByteSequence - Determine whether the given value is
1914 /// composed of a repeated sequence of identical bytes and return the
1915 /// byte value. If it is not a repeated sequence, return -1.
1916 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1917 StringRef Data = V->getRawDataValues();
1918 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1920 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1921 if (Data[i] != C) return -1;
1922 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1926 /// isRepeatedByteSequence - Determine whether the given value is
1927 /// composed of a repeated sequence of identical bytes and return the
1928 /// byte value. If it is not a repeated sequence, return -1.
1929 static int isRepeatedByteSequence(const Value *V, const DataLayout &DL) {
1930 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1931 uint64_t Size = DL.getTypeAllocSizeInBits(V->getType());
1932 assert(Size % 8 == 0);
1934 // Extend the element to take zero padding into account.
1935 APInt Value = CI->getValue().zextOrSelf(Size);
1936 if (!Value.isSplat(8))
1939 return Value.zextOrTrunc(8).getZExtValue();
1941 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1942 // Make sure all array elements are sequences of the same repeated
1944 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1945 Constant *Op0 = CA->getOperand(0);
1946 int Byte = isRepeatedByteSequence(Op0, DL);
1950 // All array elements must be equal.
1951 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i)
1952 if (CA->getOperand(i) != Op0)
1957 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1958 return isRepeatedByteSequence(CDS);
1963 static void emitGlobalConstantDataSequential(const DataLayout &DL,
1964 const ConstantDataSequential *CDS,
1967 // See if we can aggregate this into a .fill, if so, emit it as such.
1968 int Value = isRepeatedByteSequence(CDS, DL);
1970 uint64_t Bytes = DL.getTypeAllocSize(CDS->getType());
1971 // Don't emit a 1-byte object as a .fill.
1973 return AP.OutStreamer->emitFill(Bytes, Value);
1976 // If this can be emitted with .ascii/.asciz, emit it as such.
1977 if (CDS->isString())
1978 return AP.OutStreamer->EmitBytes(CDS->getAsString());
1980 // Otherwise, emit the values in successive locations.
1981 unsigned ElementByteSize = CDS->getElementByteSize();
1982 if (isa<IntegerType>(CDS->getElementType())) {
1983 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1985 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
1986 CDS->getElementAsInteger(i));
1987 AP.OutStreamer->EmitIntValue(CDS->getElementAsInteger(i),
1991 for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I)
1992 emitGlobalConstantFP(cast<ConstantFP>(CDS->getElementAsConstant(I)), AP);
1995 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1996 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1997 CDS->getNumElements();
1998 if (unsigned Padding = Size - EmittedSize)
1999 AP.OutStreamer->EmitZeros(Padding);
2003 static void emitGlobalConstantArray(const DataLayout &DL,
2004 const ConstantArray *CA, AsmPrinter &AP,
2005 const Constant *BaseCV, uint64_t Offset) {
2006 // See if we can aggregate some values. Make sure it can be
2007 // represented as a series of bytes of the constant value.
2008 int Value = isRepeatedByteSequence(CA, DL);
2011 uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
2012 AP.OutStreamer->emitFill(Bytes, Value);
2015 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
2016 emitGlobalConstantImpl(DL, CA->getOperand(i), AP, BaseCV, Offset);
2017 Offset += DL.getTypeAllocSize(CA->getOperand(i)->getType());
2022 static void emitGlobalConstantVector(const DataLayout &DL,
2023 const ConstantVector *CV, AsmPrinter &AP) {
2024 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
2025 emitGlobalConstantImpl(DL, CV->getOperand(i), AP);
2027 unsigned Size = DL.getTypeAllocSize(CV->getType());
2028 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
2029 CV->getType()->getNumElements();
2030 if (unsigned Padding = Size - EmittedSize)
2031 AP.OutStreamer->EmitZeros(Padding);
2034 static void emitGlobalConstantStruct(const DataLayout &DL,
2035 const ConstantStruct *CS, AsmPrinter &AP,
2036 const Constant *BaseCV, uint64_t Offset) {
2037 // Print the fields in successive locations. Pad to align if needed!
2038 unsigned Size = DL.getTypeAllocSize(CS->getType());
2039 const StructLayout *Layout = DL.getStructLayout(CS->getType());
2040 uint64_t SizeSoFar = 0;
2041 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
2042 const Constant *Field = CS->getOperand(i);
2044 // Print the actual field value.
2045 emitGlobalConstantImpl(DL, Field, AP, BaseCV, Offset + SizeSoFar);
2047 // Check if padding is needed and insert one or more 0s.
2048 uint64_t FieldSize = DL.getTypeAllocSize(Field->getType());
2049 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
2050 - Layout->getElementOffset(i)) - FieldSize;
2051 SizeSoFar += FieldSize + PadSize;
2053 // Insert padding - this may include padding to increase the size of the
2054 // current field up to the ABI size (if the struct is not packed) as well
2055 // as padding to ensure that the next field starts at the right offset.
2056 AP.OutStreamer->EmitZeros(PadSize);
2058 assert(SizeSoFar == Layout->getSizeInBytes() &&
2059 "Layout of constant struct may be incorrect!");
2062 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
2063 APInt API = CFP->getValueAPF().bitcastToAPInt();
2065 // First print a comment with what we think the original floating-point value
2066 // should have been.
2067 if (AP.isVerbose()) {
2068 SmallString<8> StrVal;
2069 CFP->getValueAPF().toString(StrVal);
2072 CFP->getType()->print(AP.OutStreamer->GetCommentOS());
2074 AP.OutStreamer->GetCommentOS() << "Printing <null> Type";
2075 AP.OutStreamer->GetCommentOS() << ' ' << StrVal << '\n';
2078 // Now iterate through the APInt chunks, emitting them in endian-correct
2079 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
2081 unsigned NumBytes = API.getBitWidth() / 8;
2082 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
2083 const uint64_t *p = API.getRawData();
2085 // PPC's long double has odd notions of endianness compared to how LLVM
2086 // handles it: p[0] goes first for *big* endian on PPC.
2087 if (AP.getDataLayout().isBigEndian() && !CFP->getType()->isPPC_FP128Ty()) {
2088 int Chunk = API.getNumWords() - 1;
2091 AP.OutStreamer->EmitIntValue(p[Chunk--], TrailingBytes);
2093 for (; Chunk >= 0; --Chunk)
2094 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
2097 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
2098 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
2101 AP.OutStreamer->EmitIntValue(p[Chunk], TrailingBytes);
2104 // Emit the tail padding for the long double.
2105 const DataLayout &DL = AP.getDataLayout();
2106 AP.OutStreamer->EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
2107 DL.getTypeStoreSize(CFP->getType()));
2110 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
2111 const DataLayout &DL = AP.getDataLayout();
2112 unsigned BitWidth = CI->getBitWidth();
2114 // Copy the value as we may massage the layout for constants whose bit width
2115 // is not a multiple of 64-bits.
2116 APInt Realigned(CI->getValue());
2117 uint64_t ExtraBits = 0;
2118 unsigned ExtraBitsSize = BitWidth & 63;
2120 if (ExtraBitsSize) {
2121 // The bit width of the data is not a multiple of 64-bits.
2122 // The extra bits are expected to be at the end of the chunk of the memory.
2124 // * Nothing to be done, just record the extra bits to emit.
2126 // * Record the extra bits to emit.
2127 // * Realign the raw data to emit the chunks of 64-bits.
2128 if (DL.isBigEndian()) {
2129 // Basically the structure of the raw data is a chunk of 64-bits cells:
2130 // 0 1 BitWidth / 64
2131 // [chunk1][chunk2] ... [chunkN].
2132 // The most significant chunk is chunkN and it should be emitted first.
2133 // However, due to the alignment issue chunkN contains useless bits.
2134 // Realign the chunks so that they contain only useless information:
2135 // ExtraBits 0 1 (BitWidth / 64) - 1
2136 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
2137 ExtraBits = Realigned.getRawData()[0] &
2138 (((uint64_t)-1) >> (64 - ExtraBitsSize));
2139 Realigned = Realigned.lshr(ExtraBitsSize);
2141 ExtraBits = Realigned.getRawData()[BitWidth / 64];
2144 // We don't expect assemblers to support integer data directives
2145 // for more than 64 bits, so we emit the data in at most 64-bit
2146 // quantities at a time.
2147 const uint64_t *RawData = Realigned.getRawData();
2148 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
2149 uint64_t Val = DL.isBigEndian() ? RawData[e - i - 1] : RawData[i];
2150 AP.OutStreamer->EmitIntValue(Val, 8);
2153 if (ExtraBitsSize) {
2154 // Emit the extra bits after the 64-bits chunks.
2156 // Emit a directive that fills the expected size.
2157 uint64_t Size = AP.getDataLayout().getTypeAllocSize(CI->getType());
2158 Size -= (BitWidth / 64) * 8;
2159 assert(Size && Size * 8 >= ExtraBitsSize &&
2160 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
2161 == ExtraBits && "Directive too small for extra bits.");
2162 AP.OutStreamer->EmitIntValue(ExtraBits, Size);
2166 /// \brief Transform a not absolute MCExpr containing a reference to a GOT
2167 /// equivalent global, by a target specific GOT pc relative access to the
2169 static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
2170 const Constant *BaseCst,
2172 // The global @foo below illustrates a global that uses a got equivalent.
2174 // @bar = global i32 42
2175 // @gotequiv = private unnamed_addr constant i32* @bar
2176 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
2177 // i64 ptrtoint (i32* @foo to i64))
2180 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
2181 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
2184 // foo = cstexpr, where
2185 // cstexpr := <gotequiv> - "." + <cst>
2186 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
2188 // After canonicalization by evaluateAsRelocatable `ME` turns into:
2190 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
2191 // gotpcrelcst := <offset from @foo base> + <cst>
2194 if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
2196 const MCSymbolRefExpr *SymA = MV.getSymA();
2200 // Check that GOT equivalent symbol is cached.
2201 const MCSymbol *GOTEquivSym = &SymA->getSymbol();
2202 if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
2205 const GlobalValue *BaseGV = dyn_cast_or_null<GlobalValue>(BaseCst);
2209 // Check for a valid base symbol
2210 const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
2211 const MCSymbolRefExpr *SymB = MV.getSymB();
2213 if (!SymB || BaseSym != &SymB->getSymbol())
2216 // Make sure to match:
2218 // gotpcrelcst := <offset from @foo base> + <cst>
2220 // If gotpcrelcst is positive it means that we can safely fold the pc rel
2221 // displacement into the GOTPCREL. We can also can have an extra offset <cst>
2222 // if the target knows how to encode it.
2224 int64_t GOTPCRelCst = Offset + MV.getConstant();
2225 if (GOTPCRelCst < 0)
2227 if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
2230 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
2237 // .long gotequiv - "." + <cst>
2239 // is replaced by the target specific equivalent to:
2244 // .long bar@GOTPCREL+<gotpcrelcst>
2246 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
2247 const GlobalVariable *GV = Result.first;
2248 int NumUses = (int)Result.second;
2249 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
2250 const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
2251 *ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(
2252 FinalSym, MV, Offset, AP.MMI, *AP.OutStreamer);
2254 // Update GOT equivalent usage information
2257 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
2260 static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *CV,
2261 AsmPrinter &AP, const Constant *BaseCV,
2263 uint64_t Size = DL.getTypeAllocSize(CV->getType());
2265 // Globals with sub-elements such as combinations of arrays and structs
2266 // are handled recursively by emitGlobalConstantImpl. Keep track of the
2267 // constant symbol base and the current position with BaseCV and Offset.
2268 if (!BaseCV && CV->hasOneUse())
2269 BaseCV = dyn_cast<Constant>(CV->user_back());
2271 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
2272 return AP.OutStreamer->EmitZeros(Size);
2274 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
2281 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
2282 CI->getZExtValue());
2283 AP.OutStreamer->EmitIntValue(CI->getZExtValue(), Size);
2286 emitGlobalConstantLargeInt(CI, AP);
2291 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
2292 return emitGlobalConstantFP(CFP, AP);
2294 if (isa<ConstantPointerNull>(CV)) {
2295 AP.OutStreamer->EmitIntValue(0, Size);
2299 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
2300 return emitGlobalConstantDataSequential(DL, CDS, AP);
2302 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2303 return emitGlobalConstantArray(DL, CVA, AP, BaseCV, Offset);
2305 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2306 return emitGlobalConstantStruct(DL, CVS, AP, BaseCV, Offset);
2308 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2309 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2311 if (CE->getOpcode() == Instruction::BitCast)
2312 return emitGlobalConstantImpl(DL, CE->getOperand(0), AP);
2315 // If the constant expression's size is greater than 64-bits, then we have
2316 // to emit the value in chunks. Try to constant fold the value and emit it
2318 Constant *New = ConstantFoldConstant(CE, DL);
2319 if (New && New != CE)
2320 return emitGlobalConstantImpl(DL, New, AP);
2324 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2325 return emitGlobalConstantVector(DL, V, AP);
2327 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2328 // thread the streamer with EmitValue.
2329 const MCExpr *ME = AP.lowerConstant(CV);
2331 // Since lowerConstant already folded and got rid of all IR pointer and
2332 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
2334 if (AP.getObjFileLowering().supportIndirectSymViaGOTPCRel())
2335 handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
2337 AP.OutStreamer->EmitValue(ME, Size);
2340 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2341 void AsmPrinter::EmitGlobalConstant(const DataLayout &DL, const Constant *CV) {
2342 uint64_t Size = DL.getTypeAllocSize(CV->getType());
2344 emitGlobalConstantImpl(DL, CV, *this);
2345 else if (MAI->hasSubsectionsViaSymbols()) {
2346 // If the global has zero size, emit a single byte so that two labels don't
2347 // look like they are at the same location.
2348 OutStreamer->EmitIntValue(0, 1);
2352 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2353 // Target doesn't support this yet!
2354 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2357 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2359 OS << '+' << Offset;
2360 else if (Offset < 0)
2364 //===----------------------------------------------------------------------===//
2365 // Symbol Lowering Routines.
2366 //===----------------------------------------------------------------------===//
2368 MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name) const {
2369 return OutContext.createTempSymbol(Name, true);
2372 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2373 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2376 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2377 return MMI->getAddrLabelSymbol(BB);
2380 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2381 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2382 const DataLayout &DL = getDataLayout();
2383 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
2384 "CPI" + Twine(getFunctionNumber()) + "_" +
2388 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2389 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2390 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2393 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2394 /// FIXME: privatize to AsmPrinter.
2395 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2396 const DataLayout &DL = getDataLayout();
2397 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
2398 Twine(getFunctionNumber()) + "_" +
2399 Twine(UID) + "_set_" + Twine(MBBID));
2402 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2403 StringRef Suffix) const {
2404 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, TM);
2407 /// Return the MCSymbol for the specified ExternalSymbol.
2408 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2409 SmallString<60> NameStr;
2410 Mangler::getNameWithPrefix(NameStr, Sym, getDataLayout());
2411 return OutContext.getOrCreateSymbol(NameStr);
2416 /// PrintParentLoopComment - Print comments about parent loops of this one.
2417 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2418 unsigned FunctionNumber) {
2420 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2421 OS.indent(Loop->getLoopDepth()*2)
2422 << "Parent Loop BB" << FunctionNumber << "_"
2423 << Loop->getHeader()->getNumber()
2424 << " Depth=" << Loop->getLoopDepth() << '\n';
2428 /// PrintChildLoopComment - Print comments about child loops within
2429 /// the loop for this basic block, with nesting.
2430 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2431 unsigned FunctionNumber) {
2432 // Add child loop information
2433 for (const MachineLoop *CL : *Loop) {
2434 OS.indent(CL->getLoopDepth()*2)
2435 << "Child Loop BB" << FunctionNumber << "_"
2436 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2438 PrintChildLoopComment(OS, CL, FunctionNumber);
2442 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2443 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2444 const MachineLoopInfo *LI,
2445 const AsmPrinter &AP) {
2446 // Add loop depth information
2447 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2450 MachineBasicBlock *Header = Loop->getHeader();
2451 assert(Header && "No header for loop");
2453 // If this block is not a loop header, just print out what is the loop header
2455 if (Header != &MBB) {
2456 AP.OutStreamer->AddComment(" in Loop: Header=BB" +
2457 Twine(AP.getFunctionNumber())+"_" +
2458 Twine(Loop->getHeader()->getNumber())+
2459 " Depth="+Twine(Loop->getLoopDepth()));
2463 // Otherwise, it is a loop header. Print out information about child and
2465 raw_ostream &OS = AP.OutStreamer->GetCommentOS();
2467 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2470 OS.indent(Loop->getLoopDepth()*2-2);
2475 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2477 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2481 /// EmitBasicBlockStart - This method prints the label for the specified
2482 /// MachineBasicBlock, an alignment (if present) and a comment describing
2483 /// it if appropriate.
2484 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2485 // End the previous funclet and start a new one.
2486 if (MBB.isEHFuncletEntry()) {
2487 for (const HandlerInfo &HI : Handlers) {
2488 HI.Handler->endFunclet();
2489 HI.Handler->beginFunclet(MBB);
2493 // Emit an alignment directive for this block, if needed.
2494 if (unsigned Align = MBB.getAlignment())
2495 EmitAlignment(Align);
2497 // If the block has its address taken, emit any labels that were used to
2498 // reference the block. It is possible that there is more than one label
2499 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2500 // the references were generated.
2501 if (MBB.hasAddressTaken()) {
2502 const BasicBlock *BB = MBB.getBasicBlock();
2504 OutStreamer->AddComment("Block address taken");
2506 // MBBs can have their address taken as part of CodeGen without having
2507 // their corresponding BB's address taken in IR
2508 if (BB->hasAddressTaken())
2509 for (MCSymbol *Sym : MMI->getAddrLabelSymbolToEmit(BB))
2510 OutStreamer->EmitLabel(Sym);
2513 // Print some verbose block comments.
2515 if (const BasicBlock *BB = MBB.getBasicBlock()) {
2516 if (BB->hasName()) {
2517 BB->printAsOperand(OutStreamer->GetCommentOS(),
2518 /*PrintType=*/false, BB->getModule());
2519 OutStreamer->GetCommentOS() << '\n';
2522 emitBasicBlockLoopComments(MBB, LI, *this);
2525 // Print the main label for the block.
2526 if (MBB.pred_empty() ||
2527 (isBlockOnlyReachableByFallthrough(&MBB) && !MBB.isEHFuncletEntry())) {
2529 // NOTE: Want this comment at start of line, don't emit with AddComment.
2530 OutStreamer->emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2533 OutStreamer->EmitLabel(MBB.getSymbol());
2537 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2538 bool IsDefinition) const {
2539 MCSymbolAttr Attr = MCSA_Invalid;
2541 switch (Visibility) {
2543 case GlobalValue::HiddenVisibility:
2545 Attr = MAI->getHiddenVisibilityAttr();
2547 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2549 case GlobalValue::ProtectedVisibility:
2550 Attr = MAI->getProtectedVisibilityAttr();
2554 if (Attr != MCSA_Invalid)
2555 OutStreamer->EmitSymbolAttribute(Sym, Attr);
2558 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2559 /// exactly one predecessor and the control transfer mechanism between
2560 /// the predecessor and this block is a fall-through.
2562 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2563 // If this is a landing pad, it isn't a fall through. If it has no preds,
2564 // then nothing falls through to it.
2565 if (MBB->isEHPad() || MBB->pred_empty())
2568 // If there isn't exactly one predecessor, it can't be a fall through.
2569 if (MBB->pred_size() > 1)
2572 // The predecessor has to be immediately before this block.
2573 MachineBasicBlock *Pred = *MBB->pred_begin();
2574 if (!Pred->isLayoutSuccessor(MBB))
2577 // If the block is completely empty, then it definitely does fall through.
2581 // Check the terminators in the previous blocks
2582 for (const auto &MI : Pred->terminators()) {
2583 // If it is not a simple branch, we are in a table somewhere.
2584 if (!MI.isBranch() || MI.isIndirectBranch())
2587 // If we are the operands of one of the branches, this is not a fall
2588 // through. Note that targets with delay slots will usually bundle
2589 // terminators with the delay slot instruction.
2590 for (ConstMIBundleOperands OP(MI); OP.isValid(); ++OP) {
2593 if (OP->isMBB() && OP->getMBB() == MBB)
2603 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2604 if (!S.usesMetadata())
2607 assert(!S.useStatepoints() && "statepoints do not currently support custom"
2608 " stackmap formats, please see the documentation for a description of"
2609 " the default format. If you really need a custom serialized format,"
2610 " please file a bug");
2612 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2613 gcp_map_type::iterator GCPI = GCMap.find(&S);
2614 if (GCPI != GCMap.end())
2615 return GCPI->second.get();
2617 auto Name = S.getName();
2619 for (GCMetadataPrinterRegistry::iterator
2620 I = GCMetadataPrinterRegistry::begin(),
2621 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2622 if (Name == I->getName()) {
2623 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2625 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2626 return IterBool.first->second.get();
2629 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2632 /// Pin vtable to this file.
2633 AsmPrinterHandler::~AsmPrinterHandler() {}
2635 void AsmPrinterHandler::markFunctionEnd() {}
2637 // In the binary's "xray_instr_map" section, an array of these function entries
2638 // describes each instrumentation point. When XRay patches your code, the index
2639 // into this table will be given to your handler as a patch point identifier.
2640 void AsmPrinter::XRayFunctionEntry::emit(int Bytes, MCStreamer *Out,
2641 const MCSymbol *CurrentFnSym) const {
2642 Out->EmitSymbolValue(Sled, Bytes);
2643 Out->EmitSymbolValue(CurrentFnSym, Bytes);
2644 auto Kind8 = static_cast<uint8_t>(Kind);
2645 Out->EmitBytes(StringRef(reinterpret_cast<const char *>(&Kind8), 1));
2647 StringRef(reinterpret_cast<const char *>(&AlwaysInstrument), 1));
2648 Out->EmitZeros(2 * Bytes - 2); // Pad the previous two entries
2651 void AsmPrinter::emitXRayTable() {
2655 auto PrevSection = OutStreamer->getCurrentSectionOnly();
2656 auto Fn = MF->getFunction();
2657 MCSection *Section = nullptr;
2658 if (MF->getSubtarget().getTargetTriple().isOSBinFormatELF()) {
2659 if (Fn->hasComdat()) {
2660 Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
2661 ELF::SHF_ALLOC | ELF::SHF_GROUP, 0,
2662 Fn->getComdat()->getName());
2664 Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
2667 } else if (MF->getSubtarget().getTargetTriple().isOSBinFormatMachO()) {
2668 Section = OutContext.getMachOSection("__DATA", "xray_instr_map", 0,
2669 SectionKind::getReadOnlyWithRel());
2671 llvm_unreachable("Unsupported target");
2674 // Before we switch over, we force a reference to a label inside the
2675 // xray_instr_map section. Since this function is always called just
2676 // before the function's end, we assume that this is happening after
2677 // the last return instruction.
2679 auto WordSizeBytes = TM.getPointerSize();
2680 MCSymbol *Tmp = OutContext.createTempSymbol("xray_synthetic_", true);
2681 OutStreamer->EmitCodeAlignment(16);
2682 OutStreamer->EmitSymbolValue(Tmp, WordSizeBytes, false);
2683 OutStreamer->SwitchSection(Section);
2684 OutStreamer->EmitLabel(Tmp);
2685 for (const auto &Sled : Sleds)
2686 Sled.emit(WordSizeBytes, OutStreamer.get(), CurrentFnSym);
2688 OutStreamer->SwitchSection(PrevSection);
2692 void AsmPrinter::recordSled(MCSymbol *Sled, const MachineInstr &MI,
2694 auto Fn = MI.getParent()->getParent()->getFunction();
2695 auto Attr = Fn->getFnAttribute("function-instrument");
2696 bool AlwaysInstrument =
2697 Attr.isStringAttribute() && Attr.getValueAsString() == "xray-always";
2699 XRayFunctionEntry{ Sled, CurrentFnSym, Kind, AlwaysInstrument, Fn });
2702 uint16_t AsmPrinter::getDwarfVersion() const {
2703 return OutStreamer->getContext().getDwarfVersion();
2706 void AsmPrinter::setDwarfVersion(uint16_t Version) {
2707 OutStreamer->getContext().setDwarfVersion(Version);