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 /// Emit the directive and value for debug thread local expression
572 /// \p Value - The value to emit.
573 /// \p Size - The size of the integer (in bytes) to emit.
574 void AsmPrinter::EmitDebugValue(const MCExpr *Value,
575 unsigned Size) const {
576 OutStreamer->EmitValue(Value, Size);
579 /// EmitFunctionHeader - This method emits the header for the current
581 void AsmPrinter::EmitFunctionHeader() {
582 // Print out constants referenced by the function
585 // Print the 'header' of function.
586 const Function *F = MF->getFunction();
588 OutStreamer->SwitchSection(getObjFileLowering().SectionForGlobal(F, TM));
589 EmitVisibility(CurrentFnSym, F->getVisibility());
591 EmitLinkage(F, CurrentFnSym);
592 if (MAI->hasFunctionAlignment())
593 EmitAlignment(MF->getAlignment(), F);
595 if (MAI->hasDotTypeDotSizeDirective())
596 OutStreamer->EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
599 F->printAsOperand(OutStreamer->GetCommentOS(),
600 /*PrintType=*/false, F->getParent());
601 OutStreamer->GetCommentOS() << '\n';
604 // Emit the prefix data.
605 if (F->hasPrefixData())
606 EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrefixData());
608 // Emit the CurrentFnSym. This is a virtual function to allow targets to
609 // do their wild and crazy things as required.
610 EmitFunctionEntryLabel();
612 // If the function had address-taken blocks that got deleted, then we have
613 // references to the dangling symbols. Emit them at the start of the function
614 // so that we don't get references to undefined symbols.
615 std::vector<MCSymbol*> DeadBlockSyms;
616 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
617 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
618 OutStreamer->AddComment("Address taken block that was later removed");
619 OutStreamer->EmitLabel(DeadBlockSyms[i]);
622 if (CurrentFnBegin) {
623 if (MAI->useAssignmentForEHBegin()) {
624 MCSymbol *CurPos = OutContext.createTempSymbol();
625 OutStreamer->EmitLabel(CurPos);
626 OutStreamer->EmitAssignment(CurrentFnBegin,
627 MCSymbolRefExpr::create(CurPos, OutContext));
629 OutStreamer->EmitLabel(CurrentFnBegin);
633 // Emit pre-function debug and/or EH information.
634 for (const HandlerInfo &HI : Handlers) {
635 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
636 HI.TimerGroupDescription, TimePassesIsEnabled);
637 HI.Handler->beginFunction(MF);
640 // Emit the prologue data.
641 if (F->hasPrologueData())
642 EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrologueData());
645 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
646 /// function. This can be overridden by targets as required to do custom stuff.
647 void AsmPrinter::EmitFunctionEntryLabel() {
648 CurrentFnSym->redefineIfPossible();
650 // The function label could have already been emitted if two symbols end up
651 // conflicting due to asm renaming. Detect this and emit an error.
652 if (CurrentFnSym->isVariable())
653 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
654 "' is a protected alias");
655 if (CurrentFnSym->isDefined())
656 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
657 "' label emitted multiple times to assembly file");
659 return OutStreamer->EmitLabel(CurrentFnSym);
662 /// emitComments - Pretty-print comments for instructions.
663 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
664 const MachineFunction *MF = MI.getParent()->getParent();
665 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
667 // Check for spills and reloads
670 const MachineFrameInfo &MFI = MF->getFrameInfo();
672 // We assume a single instruction only has a spill or reload, not
674 const MachineMemOperand *MMO;
675 if (TII->isLoadFromStackSlotPostFE(MI, FI)) {
676 if (MFI.isSpillSlotObjectIndex(FI)) {
677 MMO = *MI.memoperands_begin();
678 CommentOS << MMO->getSize() << "-byte Reload\n";
680 } else if (TII->hasLoadFromStackSlot(MI, MMO, FI)) {
681 if (MFI.isSpillSlotObjectIndex(FI))
682 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
683 } else if (TII->isStoreToStackSlotPostFE(MI, FI)) {
684 if (MFI.isSpillSlotObjectIndex(FI)) {
685 MMO = *MI.memoperands_begin();
686 CommentOS << MMO->getSize() << "-byte Spill\n";
688 } else if (TII->hasStoreToStackSlot(MI, MMO, FI)) {
689 if (MFI.isSpillSlotObjectIndex(FI))
690 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
693 // Check for spill-induced copies
694 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
695 CommentOS << " Reload Reuse\n";
698 /// emitImplicitDef - This method emits the specified machine instruction
699 /// that is an implicit def.
700 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
701 unsigned RegNo = MI->getOperand(0).getReg();
703 SmallString<128> Str;
704 raw_svector_ostream OS(Str);
705 OS << "implicit-def: "
706 << PrintReg(RegNo, MF->getSubtarget().getRegisterInfo());
708 OutStreamer->AddComment(OS.str());
709 OutStreamer->AddBlankLine();
712 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
714 raw_string_ostream OS(Str);
716 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
717 const MachineOperand &Op = MI->getOperand(i);
718 assert(Op.isReg() && "KILL instruction must have only register operands");
720 << PrintReg(Op.getReg(),
721 AP.MF->getSubtarget().getRegisterInfo())
722 << (Op.isDef() ? "<def>" : "<kill>");
724 AP.OutStreamer->AddComment(OS.str());
725 AP.OutStreamer->AddBlankLine();
728 /// emitDebugValueComment - This method handles the target-independent form
729 /// of DBG_VALUE, returning true if it was able to do so. A false return
730 /// means the target will need to handle MI in EmitInstruction.
731 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
732 // This code handles only the 4-operand target-independent form.
733 if (MI->getNumOperands() != 4)
736 SmallString<128> Str;
737 raw_svector_ostream OS(Str);
738 OS << "DEBUG_VALUE: ";
740 const DILocalVariable *V = MI->getDebugVariable();
741 if (auto *SP = dyn_cast<DISubprogram>(V->getScope())) {
742 StringRef Name = SP->getDisplayName();
748 const DIExpression *Expr = MI->getDebugExpression();
749 auto Fragment = Expr->getFragmentInfo();
751 OS << " [fragment offset=" << Fragment->OffsetInBits
752 << " size=" << Fragment->SizeInBits << "]";
755 // The second operand is only an offset if it's an immediate.
756 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
757 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
759 for (unsigned i = 0; i < Expr->getNumElements(); ++i) {
760 uint64_t Op = Expr->getElement(i);
761 if (Op == dwarf::DW_OP_LLVM_fragment) {
762 // There can't be any operands after this in a valid expression
765 // We currently don't support extra Offsets or derefs after the first
766 // one. Bail out early instead of emitting an incorrect comment
767 OS << " [complex expression]";
768 AP.OutStreamer->emitRawComment(OS.str());
770 } else if (Op == dwarf::DW_OP_deref) {
775 uint64_t ExtraOffset = Expr->getElement(i++);
776 if (Op == dwarf::DW_OP_plus)
777 Offset += ExtraOffset;
779 assert(Op == dwarf::DW_OP_minus);
780 Offset -= ExtraOffset;
784 // Register or immediate value. Register 0 means undef.
785 if (MI->getOperand(0).isFPImm()) {
786 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
787 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
788 OS << (double)APF.convertToFloat();
789 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
790 OS << APF.convertToDouble();
792 // There is no good way to print long double. Convert a copy to
793 // double. Ah well, it's only a comment.
795 APF.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven,
797 OS << "(long double) " << APF.convertToDouble();
799 } else if (MI->getOperand(0).isImm()) {
800 OS << MI->getOperand(0).getImm();
801 } else if (MI->getOperand(0).isCImm()) {
802 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
805 if (MI->getOperand(0).isReg()) {
806 Reg = MI->getOperand(0).getReg();
808 assert(MI->getOperand(0).isFI() && "Unknown operand type");
809 const TargetFrameLowering *TFI = AP.MF->getSubtarget().getFrameLowering();
810 Offset += TFI->getFrameIndexReference(*AP.MF,
811 MI->getOperand(0).getIndex(), Reg);
815 // Suppress offset, it is not meaningful here.
817 // NOTE: Want this comment at start of line, don't emit with AddComment.
818 AP.OutStreamer->emitRawComment(OS.str());
823 OS << PrintReg(Reg, AP.MF->getSubtarget().getRegisterInfo());
827 OS << '+' << Offset << ']';
829 // NOTE: Want this comment at start of line, don't emit with AddComment.
830 AP.OutStreamer->emitRawComment(OS.str());
834 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
835 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
836 MF->getFunction()->needsUnwindTableEntry())
839 if (MMI->hasDebugInfo())
845 bool AsmPrinter::needsSEHMoves() {
846 return MAI->usesWindowsCFI() && MF->getFunction()->needsUnwindTableEntry();
849 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
850 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
851 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
852 ExceptionHandlingType != ExceptionHandling::ARM)
855 if (needsCFIMoves() == CFI_M_None)
858 const std::vector<MCCFIInstruction> &Instrs = MF->getFrameInstructions();
859 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
860 const MCCFIInstruction &CFI = Instrs[CFIIndex];
861 emitCFIInstruction(CFI);
864 void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
865 // The operands are the MCSymbol and the frame offset of the allocation.
866 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
867 int FrameOffset = MI.getOperand(1).getImm();
869 // Emit a symbol assignment.
870 OutStreamer->EmitAssignment(FrameAllocSym,
871 MCConstantExpr::create(FrameOffset, OutContext));
874 /// EmitFunctionBody - This method emits the body and trailer for a
876 void AsmPrinter::EmitFunctionBody() {
877 EmitFunctionHeader();
879 // Emit target-specific gunk before the function body.
880 EmitFunctionBodyStart();
882 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
884 // Print out code for the function.
885 bool HasAnyRealCode = false;
886 for (auto &MBB : *MF) {
887 // Print a label for the basic block.
888 EmitBasicBlockStart(MBB);
889 for (auto &MI : MBB) {
891 // Print the assembly for the instruction.
892 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
893 !MI.isDebugValue()) {
894 HasAnyRealCode = true;
898 if (ShouldPrintDebugScopes) {
899 for (const HandlerInfo &HI : Handlers) {
900 NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
901 HI.TimerGroupName, HI.TimerGroupDescription,
902 TimePassesIsEnabled);
903 HI.Handler->beginInstruction(&MI);
908 emitComments(MI, OutStreamer->GetCommentOS());
910 switch (MI.getOpcode()) {
911 case TargetOpcode::CFI_INSTRUCTION:
912 emitCFIInstruction(MI);
915 case TargetOpcode::LOCAL_ESCAPE:
919 case TargetOpcode::EH_LABEL:
920 case TargetOpcode::GC_LABEL:
921 OutStreamer->EmitLabel(MI.getOperand(0).getMCSymbol());
923 case TargetOpcode::INLINEASM:
926 case TargetOpcode::DBG_VALUE:
928 if (!emitDebugValueComment(&MI, *this))
929 EmitInstruction(&MI);
932 case TargetOpcode::IMPLICIT_DEF:
933 if (isVerbose()) emitImplicitDef(&MI);
935 case TargetOpcode::KILL:
936 if (isVerbose()) emitKill(&MI, *this);
939 EmitInstruction(&MI);
943 if (ShouldPrintDebugScopes) {
944 for (const HandlerInfo &HI : Handlers) {
945 NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
946 HI.TimerGroupName, HI.TimerGroupDescription,
947 TimePassesIsEnabled);
948 HI.Handler->endInstruction();
953 EmitBasicBlockEnd(MBB);
956 // If the function is empty and the object file uses .subsections_via_symbols,
957 // then we need to emit *something* to the function body to prevent the
958 // labels from collapsing together. Just emit a noop.
959 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)) {
961 MF->getSubtarget().getInstrInfo()->getNoopForMachoTarget(Noop);
962 OutStreamer->AddComment("avoids zero-length function");
964 // Targets can opt-out of emitting the noop here by leaving the opcode
966 if (Noop.getOpcode())
967 OutStreamer->EmitInstruction(Noop, getSubtargetInfo());
970 const Function *F = MF->getFunction();
971 for (const auto &BB : *F) {
972 if (!BB.hasAddressTaken())
974 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
975 if (Sym->isDefined())
977 OutStreamer->AddComment("Address of block that was removed by CodeGen");
978 OutStreamer->EmitLabel(Sym);
981 // Emit target-specific gunk after the function body.
982 EmitFunctionBodyEnd();
984 if (!MF->getLandingPads().empty() || MMI->hasDebugInfo() ||
985 MF->hasEHFunclets() || MAI->hasDotTypeDotSizeDirective()) {
986 // Create a symbol for the end of function.
987 CurrentFnEnd = createTempSymbol("func_end");
988 OutStreamer->EmitLabel(CurrentFnEnd);
991 // If the target wants a .size directive for the size of the function, emit
993 if (MAI->hasDotTypeDotSizeDirective()) {
994 // We can get the size as difference between the function label and the
996 const MCExpr *SizeExp = MCBinaryExpr::createSub(
997 MCSymbolRefExpr::create(CurrentFnEnd, OutContext),
998 MCSymbolRefExpr::create(CurrentFnSymForSize, OutContext), OutContext);
999 OutStreamer->emitELFSize(CurrentFnSym, SizeExp);
1002 for (const HandlerInfo &HI : Handlers) {
1003 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1004 HI.TimerGroupDescription, TimePassesIsEnabled);
1005 HI.Handler->markFunctionEnd();
1008 // Print out jump tables referenced by the function.
1009 EmitJumpTableInfo();
1011 // Emit post-function debug and/or EH information.
1012 for (const HandlerInfo &HI : Handlers) {
1013 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1014 HI.TimerGroupDescription, TimePassesIsEnabled);
1015 HI.Handler->endFunction(MF);
1018 OutStreamer->AddBlankLine();
1021 /// \brief Compute the number of Global Variables that uses a Constant.
1022 static unsigned getNumGlobalVariableUses(const Constant *C) {
1026 if (isa<GlobalVariable>(C))
1029 unsigned NumUses = 0;
1030 for (auto *CU : C->users())
1031 NumUses += getNumGlobalVariableUses(dyn_cast<Constant>(CU));
1036 /// \brief Only consider global GOT equivalents if at least one user is a
1037 /// cstexpr inside an initializer of another global variables. Also, don't
1038 /// handle cstexpr inside instructions. During global variable emission,
1039 /// candidates are skipped and are emitted later in case at least one cstexpr
1040 /// isn't replaced by a PC relative GOT entry access.
1041 static bool isGOTEquivalentCandidate(const GlobalVariable *GV,
1042 unsigned &NumGOTEquivUsers) {
1043 // Global GOT equivalents are unnamed private globals with a constant
1044 // pointer initializer to another global symbol. They must point to a
1045 // GlobalVariable or Function, i.e., as GlobalValue.
1046 if (!GV->hasGlobalUnnamedAddr() || !GV->hasInitializer() ||
1047 !GV->isConstant() || !GV->isDiscardableIfUnused() ||
1048 !dyn_cast<GlobalValue>(GV->getOperand(0)))
1051 // To be a got equivalent, at least one of its users need to be a constant
1052 // expression used by another global variable.
1053 for (auto *U : GV->users())
1054 NumGOTEquivUsers += getNumGlobalVariableUses(dyn_cast<Constant>(U));
1056 return NumGOTEquivUsers > 0;
1059 /// \brief Unnamed constant global variables solely contaning a pointer to
1060 /// another globals variable is equivalent to a GOT table entry; it contains the
1061 /// the address of another symbol. Optimize it and replace accesses to these
1062 /// "GOT equivalents" by using the GOT entry for the final global instead.
1063 /// Compute GOT equivalent candidates among all global variables to avoid
1064 /// emitting them if possible later on, after it use is replaced by a GOT entry
1066 void AsmPrinter::computeGlobalGOTEquivs(Module &M) {
1067 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
1070 for (const auto &G : M.globals()) {
1071 unsigned NumGOTEquivUsers = 0;
1072 if (!isGOTEquivalentCandidate(&G, NumGOTEquivUsers))
1075 const MCSymbol *GOTEquivSym = getSymbol(&G);
1076 GlobalGOTEquivs[GOTEquivSym] = std::make_pair(&G, NumGOTEquivUsers);
1080 /// \brief Constant expressions using GOT equivalent globals may not be eligible
1081 /// for PC relative GOT entry conversion, in such cases we need to emit such
1082 /// globals we previously omitted in EmitGlobalVariable.
1083 void AsmPrinter::emitGlobalGOTEquivs() {
1084 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
1087 SmallVector<const GlobalVariable *, 8> FailedCandidates;
1088 for (auto &I : GlobalGOTEquivs) {
1089 const GlobalVariable *GV = I.second.first;
1090 unsigned Cnt = I.second.second;
1092 FailedCandidates.push_back(GV);
1094 GlobalGOTEquivs.clear();
1096 for (auto *GV : FailedCandidates)
1097 EmitGlobalVariable(GV);
1100 void AsmPrinter::emitGlobalIndirectSymbol(Module &M,
1101 const GlobalIndirectSymbol& GIS) {
1102 MCSymbol *Name = getSymbol(&GIS);
1104 if (GIS.hasExternalLinkage() || !MAI->getWeakRefDirective())
1105 OutStreamer->EmitSymbolAttribute(Name, MCSA_Global);
1106 else if (GIS.hasWeakLinkage() || GIS.hasLinkOnceLinkage())
1107 OutStreamer->EmitSymbolAttribute(Name, MCSA_WeakReference);
1109 assert(GIS.hasLocalLinkage() && "Invalid alias or ifunc linkage");
1111 // Set the symbol type to function if the alias has a function type.
1112 // This affects codegen when the aliasee is not a function.
1113 if (GIS.getType()->getPointerElementType()->isFunctionTy()) {
1114 OutStreamer->EmitSymbolAttribute(Name, MCSA_ELF_TypeFunction);
1115 if (isa<GlobalIFunc>(GIS))
1116 OutStreamer->EmitSymbolAttribute(Name, MCSA_ELF_TypeIndFunction);
1119 EmitVisibility(Name, GIS.getVisibility());
1121 const MCExpr *Expr = lowerConstant(GIS.getIndirectSymbol());
1123 if (isa<GlobalAlias>(&GIS) && MAI->hasAltEntry() && isa<MCBinaryExpr>(Expr))
1124 OutStreamer->EmitSymbolAttribute(Name, MCSA_AltEntry);
1126 // Emit the directives as assignments aka .set:
1127 OutStreamer->EmitAssignment(Name, Expr);
1129 if (auto *GA = dyn_cast<GlobalAlias>(&GIS)) {
1130 // If the aliasee does not correspond to a symbol in the output, i.e. the
1131 // alias is not of an object or the aliased object is private, then set the
1132 // size of the alias symbol from the type of the alias. We don't do this in
1133 // other situations as the alias and aliasee having differing types but same
1134 // size may be intentional.
1135 const GlobalObject *BaseObject = GA->getBaseObject();
1136 if (MAI->hasDotTypeDotSizeDirective() && GA->getValueType()->isSized() &&
1137 (!BaseObject || BaseObject->hasPrivateLinkage())) {
1138 const DataLayout &DL = M.getDataLayout();
1139 uint64_t Size = DL.getTypeAllocSize(GA->getValueType());
1140 OutStreamer->emitELFSize(Name, MCConstantExpr::create(Size, OutContext));
1145 bool AsmPrinter::doFinalization(Module &M) {
1146 // Set the MachineFunction to nullptr so that we can catch attempted
1147 // accesses to MF specific features at the module level and so that
1148 // we can conditionalize accesses based on whether or not it is nullptr.
1151 // Gather all GOT equivalent globals in the module. We really need two
1152 // passes over the globals: one to compute and another to avoid its emission
1153 // in EmitGlobalVariable, otherwise we would not be able to handle cases
1154 // where the got equivalent shows up before its use.
1155 computeGlobalGOTEquivs(M);
1157 // Emit global variables.
1158 for (const auto &G : M.globals())
1159 EmitGlobalVariable(&G);
1161 // Emit remaining GOT equivalent globals.
1162 emitGlobalGOTEquivs();
1164 // Emit visibility info for declarations
1165 for (const Function &F : M) {
1166 if (!F.isDeclarationForLinker())
1168 GlobalValue::VisibilityTypes V = F.getVisibility();
1169 if (V == GlobalValue::DefaultVisibility)
1172 MCSymbol *Name = getSymbol(&F);
1173 EmitVisibility(Name, V, false);
1176 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1178 // Emit module flags.
1179 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
1180 M.getModuleFlagsMetadata(ModuleFlags);
1181 if (!ModuleFlags.empty())
1182 TLOF.emitModuleFlags(*OutStreamer, ModuleFlags, TM);
1184 if (TM.getTargetTriple().isOSBinFormatELF()) {
1185 MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
1187 // Output stubs for external and common global variables.
1188 MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
1189 if (!Stubs.empty()) {
1190 OutStreamer->SwitchSection(TLOF.getDataSection());
1191 const DataLayout &DL = M.getDataLayout();
1193 for (const auto &Stub : Stubs) {
1194 OutStreamer->EmitLabel(Stub.first);
1195 OutStreamer->EmitSymbolValue(Stub.second.getPointer(),
1196 DL.getPointerSize());
1201 // Finalize debug and EH information.
1202 for (const HandlerInfo &HI : Handlers) {
1203 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1204 HI.TimerGroupDescription, TimePassesIsEnabled);
1205 HI.Handler->endModule();
1211 // If the target wants to know about weak references, print them all.
1212 if (MAI->getWeakRefDirective()) {
1213 // FIXME: This is not lazy, it would be nice to only print weak references
1214 // to stuff that is actually used. Note that doing so would require targets
1215 // to notice uses in operands (due to constant exprs etc). This should
1216 // happen with the MC stuff eventually.
1218 // Print out module-level global objects here.
1219 for (const auto &GO : M.global_objects()) {
1220 if (!GO.hasExternalWeakLinkage())
1222 OutStreamer->EmitSymbolAttribute(getSymbol(&GO), MCSA_WeakReference);
1226 OutStreamer->AddBlankLine();
1228 // Print aliases in topological order, that is, for each alias a = b,
1229 // b must be printed before a.
1230 // This is because on some targets (e.g. PowerPC) linker expects aliases in
1231 // such an order to generate correct TOC information.
1232 SmallVector<const GlobalAlias *, 16> AliasStack;
1233 SmallPtrSet<const GlobalAlias *, 16> AliasVisited;
1234 for (const auto &Alias : M.aliases()) {
1235 for (const GlobalAlias *Cur = &Alias; Cur;
1236 Cur = dyn_cast<GlobalAlias>(Cur->getAliasee())) {
1237 if (!AliasVisited.insert(Cur).second)
1239 AliasStack.push_back(Cur);
1241 for (const GlobalAlias *AncestorAlias : reverse(AliasStack))
1242 emitGlobalIndirectSymbol(M, *AncestorAlias);
1245 for (const auto &IFunc : M.ifuncs())
1246 emitGlobalIndirectSymbol(M, IFunc);
1248 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1249 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1250 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1251 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1252 MP->finishAssembly(M, *MI, *this);
1254 // Emit llvm.ident metadata in an '.ident' directive.
1255 EmitModuleIdents(M);
1257 // Emit __morestack address if needed for indirect calls.
1258 if (MMI->usesMorestackAddr()) {
1260 MCSection *ReadOnlySection = getObjFileLowering().getSectionForConstant(
1261 getDataLayout(), SectionKind::getReadOnly(),
1262 /*C=*/nullptr, Align);
1263 OutStreamer->SwitchSection(ReadOnlySection);
1265 MCSymbol *AddrSymbol =
1266 OutContext.getOrCreateSymbol(StringRef("__morestack_addr"));
1267 OutStreamer->EmitLabel(AddrSymbol);
1269 unsigned PtrSize = M.getDataLayout().getPointerSize(0);
1270 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("__morestack"),
1274 // If we don't have any trampolines, then we don't require stack memory
1275 // to be executable. Some targets have a directive to declare this.
1276 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1277 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1278 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1279 OutStreamer->SwitchSection(S);
1281 // Allow the target to emit any magic that it wants at the end of the file,
1282 // after everything else has gone out.
1283 EmitEndOfAsmFile(M);
1287 OutStreamer->Finish();
1288 OutStreamer->reset();
1293 MCSymbol *AsmPrinter::getCurExceptionSym() {
1294 if (!CurExceptionSym)
1295 CurExceptionSym = createTempSymbol("exception");
1296 return CurExceptionSym;
1299 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1301 // Get the function symbol.
1302 CurrentFnSym = getSymbol(MF.getFunction());
1303 CurrentFnSymForSize = CurrentFnSym;
1304 CurrentFnBegin = nullptr;
1305 CurExceptionSym = nullptr;
1306 bool NeedsLocalForSize = MAI->needsLocalForSize();
1307 if (!MF.getLandingPads().empty() || MMI->hasDebugInfo() ||
1308 MF.hasEHFunclets() || NeedsLocalForSize) {
1309 CurrentFnBegin = createTempSymbol("func_begin");
1310 if (NeedsLocalForSize)
1311 CurrentFnSymForSize = CurrentFnBegin;
1315 LI = &getAnalysis<MachineLoopInfo>();
1319 // Keep track the alignment, constpool entries per Section.
1323 SmallVector<unsigned, 4> CPEs;
1324 SectionCPs(MCSection *s, unsigned a) : S(s), Alignment(a) {}
1328 /// EmitConstantPool - Print to the current output stream assembly
1329 /// representations of the constants in the constant pool MCP. This is
1330 /// used to print out constants which have been "spilled to memory" by
1331 /// the code generator.
1333 void AsmPrinter::EmitConstantPool() {
1334 const MachineConstantPool *MCP = MF->getConstantPool();
1335 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1336 if (CP.empty()) return;
1338 // Calculate sections for constant pool entries. We collect entries to go into
1339 // the same section together to reduce amount of section switch statements.
1340 SmallVector<SectionCPs, 4> CPSections;
1341 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1342 const MachineConstantPoolEntry &CPE = CP[i];
1343 unsigned Align = CPE.getAlignment();
1345 SectionKind Kind = CPE.getSectionKind(&getDataLayout());
1347 const Constant *C = nullptr;
1348 if (!CPE.isMachineConstantPoolEntry())
1349 C = CPE.Val.ConstVal;
1351 MCSection *S = getObjFileLowering().getSectionForConstant(getDataLayout(),
1354 // The number of sections are small, just do a linear search from the
1355 // last section to the first.
1357 unsigned SecIdx = CPSections.size();
1358 while (SecIdx != 0) {
1359 if (CPSections[--SecIdx].S == S) {
1365 SecIdx = CPSections.size();
1366 CPSections.push_back(SectionCPs(S, Align));
1369 if (Align > CPSections[SecIdx].Alignment)
1370 CPSections[SecIdx].Alignment = Align;
1371 CPSections[SecIdx].CPEs.push_back(i);
1374 // Now print stuff into the calculated sections.
1375 const MCSection *CurSection = nullptr;
1376 unsigned Offset = 0;
1377 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1378 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1379 unsigned CPI = CPSections[i].CPEs[j];
1380 MCSymbol *Sym = GetCPISymbol(CPI);
1381 if (!Sym->isUndefined())
1384 if (CurSection != CPSections[i].S) {
1385 OutStreamer->SwitchSection(CPSections[i].S);
1386 EmitAlignment(Log2_32(CPSections[i].Alignment));
1387 CurSection = CPSections[i].S;
1391 MachineConstantPoolEntry CPE = CP[CPI];
1393 // Emit inter-object padding for alignment.
1394 unsigned AlignMask = CPE.getAlignment() - 1;
1395 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1396 OutStreamer->EmitZeros(NewOffset - Offset);
1398 Type *Ty = CPE.getType();
1399 Offset = NewOffset + getDataLayout().getTypeAllocSize(Ty);
1401 OutStreamer->EmitLabel(Sym);
1402 if (CPE.isMachineConstantPoolEntry())
1403 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1405 EmitGlobalConstant(getDataLayout(), CPE.Val.ConstVal);
1410 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1411 /// by the current function to the current output stream.
1413 void AsmPrinter::EmitJumpTableInfo() {
1414 const DataLayout &DL = MF->getDataLayout();
1415 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1417 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1418 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1419 if (JT.empty()) return;
1421 // Pick the directive to use to print the jump table entries, and switch to
1422 // the appropriate section.
1423 const Function *F = MF->getFunction();
1424 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1425 bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
1426 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
1428 if (JTInDiffSection) {
1429 // Drop it in the readonly section.
1430 MCSection *ReadOnlySection = TLOF.getSectionForJumpTable(*F, TM);
1431 OutStreamer->SwitchSection(ReadOnlySection);
1434 EmitAlignment(Log2_32(MJTI->getEntryAlignment(DL)));
1436 // Jump tables in code sections are marked with a data_region directive
1437 // where that's supported.
1438 if (!JTInDiffSection)
1439 OutStreamer->EmitDataRegion(MCDR_DataRegionJT32);
1441 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1442 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1444 // If this jump table was deleted, ignore it.
1445 if (JTBBs.empty()) continue;
1447 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1448 /// emit a .set directive for each unique entry.
1449 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1450 MAI->doesSetDirectiveSuppressReloc()) {
1451 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1452 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1453 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1454 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1455 const MachineBasicBlock *MBB = JTBBs[ii];
1456 if (!EmittedSets.insert(MBB).second)
1459 // .set LJTSet, LBB32-base
1461 MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1462 OutStreamer->EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1463 MCBinaryExpr::createSub(LHS, Base,
1468 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1469 // before each jump table. The first label is never referenced, but tells
1470 // the assembler and linker the extents of the jump table object. The
1471 // second label is actually referenced by the code.
1472 if (JTInDiffSection && DL.hasLinkerPrivateGlobalPrefix())
1473 // FIXME: This doesn't have to have any specific name, just any randomly
1474 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1475 OutStreamer->EmitLabel(GetJTISymbol(JTI, true));
1477 OutStreamer->EmitLabel(GetJTISymbol(JTI));
1479 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1480 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1482 if (!JTInDiffSection)
1483 OutStreamer->EmitDataRegion(MCDR_DataRegionEnd);
1486 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1488 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1489 const MachineBasicBlock *MBB,
1490 unsigned UID) const {
1491 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1492 const MCExpr *Value = nullptr;
1493 switch (MJTI->getEntryKind()) {
1494 case MachineJumpTableInfo::EK_Inline:
1495 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1496 case MachineJumpTableInfo::EK_Custom32:
1497 Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
1498 MJTI, MBB, UID, OutContext);
1500 case MachineJumpTableInfo::EK_BlockAddress:
1501 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1503 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1505 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1506 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1507 // with a relocation as gp-relative, e.g.:
1509 MCSymbol *MBBSym = MBB->getSymbol();
1510 OutStreamer->EmitGPRel32Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1514 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1515 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1516 // with a relocation as gp-relative, e.g.:
1518 MCSymbol *MBBSym = MBB->getSymbol();
1519 OutStreamer->EmitGPRel64Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1523 case MachineJumpTableInfo::EK_LabelDifference32: {
1524 // Each entry is the address of the block minus the address of the jump
1525 // table. This is used for PIC jump tables where gprel32 is not supported.
1527 // .word LBB123 - LJTI1_2
1528 // If the .set directive avoids relocations, this is emitted as:
1529 // .set L4_5_set_123, LBB123 - LJTI1_2
1530 // .word L4_5_set_123
1531 if (MAI->doesSetDirectiveSuppressReloc()) {
1532 Value = MCSymbolRefExpr::create(GetJTSetSymbol(UID, MBB->getNumber()),
1536 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1537 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1538 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1539 Value = MCBinaryExpr::createSub(Value, Base, OutContext);
1544 assert(Value && "Unknown entry kind!");
1546 unsigned EntrySize = MJTI->getEntrySize(getDataLayout());
1547 OutStreamer->EmitValue(Value, EntrySize);
1551 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1552 /// special global used by LLVM. If so, emit it and return true, otherwise
1553 /// do nothing and return false.
1554 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1555 if (GV->getName() == "llvm.used") {
1556 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1557 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1561 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1562 if (GV->getSection() == "llvm.metadata" ||
1563 GV->hasAvailableExternallyLinkage())
1566 if (!GV->hasAppendingLinkage()) return false;
1568 assert(GV->hasInitializer() && "Not a special LLVM global!");
1570 if (GV->getName() == "llvm.global_ctors") {
1571 EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
1577 if (GV->getName() == "llvm.global_dtors") {
1578 EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
1579 /* isCtor */ false);
1584 report_fatal_error("unknown special variable");
1587 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1588 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1589 /// is true, as being used with this directive.
1590 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1591 // Should be an array of 'i8*'.
1592 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1593 const GlobalValue *GV =
1594 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1596 OutStreamer->EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1602 Structor() : Priority(0), Func(nullptr), ComdatKey(nullptr) {}
1604 llvm::Constant *Func;
1605 llvm::GlobalValue *ComdatKey;
1609 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1611 void AsmPrinter::EmitXXStructorList(const DataLayout &DL, const Constant *List,
1613 // Should be an array of '{ int, void ()* }' structs. The first value is the
1615 if (!isa<ConstantArray>(List)) return;
1617 // Sanity check the structors list.
1618 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1619 if (!InitList) return; // Not an array!
1620 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1621 // FIXME: Only allow the 3-field form in LLVM 4.0.
1622 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1623 return; // Not an array of two or three elements!
1624 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1625 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1626 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1627 return; // Not (int, ptr, ptr).
1629 // Gather the structors in a form that's convenient for sorting by priority.
1630 SmallVector<Structor, 8> Structors;
1631 for (Value *O : InitList->operands()) {
1632 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1633 if (!CS) continue; // Malformed.
1634 if (CS->getOperand(1)->isNullValue())
1635 break; // Found a null terminator, skip the rest.
1636 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1637 if (!Priority) continue; // Malformed.
1638 Structors.push_back(Structor());
1639 Structor &S = Structors.back();
1640 S.Priority = Priority->getLimitedValue(65535);
1641 S.Func = CS->getOperand(1);
1642 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1644 dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1647 // Emit the function pointers in the target-specific order
1648 unsigned Align = Log2_32(DL.getPointerPrefAlignment());
1649 std::stable_sort(Structors.begin(), Structors.end(),
1650 [](const Structor &L,
1651 const Structor &R) { return L.Priority < R.Priority; });
1652 for (Structor &S : Structors) {
1653 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1654 const MCSymbol *KeySym = nullptr;
1655 if (GlobalValue *GV = S.ComdatKey) {
1656 if (GV->hasAvailableExternallyLinkage())
1657 // If the associated variable is available_externally, some other TU
1658 // will provide its dynamic initializer.
1661 KeySym = getSymbol(GV);
1663 MCSection *OutputSection =
1664 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1665 : Obj.getStaticDtorSection(S.Priority, KeySym));
1666 OutStreamer->SwitchSection(OutputSection);
1667 if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
1668 EmitAlignment(Align);
1669 EmitXXStructor(DL, S.Func);
1673 void AsmPrinter::EmitModuleIdents(Module &M) {
1674 if (!MAI->hasIdentDirective())
1677 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1678 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1679 const MDNode *N = NMD->getOperand(i);
1680 assert(N->getNumOperands() == 1 &&
1681 "llvm.ident metadata entry can have only one operand");
1682 const MDString *S = cast<MDString>(N->getOperand(0));
1683 OutStreamer->EmitIdent(S->getString());
1688 //===--------------------------------------------------------------------===//
1689 // Emission and print routines
1692 /// EmitInt8 - Emit a byte directive and value.
1694 void AsmPrinter::EmitInt8(int Value) const {
1695 OutStreamer->EmitIntValue(Value, 1);
1698 /// EmitInt16 - Emit a short directive and value.
1700 void AsmPrinter::EmitInt16(int Value) const {
1701 OutStreamer->EmitIntValue(Value, 2);
1704 /// EmitInt32 - Emit a long directive and value.
1706 void AsmPrinter::EmitInt32(int Value) const {
1707 OutStreamer->EmitIntValue(Value, 4);
1710 /// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1711 /// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1712 /// .set if it avoids relocations.
1713 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1714 unsigned Size) const {
1715 OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
1718 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1719 /// where the size in bytes of the directive is specified by Size and Label
1720 /// specifies the label. This implicitly uses .set if it is available.
1721 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1723 bool IsSectionRelative) const {
1724 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1725 OutStreamer->EmitCOFFSecRel32(Label, Offset);
1727 OutStreamer->EmitZeros(Size - 4);
1731 // Emit Label+Offset (or just Label if Offset is zero)
1732 const MCExpr *Expr = MCSymbolRefExpr::create(Label, OutContext);
1734 Expr = MCBinaryExpr::createAdd(
1735 Expr, MCConstantExpr::create(Offset, OutContext), OutContext);
1737 OutStreamer->EmitValue(Expr, Size);
1740 //===----------------------------------------------------------------------===//
1742 // EmitAlignment - Emit an alignment directive to the specified power of
1743 // two boundary. For example, if you pass in 3 here, you will get an 8
1744 // byte alignment. If a global value is specified, and if that global has
1745 // an explicit alignment requested, it will override the alignment request
1746 // if required for correctness.
1748 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1750 NumBits = getGVAlignmentLog2(GV, GV->getParent()->getDataLayout(), NumBits);
1752 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1755 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&
1756 "undefined behavior");
1757 if (getCurrentSection()->getKind().isText())
1758 OutStreamer->EmitCodeAlignment(1u << NumBits);
1760 OutStreamer->EmitValueToAlignment(1u << NumBits);
1763 //===----------------------------------------------------------------------===//
1764 // Constant emission.
1765 //===----------------------------------------------------------------------===//
1767 const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1768 MCContext &Ctx = OutContext;
1770 if (CV->isNullValue() || isa<UndefValue>(CV))
1771 return MCConstantExpr::create(0, Ctx);
1773 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1774 return MCConstantExpr::create(CI->getZExtValue(), Ctx);
1776 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1777 return MCSymbolRefExpr::create(getSymbol(GV), Ctx);
1779 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1780 return MCSymbolRefExpr::create(GetBlockAddressSymbol(BA), Ctx);
1782 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1784 llvm_unreachable("Unknown constant value to lower!");
1787 switch (CE->getOpcode()) {
1789 // If the code isn't optimized, there may be outstanding folding
1790 // opportunities. Attempt to fold the expression using DataLayout as a
1791 // last resort before giving up.
1792 if (Constant *C = ConstantFoldConstant(CE, getDataLayout()))
1794 return lowerConstant(C);
1796 // Otherwise report the problem to the user.
1799 raw_string_ostream OS(S);
1800 OS << "Unsupported expression in static initializer: ";
1801 CE->printAsOperand(OS, /*PrintType=*/false,
1802 !MF ? nullptr : MF->getFunction()->getParent());
1803 report_fatal_error(OS.str());
1805 case Instruction::GetElementPtr: {
1806 // Generate a symbolic expression for the byte address
1807 APInt OffsetAI(getDataLayout().getPointerTypeSizeInBits(CE->getType()), 0);
1808 cast<GEPOperator>(CE)->accumulateConstantOffset(getDataLayout(), OffsetAI);
1810 const MCExpr *Base = lowerConstant(CE->getOperand(0));
1814 int64_t Offset = OffsetAI.getSExtValue();
1815 return MCBinaryExpr::createAdd(Base, MCConstantExpr::create(Offset, Ctx),
1819 case Instruction::Trunc:
1820 // We emit the value and depend on the assembler to truncate the generated
1821 // expression properly. This is important for differences between
1822 // blockaddress labels. Since the two labels are in the same function, it
1823 // is reasonable to treat their delta as a 32-bit value.
1825 case Instruction::BitCast:
1826 return lowerConstant(CE->getOperand(0));
1828 case Instruction::IntToPtr: {
1829 const DataLayout &DL = getDataLayout();
1831 // Handle casts to pointers by changing them into casts to the appropriate
1832 // integer type. This promotes constant folding and simplifies this code.
1833 Constant *Op = CE->getOperand(0);
1834 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1836 return lowerConstant(Op);
1839 case Instruction::PtrToInt: {
1840 const DataLayout &DL = getDataLayout();
1842 // Support only foldable casts to/from pointers that can be eliminated by
1843 // changing the pointer to the appropriately sized integer type.
1844 Constant *Op = CE->getOperand(0);
1845 Type *Ty = CE->getType();
1847 const MCExpr *OpExpr = lowerConstant(Op);
1849 // We can emit the pointer value into this slot if the slot is an
1850 // integer slot equal to the size of the pointer.
1851 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1854 // Otherwise the pointer is smaller than the resultant integer, mask off
1855 // the high bits so we are sure to get a proper truncation if the input is
1857 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1858 const MCExpr *MaskExpr = MCConstantExpr::create(~0ULL >> (64-InBits), Ctx);
1859 return MCBinaryExpr::createAnd(OpExpr, MaskExpr, Ctx);
1862 case Instruction::Sub: {
1865 if (IsConstantOffsetFromGlobal(CE->getOperand(0), LHSGV, LHSOffset,
1869 if (IsConstantOffsetFromGlobal(CE->getOperand(1), RHSGV, RHSOffset,
1871 const MCExpr *RelocExpr =
1872 getObjFileLowering().lowerRelativeReference(LHSGV, RHSGV, TM);
1874 RelocExpr = MCBinaryExpr::createSub(
1875 MCSymbolRefExpr::create(getSymbol(LHSGV), Ctx),
1876 MCSymbolRefExpr::create(getSymbol(RHSGV), Ctx), Ctx);
1877 int64_t Addend = (LHSOffset - RHSOffset).getSExtValue();
1879 RelocExpr = MCBinaryExpr::createAdd(
1880 RelocExpr, MCConstantExpr::create(Addend, Ctx), Ctx);
1887 // The MC library also has a right-shift operator, but it isn't consistently
1888 // signed or unsigned between different targets.
1889 case Instruction::Add:
1890 case Instruction::Mul:
1891 case Instruction::SDiv:
1892 case Instruction::SRem:
1893 case Instruction::Shl:
1894 case Instruction::And:
1895 case Instruction::Or:
1896 case Instruction::Xor: {
1897 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
1898 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
1899 switch (CE->getOpcode()) {
1900 default: llvm_unreachable("Unknown binary operator constant cast expr");
1901 case Instruction::Add: return MCBinaryExpr::createAdd(LHS, RHS, Ctx);
1902 case Instruction::Sub: return MCBinaryExpr::createSub(LHS, RHS, Ctx);
1903 case Instruction::Mul: return MCBinaryExpr::createMul(LHS, RHS, Ctx);
1904 case Instruction::SDiv: return MCBinaryExpr::createDiv(LHS, RHS, Ctx);
1905 case Instruction::SRem: return MCBinaryExpr::createMod(LHS, RHS, Ctx);
1906 case Instruction::Shl: return MCBinaryExpr::createShl(LHS, RHS, Ctx);
1907 case Instruction::And: return MCBinaryExpr::createAnd(LHS, RHS, Ctx);
1908 case Instruction::Or: return MCBinaryExpr::createOr (LHS, RHS, Ctx);
1909 case Instruction::Xor: return MCBinaryExpr::createXor(LHS, RHS, Ctx);
1915 static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *C,
1917 const Constant *BaseCV = nullptr,
1918 uint64_t Offset = 0);
1920 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP);
1922 /// isRepeatedByteSequence - Determine whether the given value is
1923 /// composed of a repeated sequence of identical bytes and return the
1924 /// byte value. If it is not a repeated sequence, return -1.
1925 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1926 StringRef Data = V->getRawDataValues();
1927 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1929 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1930 if (Data[i] != C) return -1;
1931 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1935 /// isRepeatedByteSequence - Determine whether the given value is
1936 /// composed of a repeated sequence of identical bytes and return the
1937 /// byte value. If it is not a repeated sequence, return -1.
1938 static int isRepeatedByteSequence(const Value *V, const DataLayout &DL) {
1939 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1940 uint64_t Size = DL.getTypeAllocSizeInBits(V->getType());
1941 assert(Size % 8 == 0);
1943 // Extend the element to take zero padding into account.
1944 APInt Value = CI->getValue().zextOrSelf(Size);
1945 if (!Value.isSplat(8))
1948 return Value.zextOrTrunc(8).getZExtValue();
1950 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1951 // Make sure all array elements are sequences of the same repeated
1953 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1954 Constant *Op0 = CA->getOperand(0);
1955 int Byte = isRepeatedByteSequence(Op0, DL);
1959 // All array elements must be equal.
1960 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i)
1961 if (CA->getOperand(i) != Op0)
1966 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1967 return isRepeatedByteSequence(CDS);
1972 static void emitGlobalConstantDataSequential(const DataLayout &DL,
1973 const ConstantDataSequential *CDS,
1976 // See if we can aggregate this into a .fill, if so, emit it as such.
1977 int Value = isRepeatedByteSequence(CDS, DL);
1979 uint64_t Bytes = DL.getTypeAllocSize(CDS->getType());
1980 // Don't emit a 1-byte object as a .fill.
1982 return AP.OutStreamer->emitFill(Bytes, Value);
1985 // If this can be emitted with .ascii/.asciz, emit it as such.
1986 if (CDS->isString())
1987 return AP.OutStreamer->EmitBytes(CDS->getAsString());
1989 // Otherwise, emit the values in successive locations.
1990 unsigned ElementByteSize = CDS->getElementByteSize();
1991 if (isa<IntegerType>(CDS->getElementType())) {
1992 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1994 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
1995 CDS->getElementAsInteger(i));
1996 AP.OutStreamer->EmitIntValue(CDS->getElementAsInteger(i),
2000 for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I)
2001 emitGlobalConstantFP(cast<ConstantFP>(CDS->getElementAsConstant(I)), AP);
2004 unsigned Size = DL.getTypeAllocSize(CDS->getType());
2005 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
2006 CDS->getNumElements();
2007 if (unsigned Padding = Size - EmittedSize)
2008 AP.OutStreamer->EmitZeros(Padding);
2012 static void emitGlobalConstantArray(const DataLayout &DL,
2013 const ConstantArray *CA, AsmPrinter &AP,
2014 const Constant *BaseCV, uint64_t Offset) {
2015 // See if we can aggregate some values. Make sure it can be
2016 // represented as a series of bytes of the constant value.
2017 int Value = isRepeatedByteSequence(CA, DL);
2020 uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
2021 AP.OutStreamer->emitFill(Bytes, Value);
2024 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
2025 emitGlobalConstantImpl(DL, CA->getOperand(i), AP, BaseCV, Offset);
2026 Offset += DL.getTypeAllocSize(CA->getOperand(i)->getType());
2031 static void emitGlobalConstantVector(const DataLayout &DL,
2032 const ConstantVector *CV, AsmPrinter &AP) {
2033 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
2034 emitGlobalConstantImpl(DL, CV->getOperand(i), AP);
2036 unsigned Size = DL.getTypeAllocSize(CV->getType());
2037 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
2038 CV->getType()->getNumElements();
2039 if (unsigned Padding = Size - EmittedSize)
2040 AP.OutStreamer->EmitZeros(Padding);
2043 static void emitGlobalConstantStruct(const DataLayout &DL,
2044 const ConstantStruct *CS, AsmPrinter &AP,
2045 const Constant *BaseCV, uint64_t Offset) {
2046 // Print the fields in successive locations. Pad to align if needed!
2047 unsigned Size = DL.getTypeAllocSize(CS->getType());
2048 const StructLayout *Layout = DL.getStructLayout(CS->getType());
2049 uint64_t SizeSoFar = 0;
2050 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
2051 const Constant *Field = CS->getOperand(i);
2053 // Print the actual field value.
2054 emitGlobalConstantImpl(DL, Field, AP, BaseCV, Offset + SizeSoFar);
2056 // Check if padding is needed and insert one or more 0s.
2057 uint64_t FieldSize = DL.getTypeAllocSize(Field->getType());
2058 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
2059 - Layout->getElementOffset(i)) - FieldSize;
2060 SizeSoFar += FieldSize + PadSize;
2062 // Insert padding - this may include padding to increase the size of the
2063 // current field up to the ABI size (if the struct is not packed) as well
2064 // as padding to ensure that the next field starts at the right offset.
2065 AP.OutStreamer->EmitZeros(PadSize);
2067 assert(SizeSoFar == Layout->getSizeInBytes() &&
2068 "Layout of constant struct may be incorrect!");
2071 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
2072 APInt API = CFP->getValueAPF().bitcastToAPInt();
2074 // First print a comment with what we think the original floating-point value
2075 // should have been.
2076 if (AP.isVerbose()) {
2077 SmallString<8> StrVal;
2078 CFP->getValueAPF().toString(StrVal);
2081 CFP->getType()->print(AP.OutStreamer->GetCommentOS());
2083 AP.OutStreamer->GetCommentOS() << "Printing <null> Type";
2084 AP.OutStreamer->GetCommentOS() << ' ' << StrVal << '\n';
2087 // Now iterate through the APInt chunks, emitting them in endian-correct
2088 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
2090 unsigned NumBytes = API.getBitWidth() / 8;
2091 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
2092 const uint64_t *p = API.getRawData();
2094 // PPC's long double has odd notions of endianness compared to how LLVM
2095 // handles it: p[0] goes first for *big* endian on PPC.
2096 if (AP.getDataLayout().isBigEndian() && !CFP->getType()->isPPC_FP128Ty()) {
2097 int Chunk = API.getNumWords() - 1;
2100 AP.OutStreamer->EmitIntValue(p[Chunk--], TrailingBytes);
2102 for (; Chunk >= 0; --Chunk)
2103 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
2106 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
2107 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
2110 AP.OutStreamer->EmitIntValue(p[Chunk], TrailingBytes);
2113 // Emit the tail padding for the long double.
2114 const DataLayout &DL = AP.getDataLayout();
2115 AP.OutStreamer->EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
2116 DL.getTypeStoreSize(CFP->getType()));
2119 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
2120 const DataLayout &DL = AP.getDataLayout();
2121 unsigned BitWidth = CI->getBitWidth();
2123 // Copy the value as we may massage the layout for constants whose bit width
2124 // is not a multiple of 64-bits.
2125 APInt Realigned(CI->getValue());
2126 uint64_t ExtraBits = 0;
2127 unsigned ExtraBitsSize = BitWidth & 63;
2129 if (ExtraBitsSize) {
2130 // The bit width of the data is not a multiple of 64-bits.
2131 // The extra bits are expected to be at the end of the chunk of the memory.
2133 // * Nothing to be done, just record the extra bits to emit.
2135 // * Record the extra bits to emit.
2136 // * Realign the raw data to emit the chunks of 64-bits.
2137 if (DL.isBigEndian()) {
2138 // Basically the structure of the raw data is a chunk of 64-bits cells:
2139 // 0 1 BitWidth / 64
2140 // [chunk1][chunk2] ... [chunkN].
2141 // The most significant chunk is chunkN and it should be emitted first.
2142 // However, due to the alignment issue chunkN contains useless bits.
2143 // Realign the chunks so that they contain only useless information:
2144 // ExtraBits 0 1 (BitWidth / 64) - 1
2145 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
2146 ExtraBits = Realigned.getRawData()[0] &
2147 (((uint64_t)-1) >> (64 - ExtraBitsSize));
2148 Realigned = Realigned.lshr(ExtraBitsSize);
2150 ExtraBits = Realigned.getRawData()[BitWidth / 64];
2153 // We don't expect assemblers to support integer data directives
2154 // for more than 64 bits, so we emit the data in at most 64-bit
2155 // quantities at a time.
2156 const uint64_t *RawData = Realigned.getRawData();
2157 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
2158 uint64_t Val = DL.isBigEndian() ? RawData[e - i - 1] : RawData[i];
2159 AP.OutStreamer->EmitIntValue(Val, 8);
2162 if (ExtraBitsSize) {
2163 // Emit the extra bits after the 64-bits chunks.
2165 // Emit a directive that fills the expected size.
2166 uint64_t Size = AP.getDataLayout().getTypeAllocSize(CI->getType());
2167 Size -= (BitWidth / 64) * 8;
2168 assert(Size && Size * 8 >= ExtraBitsSize &&
2169 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
2170 == ExtraBits && "Directive too small for extra bits.");
2171 AP.OutStreamer->EmitIntValue(ExtraBits, Size);
2175 /// \brief Transform a not absolute MCExpr containing a reference to a GOT
2176 /// equivalent global, by a target specific GOT pc relative access to the
2178 static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
2179 const Constant *BaseCst,
2181 // The global @foo below illustrates a global that uses a got equivalent.
2183 // @bar = global i32 42
2184 // @gotequiv = private unnamed_addr constant i32* @bar
2185 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
2186 // i64 ptrtoint (i32* @foo to i64))
2189 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
2190 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
2193 // foo = cstexpr, where
2194 // cstexpr := <gotequiv> - "." + <cst>
2195 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
2197 // After canonicalization by evaluateAsRelocatable `ME` turns into:
2199 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
2200 // gotpcrelcst := <offset from @foo base> + <cst>
2203 if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
2205 const MCSymbolRefExpr *SymA = MV.getSymA();
2209 // Check that GOT equivalent symbol is cached.
2210 const MCSymbol *GOTEquivSym = &SymA->getSymbol();
2211 if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
2214 const GlobalValue *BaseGV = dyn_cast_or_null<GlobalValue>(BaseCst);
2218 // Check for a valid base symbol
2219 const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
2220 const MCSymbolRefExpr *SymB = MV.getSymB();
2222 if (!SymB || BaseSym != &SymB->getSymbol())
2225 // Make sure to match:
2227 // gotpcrelcst := <offset from @foo base> + <cst>
2229 // If gotpcrelcst is positive it means that we can safely fold the pc rel
2230 // displacement into the GOTPCREL. We can also can have an extra offset <cst>
2231 // if the target knows how to encode it.
2233 int64_t GOTPCRelCst = Offset + MV.getConstant();
2234 if (GOTPCRelCst < 0)
2236 if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
2239 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
2246 // .long gotequiv - "." + <cst>
2248 // is replaced by the target specific equivalent to:
2253 // .long bar@GOTPCREL+<gotpcrelcst>
2255 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
2256 const GlobalVariable *GV = Result.first;
2257 int NumUses = (int)Result.second;
2258 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
2259 const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
2260 *ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(
2261 FinalSym, MV, Offset, AP.MMI, *AP.OutStreamer);
2263 // Update GOT equivalent usage information
2266 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
2269 static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *CV,
2270 AsmPrinter &AP, const Constant *BaseCV,
2272 uint64_t Size = DL.getTypeAllocSize(CV->getType());
2274 // Globals with sub-elements such as combinations of arrays and structs
2275 // are handled recursively by emitGlobalConstantImpl. Keep track of the
2276 // constant symbol base and the current position with BaseCV and Offset.
2277 if (!BaseCV && CV->hasOneUse())
2278 BaseCV = dyn_cast<Constant>(CV->user_back());
2280 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
2281 return AP.OutStreamer->EmitZeros(Size);
2283 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
2290 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64 "\n",
2291 CI->getZExtValue());
2292 AP.OutStreamer->EmitIntValue(CI->getZExtValue(), Size);
2295 emitGlobalConstantLargeInt(CI, AP);
2300 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
2301 return emitGlobalConstantFP(CFP, AP);
2303 if (isa<ConstantPointerNull>(CV)) {
2304 AP.OutStreamer->EmitIntValue(0, Size);
2308 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
2309 return emitGlobalConstantDataSequential(DL, CDS, AP);
2311 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2312 return emitGlobalConstantArray(DL, CVA, AP, BaseCV, Offset);
2314 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2315 return emitGlobalConstantStruct(DL, CVS, AP, BaseCV, Offset);
2317 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2318 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2320 if (CE->getOpcode() == Instruction::BitCast)
2321 return emitGlobalConstantImpl(DL, CE->getOperand(0), AP);
2324 // If the constant expression's size is greater than 64-bits, then we have
2325 // to emit the value in chunks. Try to constant fold the value and emit it
2327 Constant *New = ConstantFoldConstant(CE, DL);
2328 if (New && New != CE)
2329 return emitGlobalConstantImpl(DL, New, AP);
2333 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2334 return emitGlobalConstantVector(DL, V, AP);
2336 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2337 // thread the streamer with EmitValue.
2338 const MCExpr *ME = AP.lowerConstant(CV);
2340 // Since lowerConstant already folded and got rid of all IR pointer and
2341 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
2343 if (AP.getObjFileLowering().supportIndirectSymViaGOTPCRel())
2344 handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
2346 AP.OutStreamer->EmitValue(ME, Size);
2349 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2350 void AsmPrinter::EmitGlobalConstant(const DataLayout &DL, const Constant *CV) {
2351 uint64_t Size = DL.getTypeAllocSize(CV->getType());
2353 emitGlobalConstantImpl(DL, CV, *this);
2354 else if (MAI->hasSubsectionsViaSymbols()) {
2355 // If the global has zero size, emit a single byte so that two labels don't
2356 // look like they are at the same location.
2357 OutStreamer->EmitIntValue(0, 1);
2361 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2362 // Target doesn't support this yet!
2363 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2366 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2368 OS << '+' << Offset;
2369 else if (Offset < 0)
2373 //===----------------------------------------------------------------------===//
2374 // Symbol Lowering Routines.
2375 //===----------------------------------------------------------------------===//
2377 MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name) const {
2378 return OutContext.createTempSymbol(Name, true);
2381 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2382 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2385 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2386 return MMI->getAddrLabelSymbol(BB);
2389 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2390 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2391 const DataLayout &DL = getDataLayout();
2392 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
2393 "CPI" + Twine(getFunctionNumber()) + "_" +
2397 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2398 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2399 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2402 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2403 /// FIXME: privatize to AsmPrinter.
2404 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2405 const DataLayout &DL = getDataLayout();
2406 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
2407 Twine(getFunctionNumber()) + "_" +
2408 Twine(UID) + "_set_" + Twine(MBBID));
2411 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2412 StringRef Suffix) const {
2413 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, TM);
2416 /// Return the MCSymbol for the specified ExternalSymbol.
2417 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2418 SmallString<60> NameStr;
2419 Mangler::getNameWithPrefix(NameStr, Sym, getDataLayout());
2420 return OutContext.getOrCreateSymbol(NameStr);
2425 /// PrintParentLoopComment - Print comments about parent loops of this one.
2426 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2427 unsigned FunctionNumber) {
2429 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2430 OS.indent(Loop->getLoopDepth()*2)
2431 << "Parent Loop BB" << FunctionNumber << "_"
2432 << Loop->getHeader()->getNumber()
2433 << " Depth=" << Loop->getLoopDepth() << '\n';
2437 /// PrintChildLoopComment - Print comments about child loops within
2438 /// the loop for this basic block, with nesting.
2439 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2440 unsigned FunctionNumber) {
2441 // Add child loop information
2442 for (const MachineLoop *CL : *Loop) {
2443 OS.indent(CL->getLoopDepth()*2)
2444 << "Child Loop BB" << FunctionNumber << "_"
2445 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2447 PrintChildLoopComment(OS, CL, FunctionNumber);
2451 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2452 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2453 const MachineLoopInfo *LI,
2454 const AsmPrinter &AP) {
2455 // Add loop depth information
2456 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2459 MachineBasicBlock *Header = Loop->getHeader();
2460 assert(Header && "No header for loop");
2462 // If this block is not a loop header, just print out what is the loop header
2464 if (Header != &MBB) {
2465 AP.OutStreamer->AddComment(" in Loop: Header=BB" +
2466 Twine(AP.getFunctionNumber())+"_" +
2467 Twine(Loop->getHeader()->getNumber())+
2468 " Depth="+Twine(Loop->getLoopDepth()));
2472 // Otherwise, it is a loop header. Print out information about child and
2474 raw_ostream &OS = AP.OutStreamer->GetCommentOS();
2476 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2479 OS.indent(Loop->getLoopDepth()*2-2);
2484 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2486 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2490 /// EmitBasicBlockStart - This method prints the label for the specified
2491 /// MachineBasicBlock, an alignment (if present) and a comment describing
2492 /// it if appropriate.
2493 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2494 // End the previous funclet and start a new one.
2495 if (MBB.isEHFuncletEntry()) {
2496 for (const HandlerInfo &HI : Handlers) {
2497 HI.Handler->endFunclet();
2498 HI.Handler->beginFunclet(MBB);
2502 // Emit an alignment directive for this block, if needed.
2503 if (unsigned Align = MBB.getAlignment())
2504 EmitAlignment(Align);
2506 // If the block has its address taken, emit any labels that were used to
2507 // reference the block. It is possible that there is more than one label
2508 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2509 // the references were generated.
2510 if (MBB.hasAddressTaken()) {
2511 const BasicBlock *BB = MBB.getBasicBlock();
2513 OutStreamer->AddComment("Block address taken");
2515 // MBBs can have their address taken as part of CodeGen without having
2516 // their corresponding BB's address taken in IR
2517 if (BB->hasAddressTaken())
2518 for (MCSymbol *Sym : MMI->getAddrLabelSymbolToEmit(BB))
2519 OutStreamer->EmitLabel(Sym);
2522 // Print some verbose block comments.
2524 if (const BasicBlock *BB = MBB.getBasicBlock()) {
2525 if (BB->hasName()) {
2526 BB->printAsOperand(OutStreamer->GetCommentOS(),
2527 /*PrintType=*/false, BB->getModule());
2528 OutStreamer->GetCommentOS() << '\n';
2531 emitBasicBlockLoopComments(MBB, LI, *this);
2534 // Print the main label for the block.
2535 if (MBB.pred_empty() ||
2536 (isBlockOnlyReachableByFallthrough(&MBB) && !MBB.isEHFuncletEntry())) {
2538 // NOTE: Want this comment at start of line, don't emit with AddComment.
2539 OutStreamer->emitRawComment(" BB#" + Twine(MBB.getNumber()) + ":", false);
2542 OutStreamer->EmitLabel(MBB.getSymbol());
2546 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2547 bool IsDefinition) const {
2548 MCSymbolAttr Attr = MCSA_Invalid;
2550 switch (Visibility) {
2552 case GlobalValue::HiddenVisibility:
2554 Attr = MAI->getHiddenVisibilityAttr();
2556 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2558 case GlobalValue::ProtectedVisibility:
2559 Attr = MAI->getProtectedVisibilityAttr();
2563 if (Attr != MCSA_Invalid)
2564 OutStreamer->EmitSymbolAttribute(Sym, Attr);
2567 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2568 /// exactly one predecessor and the control transfer mechanism between
2569 /// the predecessor and this block is a fall-through.
2571 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2572 // If this is a landing pad, it isn't a fall through. If it has no preds,
2573 // then nothing falls through to it.
2574 if (MBB->isEHPad() || MBB->pred_empty())
2577 // If there isn't exactly one predecessor, it can't be a fall through.
2578 if (MBB->pred_size() > 1)
2581 // The predecessor has to be immediately before this block.
2582 MachineBasicBlock *Pred = *MBB->pred_begin();
2583 if (!Pred->isLayoutSuccessor(MBB))
2586 // If the block is completely empty, then it definitely does fall through.
2590 // Check the terminators in the previous blocks
2591 for (const auto &MI : Pred->terminators()) {
2592 // If it is not a simple branch, we are in a table somewhere.
2593 if (!MI.isBranch() || MI.isIndirectBranch())
2596 // If we are the operands of one of the branches, this is not a fall
2597 // through. Note that targets with delay slots will usually bundle
2598 // terminators with the delay slot instruction.
2599 for (ConstMIBundleOperands OP(MI); OP.isValid(); ++OP) {
2602 if (OP->isMBB() && OP->getMBB() == MBB)
2612 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2613 if (!S.usesMetadata())
2616 assert(!S.useStatepoints() && "statepoints do not currently support custom"
2617 " stackmap formats, please see the documentation for a description of"
2618 " the default format. If you really need a custom serialized format,"
2619 " please file a bug");
2621 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2622 gcp_map_type::iterator GCPI = GCMap.find(&S);
2623 if (GCPI != GCMap.end())
2624 return GCPI->second.get();
2626 auto Name = S.getName();
2628 for (GCMetadataPrinterRegistry::iterator
2629 I = GCMetadataPrinterRegistry::begin(),
2630 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2631 if (Name == I->getName()) {
2632 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2634 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2635 return IterBool.first->second.get();
2638 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2641 /// Pin vtable to this file.
2642 AsmPrinterHandler::~AsmPrinterHandler() {}
2644 void AsmPrinterHandler::markFunctionEnd() {}
2646 // In the binary's "xray_instr_map" section, an array of these function entries
2647 // describes each instrumentation point. When XRay patches your code, the index
2648 // into this table will be given to your handler as a patch point identifier.
2649 void AsmPrinter::XRayFunctionEntry::emit(int Bytes, MCStreamer *Out,
2650 const MCSymbol *CurrentFnSym) const {
2651 Out->EmitSymbolValue(Sled, Bytes);
2652 Out->EmitSymbolValue(CurrentFnSym, Bytes);
2653 auto Kind8 = static_cast<uint8_t>(Kind);
2654 Out->EmitBytes(StringRef(reinterpret_cast<const char *>(&Kind8), 1));
2656 StringRef(reinterpret_cast<const char *>(&AlwaysInstrument), 1));
2657 Out->EmitZeros(2 * Bytes - 2); // Pad the previous two entries
2660 void AsmPrinter::emitXRayTable() {
2664 auto PrevSection = OutStreamer->getCurrentSectionOnly();
2665 auto Fn = MF->getFunction();
2666 MCSection *Section = nullptr;
2667 if (MF->getSubtarget().getTargetTriple().isOSBinFormatELF()) {
2668 if (Fn->hasComdat()) {
2669 Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
2670 ELF::SHF_ALLOC | ELF::SHF_GROUP, 0,
2671 Fn->getComdat()->getName());
2673 Section = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
2676 } else if (MF->getSubtarget().getTargetTriple().isOSBinFormatMachO()) {
2677 Section = OutContext.getMachOSection("__DATA", "xray_instr_map", 0,
2678 SectionKind::getReadOnlyWithRel());
2680 llvm_unreachable("Unsupported target");
2683 // Before we switch over, we force a reference to a label inside the
2684 // xray_instr_map section. Since this function is always called just
2685 // before the function's end, we assume that this is happening after
2686 // the last return instruction.
2688 auto WordSizeBytes = TM.getPointerSize();
2689 MCSymbol *Tmp = OutContext.createTempSymbol("xray_synthetic_", true);
2690 OutStreamer->EmitCodeAlignment(16);
2691 OutStreamer->EmitSymbolValue(Tmp, WordSizeBytes, false);
2692 OutStreamer->SwitchSection(Section);
2693 OutStreamer->EmitLabel(Tmp);
2694 for (const auto &Sled : Sleds)
2695 Sled.emit(WordSizeBytes, OutStreamer.get(), CurrentFnSym);
2697 OutStreamer->SwitchSection(PrevSection);
2701 void AsmPrinter::recordSled(MCSymbol *Sled, const MachineInstr &MI,
2703 auto Fn = MI.getParent()->getParent()->getFunction();
2704 auto Attr = Fn->getFnAttribute("function-instrument");
2705 bool AlwaysInstrument =
2706 Attr.isStringAttribute() && Attr.getValueAsString() == "xray-always";
2708 XRayFunctionEntry{ Sled, CurrentFnSym, Kind, AlwaysInstrument, Fn });
2711 uint16_t AsmPrinter::getDwarfVersion() const {
2712 return OutStreamer->getContext().getDwarfVersion();
2715 void AsmPrinter::setDwarfVersion(uint16_t Version) {
2716 OutStreamer->getContext().setDwarfVersion(Version);