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 "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/Statistic.h"
20 #include "llvm/Analysis/ConstantFolding.h"
21 #include "llvm/Assembly/Writer.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/MachineJumpTableInfo.h"
27 #include "llvm/CodeGen/MachineLoopInfo.h"
28 #include "llvm/CodeGen/MachineModuleInfo.h"
29 #include "llvm/DebugInfo.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/Module.h"
32 #include "llvm/IR/Operator.h"
33 #include "llvm/MC/MCAsmInfo.h"
34 #include "llvm/MC/MCContext.h"
35 #include "llvm/MC/MCExpr.h"
36 #include "llvm/MC/MCInst.h"
37 #include "llvm/MC/MCSection.h"
38 #include "llvm/MC/MCStreamer.h"
39 #include "llvm/MC/MCSymbol.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/Format.h"
42 #include "llvm/Support/MathExtras.h"
43 #include "llvm/Support/Timer.h"
44 #include "llvm/Target/Mangler.h"
45 #include "llvm/Target/TargetFrameLowering.h"
46 #include "llvm/Target/TargetInstrInfo.h"
47 #include "llvm/Target/TargetLowering.h"
48 #include "llvm/Target/TargetLoweringObjectFile.h"
49 #include "llvm/Target/TargetOptions.h"
50 #include "llvm/Target/TargetRegisterInfo.h"
53 static const char *const DWARFGroupName = "DWARF Emission";
54 static const char *const DbgTimerName = "DWARF Debug Writer";
55 static const char *const EHTimerName = "DWARF Exception Writer";
57 STATISTIC(EmittedInsts, "Number of machine instrs printed");
59 char AsmPrinter::ID = 0;
61 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
62 static gcp_map_type &getGCMap(void *&P) {
64 P = new gcp_map_type();
65 return *(gcp_map_type*)P;
69 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
70 /// value in log2 form. This rounds up to the preferred alignment if possible
72 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD,
73 unsigned InBits = 0) {
75 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
76 NumBits = TD.getPreferredAlignmentLog(GVar);
78 // If InBits is specified, round it to it.
82 // If the GV has a specified alignment, take it into account.
83 if (GV->getAlignment() == 0)
86 unsigned GVAlign = Log2_32(GV->getAlignment());
88 // If the GVAlign is larger than NumBits, or if we are required to obey
89 // NumBits because the GV has an assigned section, obey it.
90 if (GVAlign > NumBits || GV->hasSection())
95 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
96 : MachineFunctionPass(ID),
97 TM(tm), MAI(tm.getMCAsmInfo()), MII(tm.getInstrInfo()),
98 OutContext(Streamer.getContext()),
99 OutStreamer(Streamer),
100 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
101 DD = 0; DE = 0; MMI = 0; LI = 0; MF = 0;
102 CurrentFnSym = CurrentFnSymForSize = 0;
103 GCMetadataPrinters = 0;
104 VerboseAsm = Streamer.isVerboseAsm();
107 AsmPrinter::~AsmPrinter() {
108 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized");
110 if (GCMetadataPrinters != 0) {
111 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
113 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
116 GCMetadataPrinters = 0;
122 /// getFunctionNumber - Return a unique ID for the current function.
124 unsigned AsmPrinter::getFunctionNumber() const {
125 return MF->getFunctionNumber();
128 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
129 return TM.getTargetLowering()->getObjFileLowering();
132 /// getDataLayout - Return information about data layout.
133 const DataLayout &AsmPrinter::getDataLayout() const {
134 return *TM.getDataLayout();
137 StringRef AsmPrinter::getTargetTriple() const {
138 return TM.getTargetTriple();
141 /// getCurrentSection() - Return the current section we are emitting to.
142 const MCSection *AsmPrinter::getCurrentSection() const {
143 return OutStreamer.getCurrentSection().first;
148 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
149 AU.setPreservesAll();
150 MachineFunctionPass::getAnalysisUsage(AU);
151 AU.addRequired<MachineModuleInfo>();
152 AU.addRequired<GCModuleInfo>();
154 AU.addRequired<MachineLoopInfo>();
157 bool AsmPrinter::doInitialization(Module &M) {
158 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
159 MMI->AnalyzeModule(M);
161 // Initialize TargetLoweringObjectFile.
162 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
163 .Initialize(OutContext, TM);
165 OutStreamer.InitStreamer();
167 Mang = new Mangler(OutContext, &TM);
169 // Allow the target to emit any magic that it wants at the start of the file.
170 EmitStartOfAsmFile(M);
172 // Very minimal debug info. It is ignored if we emit actual debug info. If we
173 // don't, this at least helps the user find where a global came from.
174 if (MAI->hasSingleParameterDotFile()) {
176 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
179 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
180 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
181 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
182 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
183 MP->beginAssembly(*this);
185 // Emit module-level inline asm if it exists.
186 if (!M.getModuleInlineAsm().empty()) {
187 OutStreamer.AddComment("Start of file scope inline assembly");
188 OutStreamer.AddBlankLine();
189 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
190 OutStreamer.AddComment("End of file scope inline assembly");
191 OutStreamer.AddBlankLine();
194 if (MAI->doesSupportDebugInformation())
195 DD = new DwarfDebug(this, &M);
197 switch (MAI->getExceptionHandlingType()) {
198 case ExceptionHandling::None:
200 case ExceptionHandling::SjLj:
201 case ExceptionHandling::DwarfCFI:
202 DE = new DwarfCFIException(this);
204 case ExceptionHandling::ARM:
205 DE = new ARMException(this);
207 case ExceptionHandling::Win64:
208 DE = new Win64Exception(this);
212 llvm_unreachable("Unknown exception type.");
215 void AsmPrinter::EmitLinkage(unsigned L, MCSymbol *GVSym) const {
216 GlobalValue::LinkageTypes Linkage = (GlobalValue::LinkageTypes)L;
219 case GlobalValue::CommonLinkage:
220 case GlobalValue::LinkOnceAnyLinkage:
221 case GlobalValue::LinkOnceODRLinkage:
222 case GlobalValue::LinkOnceODRAutoHideLinkage:
223 case GlobalValue::WeakAnyLinkage:
224 case GlobalValue::WeakODRLinkage:
225 case GlobalValue::LinkerPrivateWeakLinkage:
226 if (MAI->getWeakDefDirective() != 0) {
228 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
230 if (Linkage != GlobalValue::LinkOnceODRAutoHideLinkage)
231 // .weak_definition _foo
232 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
234 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
235 } else if (MAI->getLinkOnceDirective() != 0) {
237 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
238 //NOTE: linkonce is handled by the section the symbol was assigned to.
241 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
244 case GlobalValue::DLLExportLinkage:
245 case GlobalValue::AppendingLinkage:
246 // FIXME: appending linkage variables should go into a section of
247 // their name or something. For now, just emit them as external.
248 case GlobalValue::ExternalLinkage:
249 // If external or appending, declare as a global symbol.
251 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
253 case GlobalValue::PrivateLinkage:
254 case GlobalValue::InternalLinkage:
255 case GlobalValue::LinkerPrivateLinkage:
257 case GlobalValue::AvailableExternallyLinkage:
258 llvm_unreachable("Should never emit this");
259 case GlobalValue::DLLImportLinkage:
260 case GlobalValue::ExternalWeakLinkage:
261 llvm_unreachable("Don't know how to emit these");
263 llvm_unreachable("Unknown linkage type!");
267 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
268 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
269 if (GV->hasInitializer()) {
270 // Check to see if this is a special global used by LLVM, if so, emit it.
271 if (EmitSpecialLLVMGlobal(GV))
275 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
276 /*PrintType=*/false, GV->getParent());
277 OutStreamer.GetCommentOS() << '\n';
281 MCSymbol *GVSym = Mang->getSymbol(GV);
282 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
284 if (!GV->hasInitializer()) // External globals require no extra code.
287 if (MAI->hasDotTypeDotSizeDirective())
288 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
290 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
292 const DataLayout *DL = TM.getDataLayout();
293 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
295 // If the alignment is specified, we *must* obey it. Overaligning a global
296 // with a specified alignment is a prompt way to break globals emitted to
297 // sections and expected to be contiguous (e.g. ObjC metadata).
298 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
301 DD->setSymbolSize(GVSym, Size);
303 // Handle common and BSS local symbols (.lcomm).
304 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
305 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
306 unsigned Align = 1 << AlignLog;
308 // Handle common symbols.
309 if (GVKind.isCommon()) {
310 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
314 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
318 // Handle local BSS symbols.
319 if (MAI->hasMachoZeroFillDirective()) {
320 const MCSection *TheSection =
321 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
322 // .zerofill __DATA, __bss, _foo, 400, 5
323 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
327 // Use .lcomm only if it supports user-specified alignment.
328 // Otherwise, while it would still be correct to use .lcomm in some
329 // cases (e.g. when Align == 1), the external assembler might enfore
330 // some -unknown- default alignment behavior, which could cause
331 // spurious differences between external and integrated assembler.
332 // Prefer to simply fall back to .local / .comm in this case.
333 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
335 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
339 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
343 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
345 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
349 const MCSection *TheSection =
350 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
352 // Handle the zerofill directive on darwin, which is a special form of BSS
354 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
355 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
358 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
359 // .zerofill __DATA, __common, _foo, 400, 5
360 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
364 // Handle thread local data for mach-o which requires us to output an
365 // additional structure of data and mangle the original symbol so that we
366 // can reference it later.
368 // TODO: This should become an "emit thread local global" method on TLOF.
369 // All of this macho specific stuff should be sunk down into TLOFMachO and
370 // stuff like "TLSExtraDataSection" should no longer be part of the parent
371 // TLOF class. This will also make it more obvious that stuff like
372 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
374 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
375 // Emit the .tbss symbol
377 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
379 if (GVKind.isThreadBSS()) {
380 TheSection = getObjFileLowering().getTLSBSSSection();
381 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
382 } else if (GVKind.isThreadData()) {
383 OutStreamer.SwitchSection(TheSection);
385 EmitAlignment(AlignLog, GV);
386 OutStreamer.EmitLabel(MangSym);
388 EmitGlobalConstant(GV->getInitializer());
391 OutStreamer.AddBlankLine();
393 // Emit the variable struct for the runtime.
394 const MCSection *TLVSect
395 = getObjFileLowering().getTLSExtraDataSection();
397 OutStreamer.SwitchSection(TLVSect);
398 // Emit the linkage here.
399 EmitLinkage(GV->getLinkage(), GVSym);
400 OutStreamer.EmitLabel(GVSym);
402 // Three pointers in size:
403 // - __tlv_bootstrap - used to make sure support exists
404 // - spare pointer, used when mapped by the runtime
405 // - pointer to mangled symbol above with initializer
406 unsigned PtrSize = DL->getPointerSizeInBits()/8;
407 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
409 OutStreamer.EmitIntValue(0, PtrSize);
410 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
412 OutStreamer.AddBlankLine();
416 OutStreamer.SwitchSection(TheSection);
418 EmitLinkage(GV->getLinkage(), GVSym);
419 EmitAlignment(AlignLog, GV);
421 OutStreamer.EmitLabel(GVSym);
423 EmitGlobalConstant(GV->getInitializer());
425 if (MAI->hasDotTypeDotSizeDirective())
427 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
429 OutStreamer.AddBlankLine();
432 /// EmitFunctionHeader - This method emits the header for the current
434 void AsmPrinter::EmitFunctionHeader() {
435 // Print out constants referenced by the function
438 // Print the 'header' of function.
439 const Function *F = MF->getFunction();
441 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
442 EmitVisibility(CurrentFnSym, F->getVisibility());
444 EmitLinkage(F->getLinkage(), CurrentFnSym);
445 EmitAlignment(MF->getAlignment(), F);
447 if (MAI->hasDotTypeDotSizeDirective())
448 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
451 WriteAsOperand(OutStreamer.GetCommentOS(), F,
452 /*PrintType=*/false, F->getParent());
453 OutStreamer.GetCommentOS() << '\n';
456 // Emit the CurrentFnSym. This is a virtual function to allow targets to
457 // do their wild and crazy things as required.
458 EmitFunctionEntryLabel();
460 // If the function had address-taken blocks that got deleted, then we have
461 // references to the dangling symbols. Emit them at the start of the function
462 // so that we don't get references to undefined symbols.
463 std::vector<MCSymbol*> DeadBlockSyms;
464 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
465 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
466 OutStreamer.AddComment("Address taken block that was later removed");
467 OutStreamer.EmitLabel(DeadBlockSyms[i]);
470 // Emit pre-function debug and/or EH information.
472 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
473 DE->BeginFunction(MF);
476 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
477 DD->beginFunction(MF);
480 // Emit the prefix data.
481 if (F->hasPrefixData())
482 EmitGlobalConstant(F->getPrefixData());
485 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
486 /// function. This can be overridden by targets as required to do custom stuff.
487 void AsmPrinter::EmitFunctionEntryLabel() {
488 // The function label could have already been emitted if two symbols end up
489 // conflicting due to asm renaming. Detect this and emit an error.
490 if (CurrentFnSym->isUndefined())
491 return OutStreamer.EmitLabel(CurrentFnSym);
493 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
494 "' label emitted multiple times to assembly file");
497 /// emitComments - Pretty-print comments for instructions.
498 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
499 const MachineFunction *MF = MI.getParent()->getParent();
500 const TargetMachine &TM = MF->getTarget();
502 // Check for spills and reloads
505 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
507 // We assume a single instruction only has a spill or reload, not
509 const MachineMemOperand *MMO;
510 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
511 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
512 MMO = *MI.memoperands_begin();
513 CommentOS << MMO->getSize() << "-byte Reload\n";
515 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
516 if (FrameInfo->isSpillSlotObjectIndex(FI))
517 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
518 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
519 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
520 MMO = *MI.memoperands_begin();
521 CommentOS << MMO->getSize() << "-byte Spill\n";
523 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
524 if (FrameInfo->isSpillSlotObjectIndex(FI))
525 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
528 // Check for spill-induced copies
529 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
530 CommentOS << " Reload Reuse\n";
533 /// emitImplicitDef - This method emits the specified machine instruction
534 /// that is an implicit def.
535 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
536 unsigned RegNo = MI->getOperand(0).getReg();
537 OutStreamer.AddComment(Twine("implicit-def: ") +
538 TM.getRegisterInfo()->getName(RegNo));
539 OutStreamer.AddBlankLine();
542 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
543 std::string Str = "kill:";
544 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
545 const MachineOperand &Op = MI->getOperand(i);
546 assert(Op.isReg() && "KILL instruction must have only register operands");
548 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
549 Str += (Op.isDef() ? "<def>" : "<kill>");
551 AP.OutStreamer.AddComment(Str);
552 AP.OutStreamer.AddBlankLine();
555 /// emitDebugValueComment - This method handles the target-independent form
556 /// of DBG_VALUE, returning true if it was able to do so. A false return
557 /// means the target will need to handle MI in EmitInstruction.
558 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
559 // This code handles only the 3-operand target-independent form.
560 if (MI->getNumOperands() != 3)
563 SmallString<128> Str;
564 raw_svector_ostream OS(Str);
565 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
567 // cast away const; DIetc do not take const operands for some reason.
568 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
569 if (V.getContext().isSubprogram()) {
570 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
574 OS << V.getName() << " <- ";
576 // The second operand is only an offset if it's an immediate.
577 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
578 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
580 // Register or immediate value. Register 0 means undef.
581 if (MI->getOperand(0).isFPImm()) {
582 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
583 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
584 OS << (double)APF.convertToFloat();
585 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
586 OS << APF.convertToDouble();
588 // There is no good way to print long double. Convert a copy to
589 // double. Ah well, it's only a comment.
591 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
593 OS << "(long double) " << APF.convertToDouble();
595 } else if (MI->getOperand(0).isImm()) {
596 OS << MI->getOperand(0).getImm();
597 } else if (MI->getOperand(0).isCImm()) {
598 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
601 if (MI->getOperand(0).isReg()) {
602 Reg = MI->getOperand(0).getReg();
604 assert(MI->getOperand(0).isFI() && "Unknown operand type");
605 const TargetFrameLowering *TFI = AP.TM.getFrameLowering();
606 Offset += TFI->getFrameIndexReference(*AP.MF,
607 MI->getOperand(0).getIndex(), Reg);
611 // Suppress offset, it is not meaningful here.
613 // NOTE: Want this comment at start of line, don't emit with AddComment.
614 AP.OutStreamer.EmitRawText(OS.str());
619 OS << AP.TM.getRegisterInfo()->getName(Reg);
623 OS << '+' << Offset << ']';
625 // NOTE: Want this comment at start of line, don't emit with AddComment.
626 AP.OutStreamer.EmitRawText(OS.str());
630 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
631 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
632 MF->getFunction()->needsUnwindTableEntry())
635 if (MMI->hasDebugInfo())
641 bool AsmPrinter::needsSEHMoves() {
642 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 &&
643 MF->getFunction()->needsUnwindTableEntry();
646 bool AsmPrinter::needsRelocationsForDwarfStringPool() const {
647 return MAI->doesDwarfUseRelocationsAcrossSections();
650 void AsmPrinter::emitPrologLabel(const MachineInstr &MI) {
651 const MCSymbol *Label = MI.getOperand(0).getMCSymbol();
653 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
656 if (needsCFIMoves() == CFI_M_None)
659 if (MMI->getCompactUnwindEncoding() != 0)
660 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding());
662 const MachineModuleInfo &MMI = MF->getMMI();
663 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
664 bool FoundOne = false;
666 for (std::vector<MCCFIInstruction>::const_iterator I = Instrs.begin(),
667 E = Instrs.end(); I != E; ++I) {
668 if (I->getLabel() == Label) {
669 emitCFIInstruction(*I);
676 /// EmitFunctionBody - This method emits the body and trailer for a
678 void AsmPrinter::EmitFunctionBody() {
679 // Emit target-specific gunk before the function body.
680 EmitFunctionBodyStart();
682 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
684 // Print out code for the function.
685 bool HasAnyRealCode = false;
686 const MachineInstr *LastMI = 0;
687 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
689 // Print a label for the basic block.
690 EmitBasicBlockStart(I);
691 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
695 // Print the assembly for the instruction.
696 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
697 !II->isDebugValue()) {
698 HasAnyRealCode = true;
702 if (ShouldPrintDebugScopes) {
703 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
704 DD->beginInstruction(II);
708 emitComments(*II, OutStreamer.GetCommentOS());
710 switch (II->getOpcode()) {
711 case TargetOpcode::PROLOG_LABEL:
712 emitPrologLabel(*II);
715 case TargetOpcode::EH_LABEL:
716 case TargetOpcode::GC_LABEL:
717 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
719 case TargetOpcode::INLINEASM:
722 case TargetOpcode::DBG_VALUE:
724 if (!emitDebugValueComment(II, *this))
728 case TargetOpcode::IMPLICIT_DEF:
729 if (isVerbose()) emitImplicitDef(II);
731 case TargetOpcode::KILL:
732 if (isVerbose()) emitKill(II, *this);
735 if (!TM.hasMCUseLoc())
736 MCLineEntry::Make(&OutStreamer, getCurrentSection());
742 if (ShouldPrintDebugScopes) {
743 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
744 DD->endInstruction(II);
749 // If the last instruction was a prolog label, then we have a situation where
750 // we emitted a prolog but no function body. This results in the ending prolog
751 // label equaling the end of function label and an invalid "row" in the
752 // FDE. We need to emit a noop in this situation so that the FDE's rows are
754 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
756 // If the function is empty and the object file uses .subsections_via_symbols,
757 // then we need to emit *something* to the function body to prevent the
758 // labels from collapsing together. Just emit a noop.
759 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
761 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
762 if (Noop.getOpcode()) {
763 OutStreamer.AddComment("avoids zero-length function");
764 OutStreamer.EmitInstruction(Noop);
765 } else // Target not mc-ized yet.
766 OutStreamer.EmitRawText(StringRef("\tnop\n"));
769 const Function *F = MF->getFunction();
770 for (Function::const_iterator i = F->begin(), e = F->end(); i != e; ++i) {
771 const BasicBlock *BB = i;
772 if (!BB->hasAddressTaken())
774 MCSymbol *Sym = GetBlockAddressSymbol(BB);
775 if (Sym->isDefined())
777 OutStreamer.AddComment("Address of block that was removed by CodeGen");
778 OutStreamer.EmitLabel(Sym);
781 // Emit target-specific gunk after the function body.
782 EmitFunctionBodyEnd();
784 // If the target wants a .size directive for the size of the function, emit
786 if (MAI->hasDotTypeDotSizeDirective()) {
787 // Create a symbol for the end of function, so we can get the size as
788 // difference between the function label and the temp label.
789 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
790 OutStreamer.EmitLabel(FnEndLabel);
792 const MCExpr *SizeExp =
793 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
794 MCSymbolRefExpr::Create(CurrentFnSymForSize,
797 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
800 // Emit post-function debug information.
802 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
806 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
811 // Print out jump tables referenced by the function.
814 OutStreamer.AddBlankLine();
817 /// EmitDwarfRegOp - Emit dwarf register operation.
818 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc,
819 bool Indirect) const {
820 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
821 int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
823 for (MCSuperRegIterator SR(MLoc.getReg(), TRI); SR.isValid() && Reg < 0;
825 Reg = TRI->getDwarfRegNum(*SR, false);
826 // FIXME: Get the bit range this register uses of the superregister
827 // so that we can produce a DW_OP_bit_piece
830 // FIXME: Handle cases like a super register being encoded as
831 // DW_OP_reg 32 DW_OP_piece 4 DW_OP_reg 33
833 // FIXME: We have no reasonable way of handling errors in here. The
834 // caller might be in the middle of an dwarf expression. We should
835 // probably assert that Reg >= 0 once debug info generation is more mature.
837 if (MLoc.isIndirect() || Indirect) {
839 OutStreamer.AddComment(
840 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg));
841 EmitInt8(dwarf::DW_OP_breg0 + Reg);
843 OutStreamer.AddComment("DW_OP_bregx");
844 EmitInt8(dwarf::DW_OP_bregx);
845 OutStreamer.AddComment(Twine(Reg));
848 EmitSLEB128(!MLoc.isIndirect() ? 0 : MLoc.getOffset());
849 if (MLoc.isIndirect() && Indirect)
850 EmitInt8(dwarf::DW_OP_deref);
853 OutStreamer.AddComment(
854 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
855 EmitInt8(dwarf::DW_OP_reg0 + Reg);
857 OutStreamer.AddComment("DW_OP_regx");
858 EmitInt8(dwarf::DW_OP_regx);
859 OutStreamer.AddComment(Twine(Reg));
864 // FIXME: Produce a DW_OP_bit_piece if we used a superregister
867 bool AsmPrinter::doFinalization(Module &M) {
868 // Emit global variables.
869 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
871 EmitGlobalVariable(I);
873 // Emit visibility info for declarations
874 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
875 const Function &F = *I;
876 if (!F.isDeclaration())
878 GlobalValue::VisibilityTypes V = F.getVisibility();
879 if (V == GlobalValue::DefaultVisibility)
882 MCSymbol *Name = Mang->getSymbol(&F);
883 EmitVisibility(Name, V, false);
886 // Emit module flags.
887 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
888 M.getModuleFlagsMetadata(ModuleFlags);
889 if (!ModuleFlags.empty())
890 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, Mang, TM);
892 // Make sure we wrote out everything we need.
895 // Finalize debug and EH information.
898 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
905 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
911 // If the target wants to know about weak references, print them all.
912 if (MAI->getWeakRefDirective()) {
913 // FIXME: This is not lazy, it would be nice to only print weak references
914 // to stuff that is actually used. Note that doing so would require targets
915 // to notice uses in operands (due to constant exprs etc). This should
916 // happen with the MC stuff eventually.
918 // Print out module-level global variables here.
919 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
921 if (!I->hasExternalWeakLinkage()) continue;
922 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
925 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
926 if (!I->hasExternalWeakLinkage()) continue;
927 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
931 if (MAI->hasSetDirective()) {
932 OutStreamer.AddBlankLine();
933 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
935 MCSymbol *Name = Mang->getSymbol(I);
937 const GlobalValue *GV = I->getAliasedGlobal();
938 MCSymbol *Target = Mang->getSymbol(GV);
940 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
941 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
942 else if (I->hasWeakLinkage() || I->hasLinkOnceLinkage())
943 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
945 assert(I->hasLocalLinkage() && "Invalid alias linkage");
947 EmitVisibility(Name, I->getVisibility());
949 // Emit the directives as assignments aka .set:
950 OutStreamer.EmitAssignment(Name,
951 MCSymbolRefExpr::Create(Target, OutContext));
955 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
956 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
957 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
958 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
959 MP->finishAssembly(*this);
961 // Emit llvm.ident metadata in an '.ident' directive.
964 // If we don't have any trampolines, then we don't require stack memory
965 // to be executable. Some targets have a directive to declare this.
966 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
967 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
968 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
969 OutStreamer.SwitchSection(S);
971 // Allow the target to emit any magic that it wants at the end of the file,
972 // after everything else has gone out.
975 delete Mang; Mang = 0;
978 OutStreamer.Finish();
984 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
986 // Get the function symbol.
987 CurrentFnSym = Mang->getSymbol(MF.getFunction());
988 CurrentFnSymForSize = CurrentFnSym;
991 LI = &getAnalysis<MachineLoopInfo>();
995 // SectionCPs - Keep track the alignment, constpool entries per Section.
999 SmallVector<unsigned, 4> CPEs;
1000 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1004 /// EmitConstantPool - Print to the current output stream assembly
1005 /// representations of the constants in the constant pool MCP. This is
1006 /// used to print out constants which have been "spilled to memory" by
1007 /// the code generator.
1009 void AsmPrinter::EmitConstantPool() {
1010 const MachineConstantPool *MCP = MF->getConstantPool();
1011 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1012 if (CP.empty()) return;
1014 // Calculate sections for constant pool entries. We collect entries to go into
1015 // the same section together to reduce amount of section switch statements.
1016 SmallVector<SectionCPs, 4> CPSections;
1017 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1018 const MachineConstantPoolEntry &CPE = CP[i];
1019 unsigned Align = CPE.getAlignment();
1022 switch (CPE.getRelocationInfo()) {
1023 default: llvm_unreachable("Unknown section kind");
1024 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
1026 Kind = SectionKind::getReadOnlyWithRelLocal();
1029 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) {
1030 case 4: Kind = SectionKind::getMergeableConst4(); break;
1031 case 8: Kind = SectionKind::getMergeableConst8(); break;
1032 case 16: Kind = SectionKind::getMergeableConst16();break;
1033 default: Kind = SectionKind::getMergeableConst(); break;
1037 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
1039 // The number of sections are small, just do a linear search from the
1040 // last section to the first.
1042 unsigned SecIdx = CPSections.size();
1043 while (SecIdx != 0) {
1044 if (CPSections[--SecIdx].S == S) {
1050 SecIdx = CPSections.size();
1051 CPSections.push_back(SectionCPs(S, Align));
1054 if (Align > CPSections[SecIdx].Alignment)
1055 CPSections[SecIdx].Alignment = Align;
1056 CPSections[SecIdx].CPEs.push_back(i);
1059 // Now print stuff into the calculated sections.
1060 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1061 OutStreamer.SwitchSection(CPSections[i].S);
1062 EmitAlignment(Log2_32(CPSections[i].Alignment));
1064 unsigned Offset = 0;
1065 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1066 unsigned CPI = CPSections[i].CPEs[j];
1067 MachineConstantPoolEntry CPE = CP[CPI];
1069 // Emit inter-object padding for alignment.
1070 unsigned AlignMask = CPE.getAlignment() - 1;
1071 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1072 OutStreamer.EmitZeros(NewOffset - Offset);
1074 Type *Ty = CPE.getType();
1075 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty);
1076 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1078 if (CPE.isMachineConstantPoolEntry())
1079 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1081 EmitGlobalConstant(CPE.Val.ConstVal);
1086 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1087 /// by the current function to the current output stream.
1089 void AsmPrinter::EmitJumpTableInfo() {
1090 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1091 if (MJTI == 0) return;
1092 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1093 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1094 if (JT.empty()) return;
1096 // Pick the directive to use to print the jump table entries, and switch to
1097 // the appropriate section.
1098 const Function *F = MF->getFunction();
1099 bool JTInDiffSection = false;
1100 if (// In PIC mode, we need to emit the jump table to the same section as the
1101 // function body itself, otherwise the label differences won't make sense.
1102 // FIXME: Need a better predicate for this: what about custom entries?
1103 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1104 // We should also do if the section name is NULL or function is declared
1105 // in discardable section
1106 // FIXME: this isn't the right predicate, should be based on the MCSection
1107 // for the function.
1108 F->isWeakForLinker()) {
1109 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
1111 // Otherwise, drop it in the readonly section.
1112 const MCSection *ReadOnlySection =
1113 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1114 OutStreamer.SwitchSection(ReadOnlySection);
1115 JTInDiffSection = true;
1118 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout())));
1120 // Jump tables in code sections are marked with a data_region directive
1121 // where that's supported.
1122 if (!JTInDiffSection)
1123 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1125 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1126 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1128 // If this jump table was deleted, ignore it.
1129 if (JTBBs.empty()) continue;
1131 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1132 // .set directive for each unique entry. This reduces the number of
1133 // relocations the assembler will generate for the jump table.
1134 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1135 MAI->hasSetDirective()) {
1136 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1137 const TargetLowering *TLI = TM.getTargetLowering();
1138 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1139 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1140 const MachineBasicBlock *MBB = JTBBs[ii];
1141 if (!EmittedSets.insert(MBB)) continue;
1143 // .set LJTSet, LBB32-base
1145 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1146 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1147 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1151 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1152 // before each jump table. The first label is never referenced, but tells
1153 // the assembler and linker the extents of the jump table object. The
1154 // second label is actually referenced by the code.
1155 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1156 // FIXME: This doesn't have to have any specific name, just any randomly
1157 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1158 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1160 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1162 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1163 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1165 if (!JTInDiffSection)
1166 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1169 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1171 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1172 const MachineBasicBlock *MBB,
1173 unsigned UID) const {
1174 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1175 const MCExpr *Value = 0;
1176 switch (MJTI->getEntryKind()) {
1177 case MachineJumpTableInfo::EK_Inline:
1178 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1179 case MachineJumpTableInfo::EK_Custom32:
1180 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1183 case MachineJumpTableInfo::EK_BlockAddress:
1184 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1186 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1188 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1189 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1190 // with a relocation as gp-relative, e.g.:
1192 MCSymbol *MBBSym = MBB->getSymbol();
1193 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1197 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1198 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1199 // with a relocation as gp-relative, e.g.:
1201 MCSymbol *MBBSym = MBB->getSymbol();
1202 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1206 case MachineJumpTableInfo::EK_LabelDifference32: {
1207 // EK_LabelDifference32 - Each entry is the address of the block minus
1208 // the address of the jump table. This is used for PIC jump tables where
1209 // gprel32 is not supported. e.g.:
1210 // .word LBB123 - LJTI1_2
1211 // If the .set directive is supported, this is emitted as:
1212 // .set L4_5_set_123, LBB123 - LJTI1_2
1213 // .word L4_5_set_123
1215 // If we have emitted set directives for the jump table entries, print
1216 // them rather than the entries themselves. If we're emitting PIC, then
1217 // emit the table entries as differences between two text section labels.
1218 if (MAI->hasSetDirective()) {
1219 // If we used .set, reference the .set's symbol.
1220 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1224 // Otherwise, use the difference as the jump table entry.
1225 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1226 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1227 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1232 assert(Value && "Unknown entry kind!");
1234 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout());
1235 OutStreamer.EmitValue(Value, EntrySize);
1239 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1240 /// special global used by LLVM. If so, emit it and return true, otherwise
1241 /// do nothing and return false.
1242 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1243 if (GV->getName() == "llvm.used") {
1244 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1245 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1249 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1250 if (GV->getSection() == "llvm.metadata" ||
1251 GV->hasAvailableExternallyLinkage())
1254 if (!GV->hasAppendingLinkage()) return false;
1256 assert(GV->hasInitializer() && "Not a special LLVM global!");
1258 if (GV->getName() == "llvm.global_ctors") {
1259 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1261 if (TM.getRelocationModel() == Reloc::Static &&
1262 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1263 StringRef Sym(".constructors_used");
1264 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1270 if (GV->getName() == "llvm.global_dtors") {
1271 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1273 if (TM.getRelocationModel() == Reloc::Static &&
1274 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1275 StringRef Sym(".destructors_used");
1276 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1285 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1286 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1287 /// is true, as being used with this directive.
1288 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1289 // Should be an array of 'i8*'.
1290 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1291 const GlobalValue *GV =
1292 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1293 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1294 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1298 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1300 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1301 // Should be an array of '{ int, void ()* }' structs. The first value is the
1303 if (!isa<ConstantArray>(List)) return;
1305 // Sanity check the structors list.
1306 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1307 if (!InitList) return; // Not an array!
1308 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1309 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs!
1310 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1311 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1313 // Gather the structors in a form that's convenient for sorting by priority.
1314 typedef std::pair<unsigned, Constant *> Structor;
1315 SmallVector<Structor, 8> Structors;
1316 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1317 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i));
1318 if (!CS) continue; // Malformed.
1319 if (CS->getOperand(1)->isNullValue())
1320 break; // Found a null terminator, skip the rest.
1321 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1322 if (!Priority) continue; // Malformed.
1323 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535),
1324 CS->getOperand(1)));
1327 // Emit the function pointers in the target-specific order
1328 const DataLayout *DL = TM.getDataLayout();
1329 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1330 std::stable_sort(Structors.begin(), Structors.end(), less_first());
1331 for (unsigned i = 0, e = Structors.size(); i != e; ++i) {
1332 const MCSection *OutputSection =
1334 getObjFileLowering().getStaticCtorSection(Structors[i].first) :
1335 getObjFileLowering().getStaticDtorSection(Structors[i].first));
1336 OutStreamer.SwitchSection(OutputSection);
1337 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1338 EmitAlignment(Align);
1339 EmitXXStructor(Structors[i].second);
1343 void AsmPrinter::EmitModuleIdents(Module &M) {
1344 if (!MAI->hasIdentDirective())
1347 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1348 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1349 const MDNode *N = NMD->getOperand(i);
1350 assert(N->getNumOperands() == 1 &&
1351 "llvm.ident metadata entry can have only one operand");
1352 const MDString *S = cast<MDString>(N->getOperand(0));
1353 OutStreamer.EmitIdent(S->getString());
1358 //===--------------------------------------------------------------------===//
1359 // Emission and print routines
1362 /// EmitInt8 - Emit a byte directive and value.
1364 void AsmPrinter::EmitInt8(int Value) const {
1365 OutStreamer.EmitIntValue(Value, 1);
1368 /// EmitInt16 - Emit a short directive and value.
1370 void AsmPrinter::EmitInt16(int Value) const {
1371 OutStreamer.EmitIntValue(Value, 2);
1374 /// EmitInt32 - Emit a long directive and value.
1376 void AsmPrinter::EmitInt32(int Value) const {
1377 OutStreamer.EmitIntValue(Value, 4);
1380 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1381 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1382 /// labels. This implicitly uses .set if it is available.
1383 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1384 unsigned Size) const {
1385 // Get the Hi-Lo expression.
1386 const MCExpr *Diff =
1387 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1388 MCSymbolRefExpr::Create(Lo, OutContext),
1391 if (!MAI->hasSetDirective()) {
1392 OutStreamer.EmitValue(Diff, Size);
1396 // Otherwise, emit with .set (aka assignment).
1397 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1398 OutStreamer.EmitAssignment(SetLabel, Diff);
1399 OutStreamer.EmitSymbolValue(SetLabel, Size);
1402 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1403 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1404 /// specify the labels. This implicitly uses .set if it is available.
1405 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1406 const MCSymbol *Lo, unsigned Size)
1409 // Emit Hi+Offset - Lo
1410 // Get the Hi+Offset expression.
1411 const MCExpr *Plus =
1412 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1413 MCConstantExpr::Create(Offset, OutContext),
1416 // Get the Hi+Offset-Lo expression.
1417 const MCExpr *Diff =
1418 MCBinaryExpr::CreateSub(Plus,
1419 MCSymbolRefExpr::Create(Lo, OutContext),
1422 if (!MAI->hasSetDirective())
1423 OutStreamer.EmitValue(Diff, 4);
1425 // Otherwise, emit with .set (aka assignment).
1426 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1427 OutStreamer.EmitAssignment(SetLabel, Diff);
1428 OutStreamer.EmitSymbolValue(SetLabel, 4);
1432 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1433 /// where the size in bytes of the directive is specified by Size and Label
1434 /// specifies the label. This implicitly uses .set if it is available.
1435 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1436 unsigned Size, bool IsSectionRelative)
1438 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1439 OutStreamer.EmitCOFFSecRel32(Label);
1443 // Emit Label+Offset (or just Label if Offset is zero)
1444 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1446 Expr = MCBinaryExpr::CreateAdd(Expr,
1447 MCConstantExpr::Create(Offset, OutContext),
1450 OutStreamer.EmitValue(Expr, Size);
1454 //===----------------------------------------------------------------------===//
1456 // EmitAlignment - Emit an alignment directive to the specified power of
1457 // two boundary. For example, if you pass in 3 here, you will get an 8
1458 // byte alignment. If a global value is specified, and if that global has
1459 // an explicit alignment requested, it will override the alignment request
1460 // if required for correctness.
1462 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1463 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits);
1465 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1467 if (getCurrentSection()->getKind().isText())
1468 OutStreamer.EmitCodeAlignment(1 << NumBits);
1470 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1473 //===----------------------------------------------------------------------===//
1474 // Constant emission.
1475 //===----------------------------------------------------------------------===//
1477 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1479 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1480 MCContext &Ctx = AP.OutContext;
1482 if (CV->isNullValue() || isa<UndefValue>(CV))
1483 return MCConstantExpr::Create(0, Ctx);
1485 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1486 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1488 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1489 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1491 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1492 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1494 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1496 llvm_unreachable("Unknown constant value to lower!");
1499 switch (CE->getOpcode()) {
1501 // If the code isn't optimized, there may be outstanding folding
1502 // opportunities. Attempt to fold the expression using DataLayout as a
1503 // last resort before giving up.
1505 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout()))
1507 return lowerConstant(C, AP);
1509 // Otherwise report the problem to the user.
1512 raw_string_ostream OS(S);
1513 OS << "Unsupported expression in static initializer: ";
1514 WriteAsOperand(OS, CE, /*PrintType=*/false,
1515 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1516 report_fatal_error(OS.str());
1518 case Instruction::GetElementPtr: {
1519 const DataLayout &DL = *AP.TM.getDataLayout();
1520 // Generate a symbolic expression for the byte address
1521 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1522 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1524 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1528 int64_t Offset = OffsetAI.getSExtValue();
1529 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1533 case Instruction::Trunc:
1534 // We emit the value and depend on the assembler to truncate the generated
1535 // expression properly. This is important for differences between
1536 // blockaddress labels. Since the two labels are in the same function, it
1537 // is reasonable to treat their delta as a 32-bit value.
1539 case Instruction::BitCast:
1540 return lowerConstant(CE->getOperand(0), AP);
1542 case Instruction::IntToPtr: {
1543 const DataLayout &DL = *AP.TM.getDataLayout();
1544 // Handle casts to pointers by changing them into casts to the appropriate
1545 // integer type. This promotes constant folding and simplifies this code.
1546 Constant *Op = CE->getOperand(0);
1547 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1549 return lowerConstant(Op, AP);
1552 case Instruction::PtrToInt: {
1553 const DataLayout &DL = *AP.TM.getDataLayout();
1554 // Support only foldable casts to/from pointers that can be eliminated by
1555 // changing the pointer to the appropriately sized integer type.
1556 Constant *Op = CE->getOperand(0);
1557 Type *Ty = CE->getType();
1559 const MCExpr *OpExpr = lowerConstant(Op, AP);
1561 // We can emit the pointer value into this slot if the slot is an
1562 // integer slot equal to the size of the pointer.
1563 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1566 // Otherwise the pointer is smaller than the resultant integer, mask off
1567 // the high bits so we are sure to get a proper truncation if the input is
1569 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1570 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1571 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1574 // The MC library also has a right-shift operator, but it isn't consistently
1575 // signed or unsigned between different targets.
1576 case Instruction::Add:
1577 case Instruction::Sub:
1578 case Instruction::Mul:
1579 case Instruction::SDiv:
1580 case Instruction::SRem:
1581 case Instruction::Shl:
1582 case Instruction::And:
1583 case Instruction::Or:
1584 case Instruction::Xor: {
1585 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1586 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1587 switch (CE->getOpcode()) {
1588 default: llvm_unreachable("Unknown binary operator constant cast expr");
1589 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1590 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1591 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1592 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1593 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1594 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1595 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1596 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1597 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1603 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1605 /// isRepeatedByteSequence - Determine whether the given value is
1606 /// composed of a repeated sequence of identical bytes and return the
1607 /// byte value. If it is not a repeated sequence, return -1.
1608 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1609 StringRef Data = V->getRawDataValues();
1610 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1612 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1613 if (Data[i] != C) return -1;
1614 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1618 /// isRepeatedByteSequence - Determine whether the given value is
1619 /// composed of a repeated sequence of identical bytes and return the
1620 /// byte value. If it is not a repeated sequence, return -1.
1621 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1623 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1624 if (CI->getBitWidth() > 64) return -1;
1626 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType());
1627 uint64_t Value = CI->getZExtValue();
1629 // Make sure the constant is at least 8 bits long and has a power
1630 // of 2 bit width. This guarantees the constant bit width is
1631 // always a multiple of 8 bits, avoiding issues with padding out
1632 // to Size and other such corner cases.
1633 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1635 uint8_t Byte = static_cast<uint8_t>(Value);
1637 for (unsigned i = 1; i < Size; ++i) {
1639 if (static_cast<uint8_t>(Value) != Byte) return -1;
1643 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1644 // Make sure all array elements are sequences of the same repeated
1646 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1647 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1648 if (Byte == -1) return -1;
1650 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1651 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1652 if (ThisByte == -1) return -1;
1653 if (Byte != ThisByte) return -1;
1658 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1659 return isRepeatedByteSequence(CDS);
1664 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1667 // See if we can aggregate this into a .fill, if so, emit it as such.
1668 int Value = isRepeatedByteSequence(CDS, AP.TM);
1670 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType());
1671 // Don't emit a 1-byte object as a .fill.
1673 return AP.OutStreamer.EmitFill(Bytes, Value);
1676 // If this can be emitted with .ascii/.asciz, emit it as such.
1677 if (CDS->isString())
1678 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1680 // Otherwise, emit the values in successive locations.
1681 unsigned ElementByteSize = CDS->getElementByteSize();
1682 if (isa<IntegerType>(CDS->getElementType())) {
1683 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1685 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1686 CDS->getElementAsInteger(i));
1687 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1690 } else if (ElementByteSize == 4) {
1691 // FP Constants are printed as integer constants to avoid losing
1693 assert(CDS->getElementType()->isFloatTy());
1694 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1700 F = CDS->getElementAsFloat(i);
1702 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1703 AP.OutStreamer.EmitIntValue(I, 4);
1706 assert(CDS->getElementType()->isDoubleTy());
1707 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1713 F = CDS->getElementAsDouble(i);
1715 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1716 AP.OutStreamer.EmitIntValue(I, 8);
1720 const DataLayout &DL = *AP.TM.getDataLayout();
1721 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1722 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1723 CDS->getNumElements();
1724 if (unsigned Padding = Size - EmittedSize)
1725 AP.OutStreamer.EmitZeros(Padding);
1729 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1730 // See if we can aggregate some values. Make sure it can be
1731 // represented as a series of bytes of the constant value.
1732 int Value = isRepeatedByteSequence(CA, AP.TM);
1735 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType());
1736 AP.OutStreamer.EmitFill(Bytes, Value);
1739 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1740 emitGlobalConstantImpl(CA->getOperand(i), AP);
1744 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1745 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1746 emitGlobalConstantImpl(CV->getOperand(i), AP);
1748 const DataLayout &DL = *AP.TM.getDataLayout();
1749 unsigned Size = DL.getTypeAllocSize(CV->getType());
1750 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1751 CV->getType()->getNumElements();
1752 if (unsigned Padding = Size - EmittedSize)
1753 AP.OutStreamer.EmitZeros(Padding);
1756 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1757 // Print the fields in successive locations. Pad to align if needed!
1758 const DataLayout *DL = AP.TM.getDataLayout();
1759 unsigned Size = DL->getTypeAllocSize(CS->getType());
1760 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1761 uint64_t SizeSoFar = 0;
1762 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1763 const Constant *Field = CS->getOperand(i);
1765 // Check if padding is needed and insert one or more 0s.
1766 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1767 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1768 - Layout->getElementOffset(i)) - FieldSize;
1769 SizeSoFar += FieldSize + PadSize;
1771 // Now print the actual field value.
1772 emitGlobalConstantImpl(Field, AP);
1774 // Insert padding - this may include padding to increase the size of the
1775 // current field up to the ABI size (if the struct is not packed) as well
1776 // as padding to ensure that the next field starts at the right offset.
1777 AP.OutStreamer.EmitZeros(PadSize);
1779 assert(SizeSoFar == Layout->getSizeInBytes() &&
1780 "Layout of constant struct may be incorrect!");
1783 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1784 APInt API = CFP->getValueAPF().bitcastToAPInt();
1786 // First print a comment with what we think the original floating-point value
1787 // should have been.
1788 if (AP.isVerbose()) {
1789 SmallString<8> StrVal;
1790 CFP->getValueAPF().toString(StrVal);
1792 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1793 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1796 // Now iterate through the APInt chunks, emitting them in endian-correct
1797 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1799 unsigned NumBytes = API.getBitWidth() / 8;
1800 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1801 const uint64_t *p = API.getRawData();
1803 // PPC's long double has odd notions of endianness compared to how LLVM
1804 // handles it: p[0] goes first for *big* endian on PPC.
1805 if (AP.TM.getDataLayout()->isBigEndian() != CFP->getType()->isPPC_FP128Ty()) {
1806 int Chunk = API.getNumWords() - 1;
1809 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1811 for (; Chunk >= 0; --Chunk)
1812 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1815 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1816 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1819 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1822 // Emit the tail padding for the long double.
1823 const DataLayout &DL = *AP.TM.getDataLayout();
1824 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1825 DL.getTypeStoreSize(CFP->getType()));
1828 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1829 const DataLayout *DL = AP.TM.getDataLayout();
1830 unsigned BitWidth = CI->getBitWidth();
1832 // Copy the value as we may massage the layout for constants whose bit width
1833 // is not a multiple of 64-bits.
1834 APInt Realigned(CI->getValue());
1835 uint64_t ExtraBits = 0;
1836 unsigned ExtraBitsSize = BitWidth & 63;
1838 if (ExtraBitsSize) {
1839 // The bit width of the data is not a multiple of 64-bits.
1840 // The extra bits are expected to be at the end of the chunk of the memory.
1842 // * Nothing to be done, just record the extra bits to emit.
1844 // * Record the extra bits to emit.
1845 // * Realign the raw data to emit the chunks of 64-bits.
1846 if (DL->isBigEndian()) {
1847 // Basically the structure of the raw data is a chunk of 64-bits cells:
1848 // 0 1 BitWidth / 64
1849 // [chunk1][chunk2] ... [chunkN].
1850 // The most significant chunk is chunkN and it should be emitted first.
1851 // However, due to the alignment issue chunkN contains useless bits.
1852 // Realign the chunks so that they contain only useless information:
1853 // ExtraBits 0 1 (BitWidth / 64) - 1
1854 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1855 ExtraBits = Realigned.getRawData()[0] &
1856 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1857 Realigned = Realigned.lshr(ExtraBitsSize);
1859 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1862 // We don't expect assemblers to support integer data directives
1863 // for more than 64 bits, so we emit the data in at most 64-bit
1864 // quantities at a time.
1865 const uint64_t *RawData = Realigned.getRawData();
1866 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1867 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1868 AP.OutStreamer.EmitIntValue(Val, 8);
1871 if (ExtraBitsSize) {
1872 // Emit the extra bits after the 64-bits chunks.
1874 // Emit a directive that fills the expected size.
1875 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(CI->getType());
1876 Size -= (BitWidth / 64) * 8;
1877 assert(Size && Size * 8 >= ExtraBitsSize &&
1878 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1879 == ExtraBits && "Directive too small for extra bits.");
1880 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1884 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1885 const DataLayout *DL = AP.TM.getDataLayout();
1886 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1887 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1888 return AP.OutStreamer.EmitZeros(Size);
1890 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1897 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1898 CI->getZExtValue());
1899 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1902 emitGlobalConstantLargeInt(CI, AP);
1907 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1908 return emitGlobalConstantFP(CFP, AP);
1910 if (isa<ConstantPointerNull>(CV)) {
1911 AP.OutStreamer.EmitIntValue(0, Size);
1915 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1916 return emitGlobalConstantDataSequential(CDS, AP);
1918 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1919 return emitGlobalConstantArray(CVA, AP);
1921 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1922 return emitGlobalConstantStruct(CVS, AP);
1924 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
1925 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
1927 if (CE->getOpcode() == Instruction::BitCast)
1928 return emitGlobalConstantImpl(CE->getOperand(0), AP);
1931 // If the constant expression's size is greater than 64-bits, then we have
1932 // to emit the value in chunks. Try to constant fold the value and emit it
1934 Constant *New = ConstantFoldConstantExpression(CE, DL);
1935 if (New && New != CE)
1936 return emitGlobalConstantImpl(New, AP);
1940 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1941 return emitGlobalConstantVector(V, AP);
1943 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1944 // thread the streamer with EmitValue.
1945 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
1948 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1949 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
1950 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType());
1952 emitGlobalConstantImpl(CV, *this);
1953 else if (MAI->hasSubsectionsViaSymbols()) {
1954 // If the global has zero size, emit a single byte so that two labels don't
1955 // look like they are at the same location.
1956 OutStreamer.EmitIntValue(0, 1);
1960 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1961 // Target doesn't support this yet!
1962 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1965 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1967 OS << '+' << Offset;
1968 else if (Offset < 0)
1972 //===----------------------------------------------------------------------===//
1973 // Symbol Lowering Routines.
1974 //===----------------------------------------------------------------------===//
1976 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1977 /// temporary label with the specified stem and unique ID.
1978 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1979 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1983 /// GetTempSymbol - Return an assembler temporary label with the specified
1985 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1986 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1991 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1992 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1995 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1996 return MMI->getAddrLabelSymbol(BB);
1999 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2000 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2001 return OutContext.GetOrCreateSymbol
2002 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2003 + "_" + Twine(CPID));
2006 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2007 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2008 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2011 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2012 /// FIXME: privatize to AsmPrinter.
2013 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2014 return OutContext.GetOrCreateSymbol
2015 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2016 Twine(UID) + "_set_" + Twine(MBBID));
2019 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
2020 /// global value name as its base, with the specified suffix, and where the
2021 /// symbol is forced to have private linkage if ForcePrivate is true.
2022 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
2024 bool ForcePrivate) const {
2025 SmallString<60> NameStr;
2026 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
2027 NameStr.append(Suffix.begin(), Suffix.end());
2028 return OutContext.GetOrCreateSymbol(NameStr.str());
2031 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2033 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2034 SmallString<60> NameStr;
2035 Mang->getNameWithPrefix(NameStr, Sym);
2036 return OutContext.GetOrCreateSymbol(NameStr.str());
2041 /// PrintParentLoopComment - Print comments about parent loops of this one.
2042 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2043 unsigned FunctionNumber) {
2044 if (Loop == 0) return;
2045 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2046 OS.indent(Loop->getLoopDepth()*2)
2047 << "Parent Loop BB" << FunctionNumber << "_"
2048 << Loop->getHeader()->getNumber()
2049 << " Depth=" << Loop->getLoopDepth() << '\n';
2053 /// PrintChildLoopComment - Print comments about child loops within
2054 /// the loop for this basic block, with nesting.
2055 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2056 unsigned FunctionNumber) {
2057 // Add child loop information
2058 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
2059 OS.indent((*CL)->getLoopDepth()*2)
2060 << "Child Loop BB" << FunctionNumber << "_"
2061 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
2063 PrintChildLoopComment(OS, *CL, FunctionNumber);
2067 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2068 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2069 const MachineLoopInfo *LI,
2070 const AsmPrinter &AP) {
2071 // Add loop depth information
2072 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2073 if (Loop == 0) return;
2075 MachineBasicBlock *Header = Loop->getHeader();
2076 assert(Header && "No header for loop");
2078 // If this block is not a loop header, just print out what is the loop header
2080 if (Header != &MBB) {
2081 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2082 Twine(AP.getFunctionNumber())+"_" +
2083 Twine(Loop->getHeader()->getNumber())+
2084 " Depth="+Twine(Loop->getLoopDepth()));
2088 // Otherwise, it is a loop header. Print out information about child and
2090 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2092 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2095 OS.indent(Loop->getLoopDepth()*2-2);
2100 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2102 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2106 /// EmitBasicBlockStart - This method prints the label for the specified
2107 /// MachineBasicBlock, an alignment (if present) and a comment describing
2108 /// it if appropriate.
2109 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
2110 // Emit an alignment directive for this block, if needed.
2111 if (unsigned Align = MBB->getAlignment())
2112 EmitAlignment(Align);
2114 // If the block has its address taken, emit any labels that were used to
2115 // reference the block. It is possible that there is more than one label
2116 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2117 // the references were generated.
2118 if (MBB->hasAddressTaken()) {
2119 const BasicBlock *BB = MBB->getBasicBlock();
2121 OutStreamer.AddComment("Block address taken");
2123 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
2125 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
2126 OutStreamer.EmitLabel(Syms[i]);
2129 // Print some verbose block comments.
2131 if (const BasicBlock *BB = MBB->getBasicBlock())
2133 OutStreamer.AddComment("%" + BB->getName());
2134 emitBasicBlockLoopComments(*MBB, LI, *this);
2137 // Print the main label for the block.
2138 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
2139 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
2140 // NOTE: Want this comment at start of line, don't emit with AddComment.
2141 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
2142 Twine(MBB->getNumber()) + ":");
2145 OutStreamer.EmitLabel(MBB->getSymbol());
2149 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2150 bool IsDefinition) const {
2151 MCSymbolAttr Attr = MCSA_Invalid;
2153 switch (Visibility) {
2155 case GlobalValue::HiddenVisibility:
2157 Attr = MAI->getHiddenVisibilityAttr();
2159 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2161 case GlobalValue::ProtectedVisibility:
2162 Attr = MAI->getProtectedVisibilityAttr();
2166 if (Attr != MCSA_Invalid)
2167 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2170 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2171 /// exactly one predecessor and the control transfer mechanism between
2172 /// the predecessor and this block is a fall-through.
2174 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2175 // If this is a landing pad, it isn't a fall through. If it has no preds,
2176 // then nothing falls through to it.
2177 if (MBB->isLandingPad() || MBB->pred_empty())
2180 // If there isn't exactly one predecessor, it can't be a fall through.
2181 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
2183 if (PI2 != MBB->pred_end())
2186 // The predecessor has to be immediately before this block.
2187 MachineBasicBlock *Pred = *PI;
2189 if (!Pred->isLayoutSuccessor(MBB))
2192 // If the block is completely empty, then it definitely does fall through.
2196 // Check the terminators in the previous blocks
2197 for (MachineBasicBlock::iterator II = Pred->getFirstTerminator(),
2198 IE = Pred->end(); II != IE; ++II) {
2199 MachineInstr &MI = *II;
2201 // If it is not a simple branch, we are in a table somewhere.
2202 if (!MI.isBranch() || MI.isIndirectBranch())
2205 // If we are the operands of one of the branches, this is not
2207 for (MachineInstr::mop_iterator OI = MI.operands_begin(),
2208 OE = MI.operands_end(); OI != OE; ++OI) {
2209 const MachineOperand& OP = *OI;
2212 if (OP.isMBB() && OP.getMBB() == MBB)
2222 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
2223 if (!S->usesMetadata())
2226 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2227 gcp_map_type::iterator GCPI = GCMap.find(S);
2228 if (GCPI != GCMap.end())
2229 return GCPI->second;
2231 const char *Name = S->getName().c_str();
2233 for (GCMetadataPrinterRegistry::iterator
2234 I = GCMetadataPrinterRegistry::begin(),
2235 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2236 if (strcmp(Name, I->getName()) == 0) {
2237 GCMetadataPrinter *GMP = I->instantiate();
2239 GCMap.insert(std::make_pair(S, GMP));
2243 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));