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 Linkage, MCSymbol *GVSym) const {
216 switch ((GlobalValue::LinkageTypes)Linkage) {
217 case GlobalValue::CommonLinkage:
218 case GlobalValue::LinkOnceAnyLinkage:
219 case GlobalValue::LinkOnceODRLinkage:
220 case GlobalValue::LinkOnceODRAutoHideLinkage:
221 case GlobalValue::WeakAnyLinkage:
222 case GlobalValue::WeakODRLinkage:
223 case GlobalValue::LinkerPrivateWeakLinkage:
224 if (MAI->getWeakDefDirective() != 0) {
226 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
228 if ((GlobalValue::LinkageTypes)Linkage !=
229 GlobalValue::LinkOnceODRAutoHideLinkage)
230 // .weak_definition _foo
231 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
233 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
234 } else if (MAI->getLinkOnceDirective() != 0) {
236 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
237 //NOTE: linkonce is handled by the section the symbol was assigned to.
240 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
243 case GlobalValue::DLLExportLinkage:
244 case GlobalValue::AppendingLinkage:
245 // FIXME: appending linkage variables should go into a section of
246 // their name or something. For now, just emit them as external.
247 case GlobalValue::ExternalLinkage:
248 // If external or appending, declare as a global symbol.
250 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
252 case GlobalValue::PrivateLinkage:
253 case GlobalValue::InternalLinkage:
254 case GlobalValue::LinkerPrivateLinkage:
257 llvm_unreachable("Unknown linkage type!");
262 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
263 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
264 if (GV->hasInitializer()) {
265 // Check to see if this is a special global used by LLVM, if so, emit it.
266 if (EmitSpecialLLVMGlobal(GV))
270 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
271 /*PrintType=*/false, GV->getParent());
272 OutStreamer.GetCommentOS() << '\n';
276 MCSymbol *GVSym = Mang->getSymbol(GV);
277 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
279 if (!GV->hasInitializer()) // External globals require no extra code.
282 if (MAI->hasDotTypeDotSizeDirective())
283 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
285 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
287 const DataLayout *DL = TM.getDataLayout();
288 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
290 // If the alignment is specified, we *must* obey it. Overaligning a global
291 // with a specified alignment is a prompt way to break globals emitted to
292 // sections and expected to be contiguous (e.g. ObjC metadata).
293 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
296 DD->setSymbolSize(GVSym, Size);
298 // Handle common and BSS local symbols (.lcomm).
299 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
300 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
301 unsigned Align = 1 << AlignLog;
303 // Handle common symbols.
304 if (GVKind.isCommon()) {
305 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
309 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
313 // Handle local BSS symbols.
314 if (MAI->hasMachoZeroFillDirective()) {
315 const MCSection *TheSection =
316 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
317 // .zerofill __DATA, __bss, _foo, 400, 5
318 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
322 // Use .lcomm only if it supports user-specified alignment.
323 // Otherwise, while it would still be correct to use .lcomm in some
324 // cases (e.g. when Align == 1), the external assembler might enfore
325 // some -unknown- default alignment behavior, which could cause
326 // spurious differences between external and integrated assembler.
327 // Prefer to simply fall back to .local / .comm in this case.
328 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
330 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
334 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
338 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
340 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
344 const MCSection *TheSection =
345 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
347 // Handle the zerofill directive on darwin, which is a special form of BSS
349 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
350 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
353 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
354 // .zerofill __DATA, __common, _foo, 400, 5
355 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
359 // Handle thread local data for mach-o which requires us to output an
360 // additional structure of data and mangle the original symbol so that we
361 // can reference it later.
363 // TODO: This should become an "emit thread local global" method on TLOF.
364 // All of this macho specific stuff should be sunk down into TLOFMachO and
365 // stuff like "TLSExtraDataSection" should no longer be part of the parent
366 // TLOF class. This will also make it more obvious that stuff like
367 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
369 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
370 // Emit the .tbss symbol
372 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
374 if (GVKind.isThreadBSS()) {
375 TheSection = getObjFileLowering().getTLSBSSSection();
376 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
377 } else if (GVKind.isThreadData()) {
378 OutStreamer.SwitchSection(TheSection);
380 EmitAlignment(AlignLog, GV);
381 OutStreamer.EmitLabel(MangSym);
383 EmitGlobalConstant(GV->getInitializer());
386 OutStreamer.AddBlankLine();
388 // Emit the variable struct for the runtime.
389 const MCSection *TLVSect
390 = getObjFileLowering().getTLSExtraDataSection();
392 OutStreamer.SwitchSection(TLVSect);
393 // Emit the linkage here.
394 EmitLinkage(GV->getLinkage(), GVSym);
395 OutStreamer.EmitLabel(GVSym);
397 // Three pointers in size:
398 // - __tlv_bootstrap - used to make sure support exists
399 // - spare pointer, used when mapped by the runtime
400 // - pointer to mangled symbol above with initializer
401 unsigned PtrSize = DL->getPointerSizeInBits()/8;
402 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
404 OutStreamer.EmitIntValue(0, PtrSize);
405 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
407 OutStreamer.AddBlankLine();
411 OutStreamer.SwitchSection(TheSection);
413 EmitLinkage(GV->getLinkage(), GVSym);
414 EmitAlignment(AlignLog, GV);
416 OutStreamer.EmitLabel(GVSym);
418 EmitGlobalConstant(GV->getInitializer());
420 if (MAI->hasDotTypeDotSizeDirective())
422 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
424 OutStreamer.AddBlankLine();
427 /// EmitFunctionHeader - This method emits the header for the current
429 void AsmPrinter::EmitFunctionHeader() {
430 // Print out constants referenced by the function
433 // Print the 'header' of function.
434 const Function *F = MF->getFunction();
436 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
437 EmitVisibility(CurrentFnSym, F->getVisibility());
439 EmitLinkage(F->getLinkage(), CurrentFnSym);
440 EmitAlignment(MF->getAlignment(), F);
442 if (MAI->hasDotTypeDotSizeDirective())
443 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
446 WriteAsOperand(OutStreamer.GetCommentOS(), F,
447 /*PrintType=*/false, F->getParent());
448 OutStreamer.GetCommentOS() << '\n';
451 // Emit the CurrentFnSym. This is a virtual function to allow targets to
452 // do their wild and crazy things as required.
453 EmitFunctionEntryLabel();
455 // If the function had address-taken blocks that got deleted, then we have
456 // references to the dangling symbols. Emit them at the start of the function
457 // so that we don't get references to undefined symbols.
458 std::vector<MCSymbol*> DeadBlockSyms;
459 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
460 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
461 OutStreamer.AddComment("Address taken block that was later removed");
462 OutStreamer.EmitLabel(DeadBlockSyms[i]);
465 // Emit the prefix data.
466 if (F->hasPrefixData())
467 EmitGlobalConstant(F->getPrefixData());
469 // Emit pre-function debug and/or EH information.
471 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
472 DE->BeginFunction(MF);
475 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
476 DD->beginFunction(MF);
480 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
481 /// function. This can be overridden by targets as required to do custom stuff.
482 void AsmPrinter::EmitFunctionEntryLabel() {
483 // The function label could have already been emitted if two symbols end up
484 // conflicting due to asm renaming. Detect this and emit an error.
485 if (CurrentFnSym->isUndefined())
486 return OutStreamer.EmitLabel(CurrentFnSym);
488 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
489 "' label emitted multiple times to assembly file");
492 /// emitComments - Pretty-print comments for instructions.
493 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
494 const MachineFunction *MF = MI.getParent()->getParent();
495 const TargetMachine &TM = MF->getTarget();
497 // Check for spills and reloads
500 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
502 // We assume a single instruction only has a spill or reload, not
504 const MachineMemOperand *MMO;
505 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
506 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
507 MMO = *MI.memoperands_begin();
508 CommentOS << MMO->getSize() << "-byte Reload\n";
510 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
511 if (FrameInfo->isSpillSlotObjectIndex(FI))
512 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
513 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
514 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
515 MMO = *MI.memoperands_begin();
516 CommentOS << MMO->getSize() << "-byte Spill\n";
518 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
519 if (FrameInfo->isSpillSlotObjectIndex(FI))
520 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
523 // Check for spill-induced copies
524 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
525 CommentOS << " Reload Reuse\n";
528 /// emitImplicitDef - This method emits the specified machine instruction
529 /// that is an implicit def.
530 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
531 unsigned RegNo = MI->getOperand(0).getReg();
532 OutStreamer.AddComment(Twine("implicit-def: ") +
533 TM.getRegisterInfo()->getName(RegNo));
534 OutStreamer.AddBlankLine();
537 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
538 std::string Str = "kill:";
539 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
540 const MachineOperand &Op = MI->getOperand(i);
541 assert(Op.isReg() && "KILL instruction must have only register operands");
543 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
544 Str += (Op.isDef() ? "<def>" : "<kill>");
546 AP.OutStreamer.AddComment(Str);
547 AP.OutStreamer.AddBlankLine();
550 /// emitDebugValueComment - This method handles the target-independent form
551 /// of DBG_VALUE, returning true if it was able to do so. A false return
552 /// means the target will need to handle MI in EmitInstruction.
553 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
554 // This code handles only the 3-operand target-independent form.
555 if (MI->getNumOperands() != 3)
558 SmallString<128> Str;
559 raw_svector_ostream OS(Str);
560 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
562 // cast away const; DIetc do not take const operands for some reason.
563 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
564 if (V.getContext().isSubprogram()) {
565 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
569 OS << V.getName() << " <- ";
571 // The second operand is only an offset if it's an immediate.
572 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
573 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
575 // Register or immediate value. Register 0 means undef.
576 if (MI->getOperand(0).isFPImm()) {
577 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
578 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
579 OS << (double)APF.convertToFloat();
580 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
581 OS << APF.convertToDouble();
583 // There is no good way to print long double. Convert a copy to
584 // double. Ah well, it's only a comment.
586 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
588 OS << "(long double) " << APF.convertToDouble();
590 } else if (MI->getOperand(0).isImm()) {
591 OS << MI->getOperand(0).getImm();
592 } else if (MI->getOperand(0).isCImm()) {
593 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
596 if (MI->getOperand(0).isReg()) {
597 Reg = MI->getOperand(0).getReg();
599 assert(MI->getOperand(0).isFI() && "Unknown operand type");
600 const TargetFrameLowering *TFI = AP.TM.getFrameLowering();
601 Offset += TFI->getFrameIndexReference(*AP.MF,
602 MI->getOperand(0).getIndex(), Reg);
606 // Suppress offset, it is not meaningful here.
608 // NOTE: Want this comment at start of line, don't emit with AddComment.
609 AP.OutStreamer.EmitRawText(OS.str());
614 OS << AP.TM.getRegisterInfo()->getName(Reg);
618 OS << '+' << Offset << ']';
620 // NOTE: Want this comment at start of line, don't emit with AddComment.
621 AP.OutStreamer.EmitRawText(OS.str());
625 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
626 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
627 MF->getFunction()->needsUnwindTableEntry())
630 if (MMI->hasDebugInfo())
636 bool AsmPrinter::needsSEHMoves() {
637 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 &&
638 MF->getFunction()->needsUnwindTableEntry();
641 bool AsmPrinter::needsRelocationsForDwarfStringPool() const {
642 return MAI->doesDwarfUseRelocationsAcrossSections();
645 void AsmPrinter::emitPrologLabel(const MachineInstr &MI) {
646 const MCSymbol *Label = MI.getOperand(0).getMCSymbol();
648 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
651 if (needsCFIMoves() == CFI_M_None)
654 if (MMI->getCompactUnwindEncoding() != 0)
655 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding());
657 const MachineModuleInfo &MMI = MF->getMMI();
658 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
659 bool FoundOne = false;
661 for (std::vector<MCCFIInstruction>::const_iterator I = Instrs.begin(),
662 E = Instrs.end(); I != E; ++I) {
663 if (I->getLabel() == Label) {
664 emitCFIInstruction(*I);
671 /// EmitFunctionBody - This method emits the body and trailer for a
673 void AsmPrinter::EmitFunctionBody() {
674 // Emit target-specific gunk before the function body.
675 EmitFunctionBodyStart();
677 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
679 // Print out code for the function.
680 bool HasAnyRealCode = false;
681 const MachineInstr *LastMI = 0;
682 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
684 // Print a label for the basic block.
685 EmitBasicBlockStart(I);
686 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
690 // Print the assembly for the instruction.
691 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
692 !II->isDebugValue()) {
693 HasAnyRealCode = true;
697 if (ShouldPrintDebugScopes) {
698 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
699 DD->beginInstruction(II);
703 emitComments(*II, OutStreamer.GetCommentOS());
705 switch (II->getOpcode()) {
706 case TargetOpcode::PROLOG_LABEL:
707 emitPrologLabel(*II);
710 case TargetOpcode::EH_LABEL:
711 case TargetOpcode::GC_LABEL:
712 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
714 case TargetOpcode::INLINEASM:
717 case TargetOpcode::DBG_VALUE:
719 if (!emitDebugValueComment(II, *this))
723 case TargetOpcode::IMPLICIT_DEF:
724 if (isVerbose()) emitImplicitDef(II);
726 case TargetOpcode::KILL:
727 if (isVerbose()) emitKill(II, *this);
730 if (!TM.hasMCUseLoc())
731 MCLineEntry::Make(&OutStreamer, getCurrentSection());
737 if (ShouldPrintDebugScopes) {
738 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
739 DD->endInstruction(II);
744 // If the last instruction was a prolog label, then we have a situation where
745 // we emitted a prolog but no function body. This results in the ending prolog
746 // label equaling the end of function label and an invalid "row" in the
747 // FDE. We need to emit a noop in this situation so that the FDE's rows are
749 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
751 // If the function is empty and the object file uses .subsections_via_symbols,
752 // then we need to emit *something* to the function body to prevent the
753 // labels from collapsing together. Just emit a noop.
754 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
756 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
757 if (Noop.getOpcode()) {
758 OutStreamer.AddComment("avoids zero-length function");
759 OutStreamer.EmitInstruction(Noop);
760 } else // Target not mc-ized yet.
761 OutStreamer.EmitRawText(StringRef("\tnop\n"));
764 const Function *F = MF->getFunction();
765 for (Function::const_iterator i = F->begin(), e = F->end(); i != e; ++i) {
766 const BasicBlock *BB = i;
767 if (!BB->hasAddressTaken())
769 MCSymbol *Sym = GetBlockAddressSymbol(BB);
770 if (Sym->isDefined())
772 OutStreamer.AddComment("Address of block that was removed by CodeGen");
773 OutStreamer.EmitLabel(Sym);
776 // Emit target-specific gunk after the function body.
777 EmitFunctionBodyEnd();
779 // If the target wants a .size directive for the size of the function, emit
781 if (MAI->hasDotTypeDotSizeDirective()) {
782 // Create a symbol for the end of function, so we can get the size as
783 // difference between the function label and the temp label.
784 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
785 OutStreamer.EmitLabel(FnEndLabel);
787 const MCExpr *SizeExp =
788 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
789 MCSymbolRefExpr::Create(CurrentFnSymForSize,
792 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
795 // Emit post-function debug information.
797 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
801 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
806 // Print out jump tables referenced by the function.
809 OutStreamer.AddBlankLine();
812 /// EmitDwarfRegOp - Emit dwarf register operation.
813 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc,
814 bool Indirect) const {
815 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
816 int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
818 for (MCSuperRegIterator SR(MLoc.getReg(), TRI); SR.isValid() && Reg < 0;
820 Reg = TRI->getDwarfRegNum(*SR, false);
821 // FIXME: Get the bit range this register uses of the superregister
822 // so that we can produce a DW_OP_bit_piece
825 // FIXME: Handle cases like a super register being encoded as
826 // DW_OP_reg 32 DW_OP_piece 4 DW_OP_reg 33
828 // FIXME: We have no reasonable way of handling errors in here. The
829 // caller might be in the middle of an dwarf expression. We should
830 // probably assert that Reg >= 0 once debug info generation is more mature.
832 if (MLoc.isIndirect() || Indirect) {
834 OutStreamer.AddComment(
835 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg));
836 EmitInt8(dwarf::DW_OP_breg0 + Reg);
838 OutStreamer.AddComment("DW_OP_bregx");
839 EmitInt8(dwarf::DW_OP_bregx);
840 OutStreamer.AddComment(Twine(Reg));
843 EmitSLEB128(!MLoc.isIndirect() ? 0 : MLoc.getOffset());
844 if (MLoc.isIndirect() && Indirect)
845 EmitInt8(dwarf::DW_OP_deref);
848 OutStreamer.AddComment(
849 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
850 EmitInt8(dwarf::DW_OP_reg0 + Reg);
852 OutStreamer.AddComment("DW_OP_regx");
853 EmitInt8(dwarf::DW_OP_regx);
854 OutStreamer.AddComment(Twine(Reg));
859 // FIXME: Produce a DW_OP_bit_piece if we used a superregister
862 bool AsmPrinter::doFinalization(Module &M) {
863 // Emit global variables.
864 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
866 EmitGlobalVariable(I);
868 // Emit visibility info for declarations
869 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
870 const Function &F = *I;
871 if (!F.isDeclaration())
873 GlobalValue::VisibilityTypes V = F.getVisibility();
874 if (V == GlobalValue::DefaultVisibility)
877 MCSymbol *Name = Mang->getSymbol(&F);
878 EmitVisibility(Name, V, false);
881 // Emit module flags.
882 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
883 M.getModuleFlagsMetadata(ModuleFlags);
884 if (!ModuleFlags.empty())
885 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, Mang, TM);
887 // Make sure we wrote out everything we need.
890 // Finalize debug and EH information.
893 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
900 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
906 // If the target wants to know about weak references, print them all.
907 if (MAI->getWeakRefDirective()) {
908 // FIXME: This is not lazy, it would be nice to only print weak references
909 // to stuff that is actually used. Note that doing so would require targets
910 // to notice uses in operands (due to constant exprs etc). This should
911 // happen with the MC stuff eventually.
913 // Print out module-level global variables here.
914 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
916 if (!I->hasExternalWeakLinkage()) continue;
917 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
920 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
921 if (!I->hasExternalWeakLinkage()) continue;
922 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
926 if (MAI->hasSetDirective()) {
927 OutStreamer.AddBlankLine();
928 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
930 MCSymbol *Name = Mang->getSymbol(I);
932 const GlobalValue *GV = I->getAliasedGlobal();
933 MCSymbol *Target = Mang->getSymbol(GV);
935 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
936 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
937 else if (I->hasWeakLinkage() || I->hasLinkOnceLinkage())
938 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
940 assert(I->hasLocalLinkage() && "Invalid alias linkage");
942 EmitVisibility(Name, I->getVisibility());
944 // Emit the directives as assignments aka .set:
945 OutStreamer.EmitAssignment(Name,
946 MCSymbolRefExpr::Create(Target, OutContext));
950 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
951 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
952 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
953 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
954 MP->finishAssembly(*this);
956 // Emit llvm.ident metadata in an '.ident' directive.
959 // If we don't have any trampolines, then we don't require stack memory
960 // to be executable. Some targets have a directive to declare this.
961 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
962 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
963 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
964 OutStreamer.SwitchSection(S);
966 // Allow the target to emit any magic that it wants at the end of the file,
967 // after everything else has gone out.
970 delete Mang; Mang = 0;
973 OutStreamer.Finish();
979 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
981 // Get the function symbol.
982 CurrentFnSym = Mang->getSymbol(MF.getFunction());
983 CurrentFnSymForSize = CurrentFnSym;
986 LI = &getAnalysis<MachineLoopInfo>();
990 // SectionCPs - Keep track the alignment, constpool entries per Section.
994 SmallVector<unsigned, 4> CPEs;
995 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
999 /// EmitConstantPool - Print to the current output stream assembly
1000 /// representations of the constants in the constant pool MCP. This is
1001 /// used to print out constants which have been "spilled to memory" by
1002 /// the code generator.
1004 void AsmPrinter::EmitConstantPool() {
1005 const MachineConstantPool *MCP = MF->getConstantPool();
1006 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1007 if (CP.empty()) return;
1009 // Calculate sections for constant pool entries. We collect entries to go into
1010 // the same section together to reduce amount of section switch statements.
1011 SmallVector<SectionCPs, 4> CPSections;
1012 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1013 const MachineConstantPoolEntry &CPE = CP[i];
1014 unsigned Align = CPE.getAlignment();
1017 switch (CPE.getRelocationInfo()) {
1018 default: llvm_unreachable("Unknown section kind");
1019 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
1021 Kind = SectionKind::getReadOnlyWithRelLocal();
1024 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) {
1025 case 4: Kind = SectionKind::getMergeableConst4(); break;
1026 case 8: Kind = SectionKind::getMergeableConst8(); break;
1027 case 16: Kind = SectionKind::getMergeableConst16();break;
1028 default: Kind = SectionKind::getMergeableConst(); break;
1032 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
1034 // The number of sections are small, just do a linear search from the
1035 // last section to the first.
1037 unsigned SecIdx = CPSections.size();
1038 while (SecIdx != 0) {
1039 if (CPSections[--SecIdx].S == S) {
1045 SecIdx = CPSections.size();
1046 CPSections.push_back(SectionCPs(S, Align));
1049 if (Align > CPSections[SecIdx].Alignment)
1050 CPSections[SecIdx].Alignment = Align;
1051 CPSections[SecIdx].CPEs.push_back(i);
1054 // Now print stuff into the calculated sections.
1055 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1056 OutStreamer.SwitchSection(CPSections[i].S);
1057 EmitAlignment(Log2_32(CPSections[i].Alignment));
1059 unsigned Offset = 0;
1060 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1061 unsigned CPI = CPSections[i].CPEs[j];
1062 MachineConstantPoolEntry CPE = CP[CPI];
1064 // Emit inter-object padding for alignment.
1065 unsigned AlignMask = CPE.getAlignment() - 1;
1066 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1067 OutStreamer.EmitZeros(NewOffset - Offset);
1069 Type *Ty = CPE.getType();
1070 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty);
1071 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1073 if (CPE.isMachineConstantPoolEntry())
1074 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1076 EmitGlobalConstant(CPE.Val.ConstVal);
1081 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1082 /// by the current function to the current output stream.
1084 void AsmPrinter::EmitJumpTableInfo() {
1085 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1086 if (MJTI == 0) return;
1087 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1088 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1089 if (JT.empty()) return;
1091 // Pick the directive to use to print the jump table entries, and switch to
1092 // the appropriate section.
1093 const Function *F = MF->getFunction();
1094 bool JTInDiffSection = false;
1095 if (// In PIC mode, we need to emit the jump table to the same section as the
1096 // function body itself, otherwise the label differences won't make sense.
1097 // FIXME: Need a better predicate for this: what about custom entries?
1098 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1099 // We should also do if the section name is NULL or function is declared
1100 // in discardable section
1101 // FIXME: this isn't the right predicate, should be based on the MCSection
1102 // for the function.
1103 F->isWeakForLinker()) {
1104 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
1106 // Otherwise, drop it in the readonly section.
1107 const MCSection *ReadOnlySection =
1108 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1109 OutStreamer.SwitchSection(ReadOnlySection);
1110 JTInDiffSection = true;
1113 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout())));
1115 // Jump tables in code sections are marked with a data_region directive
1116 // where that's supported.
1117 if (!JTInDiffSection)
1118 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1120 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1121 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1123 // If this jump table was deleted, ignore it.
1124 if (JTBBs.empty()) continue;
1126 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1127 // .set directive for each unique entry. This reduces the number of
1128 // relocations the assembler will generate for the jump table.
1129 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1130 MAI->hasSetDirective()) {
1131 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1132 const TargetLowering *TLI = TM.getTargetLowering();
1133 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1134 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1135 const MachineBasicBlock *MBB = JTBBs[ii];
1136 if (!EmittedSets.insert(MBB)) continue;
1138 // .set LJTSet, LBB32-base
1140 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1141 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1142 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1146 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1147 // before each jump table. The first label is never referenced, but tells
1148 // the assembler and linker the extents of the jump table object. The
1149 // second label is actually referenced by the code.
1150 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1151 // FIXME: This doesn't have to have any specific name, just any randomly
1152 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1153 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1155 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1157 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1158 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1160 if (!JTInDiffSection)
1161 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1164 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1166 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1167 const MachineBasicBlock *MBB,
1168 unsigned UID) const {
1169 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1170 const MCExpr *Value = 0;
1171 switch (MJTI->getEntryKind()) {
1172 case MachineJumpTableInfo::EK_Inline:
1173 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1174 case MachineJumpTableInfo::EK_Custom32:
1175 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1178 case MachineJumpTableInfo::EK_BlockAddress:
1179 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1181 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1183 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1184 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1185 // with a relocation as gp-relative, e.g.:
1187 MCSymbol *MBBSym = MBB->getSymbol();
1188 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1192 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1193 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1194 // with a relocation as gp-relative, e.g.:
1196 MCSymbol *MBBSym = MBB->getSymbol();
1197 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1201 case MachineJumpTableInfo::EK_LabelDifference32: {
1202 // EK_LabelDifference32 - Each entry is the address of the block minus
1203 // the address of the jump table. This is used for PIC jump tables where
1204 // gprel32 is not supported. e.g.:
1205 // .word LBB123 - LJTI1_2
1206 // If the .set directive is supported, this is emitted as:
1207 // .set L4_5_set_123, LBB123 - LJTI1_2
1208 // .word L4_5_set_123
1210 // If we have emitted set directives for the jump table entries, print
1211 // them rather than the entries themselves. If we're emitting PIC, then
1212 // emit the table entries as differences between two text section labels.
1213 if (MAI->hasSetDirective()) {
1214 // If we used .set, reference the .set's symbol.
1215 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1219 // Otherwise, use the difference as the jump table entry.
1220 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1221 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1222 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1227 assert(Value && "Unknown entry kind!");
1229 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout());
1230 OutStreamer.EmitValue(Value, EntrySize);
1234 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1235 /// special global used by LLVM. If so, emit it and return true, otherwise
1236 /// do nothing and return false.
1237 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1238 if (GV->getName() == "llvm.used") {
1239 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1240 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1244 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1245 if (GV->getSection() == "llvm.metadata" ||
1246 GV->hasAvailableExternallyLinkage())
1249 if (!GV->hasAppendingLinkage()) return false;
1251 assert(GV->hasInitializer() && "Not a special LLVM global!");
1253 if (GV->getName() == "llvm.global_ctors") {
1254 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1256 if (TM.getRelocationModel() == Reloc::Static &&
1257 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1258 StringRef Sym(".constructors_used");
1259 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1265 if (GV->getName() == "llvm.global_dtors") {
1266 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1268 if (TM.getRelocationModel() == Reloc::Static &&
1269 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1270 StringRef Sym(".destructors_used");
1271 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1280 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1281 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1282 /// is true, as being used with this directive.
1283 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1284 // Should be an array of 'i8*'.
1285 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1286 const GlobalValue *GV =
1287 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1288 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1289 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1293 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1295 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1296 // Should be an array of '{ int, void ()* }' structs. The first value is the
1298 if (!isa<ConstantArray>(List)) return;
1300 // Sanity check the structors list.
1301 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1302 if (!InitList) return; // Not an array!
1303 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1304 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs!
1305 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1306 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1308 // Gather the structors in a form that's convenient for sorting by priority.
1309 typedef std::pair<unsigned, Constant *> Structor;
1310 SmallVector<Structor, 8> Structors;
1311 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1312 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i));
1313 if (!CS) continue; // Malformed.
1314 if (CS->getOperand(1)->isNullValue())
1315 break; // Found a null terminator, skip the rest.
1316 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1317 if (!Priority) continue; // Malformed.
1318 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535),
1319 CS->getOperand(1)));
1322 // Emit the function pointers in the target-specific order
1323 const DataLayout *DL = TM.getDataLayout();
1324 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1325 std::stable_sort(Structors.begin(), Structors.end(), less_first());
1326 for (unsigned i = 0, e = Structors.size(); i != e; ++i) {
1327 const MCSection *OutputSection =
1329 getObjFileLowering().getStaticCtorSection(Structors[i].first) :
1330 getObjFileLowering().getStaticDtorSection(Structors[i].first));
1331 OutStreamer.SwitchSection(OutputSection);
1332 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1333 EmitAlignment(Align);
1334 EmitXXStructor(Structors[i].second);
1338 void AsmPrinter::EmitModuleIdents(Module &M) {
1339 if (!MAI->hasIdentDirective())
1342 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1343 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1344 const MDNode *N = NMD->getOperand(i);
1345 assert(N->getNumOperands() == 1 &&
1346 "llvm.ident metadata entry can have only one operand");
1347 const MDString *S = cast<MDString>(N->getOperand(0));
1348 OutStreamer.EmitIdent(S->getString());
1353 //===--------------------------------------------------------------------===//
1354 // Emission and print routines
1357 /// EmitInt8 - Emit a byte directive and value.
1359 void AsmPrinter::EmitInt8(int Value) const {
1360 OutStreamer.EmitIntValue(Value, 1);
1363 /// EmitInt16 - Emit a short directive and value.
1365 void AsmPrinter::EmitInt16(int Value) const {
1366 OutStreamer.EmitIntValue(Value, 2);
1369 /// EmitInt32 - Emit a long directive and value.
1371 void AsmPrinter::EmitInt32(int Value) const {
1372 OutStreamer.EmitIntValue(Value, 4);
1375 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1376 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1377 /// labels. This implicitly uses .set if it is available.
1378 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1379 unsigned Size) const {
1380 // Get the Hi-Lo expression.
1381 const MCExpr *Diff =
1382 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1383 MCSymbolRefExpr::Create(Lo, OutContext),
1386 if (!MAI->hasSetDirective()) {
1387 OutStreamer.EmitValue(Diff, Size);
1391 // Otherwise, emit with .set (aka assignment).
1392 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1393 OutStreamer.EmitAssignment(SetLabel, Diff);
1394 OutStreamer.EmitSymbolValue(SetLabel, Size);
1397 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1398 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1399 /// specify the labels. This implicitly uses .set if it is available.
1400 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1401 const MCSymbol *Lo, unsigned Size)
1404 // Emit Hi+Offset - Lo
1405 // Get the Hi+Offset expression.
1406 const MCExpr *Plus =
1407 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1408 MCConstantExpr::Create(Offset, OutContext),
1411 // Get the Hi+Offset-Lo expression.
1412 const MCExpr *Diff =
1413 MCBinaryExpr::CreateSub(Plus,
1414 MCSymbolRefExpr::Create(Lo, OutContext),
1417 if (!MAI->hasSetDirective())
1418 OutStreamer.EmitValue(Diff, 4);
1420 // Otherwise, emit with .set (aka assignment).
1421 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1422 OutStreamer.EmitAssignment(SetLabel, Diff);
1423 OutStreamer.EmitSymbolValue(SetLabel, 4);
1427 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1428 /// where the size in bytes of the directive is specified by Size and Label
1429 /// specifies the label. This implicitly uses .set if it is available.
1430 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1431 unsigned Size, bool IsSectionRelative)
1433 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1434 OutStreamer.EmitCOFFSecRel32(Label);
1438 // Emit Label+Offset (or just Label if Offset is zero)
1439 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1441 Expr = MCBinaryExpr::CreateAdd(Expr,
1442 MCConstantExpr::Create(Offset, OutContext),
1445 OutStreamer.EmitValue(Expr, Size);
1449 //===----------------------------------------------------------------------===//
1451 // EmitAlignment - Emit an alignment directive to the specified power of
1452 // two boundary. For example, if you pass in 3 here, you will get an 8
1453 // byte alignment. If a global value is specified, and if that global has
1454 // an explicit alignment requested, it will override the alignment request
1455 // if required for correctness.
1457 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1458 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits);
1460 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1462 if (getCurrentSection()->getKind().isText())
1463 OutStreamer.EmitCodeAlignment(1 << NumBits);
1465 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1468 //===----------------------------------------------------------------------===//
1469 // Constant emission.
1470 //===----------------------------------------------------------------------===//
1472 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1474 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1475 MCContext &Ctx = AP.OutContext;
1477 if (CV->isNullValue() || isa<UndefValue>(CV))
1478 return MCConstantExpr::Create(0, Ctx);
1480 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1481 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1483 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1484 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1486 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1487 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1489 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1491 llvm_unreachable("Unknown constant value to lower!");
1494 switch (CE->getOpcode()) {
1496 // If the code isn't optimized, there may be outstanding folding
1497 // opportunities. Attempt to fold the expression using DataLayout as a
1498 // last resort before giving up.
1500 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout()))
1502 return lowerConstant(C, AP);
1504 // Otherwise report the problem to the user.
1507 raw_string_ostream OS(S);
1508 OS << "Unsupported expression in static initializer: ";
1509 WriteAsOperand(OS, CE, /*PrintType=*/false,
1510 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1511 report_fatal_error(OS.str());
1513 case Instruction::GetElementPtr: {
1514 const DataLayout &DL = *AP.TM.getDataLayout();
1515 // Generate a symbolic expression for the byte address
1516 APInt OffsetAI(DL.getPointerSizeInBits(), 0);
1517 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1519 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1523 int64_t Offset = OffsetAI.getSExtValue();
1524 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1528 case Instruction::Trunc:
1529 // We emit the value and depend on the assembler to truncate the generated
1530 // expression properly. This is important for differences between
1531 // blockaddress labels. Since the two labels are in the same function, it
1532 // is reasonable to treat their delta as a 32-bit value.
1534 case Instruction::BitCast:
1535 return lowerConstant(CE->getOperand(0), AP);
1537 case Instruction::IntToPtr: {
1538 const DataLayout &DL = *AP.TM.getDataLayout();
1539 // Handle casts to pointers by changing them into casts to the appropriate
1540 // integer type. This promotes constant folding and simplifies this code.
1541 Constant *Op = CE->getOperand(0);
1542 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getContext()),
1544 return lowerConstant(Op, AP);
1547 case Instruction::PtrToInt: {
1548 const DataLayout &DL = *AP.TM.getDataLayout();
1549 // Support only foldable casts to/from pointers that can be eliminated by
1550 // changing the pointer to the appropriately sized integer type.
1551 Constant *Op = CE->getOperand(0);
1552 Type *Ty = CE->getType();
1554 const MCExpr *OpExpr = lowerConstant(Op, AP);
1556 // We can emit the pointer value into this slot if the slot is an
1557 // integer slot equal to the size of the pointer.
1558 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1561 // Otherwise the pointer is smaller than the resultant integer, mask off
1562 // the high bits so we are sure to get a proper truncation if the input is
1564 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1565 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1566 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1569 // The MC library also has a right-shift operator, but it isn't consistently
1570 // signed or unsigned between different targets.
1571 case Instruction::Add:
1572 case Instruction::Sub:
1573 case Instruction::Mul:
1574 case Instruction::SDiv:
1575 case Instruction::SRem:
1576 case Instruction::Shl:
1577 case Instruction::And:
1578 case Instruction::Or:
1579 case Instruction::Xor: {
1580 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1581 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1582 switch (CE->getOpcode()) {
1583 default: llvm_unreachable("Unknown binary operator constant cast expr");
1584 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1585 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1586 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1587 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1588 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1589 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1590 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1591 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1592 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1598 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1600 /// isRepeatedByteSequence - Determine whether the given value is
1601 /// composed of a repeated sequence of identical bytes and return the
1602 /// byte value. If it is not a repeated sequence, return -1.
1603 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1604 StringRef Data = V->getRawDataValues();
1605 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1607 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1608 if (Data[i] != C) return -1;
1609 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1613 /// isRepeatedByteSequence - Determine whether the given value is
1614 /// composed of a repeated sequence of identical bytes and return the
1615 /// byte value. If it is not a repeated sequence, return -1.
1616 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1618 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1619 if (CI->getBitWidth() > 64) return -1;
1621 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType());
1622 uint64_t Value = CI->getZExtValue();
1624 // Make sure the constant is at least 8 bits long and has a power
1625 // of 2 bit width. This guarantees the constant bit width is
1626 // always a multiple of 8 bits, avoiding issues with padding out
1627 // to Size and other such corner cases.
1628 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1630 uint8_t Byte = static_cast<uint8_t>(Value);
1632 for (unsigned i = 1; i < Size; ++i) {
1634 if (static_cast<uint8_t>(Value) != Byte) return -1;
1638 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1639 // Make sure all array elements are sequences of the same repeated
1641 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1642 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1643 if (Byte == -1) return -1;
1645 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1646 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1647 if (ThisByte == -1) return -1;
1648 if (Byte != ThisByte) return -1;
1653 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1654 return isRepeatedByteSequence(CDS);
1659 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1662 // See if we can aggregate this into a .fill, if so, emit it as such.
1663 int Value = isRepeatedByteSequence(CDS, AP.TM);
1665 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType());
1666 // Don't emit a 1-byte object as a .fill.
1668 return AP.OutStreamer.EmitFill(Bytes, Value);
1671 // If this can be emitted with .ascii/.asciz, emit it as such.
1672 if (CDS->isString())
1673 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1675 // Otherwise, emit the values in successive locations.
1676 unsigned ElementByteSize = CDS->getElementByteSize();
1677 if (isa<IntegerType>(CDS->getElementType())) {
1678 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1680 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1681 CDS->getElementAsInteger(i));
1682 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1685 } else if (ElementByteSize == 4) {
1686 // FP Constants are printed as integer constants to avoid losing
1688 assert(CDS->getElementType()->isFloatTy());
1689 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1695 F = CDS->getElementAsFloat(i);
1697 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1698 AP.OutStreamer.EmitIntValue(I, 4);
1701 assert(CDS->getElementType()->isDoubleTy());
1702 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1708 F = CDS->getElementAsDouble(i);
1710 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1711 AP.OutStreamer.EmitIntValue(I, 8);
1715 const DataLayout &DL = *AP.TM.getDataLayout();
1716 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1717 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1718 CDS->getNumElements();
1719 if (unsigned Padding = Size - EmittedSize)
1720 AP.OutStreamer.EmitZeros(Padding);
1724 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1725 // See if we can aggregate some values. Make sure it can be
1726 // represented as a series of bytes of the constant value.
1727 int Value = isRepeatedByteSequence(CA, AP.TM);
1730 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType());
1731 AP.OutStreamer.EmitFill(Bytes, Value);
1734 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1735 emitGlobalConstantImpl(CA->getOperand(i), AP);
1739 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1740 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1741 emitGlobalConstantImpl(CV->getOperand(i), AP);
1743 const DataLayout &DL = *AP.TM.getDataLayout();
1744 unsigned Size = DL.getTypeAllocSize(CV->getType());
1745 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1746 CV->getType()->getNumElements();
1747 if (unsigned Padding = Size - EmittedSize)
1748 AP.OutStreamer.EmitZeros(Padding);
1751 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1752 // Print the fields in successive locations. Pad to align if needed!
1753 const DataLayout *DL = AP.TM.getDataLayout();
1754 unsigned Size = DL->getTypeAllocSize(CS->getType());
1755 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1756 uint64_t SizeSoFar = 0;
1757 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1758 const Constant *Field = CS->getOperand(i);
1760 // Check if padding is needed and insert one or more 0s.
1761 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1762 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1763 - Layout->getElementOffset(i)) - FieldSize;
1764 SizeSoFar += FieldSize + PadSize;
1766 // Now print the actual field value.
1767 emitGlobalConstantImpl(Field, AP);
1769 // Insert padding - this may include padding to increase the size of the
1770 // current field up to the ABI size (if the struct is not packed) as well
1771 // as padding to ensure that the next field starts at the right offset.
1772 AP.OutStreamer.EmitZeros(PadSize);
1774 assert(SizeSoFar == Layout->getSizeInBytes() &&
1775 "Layout of constant struct may be incorrect!");
1778 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1779 APInt API = CFP->getValueAPF().bitcastToAPInt();
1781 // First print a comment with what we think the original floating-point value
1782 // should have been.
1783 if (AP.isVerbose()) {
1784 SmallString<8> StrVal;
1785 CFP->getValueAPF().toString(StrVal);
1787 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1788 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1791 // Now iterate through the APInt chunks, emitting them in endian-correct
1792 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1794 unsigned NumBytes = API.getBitWidth() / 8;
1795 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1796 const uint64_t *p = API.getRawData();
1798 // PPC's long double has odd notions of endianness compared to how LLVM
1799 // handles it: p[0] goes first for *big* endian on PPC.
1800 if (AP.TM.getDataLayout()->isBigEndian() != CFP->getType()->isPPC_FP128Ty()) {
1801 int Chunk = API.getNumWords() - 1;
1804 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1806 for (; Chunk >= 0; --Chunk)
1807 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1810 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1811 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1814 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1817 // Emit the tail padding for the long double.
1818 const DataLayout &DL = *AP.TM.getDataLayout();
1819 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1820 DL.getTypeStoreSize(CFP->getType()));
1823 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1824 const DataLayout *DL = AP.TM.getDataLayout();
1825 unsigned BitWidth = CI->getBitWidth();
1827 // Copy the value as we may massage the layout for constants whose bit width
1828 // is not a multiple of 64-bits.
1829 APInt Realigned(CI->getValue());
1830 uint64_t ExtraBits = 0;
1831 unsigned ExtraBitsSize = BitWidth & 63;
1833 if (ExtraBitsSize) {
1834 // The bit width of the data is not a multiple of 64-bits.
1835 // The extra bits are expected to be at the end of the chunk of the memory.
1837 // * Nothing to be done, just record the extra bits to emit.
1839 // * Record the extra bits to emit.
1840 // * Realign the raw data to emit the chunks of 64-bits.
1841 if (DL->isBigEndian()) {
1842 // Basically the structure of the raw data is a chunk of 64-bits cells:
1843 // 0 1 BitWidth / 64
1844 // [chunk1][chunk2] ... [chunkN].
1845 // The most significant chunk is chunkN and it should be emitted first.
1846 // However, due to the alignment issue chunkN contains useless bits.
1847 // Realign the chunks so that they contain only useless information:
1848 // ExtraBits 0 1 (BitWidth / 64) - 1
1849 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1850 ExtraBits = Realigned.getRawData()[0] &
1851 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1852 Realigned = Realigned.lshr(ExtraBitsSize);
1854 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1857 // We don't expect assemblers to support integer data directives
1858 // for more than 64 bits, so we emit the data in at most 64-bit
1859 // quantities at a time.
1860 const uint64_t *RawData = Realigned.getRawData();
1861 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1862 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1863 AP.OutStreamer.EmitIntValue(Val, 8);
1866 if (ExtraBitsSize) {
1867 // Emit the extra bits after the 64-bits chunks.
1869 // Emit a directive that fills the expected size.
1870 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(CI->getType());
1871 Size -= (BitWidth / 64) * 8;
1872 assert(Size && Size * 8 >= ExtraBitsSize &&
1873 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1874 == ExtraBits && "Directive too small for extra bits.");
1875 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1879 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1880 const DataLayout *DL = AP.TM.getDataLayout();
1881 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1882 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1883 return AP.OutStreamer.EmitZeros(Size);
1885 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1892 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1893 CI->getZExtValue());
1894 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1897 emitGlobalConstantLargeInt(CI, AP);
1902 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1903 return emitGlobalConstantFP(CFP, AP);
1905 if (isa<ConstantPointerNull>(CV)) {
1906 AP.OutStreamer.EmitIntValue(0, Size);
1910 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1911 return emitGlobalConstantDataSequential(CDS, AP);
1913 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1914 return emitGlobalConstantArray(CVA, AP);
1916 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1917 return emitGlobalConstantStruct(CVS, AP);
1919 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
1920 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
1922 if (CE->getOpcode() == Instruction::BitCast)
1923 return emitGlobalConstantImpl(CE->getOperand(0), AP);
1926 // If the constant expression's size is greater than 64-bits, then we have
1927 // to emit the value in chunks. Try to constant fold the value and emit it
1929 Constant *New = ConstantFoldConstantExpression(CE, DL);
1930 if (New && New != CE)
1931 return emitGlobalConstantImpl(New, AP);
1935 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1936 return emitGlobalConstantVector(V, AP);
1938 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1939 // thread the streamer with EmitValue.
1940 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
1943 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1944 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
1945 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType());
1947 emitGlobalConstantImpl(CV, *this);
1948 else if (MAI->hasSubsectionsViaSymbols()) {
1949 // If the global has zero size, emit a single byte so that two labels don't
1950 // look like they are at the same location.
1951 OutStreamer.EmitIntValue(0, 1);
1955 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1956 // Target doesn't support this yet!
1957 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1960 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1962 OS << '+' << Offset;
1963 else if (Offset < 0)
1967 //===----------------------------------------------------------------------===//
1968 // Symbol Lowering Routines.
1969 //===----------------------------------------------------------------------===//
1971 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1972 /// temporary label with the specified stem and unique ID.
1973 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1974 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1978 /// GetTempSymbol - Return an assembler temporary label with the specified
1980 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1981 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1986 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1987 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1990 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1991 return MMI->getAddrLabelSymbol(BB);
1994 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1995 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1996 return OutContext.GetOrCreateSymbol
1997 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1998 + "_" + Twine(CPID));
2001 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2002 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2003 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2006 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2007 /// FIXME: privatize to AsmPrinter.
2008 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2009 return OutContext.GetOrCreateSymbol
2010 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2011 Twine(UID) + "_set_" + Twine(MBBID));
2014 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
2015 /// global value name as its base, with the specified suffix, and where the
2016 /// symbol is forced to have private linkage if ForcePrivate is true.
2017 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
2019 bool ForcePrivate) const {
2020 SmallString<60> NameStr;
2021 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
2022 NameStr.append(Suffix.begin(), Suffix.end());
2023 return OutContext.GetOrCreateSymbol(NameStr.str());
2026 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2028 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2029 SmallString<60> NameStr;
2030 Mang->getNameWithPrefix(NameStr, Sym);
2031 return OutContext.GetOrCreateSymbol(NameStr.str());
2036 /// PrintParentLoopComment - Print comments about parent loops of this one.
2037 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2038 unsigned FunctionNumber) {
2039 if (Loop == 0) return;
2040 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2041 OS.indent(Loop->getLoopDepth()*2)
2042 << "Parent Loop BB" << FunctionNumber << "_"
2043 << Loop->getHeader()->getNumber()
2044 << " Depth=" << Loop->getLoopDepth() << '\n';
2048 /// PrintChildLoopComment - Print comments about child loops within
2049 /// the loop for this basic block, with nesting.
2050 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2051 unsigned FunctionNumber) {
2052 // Add child loop information
2053 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
2054 OS.indent((*CL)->getLoopDepth()*2)
2055 << "Child Loop BB" << FunctionNumber << "_"
2056 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
2058 PrintChildLoopComment(OS, *CL, FunctionNumber);
2062 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2063 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2064 const MachineLoopInfo *LI,
2065 const AsmPrinter &AP) {
2066 // Add loop depth information
2067 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2068 if (Loop == 0) return;
2070 MachineBasicBlock *Header = Loop->getHeader();
2071 assert(Header && "No header for loop");
2073 // If this block is not a loop header, just print out what is the loop header
2075 if (Header != &MBB) {
2076 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2077 Twine(AP.getFunctionNumber())+"_" +
2078 Twine(Loop->getHeader()->getNumber())+
2079 " Depth="+Twine(Loop->getLoopDepth()));
2083 // Otherwise, it is a loop header. Print out information about child and
2085 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2087 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2090 OS.indent(Loop->getLoopDepth()*2-2);
2095 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2097 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2101 /// EmitBasicBlockStart - This method prints the label for the specified
2102 /// MachineBasicBlock, an alignment (if present) and a comment describing
2103 /// it if appropriate.
2104 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
2105 // Emit an alignment directive for this block, if needed.
2106 if (unsigned Align = MBB->getAlignment())
2107 EmitAlignment(Align);
2109 // If the block has its address taken, emit any labels that were used to
2110 // reference the block. It is possible that there is more than one label
2111 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2112 // the references were generated.
2113 if (MBB->hasAddressTaken()) {
2114 const BasicBlock *BB = MBB->getBasicBlock();
2116 OutStreamer.AddComment("Block address taken");
2118 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
2120 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
2121 OutStreamer.EmitLabel(Syms[i]);
2124 // Print some verbose block comments.
2126 if (const BasicBlock *BB = MBB->getBasicBlock())
2128 OutStreamer.AddComment("%" + BB->getName());
2129 emitBasicBlockLoopComments(*MBB, LI, *this);
2132 // Print the main label for the block.
2133 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
2134 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
2135 // NOTE: Want this comment at start of line, don't emit with AddComment.
2136 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
2137 Twine(MBB->getNumber()) + ":");
2140 OutStreamer.EmitLabel(MBB->getSymbol());
2144 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2145 bool IsDefinition) const {
2146 MCSymbolAttr Attr = MCSA_Invalid;
2148 switch (Visibility) {
2150 case GlobalValue::HiddenVisibility:
2152 Attr = MAI->getHiddenVisibilityAttr();
2154 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2156 case GlobalValue::ProtectedVisibility:
2157 Attr = MAI->getProtectedVisibilityAttr();
2161 if (Attr != MCSA_Invalid)
2162 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2165 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2166 /// exactly one predecessor and the control transfer mechanism between
2167 /// the predecessor and this block is a fall-through.
2169 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2170 // If this is a landing pad, it isn't a fall through. If it has no preds,
2171 // then nothing falls through to it.
2172 if (MBB->isLandingPad() || MBB->pred_empty())
2175 // If there isn't exactly one predecessor, it can't be a fall through.
2176 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
2178 if (PI2 != MBB->pred_end())
2181 // The predecessor has to be immediately before this block.
2182 MachineBasicBlock *Pred = *PI;
2184 if (!Pred->isLayoutSuccessor(MBB))
2187 // If the block is completely empty, then it definitely does fall through.
2191 // Check the terminators in the previous blocks
2192 for (MachineBasicBlock::iterator II = Pred->getFirstTerminator(),
2193 IE = Pred->end(); II != IE; ++II) {
2194 MachineInstr &MI = *II;
2196 // If it is not a simple branch, we are in a table somewhere.
2197 if (!MI.isBranch() || MI.isIndirectBranch())
2200 // If we are the operands of one of the branches, this is not
2202 for (MachineInstr::mop_iterator OI = MI.operands_begin(),
2203 OE = MI.operands_end(); OI != OE; ++OI) {
2204 const MachineOperand& OP = *OI;
2207 if (OP.isMBB() && OP.getMBB() == MBB)
2217 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
2218 if (!S->usesMetadata())
2221 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2222 gcp_map_type::iterator GCPI = GCMap.find(S);
2223 if (GCPI != GCMap.end())
2224 return GCPI->second;
2226 const char *Name = S->getName().c_str();
2228 for (GCMetadataPrinterRegistry::iterator
2229 I = GCMetadataPrinterRegistry::begin(),
2230 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2231 if (strcmp(Name, I->getName()) == 0) {
2232 GCMetadataPrinter *GMP = I->instantiate();
2234 GCMap.insert(std::make_pair(S, GMP));
2238 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));