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 #define DEBUG_TYPE "asm-printer"
15 #include "llvm/CodeGen/AsmPrinter.h"
16 #include "DwarfDebug.h"
17 #include "DwarfException.h"
18 #include "WinCodeViewLineTables.h"
19 #include "llvm/ADT/SmallString.h"
20 #include "llvm/ADT/Statistic.h"
21 #include "llvm/Analysis/ConstantFolding.h"
22 #include "llvm/CodeGen/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/MachineModuleInfo.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/MCStreamer.h"
41 #include "llvm/MC/MCSymbol.h"
42 #include "llvm/Support/ErrorHandling.h"
43 #include "llvm/Support/Format.h"
44 #include "llvm/Support/MathExtras.h"
45 #include "llvm/Support/Timer.h"
46 #include "llvm/Target/TargetFrameLowering.h"
47 #include "llvm/Target/TargetInstrInfo.h"
48 #include "llvm/Target/TargetLowering.h"
49 #include "llvm/Target/TargetLoweringObjectFile.h"
50 #include "llvm/Target/TargetOptions.h"
51 #include "llvm/Target/TargetRegisterInfo.h"
52 #include "llvm/Target/TargetSubtargetInfo.h"
53 #include "llvm/Transforms/Utils/GlobalStatus.h"
56 static const char *const DWARFGroupName = "DWARF Emission";
57 static const char *const DbgTimerName = "Debug Info Emission";
58 static const char *const EHTimerName = "DWARF Exception Writer";
59 static const char *const CodeViewLineTablesGroupName = "CodeView Line Tables";
61 STATISTIC(EmittedInsts, "Number of machine instrs printed");
63 char AsmPrinter::ID = 0;
65 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
66 static gcp_map_type &getGCMap(void *&P) {
68 P = new gcp_map_type();
69 return *(gcp_map_type*)P;
73 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
74 /// value in log2 form. This rounds up to the preferred alignment if possible
76 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD,
77 unsigned InBits = 0) {
79 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
80 NumBits = TD.getPreferredAlignmentLog(GVar);
82 // If InBits is specified, round it to it.
86 // If the GV has a specified alignment, take it into account.
87 if (GV->getAlignment() == 0)
90 unsigned GVAlign = Log2_32(GV->getAlignment());
92 // If the GVAlign is larger than NumBits, or if we are required to obey
93 // NumBits because the GV has an assigned section, obey it.
94 if (GVAlign > NumBits || GV->hasSection())
99 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
100 : MachineFunctionPass(ID),
101 TM(tm), MAI(tm.getMCAsmInfo()), MII(tm.getInstrInfo()),
102 OutContext(Streamer.getContext()),
103 OutStreamer(Streamer),
104 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
105 DD = 0; MMI = 0; LI = 0; MF = 0;
106 CurrentFnSym = CurrentFnSymForSize = 0;
107 GCMetadataPrinters = 0;
108 VerboseAsm = Streamer.isVerboseAsm();
111 AsmPrinter::~AsmPrinter() {
112 assert(DD == 0 && Handlers.empty() && "Debug/EH info didn't get finalized");
114 if (GCMetadataPrinters != 0) {
115 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
117 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
120 GCMetadataPrinters = 0;
126 /// getFunctionNumber - Return a unique ID for the current function.
128 unsigned AsmPrinter::getFunctionNumber() const {
129 return MF->getFunctionNumber();
132 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
133 return TM.getTargetLowering()->getObjFileLowering();
136 /// getDataLayout - Return information about data layout.
137 const DataLayout &AsmPrinter::getDataLayout() const {
138 return *TM.getDataLayout();
141 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
142 return TM.getSubtarget<MCSubtargetInfo>();
145 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
146 S.EmitInstruction(Inst, getSubtargetInfo());
149 StringRef AsmPrinter::getTargetTriple() const {
150 return TM.getTargetTriple();
153 /// getCurrentSection() - Return the current section we are emitting to.
154 const MCSection *AsmPrinter::getCurrentSection() const {
155 return OutStreamer.getCurrentSection().first;
160 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
161 AU.setPreservesAll();
162 MachineFunctionPass::getAnalysisUsage(AU);
163 AU.addRequired<MachineModuleInfo>();
164 AU.addRequired<GCModuleInfo>();
166 AU.addRequired<MachineLoopInfo>();
169 bool AsmPrinter::doInitialization(Module &M) {
170 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
171 MMI->AnalyzeModule(M);
173 // Initialize TargetLoweringObjectFile.
174 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
175 .Initialize(OutContext, TM);
177 OutStreamer.InitSections();
179 Mang = new Mangler(TM.getDataLayout());
181 // Emit the version-min deplyment target directive if needed.
183 // FIXME: If we end up with a collection of these sorts of Darwin-specific
184 // or ELF-specific things, it may make sense to have a platform helper class
185 // that will work with the target helper class. For now keep it here, as the
186 // alternative is duplicated code in each of the target asm printers that
187 // use the directive, where it would need the same conditionalization
189 Triple TT(getTargetTriple());
190 if (TT.isOSDarwin()) {
191 unsigned Major, Minor, Update;
192 TT.getOSVersion(Major, Minor, Update);
193 // If there is a version specified, Major will be non-zero.
195 OutStreamer.EmitVersionMin((TT.isMacOSX() ?
196 MCVM_OSXVersionMin : MCVM_IOSVersionMin),
197 Major, Minor, Update);
200 // Allow the target to emit any magic that it wants at the start of the file.
201 EmitStartOfAsmFile(M);
203 // Very minimal debug info. It is ignored if we emit actual debug info. If we
204 // don't, this at least helps the user find where a global came from.
205 if (MAI->hasSingleParameterDotFile()) {
207 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
210 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
211 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
212 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
213 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
214 MP->beginAssembly(*this);
216 // Emit module-level inline asm if it exists.
217 if (!M.getModuleInlineAsm().empty()) {
218 OutStreamer.AddComment("Start of file scope inline assembly");
219 OutStreamer.AddBlankLine();
220 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
221 OutStreamer.AddComment("End of file scope inline assembly");
222 OutStreamer.AddBlankLine();
225 if (MAI->doesSupportDebugInformation()) {
226 if (Triple(TM.getTargetTriple()).isKnownWindowsMSVCEnvironment()) {
227 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this),
229 CodeViewLineTablesGroupName));
231 DD = new DwarfDebug(this, &M);
232 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
236 DwarfException *DE = 0;
237 switch (MAI->getExceptionHandlingType()) {
238 case ExceptionHandling::None:
240 case ExceptionHandling::SjLj:
241 case ExceptionHandling::DwarfCFI:
242 DE = new DwarfCFIException(this);
244 case ExceptionHandling::ARM:
245 DE = new ARMException(this);
247 case ExceptionHandling::Win64:
248 DE = new Win64Exception(this);
252 Handlers.push_back(HandlerInfo(DE, EHTimerName, DWARFGroupName));
256 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
257 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
258 if (Linkage != GlobalValue::LinkOnceODRLinkage)
261 if (!MAI.hasWeakDefCanBeHiddenDirective())
264 if (GV->hasUnnamedAddr())
267 // This is only used for MachO, so right now it doesn't really matter how
268 // we handle alias. Revisit this once the MachO linker implements aliases.
269 if (isa<GlobalAlias>(GV))
272 // If it is a non constant variable, it needs to be uniqued across shared
274 if (const GlobalVariable *Var = dyn_cast<GlobalVariable>(GV)) {
275 if (!Var->isConstant())
280 if (!GlobalStatus::analyzeGlobal(GV, GS) && !GS.IsCompared)
286 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
287 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
289 case GlobalValue::CommonLinkage:
290 case GlobalValue::LinkOnceAnyLinkage:
291 case GlobalValue::LinkOnceODRLinkage:
292 case GlobalValue::WeakAnyLinkage:
293 case GlobalValue::WeakODRLinkage:
294 if (MAI->hasWeakDefDirective()) {
296 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
298 if (!canBeHidden(GV, *MAI))
299 // .weak_definition _foo
300 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
302 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
303 } else if (MAI->hasLinkOnceDirective()) {
305 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
306 //NOTE: linkonce is handled by the section the symbol was assigned to.
309 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
312 case GlobalValue::AppendingLinkage:
313 // FIXME: appending linkage variables should go into a section of
314 // their name or something. For now, just emit them as external.
315 case GlobalValue::ExternalLinkage:
316 // If external or appending, declare as a global symbol.
318 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
320 case GlobalValue::PrivateLinkage:
321 case GlobalValue::InternalLinkage:
323 case GlobalValue::AvailableExternallyLinkage:
324 llvm_unreachable("Should never emit this");
325 case GlobalValue::ExternalWeakLinkage:
326 llvm_unreachable("Don't know how to emit these");
328 llvm_unreachable("Unknown linkage type!");
331 void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
332 const GlobalValue *GV) const {
333 TM.getNameWithPrefix(Name, GV, *Mang);
336 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
337 return TM.getSymbol(GV, *Mang);
340 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
341 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
342 if (GV->hasInitializer()) {
343 // Check to see if this is a special global used by LLVM, if so, emit it.
344 if (EmitSpecialLLVMGlobal(GV))
348 GV->printAsOperand(OutStreamer.GetCommentOS(),
349 /*PrintType=*/false, GV->getParent());
350 OutStreamer.GetCommentOS() << '\n';
354 MCSymbol *GVSym = getSymbol(GV);
355 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
357 if (!GV->hasInitializer()) // External globals require no extra code.
360 if (MAI->hasDotTypeDotSizeDirective())
361 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
363 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
365 const DataLayout *DL = TM.getDataLayout();
366 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
368 // If the alignment is specified, we *must* obey it. Overaligning a global
369 // with a specified alignment is a prompt way to break globals emitted to
370 // sections and expected to be contiguous (e.g. ObjC metadata).
371 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
373 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
374 const HandlerInfo &OI = Handlers[I];
375 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, TimePassesIsEnabled);
376 OI.Handler->setSymbolSize(GVSym, Size);
379 // Handle common and BSS local symbols (.lcomm).
380 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
381 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
382 unsigned Align = 1 << AlignLog;
384 // Handle common symbols.
385 if (GVKind.isCommon()) {
386 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
390 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
394 // Handle local BSS symbols.
395 if (MAI->hasMachoZeroFillDirective()) {
396 const MCSection *TheSection =
397 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
398 // .zerofill __DATA, __bss, _foo, 400, 5
399 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
403 // Use .lcomm only if it supports user-specified alignment.
404 // Otherwise, while it would still be correct to use .lcomm in some
405 // cases (e.g. when Align == 1), the external assembler might enfore
406 // some -unknown- default alignment behavior, which could cause
407 // spurious differences between external and integrated assembler.
408 // Prefer to simply fall back to .local / .comm in this case.
409 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
411 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
415 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
419 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
421 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
425 const MCSection *TheSection =
426 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
428 // Handle the zerofill directive on darwin, which is a special form of BSS
430 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
431 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
434 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
435 // .zerofill __DATA, __common, _foo, 400, 5
436 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
440 // Handle thread local data for mach-o which requires us to output an
441 // additional structure of data and mangle the original symbol so that we
442 // can reference it later.
444 // TODO: This should become an "emit thread local global" method on TLOF.
445 // All of this macho specific stuff should be sunk down into TLOFMachO and
446 // stuff like "TLSExtraDataSection" should no longer be part of the parent
447 // TLOF class. This will also make it more obvious that stuff like
448 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
450 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
451 // Emit the .tbss symbol
453 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
455 if (GVKind.isThreadBSS()) {
456 TheSection = getObjFileLowering().getTLSBSSSection();
457 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
458 } else if (GVKind.isThreadData()) {
459 OutStreamer.SwitchSection(TheSection);
461 EmitAlignment(AlignLog, GV);
462 OutStreamer.EmitLabel(MangSym);
464 EmitGlobalConstant(GV->getInitializer());
467 OutStreamer.AddBlankLine();
469 // Emit the variable struct for the runtime.
470 const MCSection *TLVSect
471 = getObjFileLowering().getTLSExtraDataSection();
473 OutStreamer.SwitchSection(TLVSect);
474 // Emit the linkage here.
475 EmitLinkage(GV, GVSym);
476 OutStreamer.EmitLabel(GVSym);
478 // Three pointers in size:
479 // - __tlv_bootstrap - used to make sure support exists
480 // - spare pointer, used when mapped by the runtime
481 // - pointer to mangled symbol above with initializer
482 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
483 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
485 OutStreamer.EmitIntValue(0, PtrSize);
486 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
488 OutStreamer.AddBlankLine();
492 OutStreamer.SwitchSection(TheSection);
494 EmitLinkage(GV, GVSym);
495 EmitAlignment(AlignLog, GV);
497 OutStreamer.EmitLabel(GVSym);
499 EmitGlobalConstant(GV->getInitializer());
501 if (MAI->hasDotTypeDotSizeDirective())
503 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
505 OutStreamer.AddBlankLine();
508 /// EmitFunctionHeader - This method emits the header for the current
510 void AsmPrinter::EmitFunctionHeader() {
511 // Print out constants referenced by the function
514 // Print the 'header' of function.
515 const Function *F = MF->getFunction();
517 OutStreamer.SwitchSection(
518 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
519 EmitVisibility(CurrentFnSym, F->getVisibility());
521 EmitLinkage(F, CurrentFnSym);
522 EmitAlignment(MF->getAlignment(), F);
524 if (MAI->hasDotTypeDotSizeDirective())
525 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
528 F->printAsOperand(OutStreamer.GetCommentOS(),
529 /*PrintType=*/false, F->getParent());
530 OutStreamer.GetCommentOS() << '\n';
533 // Emit the CurrentFnSym. This is a virtual function to allow targets to
534 // do their wild and crazy things as required.
535 EmitFunctionEntryLabel();
537 // If the function had address-taken blocks that got deleted, then we have
538 // references to the dangling symbols. Emit them at the start of the function
539 // so that we don't get references to undefined symbols.
540 std::vector<MCSymbol*> DeadBlockSyms;
541 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
542 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
543 OutStreamer.AddComment("Address taken block that was later removed");
544 OutStreamer.EmitLabel(DeadBlockSyms[i]);
547 // Emit pre-function debug and/or EH information.
548 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
549 const HandlerInfo &OI = Handlers[I];
550 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, TimePassesIsEnabled);
551 OI.Handler->beginFunction(MF);
554 // Emit the prefix data.
555 if (F->hasPrefixData())
556 EmitGlobalConstant(F->getPrefixData());
559 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
560 /// function. This can be overridden by targets as required to do custom stuff.
561 void AsmPrinter::EmitFunctionEntryLabel() {
562 // The function label could have already been emitted if two symbols end up
563 // conflicting due to asm renaming. Detect this and emit an error.
564 if (CurrentFnSym->isUndefined())
565 return OutStreamer.EmitLabel(CurrentFnSym);
567 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
568 "' label emitted multiple times to assembly file");
571 /// emitComments - Pretty-print comments for instructions.
572 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
573 const MachineFunction *MF = MI.getParent()->getParent();
574 const TargetMachine &TM = MF->getTarget();
576 // Check for spills and reloads
579 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
581 // We assume a single instruction only has a spill or reload, not
583 const MachineMemOperand *MMO;
584 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
585 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
586 MMO = *MI.memoperands_begin();
587 CommentOS << MMO->getSize() << "-byte Reload\n";
589 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
590 if (FrameInfo->isSpillSlotObjectIndex(FI))
591 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
592 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
593 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
594 MMO = *MI.memoperands_begin();
595 CommentOS << MMO->getSize() << "-byte Spill\n";
597 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
598 if (FrameInfo->isSpillSlotObjectIndex(FI))
599 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
602 // Check for spill-induced copies
603 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
604 CommentOS << " Reload Reuse\n";
607 /// emitImplicitDef - This method emits the specified machine instruction
608 /// that is an implicit def.
609 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
610 unsigned RegNo = MI->getOperand(0).getReg();
611 OutStreamer.AddComment(Twine("implicit-def: ") +
612 TM.getRegisterInfo()->getName(RegNo));
613 OutStreamer.AddBlankLine();
616 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
617 std::string Str = "kill:";
618 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
619 const MachineOperand &Op = MI->getOperand(i);
620 assert(Op.isReg() && "KILL instruction must have only register operands");
622 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
623 Str += (Op.isDef() ? "<def>" : "<kill>");
625 AP.OutStreamer.AddComment(Str);
626 AP.OutStreamer.AddBlankLine();
629 /// emitDebugValueComment - This method handles the target-independent form
630 /// of DBG_VALUE, returning true if it was able to do so. A false return
631 /// means the target will need to handle MI in EmitInstruction.
632 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
633 // This code handles only the 3-operand target-independent form.
634 if (MI->getNumOperands() != 3)
637 SmallString<128> Str;
638 raw_svector_ostream OS(Str);
639 OS << "DEBUG_VALUE: ";
641 DIVariable V(MI->getOperand(2).getMetadata());
642 if (V.getContext().isSubprogram()) {
643 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
647 OS << V.getName() << " <- ";
649 // The second operand is only an offset if it's an immediate.
650 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
651 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
653 // Register or immediate value. Register 0 means undef.
654 if (MI->getOperand(0).isFPImm()) {
655 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
656 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
657 OS << (double)APF.convertToFloat();
658 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
659 OS << APF.convertToDouble();
661 // There is no good way to print long double. Convert a copy to
662 // double. Ah well, it's only a comment.
664 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
666 OS << "(long double) " << APF.convertToDouble();
668 } else if (MI->getOperand(0).isImm()) {
669 OS << MI->getOperand(0).getImm();
670 } else if (MI->getOperand(0).isCImm()) {
671 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
674 if (MI->getOperand(0).isReg()) {
675 Reg = MI->getOperand(0).getReg();
677 assert(MI->getOperand(0).isFI() && "Unknown operand type");
678 const TargetFrameLowering *TFI = AP.TM.getFrameLowering();
679 Offset += TFI->getFrameIndexReference(*AP.MF,
680 MI->getOperand(0).getIndex(), Reg);
684 // Suppress offset, it is not meaningful here.
686 // NOTE: Want this comment at start of line, don't emit with AddComment.
687 AP.OutStreamer.emitRawComment(OS.str());
692 OS << AP.TM.getRegisterInfo()->getName(Reg);
696 OS << '+' << Offset << ']';
698 // NOTE: Want this comment at start of line, don't emit with AddComment.
699 AP.OutStreamer.emitRawComment(OS.str());
703 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
704 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
705 MF->getFunction()->needsUnwindTableEntry())
708 if (MMI->hasDebugInfo())
714 bool AsmPrinter::needsSEHMoves() {
715 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 &&
716 MF->getFunction()->needsUnwindTableEntry();
719 void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
720 ExceptionHandling::ExceptionsType ExceptionHandlingType =
721 MAI->getExceptionHandlingType();
722 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
723 ExceptionHandlingType != ExceptionHandling::ARM)
726 if (needsCFIMoves() == CFI_M_None)
729 if (MMI->getCompactUnwindEncoding() != 0)
730 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding());
732 const MachineModuleInfo &MMI = MF->getMMI();
733 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
734 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
735 const MCCFIInstruction &CFI = Instrs[CFIIndex];
736 emitCFIInstruction(CFI);
739 /// EmitFunctionBody - This method emits the body and trailer for a
741 void AsmPrinter::EmitFunctionBody() {
742 // Emit target-specific gunk before the function body.
743 EmitFunctionBodyStart();
745 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
747 // Print out code for the function.
748 bool HasAnyRealCode = false;
749 const MachineInstr *LastMI = 0;
750 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
752 // Print a label for the basic block.
753 EmitBasicBlockStart(I);
754 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
758 // Print the assembly for the instruction.
759 if (!II->isPosition() && !II->isImplicitDef() && !II->isKill() &&
760 !II->isDebugValue()) {
761 HasAnyRealCode = true;
765 if (ShouldPrintDebugScopes) {
766 for (unsigned III = 0, EEE = Handlers.size(); III != EEE; ++III) {
767 const HandlerInfo &OI = Handlers[III];
768 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName,
769 TimePassesIsEnabled);
770 OI.Handler->beginInstruction(II);
775 emitComments(*II, OutStreamer.GetCommentOS());
777 switch (II->getOpcode()) {
778 case TargetOpcode::CFI_INSTRUCTION:
779 emitCFIInstruction(*II);
782 case TargetOpcode::EH_LABEL:
783 case TargetOpcode::GC_LABEL:
784 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
786 case TargetOpcode::INLINEASM:
789 case TargetOpcode::DBG_VALUE:
791 if (!emitDebugValueComment(II, *this))
795 case TargetOpcode::IMPLICIT_DEF:
796 if (isVerbose()) emitImplicitDef(II);
798 case TargetOpcode::KILL:
799 if (isVerbose()) emitKill(II, *this);
806 if (ShouldPrintDebugScopes) {
807 for (unsigned III = 0, EEE = Handlers.size(); III != EEE; ++III) {
808 const HandlerInfo &OI = Handlers[III];
809 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName,
810 TimePassesIsEnabled);
811 OI.Handler->endInstruction();
817 // If the last instruction was a prolog label, then we have a situation where
818 // we emitted a prolog but no function body. This results in the ending prolog
819 // label equaling the end of function label and an invalid "row" in the
820 // FDE. We need to emit a noop in this situation so that the FDE's rows are
822 bool RequiresNoop = LastMI && LastMI->isCFIInstruction();
824 // If the function is empty and the object file uses .subsections_via_symbols,
825 // then we need to emit *something* to the function body to prevent the
826 // labels from collapsing together. Just emit a noop.
827 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
829 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
830 if (Noop.getOpcode()) {
831 OutStreamer.AddComment("avoids zero-length function");
832 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
833 } else // Target not mc-ized yet.
834 OutStreamer.EmitRawText(StringRef("\tnop\n"));
837 const Function *F = MF->getFunction();
838 for (Function::const_iterator i = F->begin(), e = F->end(); i != e; ++i) {
839 const BasicBlock *BB = i;
840 if (!BB->hasAddressTaken())
842 MCSymbol *Sym = GetBlockAddressSymbol(BB);
843 if (Sym->isDefined())
845 OutStreamer.AddComment("Address of block that was removed by CodeGen");
846 OutStreamer.EmitLabel(Sym);
849 // Emit target-specific gunk after the function body.
850 EmitFunctionBodyEnd();
852 // If the target wants a .size directive for the size of the function, emit
854 if (MAI->hasDotTypeDotSizeDirective()) {
855 // Create a symbol for the end of function, so we can get the size as
856 // difference between the function label and the temp label.
857 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
858 OutStreamer.EmitLabel(FnEndLabel);
860 const MCExpr *SizeExp =
861 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
862 MCSymbolRefExpr::Create(CurrentFnSymForSize,
865 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
868 // Emit post-function debug and/or EH information.
869 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
870 const HandlerInfo &OI = Handlers[I];
871 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, TimePassesIsEnabled);
872 OI.Handler->endFunction(MF);
876 // Print out jump tables referenced by the function.
879 OutStreamer.AddBlankLine();
882 bool AsmPrinter::doFinalization(Module &M) {
883 // Emit global variables.
884 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
886 EmitGlobalVariable(I);
888 // Emit visibility info for declarations
889 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
890 const Function &F = *I;
891 if (!F.isDeclaration())
893 GlobalValue::VisibilityTypes V = F.getVisibility();
894 if (V == GlobalValue::DefaultVisibility)
897 MCSymbol *Name = getSymbol(&F);
898 EmitVisibility(Name, V, false);
901 // Emit module flags.
902 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
903 M.getModuleFlagsMetadata(ModuleFlags);
904 if (!ModuleFlags.empty())
905 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
907 // Make sure we wrote out everything we need.
910 // Finalize debug and EH information.
911 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
912 const HandlerInfo &OI = Handlers[I];
913 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName,
914 TimePassesIsEnabled);
915 OI.Handler->endModule();
921 // If the target wants to know about weak references, print them all.
922 if (MAI->getWeakRefDirective()) {
923 // FIXME: This is not lazy, it would be nice to only print weak references
924 // to stuff that is actually used. Note that doing so would require targets
925 // to notice uses in operands (due to constant exprs etc). This should
926 // happen with the MC stuff eventually.
928 // Print out module-level global variables here.
929 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
931 if (!I->hasExternalWeakLinkage()) continue;
932 OutStreamer.EmitSymbolAttribute(getSymbol(I), MCSA_WeakReference);
935 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
936 if (!I->hasExternalWeakLinkage()) continue;
937 OutStreamer.EmitSymbolAttribute(getSymbol(I), MCSA_WeakReference);
941 if (MAI->hasSetDirective()) {
942 OutStreamer.AddBlankLine();
943 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
945 MCSymbol *Name = getSymbol(I);
947 const GlobalValue *GV = I->getAliasedGlobal();
948 assert(!GV->isDeclaration());
949 MCSymbol *Target = getSymbol(GV);
951 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
952 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
953 else if (I->hasWeakLinkage() || I->hasLinkOnceLinkage())
954 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
956 assert(I->hasLocalLinkage() && "Invalid alias linkage");
958 EmitVisibility(Name, I->getVisibility());
960 // Emit the directives as assignments aka .set:
961 OutStreamer.EmitAssignment(Name,
962 MCSymbolRefExpr::Create(Target, OutContext));
966 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
967 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
968 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
969 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
970 MP->finishAssembly(*this);
972 // Emit llvm.ident metadata in an '.ident' directive.
975 // If we don't have any trampolines, then we don't require stack memory
976 // to be executable. Some targets have a directive to declare this.
977 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
978 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
979 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
980 OutStreamer.SwitchSection(S);
982 // Allow the target to emit any magic that it wants at the end of the file,
983 // after everything else has gone out.
986 delete Mang; Mang = 0;
989 OutStreamer.Finish();
995 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
997 // Get the function symbol.
998 CurrentFnSym = getSymbol(MF.getFunction());
999 CurrentFnSymForSize = CurrentFnSym;
1002 LI = &getAnalysis<MachineLoopInfo>();
1006 // SectionCPs - Keep track the alignment, constpool entries per Section.
1010 SmallVector<unsigned, 4> CPEs;
1011 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1015 /// EmitConstantPool - Print to the current output stream assembly
1016 /// representations of the constants in the constant pool MCP. This is
1017 /// used to print out constants which have been "spilled to memory" by
1018 /// the code generator.
1020 void AsmPrinter::EmitConstantPool() {
1021 const MachineConstantPool *MCP = MF->getConstantPool();
1022 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1023 if (CP.empty()) return;
1025 // Calculate sections for constant pool entries. We collect entries to go into
1026 // the same section together to reduce amount of section switch statements.
1027 SmallVector<SectionCPs, 4> CPSections;
1028 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1029 const MachineConstantPoolEntry &CPE = CP[i];
1030 unsigned Align = CPE.getAlignment();
1033 switch (CPE.getRelocationInfo()) {
1034 default: llvm_unreachable("Unknown section kind");
1035 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
1037 Kind = SectionKind::getReadOnlyWithRelLocal();
1040 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) {
1041 case 4: Kind = SectionKind::getMergeableConst4(); break;
1042 case 8: Kind = SectionKind::getMergeableConst8(); break;
1043 case 16: Kind = SectionKind::getMergeableConst16();break;
1044 default: Kind = SectionKind::getMergeableConst(); break;
1048 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
1050 // The number of sections are small, just do a linear search from the
1051 // last section to the first.
1053 unsigned SecIdx = CPSections.size();
1054 while (SecIdx != 0) {
1055 if (CPSections[--SecIdx].S == S) {
1061 SecIdx = CPSections.size();
1062 CPSections.push_back(SectionCPs(S, Align));
1065 if (Align > CPSections[SecIdx].Alignment)
1066 CPSections[SecIdx].Alignment = Align;
1067 CPSections[SecIdx].CPEs.push_back(i);
1070 // Now print stuff into the calculated sections.
1071 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1072 OutStreamer.SwitchSection(CPSections[i].S);
1073 EmitAlignment(Log2_32(CPSections[i].Alignment));
1075 unsigned Offset = 0;
1076 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1077 unsigned CPI = CPSections[i].CPEs[j];
1078 MachineConstantPoolEntry CPE = CP[CPI];
1080 // Emit inter-object padding for alignment.
1081 unsigned AlignMask = CPE.getAlignment() - 1;
1082 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1083 OutStreamer.EmitZeros(NewOffset - Offset);
1085 Type *Ty = CPE.getType();
1086 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty);
1087 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1089 if (CPE.isMachineConstantPoolEntry())
1090 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1092 EmitGlobalConstant(CPE.Val.ConstVal);
1097 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1098 /// by the current function to the current output stream.
1100 void AsmPrinter::EmitJumpTableInfo() {
1101 const DataLayout *DL = MF->getTarget().getDataLayout();
1102 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1103 if (MJTI == 0) return;
1104 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1105 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1106 if (JT.empty()) return;
1108 // Pick the directive to use to print the jump table entries, and switch to
1109 // the appropriate section.
1110 const Function *F = MF->getFunction();
1111 bool JTInDiffSection = false;
1112 if (// In PIC mode, we need to emit the jump table to the same section as the
1113 // function body itself, otherwise the label differences won't make sense.
1114 // FIXME: Need a better predicate for this: what about custom entries?
1115 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1116 // We should also do if the section name is NULL or function is declared
1117 // in discardable section
1118 // FIXME: this isn't the right predicate, should be based on the MCSection
1119 // for the function.
1120 F->isWeakForLinker()) {
1121 OutStreamer.SwitchSection(
1122 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1124 // Otherwise, drop it in the readonly section.
1125 const MCSection *ReadOnlySection =
1126 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1127 OutStreamer.SwitchSection(ReadOnlySection);
1128 JTInDiffSection = true;
1131 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout())));
1133 // Jump tables in code sections are marked with a data_region directive
1134 // where that's supported.
1135 if (!JTInDiffSection)
1136 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1138 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1139 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1141 // If this jump table was deleted, ignore it.
1142 if (JTBBs.empty()) continue;
1144 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1145 // .set directive for each unique entry. This reduces the number of
1146 // relocations the assembler will generate for the jump table.
1147 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1148 MAI->hasSetDirective()) {
1149 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1150 const TargetLowering *TLI = TM.getTargetLowering();
1151 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1152 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1153 const MachineBasicBlock *MBB = JTBBs[ii];
1154 if (!EmittedSets.insert(MBB)) continue;
1156 // .set LJTSet, LBB32-base
1158 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1159 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1160 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1164 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1165 // before each jump table. The first label is never referenced, but tells
1166 // the assembler and linker the extents of the jump table object. The
1167 // second label is actually referenced by the code.
1168 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1169 // FIXME: This doesn't have to have any specific name, just any randomly
1170 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1171 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1173 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1175 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1176 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1178 if (!JTInDiffSection)
1179 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1182 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1184 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1185 const MachineBasicBlock *MBB,
1186 unsigned UID) const {
1187 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1188 const MCExpr *Value = 0;
1189 switch (MJTI->getEntryKind()) {
1190 case MachineJumpTableInfo::EK_Inline:
1191 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1192 case MachineJumpTableInfo::EK_Custom32:
1193 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1196 case MachineJumpTableInfo::EK_BlockAddress:
1197 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1199 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1201 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1202 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1203 // with a relocation as gp-relative, e.g.:
1205 MCSymbol *MBBSym = MBB->getSymbol();
1206 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1210 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1211 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1212 // with a relocation as gp-relative, e.g.:
1214 MCSymbol *MBBSym = MBB->getSymbol();
1215 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1219 case MachineJumpTableInfo::EK_LabelDifference32: {
1220 // EK_LabelDifference32 - Each entry is the address of the block minus
1221 // the address of the jump table. This is used for PIC jump tables where
1222 // gprel32 is not supported. e.g.:
1223 // .word LBB123 - LJTI1_2
1224 // If the .set directive is supported, this is emitted as:
1225 // .set L4_5_set_123, LBB123 - LJTI1_2
1226 // .word L4_5_set_123
1228 // If we have emitted set directives for the jump table entries, print
1229 // them rather than the entries themselves. If we're emitting PIC, then
1230 // emit the table entries as differences between two text section labels.
1231 if (MAI->hasSetDirective()) {
1232 // If we used .set, reference the .set's symbol.
1233 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1237 // Otherwise, use the difference as the jump table entry.
1238 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1239 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1240 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1245 assert(Value && "Unknown entry kind!");
1247 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout());
1248 OutStreamer.EmitValue(Value, EntrySize);
1252 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1253 /// special global used by LLVM. If so, emit it and return true, otherwise
1254 /// do nothing and return false.
1255 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1256 if (GV->getName() == "llvm.used") {
1257 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1258 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1262 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1263 if (GV->getSection() == "llvm.metadata" ||
1264 GV->hasAvailableExternallyLinkage())
1267 if (!GV->hasAppendingLinkage()) return false;
1269 assert(GV->hasInitializer() && "Not a special LLVM global!");
1271 if (GV->getName() == "llvm.global_ctors") {
1272 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1274 if (TM.getRelocationModel() == Reloc::Static &&
1275 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1276 StringRef Sym(".constructors_used");
1277 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1283 if (GV->getName() == "llvm.global_dtors") {
1284 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1286 if (TM.getRelocationModel() == Reloc::Static &&
1287 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1288 StringRef Sym(".destructors_used");
1289 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1298 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1299 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1300 /// is true, as being used with this directive.
1301 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1302 // Should be an array of 'i8*'.
1303 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1304 const GlobalValue *GV =
1305 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1307 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1311 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1313 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1314 // Should be an array of '{ int, void ()* }' structs. The first value is the
1316 if (!isa<ConstantArray>(List)) return;
1318 // Sanity check the structors list.
1319 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1320 if (!InitList) return; // Not an array!
1321 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1322 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs!
1323 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1324 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1326 // Gather the structors in a form that's convenient for sorting by priority.
1327 typedef std::pair<unsigned, Constant *> Structor;
1328 SmallVector<Structor, 8> Structors;
1329 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1330 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i));
1331 if (!CS) continue; // Malformed.
1332 if (CS->getOperand(1)->isNullValue())
1333 break; // Found a null terminator, skip the rest.
1334 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1335 if (!Priority) continue; // Malformed.
1336 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535),
1337 CS->getOperand(1)));
1340 // Emit the function pointers in the target-specific order
1341 const DataLayout *DL = TM.getDataLayout();
1342 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1343 std::stable_sort(Structors.begin(), Structors.end(), less_first());
1344 for (unsigned i = 0, e = Structors.size(); i != e; ++i) {
1345 const MCSection *OutputSection =
1347 getObjFileLowering().getStaticCtorSection(Structors[i].first) :
1348 getObjFileLowering().getStaticDtorSection(Structors[i].first));
1349 OutStreamer.SwitchSection(OutputSection);
1350 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1351 EmitAlignment(Align);
1352 EmitXXStructor(Structors[i].second);
1356 void AsmPrinter::EmitModuleIdents(Module &M) {
1357 if (!MAI->hasIdentDirective())
1360 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1361 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1362 const MDNode *N = NMD->getOperand(i);
1363 assert(N->getNumOperands() == 1 &&
1364 "llvm.ident metadata entry can have only one operand");
1365 const MDString *S = cast<MDString>(N->getOperand(0));
1366 OutStreamer.EmitIdent(S->getString());
1371 //===--------------------------------------------------------------------===//
1372 // Emission and print routines
1375 /// EmitInt8 - Emit a byte directive and value.
1377 void AsmPrinter::EmitInt8(int Value) const {
1378 OutStreamer.EmitIntValue(Value, 1);
1381 /// EmitInt16 - Emit a short directive and value.
1383 void AsmPrinter::EmitInt16(int Value) const {
1384 OutStreamer.EmitIntValue(Value, 2);
1387 /// EmitInt32 - Emit a long directive and value.
1389 void AsmPrinter::EmitInt32(int Value) const {
1390 OutStreamer.EmitIntValue(Value, 4);
1393 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1394 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1395 /// labels. This implicitly uses .set if it is available.
1396 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1397 unsigned Size) const {
1398 // Get the Hi-Lo expression.
1399 const MCExpr *Diff =
1400 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1401 MCSymbolRefExpr::Create(Lo, OutContext),
1404 if (!MAI->hasSetDirective()) {
1405 OutStreamer.EmitValue(Diff, Size);
1409 // Otherwise, emit with .set (aka assignment).
1410 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1411 OutStreamer.EmitAssignment(SetLabel, Diff);
1412 OutStreamer.EmitSymbolValue(SetLabel, Size);
1415 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1416 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1417 /// specify the labels. This implicitly uses .set if it is available.
1418 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1420 unsigned Size) const {
1422 // Emit Hi+Offset - Lo
1423 // Get the Hi+Offset expression.
1424 const MCExpr *Plus =
1425 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1426 MCConstantExpr::Create(Offset, OutContext),
1429 // Get the Hi+Offset-Lo expression.
1430 const MCExpr *Diff =
1431 MCBinaryExpr::CreateSub(Plus,
1432 MCSymbolRefExpr::Create(Lo, OutContext),
1435 if (!MAI->hasSetDirective())
1436 OutStreamer.EmitValue(Diff, Size);
1438 // Otherwise, emit with .set (aka assignment).
1439 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1440 OutStreamer.EmitAssignment(SetLabel, Diff);
1441 OutStreamer.EmitSymbolValue(SetLabel, Size);
1445 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1446 /// where the size in bytes of the directive is specified by Size and Label
1447 /// specifies the label. This implicitly uses .set if it is available.
1448 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1450 bool IsSectionRelative) const {
1451 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1452 OutStreamer.EmitCOFFSecRel32(Label);
1456 // Emit Label+Offset (or just Label if Offset is zero)
1457 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1459 Expr = MCBinaryExpr::CreateAdd(
1460 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1462 OutStreamer.EmitValue(Expr, Size);
1465 //===----------------------------------------------------------------------===//
1467 // EmitAlignment - Emit an alignment directive to the specified power of
1468 // two boundary. For example, if you pass in 3 here, you will get an 8
1469 // byte alignment. If a global value is specified, and if that global has
1470 // an explicit alignment requested, it will override the alignment request
1471 // if required for correctness.
1473 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1474 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits);
1476 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1478 if (getCurrentSection()->getKind().isText())
1479 OutStreamer.EmitCodeAlignment(1 << NumBits);
1481 OutStreamer.EmitValueToAlignment(1 << NumBits);
1484 //===----------------------------------------------------------------------===//
1485 // Constant emission.
1486 //===----------------------------------------------------------------------===//
1488 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1490 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1491 MCContext &Ctx = AP.OutContext;
1493 if (CV->isNullValue() || isa<UndefValue>(CV))
1494 return MCConstantExpr::Create(0, Ctx);
1496 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1497 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1499 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1500 return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx);
1502 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1503 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1505 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1507 llvm_unreachable("Unknown constant value to lower!");
1510 if (const MCExpr *RelocExpr =
1511 AP.getObjFileLowering().getExecutableRelativeSymbol(CE, *AP.Mang,
1515 switch (CE->getOpcode()) {
1517 // If the code isn't optimized, there may be outstanding folding
1518 // opportunities. Attempt to fold the expression using DataLayout as a
1519 // last resort before giving up.
1521 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout()))
1523 return lowerConstant(C, AP);
1525 // Otherwise report the problem to the user.
1528 raw_string_ostream OS(S);
1529 OS << "Unsupported expression in static initializer: ";
1530 CE->printAsOperand(OS, /*PrintType=*/false,
1531 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1532 report_fatal_error(OS.str());
1534 case Instruction::GetElementPtr: {
1535 const DataLayout &DL = *AP.TM.getDataLayout();
1536 // Generate a symbolic expression for the byte address
1537 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1538 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1540 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1544 int64_t Offset = OffsetAI.getSExtValue();
1545 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1549 case Instruction::Trunc:
1550 // We emit the value and depend on the assembler to truncate the generated
1551 // expression properly. This is important for differences between
1552 // blockaddress labels. Since the two labels are in the same function, it
1553 // is reasonable to treat their delta as a 32-bit value.
1555 case Instruction::BitCast:
1556 return lowerConstant(CE->getOperand(0), AP);
1558 case Instruction::IntToPtr: {
1559 const DataLayout &DL = *AP.TM.getDataLayout();
1560 // Handle casts to pointers by changing them into casts to the appropriate
1561 // integer type. This promotes constant folding and simplifies this code.
1562 Constant *Op = CE->getOperand(0);
1563 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1565 return lowerConstant(Op, AP);
1568 case Instruction::PtrToInt: {
1569 const DataLayout &DL = *AP.TM.getDataLayout();
1570 // Support only foldable casts to/from pointers that can be eliminated by
1571 // changing the pointer to the appropriately sized integer type.
1572 Constant *Op = CE->getOperand(0);
1573 Type *Ty = CE->getType();
1575 const MCExpr *OpExpr = lowerConstant(Op, AP);
1577 // We can emit the pointer value into this slot if the slot is an
1578 // integer slot equal to the size of the pointer.
1579 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1582 // Otherwise the pointer is smaller than the resultant integer, mask off
1583 // the high bits so we are sure to get a proper truncation if the input is
1585 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1586 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1587 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1590 // The MC library also has a right-shift operator, but it isn't consistently
1591 // signed or unsigned between different targets.
1592 case Instruction::Add:
1593 case Instruction::Sub:
1594 case Instruction::Mul:
1595 case Instruction::SDiv:
1596 case Instruction::SRem:
1597 case Instruction::Shl:
1598 case Instruction::And:
1599 case Instruction::Or:
1600 case Instruction::Xor: {
1601 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1602 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1603 switch (CE->getOpcode()) {
1604 default: llvm_unreachable("Unknown binary operator constant cast expr");
1605 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1606 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1607 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1608 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1609 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1610 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1611 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1612 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1613 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1619 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1621 /// isRepeatedByteSequence - Determine whether the given value is
1622 /// composed of a repeated sequence of identical bytes and return the
1623 /// byte value. If it is not a repeated sequence, return -1.
1624 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1625 StringRef Data = V->getRawDataValues();
1626 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1628 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1629 if (Data[i] != C) return -1;
1630 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1634 /// isRepeatedByteSequence - Determine whether the given value is
1635 /// composed of a repeated sequence of identical bytes and return the
1636 /// byte value. If it is not a repeated sequence, return -1.
1637 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1639 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1640 if (CI->getBitWidth() > 64) return -1;
1642 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType());
1643 uint64_t Value = CI->getZExtValue();
1645 // Make sure the constant is at least 8 bits long and has a power
1646 // of 2 bit width. This guarantees the constant bit width is
1647 // always a multiple of 8 bits, avoiding issues with padding out
1648 // to Size and other such corner cases.
1649 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1651 uint8_t Byte = static_cast<uint8_t>(Value);
1653 for (unsigned i = 1; i < Size; ++i) {
1655 if (static_cast<uint8_t>(Value) != Byte) return -1;
1659 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1660 // Make sure all array elements are sequences of the same repeated
1662 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1663 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1664 if (Byte == -1) return -1;
1666 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1667 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1668 if (ThisByte == -1) return -1;
1669 if (Byte != ThisByte) return -1;
1674 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1675 return isRepeatedByteSequence(CDS);
1680 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1683 // See if we can aggregate this into a .fill, if so, emit it as such.
1684 int Value = isRepeatedByteSequence(CDS, AP.TM);
1686 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType());
1687 // Don't emit a 1-byte object as a .fill.
1689 return AP.OutStreamer.EmitFill(Bytes, Value);
1692 // If this can be emitted with .ascii/.asciz, emit it as such.
1693 if (CDS->isString())
1694 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1696 // Otherwise, emit the values in successive locations.
1697 unsigned ElementByteSize = CDS->getElementByteSize();
1698 if (isa<IntegerType>(CDS->getElementType())) {
1699 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1701 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1702 CDS->getElementAsInteger(i));
1703 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1706 } else if (ElementByteSize == 4) {
1707 // FP Constants are printed as integer constants to avoid losing
1709 assert(CDS->getElementType()->isFloatTy());
1710 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1716 F = CDS->getElementAsFloat(i);
1718 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1719 AP.OutStreamer.EmitIntValue(I, 4);
1722 assert(CDS->getElementType()->isDoubleTy());
1723 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1729 F = CDS->getElementAsDouble(i);
1731 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1732 AP.OutStreamer.EmitIntValue(I, 8);
1736 const DataLayout &DL = *AP.TM.getDataLayout();
1737 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1738 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1739 CDS->getNumElements();
1740 if (unsigned Padding = Size - EmittedSize)
1741 AP.OutStreamer.EmitZeros(Padding);
1745 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1746 // See if we can aggregate some values. Make sure it can be
1747 // represented as a series of bytes of the constant value.
1748 int Value = isRepeatedByteSequence(CA, AP.TM);
1751 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType());
1752 AP.OutStreamer.EmitFill(Bytes, Value);
1755 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1756 emitGlobalConstantImpl(CA->getOperand(i), AP);
1760 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1761 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1762 emitGlobalConstantImpl(CV->getOperand(i), AP);
1764 const DataLayout &DL = *AP.TM.getDataLayout();
1765 unsigned Size = DL.getTypeAllocSize(CV->getType());
1766 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1767 CV->getType()->getNumElements();
1768 if (unsigned Padding = Size - EmittedSize)
1769 AP.OutStreamer.EmitZeros(Padding);
1772 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1773 // Print the fields in successive locations. Pad to align if needed!
1774 const DataLayout *DL = AP.TM.getDataLayout();
1775 unsigned Size = DL->getTypeAllocSize(CS->getType());
1776 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1777 uint64_t SizeSoFar = 0;
1778 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1779 const Constant *Field = CS->getOperand(i);
1781 // Check if padding is needed and insert one or more 0s.
1782 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1783 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1784 - Layout->getElementOffset(i)) - FieldSize;
1785 SizeSoFar += FieldSize + PadSize;
1787 // Now print the actual field value.
1788 emitGlobalConstantImpl(Field, AP);
1790 // Insert padding - this may include padding to increase the size of the
1791 // current field up to the ABI size (if the struct is not packed) as well
1792 // as padding to ensure that the next field starts at the right offset.
1793 AP.OutStreamer.EmitZeros(PadSize);
1795 assert(SizeSoFar == Layout->getSizeInBytes() &&
1796 "Layout of constant struct may be incorrect!");
1799 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1800 APInt API = CFP->getValueAPF().bitcastToAPInt();
1802 // First print a comment with what we think the original floating-point value
1803 // should have been.
1804 if (AP.isVerbose()) {
1805 SmallString<8> StrVal;
1806 CFP->getValueAPF().toString(StrVal);
1808 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1809 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1812 // Now iterate through the APInt chunks, emitting them in endian-correct
1813 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1815 unsigned NumBytes = API.getBitWidth() / 8;
1816 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1817 const uint64_t *p = API.getRawData();
1819 // PPC's long double has odd notions of endianness compared to how LLVM
1820 // handles it: p[0] goes first for *big* endian on PPC.
1821 if (AP.TM.getDataLayout()->isBigEndian() != CFP->getType()->isPPC_FP128Ty()) {
1822 int Chunk = API.getNumWords() - 1;
1825 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1827 for (; Chunk >= 0; --Chunk)
1828 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1831 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1832 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1835 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1838 // Emit the tail padding for the long double.
1839 const DataLayout &DL = *AP.TM.getDataLayout();
1840 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1841 DL.getTypeStoreSize(CFP->getType()));
1844 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1845 const DataLayout *DL = AP.TM.getDataLayout();
1846 unsigned BitWidth = CI->getBitWidth();
1848 // Copy the value as we may massage the layout for constants whose bit width
1849 // is not a multiple of 64-bits.
1850 APInt Realigned(CI->getValue());
1851 uint64_t ExtraBits = 0;
1852 unsigned ExtraBitsSize = BitWidth & 63;
1854 if (ExtraBitsSize) {
1855 // The bit width of the data is not a multiple of 64-bits.
1856 // The extra bits are expected to be at the end of the chunk of the memory.
1858 // * Nothing to be done, just record the extra bits to emit.
1860 // * Record the extra bits to emit.
1861 // * Realign the raw data to emit the chunks of 64-bits.
1862 if (DL->isBigEndian()) {
1863 // Basically the structure of the raw data is a chunk of 64-bits cells:
1864 // 0 1 BitWidth / 64
1865 // [chunk1][chunk2] ... [chunkN].
1866 // The most significant chunk is chunkN and it should be emitted first.
1867 // However, due to the alignment issue chunkN contains useless bits.
1868 // Realign the chunks so that they contain only useless information:
1869 // ExtraBits 0 1 (BitWidth / 64) - 1
1870 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1871 ExtraBits = Realigned.getRawData()[0] &
1872 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1873 Realigned = Realigned.lshr(ExtraBitsSize);
1875 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1878 // We don't expect assemblers to support integer data directives
1879 // for more than 64 bits, so we emit the data in at most 64-bit
1880 // quantities at a time.
1881 const uint64_t *RawData = Realigned.getRawData();
1882 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1883 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1884 AP.OutStreamer.EmitIntValue(Val, 8);
1887 if (ExtraBitsSize) {
1888 // Emit the extra bits after the 64-bits chunks.
1890 // Emit a directive that fills the expected size.
1891 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(CI->getType());
1892 Size -= (BitWidth / 64) * 8;
1893 assert(Size && Size * 8 >= ExtraBitsSize &&
1894 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1895 == ExtraBits && "Directive too small for extra bits.");
1896 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1900 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1901 const DataLayout *DL = AP.TM.getDataLayout();
1902 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1903 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1904 return AP.OutStreamer.EmitZeros(Size);
1906 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1913 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1914 CI->getZExtValue());
1915 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1918 emitGlobalConstantLargeInt(CI, AP);
1923 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1924 return emitGlobalConstantFP(CFP, AP);
1926 if (isa<ConstantPointerNull>(CV)) {
1927 AP.OutStreamer.EmitIntValue(0, Size);
1931 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1932 return emitGlobalConstantDataSequential(CDS, AP);
1934 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1935 return emitGlobalConstantArray(CVA, AP);
1937 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1938 return emitGlobalConstantStruct(CVS, AP);
1940 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
1941 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
1943 if (CE->getOpcode() == Instruction::BitCast)
1944 return emitGlobalConstantImpl(CE->getOperand(0), AP);
1947 // If the constant expression's size is greater than 64-bits, then we have
1948 // to emit the value in chunks. Try to constant fold the value and emit it
1950 Constant *New = ConstantFoldConstantExpression(CE, DL);
1951 if (New && New != CE)
1952 return emitGlobalConstantImpl(New, AP);
1956 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1957 return emitGlobalConstantVector(V, AP);
1959 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1960 // thread the streamer with EmitValue.
1961 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
1964 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1965 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
1966 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType());
1968 emitGlobalConstantImpl(CV, *this);
1969 else if (MAI->hasSubsectionsViaSymbols()) {
1970 // If the global has zero size, emit a single byte so that two labels don't
1971 // look like they are at the same location.
1972 OutStreamer.EmitIntValue(0, 1);
1976 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1977 // Target doesn't support this yet!
1978 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1981 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1983 OS << '+' << Offset;
1984 else if (Offset < 0)
1988 //===----------------------------------------------------------------------===//
1989 // Symbol Lowering Routines.
1990 //===----------------------------------------------------------------------===//
1992 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1993 /// temporary label with the specified stem and unique ID.
1994 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const {
1995 const DataLayout *DL = TM.getDataLayout();
1996 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2000 /// GetTempSymbol - Return an assembler temporary label with the specified
2002 MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const {
2003 const DataLayout *DL = TM.getDataLayout();
2004 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2009 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2010 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2013 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2014 return MMI->getAddrLabelSymbol(BB);
2017 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2018 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2019 const DataLayout *DL = TM.getDataLayout();
2020 return OutContext.GetOrCreateSymbol
2021 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2022 + "_" + Twine(CPID));
2025 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2026 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2027 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2030 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2031 /// FIXME: privatize to AsmPrinter.
2032 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2033 const DataLayout *DL = TM.getDataLayout();
2034 return OutContext.GetOrCreateSymbol
2035 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2036 Twine(UID) + "_set_" + Twine(MBBID));
2039 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2040 StringRef Suffix) const {
2041 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang,
2045 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2047 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2048 SmallString<60> NameStr;
2049 Mang->getNameWithPrefix(NameStr, Sym);
2050 return OutContext.GetOrCreateSymbol(NameStr.str());
2055 /// PrintParentLoopComment - Print comments about parent loops of this one.
2056 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2057 unsigned FunctionNumber) {
2058 if (Loop == 0) return;
2059 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2060 OS.indent(Loop->getLoopDepth()*2)
2061 << "Parent Loop BB" << FunctionNumber << "_"
2062 << Loop->getHeader()->getNumber()
2063 << " Depth=" << Loop->getLoopDepth() << '\n';
2067 /// PrintChildLoopComment - Print comments about child loops within
2068 /// the loop for this basic block, with nesting.
2069 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2070 unsigned FunctionNumber) {
2071 // Add child loop information
2072 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
2073 OS.indent((*CL)->getLoopDepth()*2)
2074 << "Child Loop BB" << FunctionNumber << "_"
2075 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
2077 PrintChildLoopComment(OS, *CL, FunctionNumber);
2081 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2082 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2083 const MachineLoopInfo *LI,
2084 const AsmPrinter &AP) {
2085 // Add loop depth information
2086 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2087 if (Loop == 0) return;
2089 MachineBasicBlock *Header = Loop->getHeader();
2090 assert(Header && "No header for loop");
2092 // If this block is not a loop header, just print out what is the loop header
2094 if (Header != &MBB) {
2095 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2096 Twine(AP.getFunctionNumber())+"_" +
2097 Twine(Loop->getHeader()->getNumber())+
2098 " Depth="+Twine(Loop->getLoopDepth()));
2102 // Otherwise, it is a loop header. Print out information about child and
2104 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2106 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2109 OS.indent(Loop->getLoopDepth()*2-2);
2114 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2116 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2120 /// EmitBasicBlockStart - This method prints the label for the specified
2121 /// MachineBasicBlock, an alignment (if present) and a comment describing
2122 /// it if appropriate.
2123 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
2124 // Emit an alignment directive for this block, if needed.
2125 if (unsigned Align = MBB->getAlignment())
2126 EmitAlignment(Align);
2128 // If the block has its address taken, emit any labels that were used to
2129 // reference the block. It is possible that there is more than one label
2130 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2131 // the references were generated.
2132 if (MBB->hasAddressTaken()) {
2133 const BasicBlock *BB = MBB->getBasicBlock();
2135 OutStreamer.AddComment("Block address taken");
2137 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
2139 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
2140 OutStreamer.EmitLabel(Syms[i]);
2143 // Print some verbose block comments.
2145 if (const BasicBlock *BB = MBB->getBasicBlock())
2147 OutStreamer.AddComment("%" + BB->getName());
2148 emitBasicBlockLoopComments(*MBB, LI, *this);
2151 // Print the main label for the block.
2152 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
2154 // NOTE: Want this comment at start of line, don't emit with AddComment.
2155 OutStreamer.emitRawComment(" BB#" + Twine(MBB->getNumber()) + ":", false);
2158 OutStreamer.EmitLabel(MBB->getSymbol());
2162 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2163 bool IsDefinition) const {
2164 MCSymbolAttr Attr = MCSA_Invalid;
2166 switch (Visibility) {
2168 case GlobalValue::HiddenVisibility:
2170 Attr = MAI->getHiddenVisibilityAttr();
2172 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2174 case GlobalValue::ProtectedVisibility:
2175 Attr = MAI->getProtectedVisibilityAttr();
2179 if (Attr != MCSA_Invalid)
2180 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2183 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2184 /// exactly one predecessor and the control transfer mechanism between
2185 /// the predecessor and this block is a fall-through.
2187 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2188 // If this is a landing pad, it isn't a fall through. If it has no preds,
2189 // then nothing falls through to it.
2190 if (MBB->isLandingPad() || MBB->pred_empty())
2193 // If there isn't exactly one predecessor, it can't be a fall through.
2194 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
2196 if (PI2 != MBB->pred_end())
2199 // The predecessor has to be immediately before this block.
2200 MachineBasicBlock *Pred = *PI;
2202 if (!Pred->isLayoutSuccessor(MBB))
2205 // If the block is completely empty, then it definitely does fall through.
2209 // Check the terminators in the previous blocks
2210 for (MachineBasicBlock::iterator II = Pred->getFirstTerminator(),
2211 IE = Pred->end(); II != IE; ++II) {
2212 MachineInstr &MI = *II;
2214 // If it is not a simple branch, we are in a table somewhere.
2215 if (!MI.isBranch() || MI.isIndirectBranch())
2218 // If we are the operands of one of the branches, this is not a fall
2219 // through. Note that targets with delay slots will usually bundle
2220 // terminators with the delay slot instruction.
2221 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2224 if (OP->isMBB() && OP->getMBB() == MBB)
2234 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
2235 if (!S->usesMetadata())
2238 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2239 gcp_map_type::iterator GCPI = GCMap.find(S);
2240 if (GCPI != GCMap.end())
2241 return GCPI->second;
2243 const char *Name = S->getName().c_str();
2245 for (GCMetadataPrinterRegistry::iterator
2246 I = GCMetadataPrinterRegistry::begin(),
2247 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2248 if (strcmp(Name, I->getName()) == 0) {
2249 GCMetadataPrinter *GMP = I->instantiate();
2251 GCMap.insert(std::make_pair(S, GMP));
2255 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2258 /// Pin vtable to this file.
2259 AsmPrinterHandler::~AsmPrinterHandler() {}