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 *DWARFGroupName = "DWARF Emission";
54 static const char *DbgTimerName = "DWARF Debug Writer";
55 static const char *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()),
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;
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 OutStreamer.InitStreamer();
160 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
161 MMI->AnalyzeModule(M);
163 // Initialize TargetLoweringObjectFile.
164 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
165 .Initialize(OutContext, TM);
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 *TD = TM.getDataLayout();
288 uint64_t Size = TD->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, *TD);
295 // Handle common and BSS local symbols (.lcomm).
296 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
297 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
298 unsigned Align = 1 << AlignLog;
300 // Handle common symbols.
301 if (GVKind.isCommon()) {
302 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
306 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
310 // Handle local BSS symbols.
311 if (MAI->hasMachoZeroFillDirective()) {
312 const MCSection *TheSection =
313 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
314 // .zerofill __DATA, __bss, _foo, 400, 5
315 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
319 // Use .lcomm only if it supports user-specified alignment.
320 // Otherwise, while it would still be correct to use .lcomm in some
321 // cases (e.g. when Align == 1), the external assembler might enfore
322 // some -unknown- default alignment behavior, which could cause
323 // spurious differences between external and integrated assembler.
324 // Prefer to simply fall back to .local / .comm in this case.
325 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
327 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
331 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
335 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
337 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
341 const MCSection *TheSection =
342 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
344 // Handle the zerofill directive on darwin, which is a special form of BSS
346 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
347 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
350 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
351 // .zerofill __DATA, __common, _foo, 400, 5
352 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
356 // Handle thread local data for mach-o which requires us to output an
357 // additional structure of data and mangle the original symbol so that we
358 // can reference it later.
360 // TODO: This should become an "emit thread local global" method on TLOF.
361 // All of this macho specific stuff should be sunk down into TLOFMachO and
362 // stuff like "TLSExtraDataSection" should no longer be part of the parent
363 // TLOF class. This will also make it more obvious that stuff like
364 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
366 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
367 // Emit the .tbss symbol
369 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
371 if (GVKind.isThreadBSS())
372 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
373 else if (GVKind.isThreadData()) {
374 OutStreamer.SwitchSection(TheSection);
376 EmitAlignment(AlignLog, GV);
377 OutStreamer.EmitLabel(MangSym);
379 EmitGlobalConstant(GV->getInitializer());
382 OutStreamer.AddBlankLine();
384 // Emit the variable struct for the runtime.
385 const MCSection *TLVSect
386 = getObjFileLowering().getTLSExtraDataSection();
388 OutStreamer.SwitchSection(TLVSect);
389 // Emit the linkage here.
390 EmitLinkage(GV->getLinkage(), GVSym);
391 OutStreamer.EmitLabel(GVSym);
393 // Three pointers in size:
394 // - __tlv_bootstrap - used to make sure support exists
395 // - spare pointer, used when mapped by the runtime
396 // - pointer to mangled symbol above with initializer
397 unsigned PtrSize = TD->getPointerSizeInBits()/8;
398 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
400 OutStreamer.EmitIntValue(0, PtrSize);
401 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
403 OutStreamer.AddBlankLine();
407 OutStreamer.SwitchSection(TheSection);
409 EmitLinkage(GV->getLinkage(), GVSym);
410 EmitAlignment(AlignLog, GV);
412 OutStreamer.EmitLabel(GVSym);
414 EmitGlobalConstant(GV->getInitializer());
416 if (MAI->hasDotTypeDotSizeDirective())
418 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
420 OutStreamer.AddBlankLine();
423 /// EmitFunctionHeader - This method emits the header for the current
425 void AsmPrinter::EmitFunctionHeader() {
426 // Print out constants referenced by the function
429 // Print the 'header' of function.
430 const Function *F = MF->getFunction();
432 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
433 EmitVisibility(CurrentFnSym, F->getVisibility());
435 EmitLinkage(F->getLinkage(), CurrentFnSym);
436 EmitAlignment(MF->getAlignment(), F);
438 if (MAI->hasDotTypeDotSizeDirective())
439 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
442 WriteAsOperand(OutStreamer.GetCommentOS(), F,
443 /*PrintType=*/false, F->getParent());
444 OutStreamer.GetCommentOS() << '\n';
447 // Emit the CurrentFnSym. This is a virtual function to allow targets to
448 // do their wild and crazy things as required.
449 EmitFunctionEntryLabel();
451 // If the function had address-taken blocks that got deleted, then we have
452 // references to the dangling symbols. Emit them at the start of the function
453 // so that we don't get references to undefined symbols.
454 std::vector<MCSymbol*> DeadBlockSyms;
455 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
456 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
457 OutStreamer.AddComment("Address taken block that was later removed");
458 OutStreamer.EmitLabel(DeadBlockSyms[i]);
461 // Add some workaround for linkonce linkage on Cygwin\MinGW.
462 if (MAI->getLinkOnceDirective() != 0 &&
463 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
464 // FIXME: What is this?
466 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
467 CurrentFnSym->getName());
468 OutStreamer.EmitLabel(FakeStub);
471 // Emit pre-function debug and/or EH information.
473 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
474 DE->BeginFunction(MF);
477 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
478 DD->beginFunction(MF);
482 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
483 /// function. This can be overridden by targets as required to do custom stuff.
484 void AsmPrinter::EmitFunctionEntryLabel() {
485 // The function label could have already been emitted if two symbols end up
486 // conflicting due to asm renaming. Detect this and emit an error.
487 if (CurrentFnSym->isUndefined())
488 return OutStreamer.EmitLabel(CurrentFnSym);
490 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
491 "' label emitted multiple times to assembly file");
494 /// emitComments - Pretty-print comments for instructions.
495 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
496 const MachineFunction *MF = MI.getParent()->getParent();
497 const TargetMachine &TM = MF->getTarget();
499 // Check for spills and reloads
502 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
504 // We assume a single instruction only has a spill or reload, not
506 const MachineMemOperand *MMO;
507 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
508 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
509 MMO = *MI.memoperands_begin();
510 CommentOS << MMO->getSize() << "-byte Reload\n";
512 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
513 if (FrameInfo->isSpillSlotObjectIndex(FI))
514 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
515 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
516 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
517 MMO = *MI.memoperands_begin();
518 CommentOS << MMO->getSize() << "-byte Spill\n";
520 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
521 if (FrameInfo->isSpillSlotObjectIndex(FI))
522 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
525 // Check for spill-induced copies
526 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
527 CommentOS << " Reload Reuse\n";
530 /// emitImplicitDef - This method emits the specified machine instruction
531 /// that is an implicit def.
532 static void emitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
533 unsigned RegNo = MI->getOperand(0).getReg();
534 AP.OutStreamer.AddComment(Twine("implicit-def: ") +
535 AP.TM.getRegisterInfo()->getName(RegNo));
536 AP.OutStreamer.AddBlankLine();
539 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
540 std::string Str = "kill:";
541 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
542 const MachineOperand &Op = MI->getOperand(i);
543 assert(Op.isReg() && "KILL instruction must have only register operands");
545 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
546 Str += (Op.isDef() ? "<def>" : "<kill>");
548 AP.OutStreamer.AddComment(Str);
549 AP.OutStreamer.AddBlankLine();
552 /// emitDebugValueComment - This method handles the target-independent form
553 /// of DBG_VALUE, returning true if it was able to do so. A false return
554 /// means the target will need to handle MI in EmitInstruction.
555 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
556 // This code handles only the 3-operand target-independent form.
557 if (MI->getNumOperands() != 3)
560 SmallString<128> Str;
561 raw_svector_ostream OS(Str);
562 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
564 // cast away const; DIetc do not take const operands for some reason.
565 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
566 if (V.getContext().isSubprogram()) {
567 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
571 OS << V.getName() << " <- ";
573 int64_t Offset = MI->getOperand(1).getImm();
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();
598 Deref = Offset != 0; // FIXME: use a better sentinel value so that deref
599 // of a reg with a zero offset is valid
601 assert(MI->getOperand(0).isFI() && "Unknown operand type");
602 const TargetFrameLowering *TFI = AP.TM.getFrameLowering();
603 Offset += TFI->getFrameIndexReference(*AP.MF,
604 MI->getOperand(0).getIndex(), Reg);
608 // Suppress offset, it is not meaningful here.
610 // NOTE: Want this comment at start of line, don't emit with AddComment.
611 AP.OutStreamer.EmitRawText(OS.str());
616 OS << AP.TM.getRegisterInfo()->getName(Reg);
623 // NOTE: Want this comment at start of line, don't emit with AddComment.
624 AP.OutStreamer.EmitRawText(OS.str());
628 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
629 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
630 MF->getFunction()->needsUnwindTableEntry())
633 if (MMI->hasDebugInfo())
639 bool AsmPrinter::needsSEHMoves() {
640 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 &&
641 MF->getFunction()->needsUnwindTableEntry();
644 bool AsmPrinter::needsRelocationsForDwarfStringPool() const {
645 return MAI->doesDwarfUseRelocationsAcrossSections();
648 void AsmPrinter::emitPrologLabel(const MachineInstr &MI) {
649 MCSymbol *Label = MI.getOperand(0).getMCSymbol();
651 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
654 if (needsCFIMoves() == CFI_M_None)
657 if (MMI->getCompactUnwindEncoding() != 0)
658 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding());
660 MachineModuleInfo &MMI = MF->getMMI();
661 std::vector<MCCFIInstruction> Instructions = MMI.getFrameInstructions();
662 bool FoundOne = false;
664 for (std::vector<MCCFIInstruction>::iterator I = Instructions.begin(),
665 E = Instructions.end(); I != E; ++I) {
666 if (I->getLabel() == Label) {
667 emitCFIInstruction(*I);
674 /// EmitFunctionBody - This method emits the body and trailer for a
676 void AsmPrinter::EmitFunctionBody() {
677 // Emit target-specific gunk before the function body.
678 EmitFunctionBodyStart();
680 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
682 // Print out code for the function.
683 bool HasAnyRealCode = false;
684 const MachineInstr *LastMI = 0;
685 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
687 // Print a label for the basic block.
688 EmitBasicBlockStart(I);
689 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
693 // Print the assembly for the instruction.
694 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
695 !II->isDebugValue()) {
696 HasAnyRealCode = true;
700 if (ShouldPrintDebugScopes) {
701 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
702 DD->beginInstruction(II);
706 emitComments(*II, OutStreamer.GetCommentOS());
708 switch (II->getOpcode()) {
709 case TargetOpcode::PROLOG_LABEL:
710 emitPrologLabel(*II);
713 case TargetOpcode::EH_LABEL:
714 case TargetOpcode::GC_LABEL:
715 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
717 case TargetOpcode::INLINEASM:
720 case TargetOpcode::DBG_VALUE:
722 if (!emitDebugValueComment(II, *this))
726 case TargetOpcode::IMPLICIT_DEF:
727 if (isVerbose()) emitImplicitDef(II, *this);
729 case TargetOpcode::KILL:
730 if (isVerbose()) emitKill(II, *this);
733 if (!TM.hasMCUseLoc())
734 MCLineEntry::Make(&OutStreamer, getCurrentSection());
740 if (ShouldPrintDebugScopes) {
741 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
742 DD->endInstruction(II);
747 // If the last instruction was a prolog label, then we have a situation where
748 // we emitted a prolog but no function body. This results in the ending prolog
749 // label equaling the end of function label and an invalid "row" in the
750 // FDE. We need to emit a noop in this situation so that the FDE's rows are
752 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
754 // If the function is empty and the object file uses .subsections_via_symbols,
755 // then we need to emit *something* to the function body to prevent the
756 // labels from collapsing together. Just emit a noop.
757 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
759 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
760 if (Noop.getOpcode()) {
761 OutStreamer.AddComment("avoids zero-length function");
762 OutStreamer.EmitInstruction(Noop);
763 } else // Target not mc-ized yet.
764 OutStreamer.EmitRawText(StringRef("\tnop\n"));
767 const Function *F = MF->getFunction();
768 for (Function::const_iterator i = F->begin(), e = F->end(); i != e; ++i) {
769 const BasicBlock *BB = i;
770 if (!BB->hasAddressTaken())
772 MCSymbol *Sym = GetBlockAddressSymbol(BB);
773 if (Sym->isDefined())
775 OutStreamer.AddComment("Address of block that was removed by CodeGen");
776 OutStreamer.EmitLabel(Sym);
779 // Emit target-specific gunk after the function body.
780 EmitFunctionBodyEnd();
782 // If the target wants a .size directive for the size of the function, emit
784 if (MAI->hasDotTypeDotSizeDirective()) {
785 // Create a symbol for the end of function, so we can get the size as
786 // difference between the function label and the temp label.
787 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
788 OutStreamer.EmitLabel(FnEndLabel);
790 const MCExpr *SizeExp =
791 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
792 MCSymbolRefExpr::Create(CurrentFnSymForSize,
795 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
798 // Emit post-function debug information.
800 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
804 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
809 // Print out jump tables referenced by the function.
812 OutStreamer.AddBlankLine();
815 /// EmitDwarfRegOp - Emit dwarf register operation.
816 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc,
817 bool Indirect) const {
818 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
819 int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
821 for (MCSuperRegIterator SR(MLoc.getReg(), TRI); SR.isValid() && Reg < 0;
823 Reg = TRI->getDwarfRegNum(*SR, false);
824 // FIXME: Get the bit range this register uses of the superregister
825 // so that we can produce a DW_OP_bit_piece
828 // FIXME: Handle cases like a super register being encoded as
829 // DW_OP_reg 32 DW_OP_piece 4 DW_OP_reg 33
831 // FIXME: We have no reasonable way of handling errors in here. The
832 // caller might be in the middle of an dwarf expression. We should
833 // probably assert that Reg >= 0 once debug info generation is more mature.
835 if (MLoc.isIndirect() || Indirect) {
837 OutStreamer.AddComment(
838 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg));
839 EmitInt8(dwarf::DW_OP_breg0 + Reg);
841 OutStreamer.AddComment("DW_OP_bregx");
842 EmitInt8(dwarf::DW_OP_bregx);
843 OutStreamer.AddComment(Twine(Reg));
846 EmitSLEB128(!MLoc.isIndirect() ? 0 : MLoc.getOffset());
847 if (MLoc.isIndirect() && Indirect)
848 EmitInt8(dwarf::DW_OP_deref);
851 OutStreamer.AddComment(
852 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
853 EmitInt8(dwarf::DW_OP_reg0 + Reg);
855 OutStreamer.AddComment("DW_OP_regx");
856 EmitInt8(dwarf::DW_OP_regx);
857 OutStreamer.AddComment(Twine(Reg));
862 // FIXME: Produce a DW_OP_bit_piece if we used a superregister
865 bool AsmPrinter::doFinalization(Module &M) {
866 // Emit global variables.
867 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
869 EmitGlobalVariable(I);
871 // Emit visibility info for declarations
872 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
873 const Function &F = *I;
874 if (!F.isDeclaration())
876 GlobalValue::VisibilityTypes V = F.getVisibility();
877 if (V == GlobalValue::DefaultVisibility)
880 MCSymbol *Name = Mang->getSymbol(&F);
881 EmitVisibility(Name, V, false);
884 // Emit module flags.
885 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
886 M.getModuleFlagsMetadata(ModuleFlags);
887 if (!ModuleFlags.empty())
888 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, Mang, TM);
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())
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 // If we don't have any trampolines, then we don't require stack memory
957 // to be executable. Some targets have a directive to declare this.
958 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
959 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
960 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
961 OutStreamer.SwitchSection(S);
963 // Allow the target to emit any magic that it wants at the end of the file,
964 // after everything else has gone out.
967 delete Mang; Mang = 0;
970 OutStreamer.Finish();
976 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
978 // Get the function symbol.
979 CurrentFnSym = Mang->getSymbol(MF.getFunction());
980 CurrentFnSymForSize = CurrentFnSym;
983 LI = &getAnalysis<MachineLoopInfo>();
987 // SectionCPs - Keep track the alignment, constpool entries per Section.
991 SmallVector<unsigned, 4> CPEs;
992 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
996 /// EmitConstantPool - Print to the current output stream assembly
997 /// representations of the constants in the constant pool MCP. This is
998 /// used to print out constants which have been "spilled to memory" by
999 /// the code generator.
1001 void AsmPrinter::EmitConstantPool() {
1002 const MachineConstantPool *MCP = MF->getConstantPool();
1003 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1004 if (CP.empty()) return;
1006 // Calculate sections for constant pool entries. We collect entries to go into
1007 // the same section together to reduce amount of section switch statements.
1008 SmallVector<SectionCPs, 4> CPSections;
1009 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1010 const MachineConstantPoolEntry &CPE = CP[i];
1011 unsigned Align = CPE.getAlignment();
1014 switch (CPE.getRelocationInfo()) {
1015 default: llvm_unreachable("Unknown section kind");
1016 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
1018 Kind = SectionKind::getReadOnlyWithRelLocal();
1021 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) {
1022 case 4: Kind = SectionKind::getMergeableConst4(); break;
1023 case 8: Kind = SectionKind::getMergeableConst8(); break;
1024 case 16: Kind = SectionKind::getMergeableConst16();break;
1025 default: Kind = SectionKind::getMergeableConst(); break;
1029 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
1031 // The number of sections are small, just do a linear search from the
1032 // last section to the first.
1034 unsigned SecIdx = CPSections.size();
1035 while (SecIdx != 0) {
1036 if (CPSections[--SecIdx].S == S) {
1042 SecIdx = CPSections.size();
1043 CPSections.push_back(SectionCPs(S, Align));
1046 if (Align > CPSections[SecIdx].Alignment)
1047 CPSections[SecIdx].Alignment = Align;
1048 CPSections[SecIdx].CPEs.push_back(i);
1051 // Now print stuff into the calculated sections.
1052 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1053 OutStreamer.SwitchSection(CPSections[i].S);
1054 EmitAlignment(Log2_32(CPSections[i].Alignment));
1056 unsigned Offset = 0;
1057 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1058 unsigned CPI = CPSections[i].CPEs[j];
1059 MachineConstantPoolEntry CPE = CP[CPI];
1061 // Emit inter-object padding for alignment.
1062 unsigned AlignMask = CPE.getAlignment() - 1;
1063 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1064 OutStreamer.EmitZeros(NewOffset - Offset);
1066 Type *Ty = CPE.getType();
1067 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty);
1068 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1070 if (CPE.isMachineConstantPoolEntry())
1071 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1073 EmitGlobalConstant(CPE.Val.ConstVal);
1078 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1079 /// by the current function to the current output stream.
1081 void AsmPrinter::EmitJumpTableInfo() {
1082 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1083 if (MJTI == 0) return;
1084 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1085 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1086 if (JT.empty()) return;
1088 // Pick the directive to use to print the jump table entries, and switch to
1089 // the appropriate section.
1090 const Function *F = MF->getFunction();
1091 bool JTInDiffSection = false;
1092 if (// In PIC mode, we need to emit the jump table to the same section as the
1093 // function body itself, otherwise the label differences won't make sense.
1094 // FIXME: Need a better predicate for this: what about custom entries?
1095 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1096 // We should also do if the section name is NULL or function is declared
1097 // in discardable section
1098 // FIXME: this isn't the right predicate, should be based on the MCSection
1099 // for the function.
1100 F->isWeakForLinker()) {
1101 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
1103 // Otherwise, drop it in the readonly section.
1104 const MCSection *ReadOnlySection =
1105 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1106 OutStreamer.SwitchSection(ReadOnlySection);
1107 JTInDiffSection = true;
1110 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout())));
1112 // Jump tables in code sections are marked with a data_region directive
1113 // where that's supported.
1114 if (!JTInDiffSection)
1115 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1117 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1118 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1120 // If this jump table was deleted, ignore it.
1121 if (JTBBs.empty()) continue;
1123 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1124 // .set directive for each unique entry. This reduces the number of
1125 // relocations the assembler will generate for the jump table.
1126 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1127 MAI->hasSetDirective()) {
1128 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1129 const TargetLowering *TLI = TM.getTargetLowering();
1130 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1131 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1132 const MachineBasicBlock *MBB = JTBBs[ii];
1133 if (!EmittedSets.insert(MBB)) continue;
1135 // .set LJTSet, LBB32-base
1137 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1138 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1139 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1143 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1144 // before each jump table. The first label is never referenced, but tells
1145 // the assembler and linker the extents of the jump table object. The
1146 // second label is actually referenced by the code.
1147 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1148 // FIXME: This doesn't have to have any specific name, just any randomly
1149 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1150 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1152 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1154 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1155 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1157 if (!JTInDiffSection)
1158 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1161 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1163 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1164 const MachineBasicBlock *MBB,
1165 unsigned UID) const {
1166 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1167 const MCExpr *Value = 0;
1168 switch (MJTI->getEntryKind()) {
1169 case MachineJumpTableInfo::EK_Inline:
1170 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1171 case MachineJumpTableInfo::EK_Custom32:
1172 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1175 case MachineJumpTableInfo::EK_BlockAddress:
1176 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1178 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1180 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1181 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1182 // with a relocation as gp-relative, e.g.:
1184 MCSymbol *MBBSym = MBB->getSymbol();
1185 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1189 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1190 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1191 // with a relocation as gp-relative, e.g.:
1193 MCSymbol *MBBSym = MBB->getSymbol();
1194 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1198 case MachineJumpTableInfo::EK_LabelDifference32: {
1199 // EK_LabelDifference32 - Each entry is the address of the block minus
1200 // the address of the jump table. This is used for PIC jump tables where
1201 // gprel32 is not supported. e.g.:
1202 // .word LBB123 - LJTI1_2
1203 // If the .set directive is supported, this is emitted as:
1204 // .set L4_5_set_123, LBB123 - LJTI1_2
1205 // .word L4_5_set_123
1207 // If we have emitted set directives for the jump table entries, print
1208 // them rather than the entries themselves. If we're emitting PIC, then
1209 // emit the table entries as differences between two text section labels.
1210 if (MAI->hasSetDirective()) {
1211 // If we used .set, reference the .set's symbol.
1212 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1216 // Otherwise, use the difference as the jump table entry.
1217 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1218 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1219 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1224 assert(Value && "Unknown entry kind!");
1226 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout());
1227 OutStreamer.EmitValue(Value, EntrySize);
1231 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1232 /// special global used by LLVM. If so, emit it and return true, otherwise
1233 /// do nothing and return false.
1234 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1235 if (GV->getName() == "llvm.used") {
1236 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1237 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1241 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1242 if (GV->getSection() == "llvm.metadata" ||
1243 GV->hasAvailableExternallyLinkage())
1246 if (!GV->hasAppendingLinkage()) return false;
1248 assert(GV->hasInitializer() && "Not a special LLVM global!");
1250 if (GV->getName() == "llvm.global_ctors") {
1251 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1253 if (TM.getRelocationModel() == Reloc::Static &&
1254 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1255 StringRef Sym(".constructors_used");
1256 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1262 if (GV->getName() == "llvm.global_dtors") {
1263 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1265 if (TM.getRelocationModel() == Reloc::Static &&
1266 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1267 StringRef Sym(".destructors_used");
1268 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1277 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1278 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1279 /// is true, as being used with this directive.
1280 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1281 // Should be an array of 'i8*'.
1282 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1283 const GlobalValue *GV =
1284 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1285 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1286 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1290 typedef std::pair<unsigned, Constant*> Structor;
1292 static bool priority_order(const Structor& lhs, const Structor& rhs) {
1293 return lhs.first < rhs.first;
1296 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1298 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1299 // Should be an array of '{ int, void ()* }' structs. The first value is the
1301 if (!isa<ConstantArray>(List)) return;
1303 // Sanity check the structors list.
1304 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1305 if (!InitList) return; // Not an array!
1306 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1307 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs!
1308 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1309 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1311 // Gather the structors in a form that's convenient for sorting by priority.
1312 SmallVector<Structor, 8> Structors;
1313 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1314 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i));
1315 if (!CS) continue; // Malformed.
1316 if (CS->getOperand(1)->isNullValue())
1317 break; // Found a null terminator, skip the rest.
1318 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1319 if (!Priority) continue; // Malformed.
1320 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535),
1321 CS->getOperand(1)));
1324 // Emit the function pointers in the target-specific order
1325 const DataLayout *TD = TM.getDataLayout();
1326 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1327 std::stable_sort(Structors.begin(), Structors.end(), priority_order);
1328 for (unsigned i = 0, e = Structors.size(); i != e; ++i) {
1329 const MCSection *OutputSection =
1331 getObjFileLowering().getStaticCtorSection(Structors[i].first) :
1332 getObjFileLowering().getStaticDtorSection(Structors[i].first));
1333 OutStreamer.SwitchSection(OutputSection);
1334 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1335 EmitAlignment(Align);
1336 EmitXXStructor(Structors[i].second);
1340 //===--------------------------------------------------------------------===//
1341 // Emission and print routines
1344 /// EmitInt8 - Emit a byte directive and value.
1346 void AsmPrinter::EmitInt8(int Value) const {
1347 OutStreamer.EmitIntValue(Value, 1);
1350 /// EmitInt16 - Emit a short directive and value.
1352 void AsmPrinter::EmitInt16(int Value) const {
1353 OutStreamer.EmitIntValue(Value, 2);
1356 /// EmitInt32 - Emit a long directive and value.
1358 void AsmPrinter::EmitInt32(int Value) const {
1359 OutStreamer.EmitIntValue(Value, 4);
1362 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1363 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1364 /// labels. This implicitly uses .set if it is available.
1365 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1366 unsigned Size) const {
1367 // Get the Hi-Lo expression.
1368 const MCExpr *Diff =
1369 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1370 MCSymbolRefExpr::Create(Lo, OutContext),
1373 if (!MAI->hasSetDirective()) {
1374 OutStreamer.EmitValue(Diff, Size);
1378 // Otherwise, emit with .set (aka assignment).
1379 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1380 OutStreamer.EmitAssignment(SetLabel, Diff);
1381 OutStreamer.EmitSymbolValue(SetLabel, Size);
1384 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1385 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1386 /// specify the labels. This implicitly uses .set if it is available.
1387 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1388 const MCSymbol *Lo, unsigned Size)
1391 // Emit Hi+Offset - Lo
1392 // Get the Hi+Offset expression.
1393 const MCExpr *Plus =
1394 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1395 MCConstantExpr::Create(Offset, OutContext),
1398 // Get the Hi+Offset-Lo expression.
1399 const MCExpr *Diff =
1400 MCBinaryExpr::CreateSub(Plus,
1401 MCSymbolRefExpr::Create(Lo, OutContext),
1404 if (!MAI->hasSetDirective())
1405 OutStreamer.EmitValue(Diff, 4);
1407 // Otherwise, emit with .set (aka assignment).
1408 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1409 OutStreamer.EmitAssignment(SetLabel, Diff);
1410 OutStreamer.EmitSymbolValue(SetLabel, 4);
1414 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1415 /// where the size in bytes of the directive is specified by Size and Label
1416 /// specifies the label. This implicitly uses .set if it is available.
1417 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1421 // Emit Label+Offset (or just Label if Offset is zero)
1422 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1424 Expr = MCBinaryExpr::CreateAdd(Expr,
1425 MCConstantExpr::Create(Offset, OutContext),
1428 OutStreamer.EmitValue(Expr, Size);
1432 //===----------------------------------------------------------------------===//
1434 // EmitAlignment - Emit an alignment directive to the specified power of
1435 // two boundary. For example, if you pass in 3 here, you will get an 8
1436 // byte alignment. If a global value is specified, and if that global has
1437 // an explicit alignment requested, it will override the alignment request
1438 // if required for correctness.
1440 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1441 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits);
1443 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1445 if (getCurrentSection()->getKind().isText())
1446 OutStreamer.EmitCodeAlignment(1 << NumBits);
1448 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1451 //===----------------------------------------------------------------------===//
1452 // Constant emission.
1453 //===----------------------------------------------------------------------===//
1455 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1457 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1458 MCContext &Ctx = AP.OutContext;
1460 if (CV->isNullValue() || isa<UndefValue>(CV))
1461 return MCConstantExpr::Create(0, Ctx);
1463 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1464 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1466 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1467 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1469 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1470 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1472 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1474 llvm_unreachable("Unknown constant value to lower!");
1477 switch (CE->getOpcode()) {
1479 // If the code isn't optimized, there may be outstanding folding
1480 // opportunities. Attempt to fold the expression using DataLayout as a
1481 // last resort before giving up.
1483 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout()))
1485 return lowerConstant(C, AP);
1487 // Otherwise report the problem to the user.
1490 raw_string_ostream OS(S);
1491 OS << "Unsupported expression in static initializer: ";
1492 WriteAsOperand(OS, CE, /*PrintType=*/false,
1493 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1494 report_fatal_error(OS.str());
1496 case Instruction::GetElementPtr: {
1497 const DataLayout &TD = *AP.TM.getDataLayout();
1498 // Generate a symbolic expression for the byte address
1499 APInt OffsetAI(TD.getPointerSizeInBits(), 0);
1500 cast<GEPOperator>(CE)->accumulateConstantOffset(TD, OffsetAI);
1502 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1506 int64_t Offset = OffsetAI.getSExtValue();
1507 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1511 case Instruction::Trunc:
1512 // We emit the value and depend on the assembler to truncate the generated
1513 // expression properly. This is important for differences between
1514 // blockaddress labels. Since the two labels are in the same function, it
1515 // is reasonable to treat their delta as a 32-bit value.
1517 case Instruction::BitCast:
1518 return lowerConstant(CE->getOperand(0), AP);
1520 case Instruction::IntToPtr: {
1521 const DataLayout &TD = *AP.TM.getDataLayout();
1522 // Handle casts to pointers by changing them into casts to the appropriate
1523 // integer type. This promotes constant folding and simplifies this code.
1524 Constant *Op = CE->getOperand(0);
1525 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1527 return lowerConstant(Op, AP);
1530 case Instruction::PtrToInt: {
1531 const DataLayout &TD = *AP.TM.getDataLayout();
1532 // Support only foldable casts to/from pointers that can be eliminated by
1533 // changing the pointer to the appropriately sized integer type.
1534 Constant *Op = CE->getOperand(0);
1535 Type *Ty = CE->getType();
1537 const MCExpr *OpExpr = lowerConstant(Op, AP);
1539 // We can emit the pointer value into this slot if the slot is an
1540 // integer slot equal to the size of the pointer.
1541 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1544 // Otherwise the pointer is smaller than the resultant integer, mask off
1545 // the high bits so we are sure to get a proper truncation if the input is
1547 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1548 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1549 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1552 // The MC library also has a right-shift operator, but it isn't consistently
1553 // signed or unsigned between different targets.
1554 case Instruction::Add:
1555 case Instruction::Sub:
1556 case Instruction::Mul:
1557 case Instruction::SDiv:
1558 case Instruction::SRem:
1559 case Instruction::Shl:
1560 case Instruction::And:
1561 case Instruction::Or:
1562 case Instruction::Xor: {
1563 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1564 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1565 switch (CE->getOpcode()) {
1566 default: llvm_unreachable("Unknown binary operator constant cast expr");
1567 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1568 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1569 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1570 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1571 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1572 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1573 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1574 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1575 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1581 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1583 /// isRepeatedByteSequence - Determine whether the given value is
1584 /// composed of a repeated sequence of identical bytes and return the
1585 /// byte value. If it is not a repeated sequence, return -1.
1586 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1587 StringRef Data = V->getRawDataValues();
1588 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1590 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1591 if (Data[i] != C) return -1;
1592 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1596 /// isRepeatedByteSequence - Determine whether the given value is
1597 /// composed of a repeated sequence of identical bytes and return the
1598 /// byte value. If it is not a repeated sequence, return -1.
1599 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1601 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1602 if (CI->getBitWidth() > 64) return -1;
1604 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType());
1605 uint64_t Value = CI->getZExtValue();
1607 // Make sure the constant is at least 8 bits long and has a power
1608 // of 2 bit width. This guarantees the constant bit width is
1609 // always a multiple of 8 bits, avoiding issues with padding out
1610 // to Size and other such corner cases.
1611 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1613 uint8_t Byte = static_cast<uint8_t>(Value);
1615 for (unsigned i = 1; i < Size; ++i) {
1617 if (static_cast<uint8_t>(Value) != Byte) return -1;
1621 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1622 // Make sure all array elements are sequences of the same repeated
1624 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1625 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1626 if (Byte == -1) return -1;
1628 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1629 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1630 if (ThisByte == -1) return -1;
1631 if (Byte != ThisByte) return -1;
1636 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1637 return isRepeatedByteSequence(CDS);
1642 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1645 // See if we can aggregate this into a .fill, if so, emit it as such.
1646 int Value = isRepeatedByteSequence(CDS, AP.TM);
1648 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType());
1649 // Don't emit a 1-byte object as a .fill.
1651 return AP.OutStreamer.EmitFill(Bytes, Value);
1654 // If this can be emitted with .ascii/.asciz, emit it as such.
1655 if (CDS->isString())
1656 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1658 // Otherwise, emit the values in successive locations.
1659 unsigned ElementByteSize = CDS->getElementByteSize();
1660 if (isa<IntegerType>(CDS->getElementType())) {
1661 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1663 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1664 CDS->getElementAsInteger(i));
1665 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1668 } else if (ElementByteSize == 4) {
1669 // FP Constants are printed as integer constants to avoid losing
1671 assert(CDS->getElementType()->isFloatTy());
1672 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1678 F = CDS->getElementAsFloat(i);
1680 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1681 AP.OutStreamer.EmitIntValue(I, 4);
1684 assert(CDS->getElementType()->isDoubleTy());
1685 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1691 F = CDS->getElementAsDouble(i);
1693 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1694 AP.OutStreamer.EmitIntValue(I, 8);
1698 const DataLayout &TD = *AP.TM.getDataLayout();
1699 unsigned Size = TD.getTypeAllocSize(CDS->getType());
1700 unsigned EmittedSize = TD.getTypeAllocSize(CDS->getType()->getElementType()) *
1701 CDS->getNumElements();
1702 if (unsigned Padding = Size - EmittedSize)
1703 AP.OutStreamer.EmitZeros(Padding);
1707 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1708 // See if we can aggregate some values. Make sure it can be
1709 // represented as a series of bytes of the constant value.
1710 int Value = isRepeatedByteSequence(CA, AP.TM);
1713 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType());
1714 AP.OutStreamer.EmitFill(Bytes, Value);
1717 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1718 emitGlobalConstantImpl(CA->getOperand(i), AP);
1722 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1723 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1724 emitGlobalConstantImpl(CV->getOperand(i), AP);
1726 const DataLayout &TD = *AP.TM.getDataLayout();
1727 unsigned Size = TD.getTypeAllocSize(CV->getType());
1728 unsigned EmittedSize = TD.getTypeAllocSize(CV->getType()->getElementType()) *
1729 CV->getType()->getNumElements();
1730 if (unsigned Padding = Size - EmittedSize)
1731 AP.OutStreamer.EmitZeros(Padding);
1734 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1735 // Print the fields in successive locations. Pad to align if needed!
1736 const DataLayout *TD = AP.TM.getDataLayout();
1737 unsigned Size = TD->getTypeAllocSize(CS->getType());
1738 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1739 uint64_t SizeSoFar = 0;
1740 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1741 const Constant *Field = CS->getOperand(i);
1743 // Check if padding is needed and insert one or more 0s.
1744 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1745 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1746 - Layout->getElementOffset(i)) - FieldSize;
1747 SizeSoFar += FieldSize + PadSize;
1749 // Now print the actual field value.
1750 emitGlobalConstantImpl(Field, AP);
1752 // Insert padding - this may include padding to increase the size of the
1753 // current field up to the ABI size (if the struct is not packed) as well
1754 // as padding to ensure that the next field starts at the right offset.
1755 AP.OutStreamer.EmitZeros(PadSize);
1757 assert(SizeSoFar == Layout->getSizeInBytes() &&
1758 "Layout of constant struct may be incorrect!");
1761 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1762 APInt API = CFP->getValueAPF().bitcastToAPInt();
1764 // First print a comment with what we think the original floating-point value
1765 // should have been.
1766 if (AP.isVerbose()) {
1767 SmallString<8> StrVal;
1768 CFP->getValueAPF().toString(StrVal);
1770 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1771 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1774 // Now iterate through the APInt chunks, emitting them in endian-correct
1775 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1777 unsigned NumBytes = API.getBitWidth() / 8;
1778 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1779 const uint64_t *p = API.getRawData();
1781 // PPC's long double has odd notions of endianness compared to how LLVM
1782 // handles it: p[0] goes first for *big* endian on PPC.
1783 if (AP.TM.getDataLayout()->isBigEndian() != CFP->getType()->isPPC_FP128Ty()) {
1784 int Chunk = API.getNumWords() - 1;
1787 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1789 for (; Chunk >= 0; --Chunk)
1790 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1793 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1794 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1797 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1800 // Emit the tail padding for the long double.
1801 const DataLayout &TD = *AP.TM.getDataLayout();
1802 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1803 TD.getTypeStoreSize(CFP->getType()));
1806 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1807 const DataLayout *TD = AP.TM.getDataLayout();
1808 unsigned BitWidth = CI->getBitWidth();
1810 // Copy the value as we may massage the layout for constants whose bit width
1811 // is not a multiple of 64-bits.
1812 APInt Realigned(CI->getValue());
1813 uint64_t ExtraBits = 0;
1814 unsigned ExtraBitsSize = BitWidth & 63;
1816 if (ExtraBitsSize) {
1817 // The bit width of the data is not a multiple of 64-bits.
1818 // The extra bits are expected to be at the end of the chunk of the memory.
1820 // * Nothing to be done, just record the extra bits to emit.
1822 // * Record the extra bits to emit.
1823 // * Realign the raw data to emit the chunks of 64-bits.
1824 if (TD->isBigEndian()) {
1825 // Basically the structure of the raw data is a chunk of 64-bits cells:
1826 // 0 1 BitWidth / 64
1827 // [chunk1][chunk2] ... [chunkN].
1828 // The most significant chunk is chunkN and it should be emitted first.
1829 // However, due to the alignment issue chunkN contains useless bits.
1830 // Realign the chunks so that they contain only useless information:
1831 // ExtraBits 0 1 (BitWidth / 64) - 1
1832 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1833 ExtraBits = Realigned.getRawData()[0] &
1834 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1835 Realigned = Realigned.lshr(ExtraBitsSize);
1837 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1840 // We don't expect assemblers to support integer data directives
1841 // for more than 64 bits, so we emit the data in at most 64-bit
1842 // quantities at a time.
1843 const uint64_t *RawData = Realigned.getRawData();
1844 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1845 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1846 AP.OutStreamer.EmitIntValue(Val, 8);
1849 if (ExtraBitsSize) {
1850 // Emit the extra bits after the 64-bits chunks.
1852 // Emit a directive that fills the expected size.
1853 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(CI->getType());
1854 Size -= (BitWidth / 64) * 8;
1855 assert(Size && Size * 8 >= ExtraBitsSize &&
1856 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1857 == ExtraBits && "Directive too small for extra bits.");
1858 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1862 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1863 const DataLayout *TD = AP.TM.getDataLayout();
1864 uint64_t Size = TD->getTypeAllocSize(CV->getType());
1865 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1866 return AP.OutStreamer.EmitZeros(Size);
1868 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1875 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1876 CI->getZExtValue());
1877 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1880 emitGlobalConstantLargeInt(CI, AP);
1885 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1886 return emitGlobalConstantFP(CFP, AP);
1888 if (isa<ConstantPointerNull>(CV)) {
1889 AP.OutStreamer.EmitIntValue(0, Size);
1893 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1894 return emitGlobalConstantDataSequential(CDS, AP);
1896 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1897 return emitGlobalConstantArray(CVA, AP);
1899 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1900 return emitGlobalConstantStruct(CVS, AP);
1902 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
1903 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
1905 if (CE->getOpcode() == Instruction::BitCast)
1906 return emitGlobalConstantImpl(CE->getOperand(0), AP);
1909 // If the constant expression's size is greater than 64-bits, then we have
1910 // to emit the value in chunks. Try to constant fold the value and emit it
1912 Constant *New = ConstantFoldConstantExpression(CE, TD);
1913 if (New && New != CE)
1914 return emitGlobalConstantImpl(New, AP);
1918 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1919 return emitGlobalConstantVector(V, AP);
1921 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1922 // thread the streamer with EmitValue.
1923 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
1926 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1927 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
1928 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType());
1930 emitGlobalConstantImpl(CV, *this);
1931 else if (MAI->hasSubsectionsViaSymbols()) {
1932 // If the global has zero size, emit a single byte so that two labels don't
1933 // look like they are at the same location.
1934 OutStreamer.EmitIntValue(0, 1);
1938 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1939 // Target doesn't support this yet!
1940 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1943 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1945 OS << '+' << Offset;
1946 else if (Offset < 0)
1950 //===----------------------------------------------------------------------===//
1951 // Symbol Lowering Routines.
1952 //===----------------------------------------------------------------------===//
1954 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1955 /// temporary label with the specified stem and unique ID.
1956 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1957 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1961 /// GetTempSymbol - Return an assembler temporary label with the specified
1963 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1964 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1969 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1970 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1973 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1974 return MMI->getAddrLabelSymbol(BB);
1977 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1978 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1979 return OutContext.GetOrCreateSymbol
1980 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1981 + "_" + Twine(CPID));
1984 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1985 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1986 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1989 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1990 /// FIXME: privatize to AsmPrinter.
1991 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1992 return OutContext.GetOrCreateSymbol
1993 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1994 Twine(UID) + "_set_" + Twine(MBBID));
1997 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1998 /// global value name as its base, with the specified suffix, and where the
1999 /// symbol is forced to have private linkage if ForcePrivate is true.
2000 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
2002 bool ForcePrivate) const {
2003 SmallString<60> NameStr;
2004 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
2005 NameStr.append(Suffix.begin(), Suffix.end());
2006 return OutContext.GetOrCreateSymbol(NameStr.str());
2009 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2011 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2012 SmallString<60> NameStr;
2013 Mang->getNameWithPrefix(NameStr, Sym);
2014 return OutContext.GetOrCreateSymbol(NameStr.str());
2019 /// PrintParentLoopComment - Print comments about parent loops of this one.
2020 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2021 unsigned FunctionNumber) {
2022 if (Loop == 0) return;
2023 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2024 OS.indent(Loop->getLoopDepth()*2)
2025 << "Parent Loop BB" << FunctionNumber << "_"
2026 << Loop->getHeader()->getNumber()
2027 << " Depth=" << Loop->getLoopDepth() << '\n';
2031 /// PrintChildLoopComment - Print comments about child loops within
2032 /// the loop for this basic block, with nesting.
2033 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2034 unsigned FunctionNumber) {
2035 // Add child loop information
2036 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
2037 OS.indent((*CL)->getLoopDepth()*2)
2038 << "Child Loop BB" << FunctionNumber << "_"
2039 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
2041 PrintChildLoopComment(OS, *CL, FunctionNumber);
2045 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2046 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2047 const MachineLoopInfo *LI,
2048 const AsmPrinter &AP) {
2049 // Add loop depth information
2050 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2051 if (Loop == 0) return;
2053 MachineBasicBlock *Header = Loop->getHeader();
2054 assert(Header && "No header for loop");
2056 // If this block is not a loop header, just print out what is the loop header
2058 if (Header != &MBB) {
2059 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2060 Twine(AP.getFunctionNumber())+"_" +
2061 Twine(Loop->getHeader()->getNumber())+
2062 " Depth="+Twine(Loop->getLoopDepth()));
2066 // Otherwise, it is a loop header. Print out information about child and
2068 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2070 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2073 OS.indent(Loop->getLoopDepth()*2-2);
2078 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2080 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2084 /// EmitBasicBlockStart - This method prints the label for the specified
2085 /// MachineBasicBlock, an alignment (if present) and a comment describing
2086 /// it if appropriate.
2087 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
2088 // Emit an alignment directive for this block, if needed.
2089 if (unsigned Align = MBB->getAlignment())
2090 EmitAlignment(Align);
2092 // If the block has its address taken, emit any labels that were used to
2093 // reference the block. It is possible that there is more than one label
2094 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2095 // the references were generated.
2096 if (MBB->hasAddressTaken()) {
2097 const BasicBlock *BB = MBB->getBasicBlock();
2099 OutStreamer.AddComment("Block address taken");
2101 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
2103 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
2104 OutStreamer.EmitLabel(Syms[i]);
2107 // Print some verbose block comments.
2109 if (const BasicBlock *BB = MBB->getBasicBlock())
2111 OutStreamer.AddComment("%" + BB->getName());
2112 emitBasicBlockLoopComments(*MBB, LI, *this);
2115 // Print the main label for the block.
2116 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
2117 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
2118 // NOTE: Want this comment at start of line, don't emit with AddComment.
2119 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
2120 Twine(MBB->getNumber()) + ":");
2123 OutStreamer.EmitLabel(MBB->getSymbol());
2127 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2128 bool IsDefinition) const {
2129 MCSymbolAttr Attr = MCSA_Invalid;
2131 switch (Visibility) {
2133 case GlobalValue::HiddenVisibility:
2135 Attr = MAI->getHiddenVisibilityAttr();
2137 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2139 case GlobalValue::ProtectedVisibility:
2140 Attr = MAI->getProtectedVisibilityAttr();
2144 if (Attr != MCSA_Invalid)
2145 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2148 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2149 /// exactly one predecessor and the control transfer mechanism between
2150 /// the predecessor and this block is a fall-through.
2152 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2153 // If this is a landing pad, it isn't a fall through. If it has no preds,
2154 // then nothing falls through to it.
2155 if (MBB->isLandingPad() || MBB->pred_empty())
2158 // If there isn't exactly one predecessor, it can't be a fall through.
2159 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
2161 if (PI2 != MBB->pred_end())
2164 // The predecessor has to be immediately before this block.
2165 MachineBasicBlock *Pred = *PI;
2167 if (!Pred->isLayoutSuccessor(MBB))
2170 // If the block is completely empty, then it definitely does fall through.
2174 // Check the terminators in the previous blocks
2175 for (MachineBasicBlock::iterator II = Pred->getFirstTerminator(),
2176 IE = Pred->end(); II != IE; ++II) {
2177 MachineInstr &MI = *II;
2179 // If it is not a simple branch, we are in a table somewhere.
2180 if (!MI.isBranch() || MI.isIndirectBranch())
2183 // If we are the operands of one of the branches, this is not
2185 for (MachineInstr::mop_iterator OI = MI.operands_begin(),
2186 OE = MI.operands_end(); OI != OE; ++OI) {
2187 const MachineOperand& OP = *OI;
2190 if (OP.isMBB() && OP.getMBB() == MBB)
2200 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
2201 if (!S->usesMetadata())
2204 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2205 gcp_map_type::iterator GCPI = GCMap.find(S);
2206 if (GCPI != GCMap.end())
2207 return GCPI->second;
2209 const char *Name = S->getName().c_str();
2211 for (GCMetadataPrinterRegistry::iterator
2212 I = GCMetadataPrinterRegistry::begin(),
2213 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2214 if (strcmp(Name, I->getName()) == 0) {
2215 GCMetadataPrinter *GMP = I->instantiate();
2217 GCMap.insert(std::make_pair(S, GMP));
2221 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));