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/CodeGen/GCMetadataPrinter.h"
22 #include "llvm/CodeGen/MachineConstantPool.h"
23 #include "llvm/CodeGen/MachineFrameInfo.h"
24 #include "llvm/CodeGen/MachineFunction.h"
25 #include "llvm/CodeGen/MachineInstrBundle.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/Mangler.h"
32 #include "llvm/IR/Module.h"
33 #include "llvm/IR/Operator.h"
34 #include "llvm/MC/MCAsmInfo.h"
35 #include "llvm/MC/MCContext.h"
36 #include "llvm/MC/MCExpr.h"
37 #include "llvm/MC/MCInst.h"
38 #include "llvm/MC/MCSection.h"
39 #include "llvm/MC/MCStreamer.h"
40 #include "llvm/MC/MCSymbol.h"
41 #include "llvm/Support/ErrorHandling.h"
42 #include "llvm/Support/Format.h"
43 #include "llvm/Support/MathExtras.h"
44 #include "llvm/Support/Timer.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"
51 #include "llvm/Target/TargetSubtargetInfo.h"
52 #include "llvm/Transforms/Utils/GlobalStatus.h"
53 #include "WinCodeViewLineTables.h"
56 static const char *const DWARFGroupName = "DWARF Emission";
57 static const char *const DbgTimerName = "Debug Info Emission";
58 static const char *const EHTimerName = "DWARF Exception Writer";
59 static const char *const CodeViewLineTablesGroupName = "CodeView Line Tables";
61 STATISTIC(EmittedInsts, "Number of machine instrs printed");
63 char AsmPrinter::ID = 0;
65 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
66 static gcp_map_type &getGCMap(void *&P) {
68 P = new gcp_map_type();
69 return *(gcp_map_type*)P;
73 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
74 /// value in log2 form. This rounds up to the preferred alignment if possible
76 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD,
77 unsigned InBits = 0) {
79 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
80 NumBits = TD.getPreferredAlignmentLog(GVar);
82 // If InBits is specified, round it to it.
86 // If the GV has a specified alignment, take it into account.
87 if (GV->getAlignment() == 0)
90 unsigned GVAlign = Log2_32(GV->getAlignment());
92 // If the GVAlign is larger than NumBits, or if we are required to obey
93 // NumBits because the GV has an assigned section, obey it.
94 if (GVAlign > NumBits || GV->hasSection())
99 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
100 : MachineFunctionPass(ID),
101 TM(tm), MAI(tm.getMCAsmInfo()), MII(tm.getInstrInfo()),
102 OutContext(Streamer.getContext()),
103 OutStreamer(Streamer),
104 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
105 DD = 0; MMI = 0; LI = 0; MF = 0;
106 CurrentFnSym = CurrentFnSymForSize = 0;
107 GCMetadataPrinters = 0;
108 VerboseAsm = Streamer.isVerboseAsm();
111 AsmPrinter::~AsmPrinter() {
112 assert(DD == 0 && Handlers.empty() && "Debug/EH info didn't get finalized");
114 if (GCMetadataPrinters != 0) {
115 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
117 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
120 GCMetadataPrinters = 0;
126 /// getFunctionNumber - Return a unique ID for the current function.
128 unsigned AsmPrinter::getFunctionNumber() const {
129 return MF->getFunctionNumber();
132 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
133 return TM.getTargetLowering()->getObjFileLowering();
136 /// getDataLayout - Return information about data layout.
137 const DataLayout &AsmPrinter::getDataLayout() const {
138 return *TM.getDataLayout();
141 const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
142 return TM.getSubtarget<MCSubtargetInfo>();
145 void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
146 S.EmitInstruction(Inst, getSubtargetInfo());
149 StringRef AsmPrinter::getTargetTriple() const {
150 return TM.getTargetTriple();
153 /// getCurrentSection() - Return the current section we are emitting to.
154 const MCSection *AsmPrinter::getCurrentSection() const {
155 return OutStreamer.getCurrentSection().first;
160 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
161 AU.setPreservesAll();
162 MachineFunctionPass::getAnalysisUsage(AU);
163 AU.addRequired<MachineModuleInfo>();
164 AU.addRequired<GCModuleInfo>();
166 AU.addRequired<MachineLoopInfo>();
169 bool AsmPrinter::doInitialization(Module &M) {
170 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
171 MMI->AnalyzeModule(M);
173 // Initialize TargetLoweringObjectFile.
174 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
175 .Initialize(OutContext, TM);
177 OutStreamer.InitSections(false);
179 Mang = new Mangler(TM.getDataLayout());
181 // Allow the target to emit any magic that it wants at the start of the file.
182 EmitStartOfAsmFile(M);
184 // Very minimal debug info. It is ignored if we emit actual debug info. If we
185 // don't, this at least helps the user find where a global came from.
186 if (MAI->hasSingleParameterDotFile()) {
188 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
191 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
192 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
193 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
194 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
195 MP->beginAssembly(*this);
197 // Emit module-level inline asm if it exists.
198 if (!M.getModuleInlineAsm().empty()) {
199 OutStreamer.AddComment("Start of file scope inline assembly");
200 OutStreamer.AddBlankLine();
201 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
202 OutStreamer.AddComment("End of file scope inline assembly");
203 OutStreamer.AddBlankLine();
206 if (MAI->doesSupportDebugInformation()) {
207 if (Triple(TM.getTargetTriple()).getOS() == Triple::Win32) {
208 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this),
210 CodeViewLineTablesGroupName));
212 DD = new DwarfDebug(this, &M);
213 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
217 DwarfException *DE = 0;
218 switch (MAI->getExceptionHandlingType()) {
219 case ExceptionHandling::None:
221 case ExceptionHandling::SjLj:
222 case ExceptionHandling::DwarfCFI:
223 DE = new DwarfCFIException(this);
225 case ExceptionHandling::ARM:
226 DE = new ARMException(this);
228 case ExceptionHandling::Win64:
229 DE = new Win64Exception(this);
233 Handlers.push_back(HandlerInfo(DE, EHTimerName, DWARFGroupName));
237 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
238 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
239 if (Linkage != GlobalValue::LinkOnceODRLinkage)
242 if (!MAI.hasWeakDefCanBeHiddenDirective())
245 if (GV->hasUnnamedAddr())
248 // This is only used for MachO, so right now it doesn't really matter how
249 // we handle alias. Revisit this once the MachO linker implements aliases.
250 if (isa<GlobalAlias>(GV))
253 // If it is a non constant variable, it needs to be uniqued across shared
255 if (const GlobalVariable *Var = dyn_cast<GlobalVariable>(GV)) {
256 if (!Var->isConstant())
261 if (!GlobalStatus::analyzeGlobal(GV, GS) && !GS.IsCompared)
267 void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
268 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
270 case GlobalValue::CommonLinkage:
271 case GlobalValue::LinkOnceAnyLinkage:
272 case GlobalValue::LinkOnceODRLinkage:
273 case GlobalValue::WeakAnyLinkage:
274 case GlobalValue::WeakODRLinkage:
275 case GlobalValue::LinkerPrivateWeakLinkage:
276 if (MAI->hasWeakDefDirective()) {
278 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
280 if (!canBeHidden(GV, *MAI))
281 // .weak_definition _foo
282 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
284 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
285 } else if (MAI->hasLinkOnceDirective()) {
287 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
288 //NOTE: linkonce is handled by the section the symbol was assigned to.
291 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
294 case GlobalValue::AppendingLinkage:
295 // FIXME: appending linkage variables should go into a section of
296 // their name or something. For now, just emit them as external.
297 case GlobalValue::ExternalLinkage:
298 // If external or appending, declare as a global symbol.
300 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
302 case GlobalValue::PrivateLinkage:
303 case GlobalValue::InternalLinkage:
304 case GlobalValue::LinkerPrivateLinkage:
306 case GlobalValue::AvailableExternallyLinkage:
307 llvm_unreachable("Should never emit this");
308 case GlobalValue::ExternalWeakLinkage:
309 llvm_unreachable("Don't know how to emit these");
311 llvm_unreachable("Unknown linkage type!");
314 MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
315 return getObjFileLowering().getSymbol(GV, *Mang);
318 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
319 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
320 if (GV->hasInitializer()) {
321 // Check to see if this is a special global used by LLVM, if so, emit it.
322 if (EmitSpecialLLVMGlobal(GV))
326 GV->printAsOperand(OutStreamer.GetCommentOS(),
327 /*PrintType=*/false, GV->getParent());
328 OutStreamer.GetCommentOS() << '\n';
332 MCSymbol *GVSym = getSymbol(GV);
333 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
335 if (!GV->hasInitializer()) // External globals require no extra code.
338 if (MAI->hasDotTypeDotSizeDirective())
339 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
341 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
343 const DataLayout *DL = TM.getDataLayout();
344 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
346 // If the alignment is specified, we *must* obey it. Overaligning a global
347 // with a specified alignment is a prompt way to break globals emitted to
348 // sections and expected to be contiguous (e.g. ObjC metadata).
349 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
351 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
352 const HandlerInfo &OI = Handlers[I];
353 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, TimePassesIsEnabled);
354 OI.Handler->setSymbolSize(GVSym, Size);
357 // Handle common and BSS local symbols (.lcomm).
358 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
359 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
360 unsigned Align = 1 << AlignLog;
362 // Handle common symbols.
363 if (GVKind.isCommon()) {
364 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
368 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
372 // Handle local BSS symbols.
373 if (MAI->hasMachoZeroFillDirective()) {
374 const MCSection *TheSection =
375 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
376 // .zerofill __DATA, __bss, _foo, 400, 5
377 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
381 // Use .lcomm only if it supports user-specified alignment.
382 // Otherwise, while it would still be correct to use .lcomm in some
383 // cases (e.g. when Align == 1), the external assembler might enfore
384 // some -unknown- default alignment behavior, which could cause
385 // spurious differences between external and integrated assembler.
386 // Prefer to simply fall back to .local / .comm in this case.
387 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
389 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
393 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
397 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
399 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
403 const MCSection *TheSection =
404 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM);
406 // Handle the zerofill directive on darwin, which is a special form of BSS
408 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
409 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
412 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
413 // .zerofill __DATA, __common, _foo, 400, 5
414 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
418 // Handle thread local data for mach-o which requires us to output an
419 // additional structure of data and mangle the original symbol so that we
420 // can reference it later.
422 // TODO: This should become an "emit thread local global" method on TLOF.
423 // All of this macho specific stuff should be sunk down into TLOFMachO and
424 // stuff like "TLSExtraDataSection" should no longer be part of the parent
425 // TLOF class. This will also make it more obvious that stuff like
426 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
428 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
429 // Emit the .tbss symbol
431 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
433 if (GVKind.isThreadBSS()) {
434 TheSection = getObjFileLowering().getTLSBSSSection();
435 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
436 } else if (GVKind.isThreadData()) {
437 OutStreamer.SwitchSection(TheSection);
439 EmitAlignment(AlignLog, GV);
440 OutStreamer.EmitLabel(MangSym);
442 EmitGlobalConstant(GV->getInitializer());
445 OutStreamer.AddBlankLine();
447 // Emit the variable struct for the runtime.
448 const MCSection *TLVSect
449 = getObjFileLowering().getTLSExtraDataSection();
451 OutStreamer.SwitchSection(TLVSect);
452 // Emit the linkage here.
453 EmitLinkage(GV, GVSym);
454 OutStreamer.EmitLabel(GVSym);
456 // Three pointers in size:
457 // - __tlv_bootstrap - used to make sure support exists
458 // - spare pointer, used when mapped by the runtime
459 // - pointer to mangled symbol above with initializer
460 unsigned PtrSize = DL->getPointerTypeSize(GV->getType());
461 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
463 OutStreamer.EmitIntValue(0, PtrSize);
464 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
466 OutStreamer.AddBlankLine();
470 OutStreamer.SwitchSection(TheSection);
472 EmitLinkage(GV, GVSym);
473 EmitAlignment(AlignLog, GV);
475 OutStreamer.EmitLabel(GVSym);
477 EmitGlobalConstant(GV->getInitializer());
479 if (MAI->hasDotTypeDotSizeDirective())
481 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
483 OutStreamer.AddBlankLine();
486 /// EmitFunctionHeader - This method emits the header for the current
488 void AsmPrinter::EmitFunctionHeader() {
489 // Print out constants referenced by the function
492 // Print the 'header' of function.
493 const Function *F = MF->getFunction();
495 OutStreamer.SwitchSection(
496 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
497 EmitVisibility(CurrentFnSym, F->getVisibility());
499 EmitLinkage(F, CurrentFnSym);
500 EmitAlignment(MF->getAlignment(), F);
502 if (MAI->hasDotTypeDotSizeDirective())
503 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
506 F->printAsOperand(OutStreamer.GetCommentOS(),
507 /*PrintType=*/false, F->getParent());
508 OutStreamer.GetCommentOS() << '\n';
511 // Emit the CurrentFnSym. This is a virtual function to allow targets to
512 // do their wild and crazy things as required.
513 EmitFunctionEntryLabel();
515 // If the function had address-taken blocks that got deleted, then we have
516 // references to the dangling symbols. Emit them at the start of the function
517 // so that we don't get references to undefined symbols.
518 std::vector<MCSymbol*> DeadBlockSyms;
519 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
520 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
521 OutStreamer.AddComment("Address taken block that was later removed");
522 OutStreamer.EmitLabel(DeadBlockSyms[i]);
525 // Emit pre-function debug and/or EH information.
526 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
527 const HandlerInfo &OI = Handlers[I];
528 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, TimePassesIsEnabled);
529 OI.Handler->beginFunction(MF);
532 // Emit the prefix data.
533 if (F->hasPrefixData())
534 EmitGlobalConstant(F->getPrefixData());
537 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
538 /// function. This can be overridden by targets as required to do custom stuff.
539 void AsmPrinter::EmitFunctionEntryLabel() {
540 // The function label could have already been emitted if two symbols end up
541 // conflicting due to asm renaming. Detect this and emit an error.
542 if (CurrentFnSym->isUndefined())
543 return OutStreamer.EmitLabel(CurrentFnSym);
545 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
546 "' label emitted multiple times to assembly file");
549 /// emitComments - Pretty-print comments for instructions.
550 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
551 const MachineFunction *MF = MI.getParent()->getParent();
552 const TargetMachine &TM = MF->getTarget();
554 // Check for spills and reloads
557 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
559 // We assume a single instruction only has a spill or reload, not
561 const MachineMemOperand *MMO;
562 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
563 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
564 MMO = *MI.memoperands_begin();
565 CommentOS << MMO->getSize() << "-byte Reload\n";
567 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
568 if (FrameInfo->isSpillSlotObjectIndex(FI))
569 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
570 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
571 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
572 MMO = *MI.memoperands_begin();
573 CommentOS << MMO->getSize() << "-byte Spill\n";
575 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
576 if (FrameInfo->isSpillSlotObjectIndex(FI))
577 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
580 // Check for spill-induced copies
581 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
582 CommentOS << " Reload Reuse\n";
585 /// emitImplicitDef - This method emits the specified machine instruction
586 /// that is an implicit def.
587 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
588 unsigned RegNo = MI->getOperand(0).getReg();
589 OutStreamer.AddComment(Twine("implicit-def: ") +
590 TM.getRegisterInfo()->getName(RegNo));
591 OutStreamer.AddBlankLine();
594 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
595 std::string Str = "kill:";
596 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
597 const MachineOperand &Op = MI->getOperand(i);
598 assert(Op.isReg() && "KILL instruction must have only register operands");
600 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
601 Str += (Op.isDef() ? "<def>" : "<kill>");
603 AP.OutStreamer.AddComment(Str);
604 AP.OutStreamer.AddBlankLine();
607 /// emitDebugValueComment - This method handles the target-independent form
608 /// of DBG_VALUE, returning true if it was able to do so. A false return
609 /// means the target will need to handle MI in EmitInstruction.
610 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
611 // This code handles only the 3-operand target-independent form.
612 if (MI->getNumOperands() != 3)
615 SmallString<128> Str;
616 raw_svector_ostream OS(Str);
617 OS << "DEBUG_VALUE: ";
619 DIVariable V(MI->getOperand(2).getMetadata());
620 if (V.getContext().isSubprogram()) {
621 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
625 OS << V.getName() << " <- ";
627 // The second operand is only an offset if it's an immediate.
628 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
629 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
631 // Register or immediate value. Register 0 means undef.
632 if (MI->getOperand(0).isFPImm()) {
633 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
634 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
635 OS << (double)APF.convertToFloat();
636 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
637 OS << APF.convertToDouble();
639 // There is no good way to print long double. Convert a copy to
640 // double. Ah well, it's only a comment.
642 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
644 OS << "(long double) " << APF.convertToDouble();
646 } else if (MI->getOperand(0).isImm()) {
647 OS << MI->getOperand(0).getImm();
648 } else if (MI->getOperand(0).isCImm()) {
649 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
652 if (MI->getOperand(0).isReg()) {
653 Reg = MI->getOperand(0).getReg();
655 assert(MI->getOperand(0).isFI() && "Unknown operand type");
656 const TargetFrameLowering *TFI = AP.TM.getFrameLowering();
657 Offset += TFI->getFrameIndexReference(*AP.MF,
658 MI->getOperand(0).getIndex(), Reg);
662 // Suppress offset, it is not meaningful here.
664 // NOTE: Want this comment at start of line, don't emit with AddComment.
665 AP.OutStreamer.emitRawComment(OS.str());
670 OS << AP.TM.getRegisterInfo()->getName(Reg);
674 OS << '+' << Offset << ']';
676 // NOTE: Want this comment at start of line, don't emit with AddComment.
677 AP.OutStreamer.emitRawComment(OS.str());
681 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
682 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
683 MF->getFunction()->needsUnwindTableEntry())
686 if (MMI->hasDebugInfo())
692 bool AsmPrinter::needsSEHMoves() {
693 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 &&
694 MF->getFunction()->needsUnwindTableEntry();
697 void AsmPrinter::emitPrologLabel(const MachineInstr &MI) {
698 const MCSymbol *Label = MI.getOperand(0).getMCSymbol();
700 ExceptionHandling::ExceptionsType ExceptionHandlingType =
701 MAI->getExceptionHandlingType();
702 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
703 ExceptionHandlingType != ExceptionHandling::ARM)
706 if (needsCFIMoves() == CFI_M_None)
709 if (MMI->getCompactUnwindEncoding() != 0)
710 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding());
712 const MachineModuleInfo &MMI = MF->getMMI();
713 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
714 bool FoundOne = false;
716 for (std::vector<MCCFIInstruction>::const_iterator I = Instrs.begin(),
717 E = Instrs.end(); I != E; ++I) {
718 if (I->getLabel() == Label) {
719 emitCFIInstruction(*I);
726 /// EmitFunctionBody - This method emits the body and trailer for a
728 void AsmPrinter::EmitFunctionBody() {
729 // Emit target-specific gunk before the function body.
730 EmitFunctionBodyStart();
732 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
734 // Print out code for the function.
735 bool HasAnyRealCode = false;
736 const MachineInstr *LastMI = 0;
737 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
739 // Print a label for the basic block.
740 EmitBasicBlockStart(I);
741 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
745 // Print the assembly for the instruction.
746 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
747 !II->isDebugValue()) {
748 HasAnyRealCode = true;
752 if (ShouldPrintDebugScopes) {
753 for (unsigned III = 0, EEE = Handlers.size(); III != EEE; ++III) {
754 const HandlerInfo &OI = Handlers[III];
755 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName,
756 TimePassesIsEnabled);
757 OI.Handler->beginInstruction(II);
762 emitComments(*II, OutStreamer.GetCommentOS());
764 switch (II->getOpcode()) {
765 case TargetOpcode::PROLOG_LABEL:
766 emitPrologLabel(*II);
769 case TargetOpcode::EH_LABEL:
770 case TargetOpcode::GC_LABEL:
771 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
773 case TargetOpcode::INLINEASM:
776 case TargetOpcode::DBG_VALUE:
778 if (!emitDebugValueComment(II, *this))
782 case TargetOpcode::IMPLICIT_DEF:
783 if (isVerbose()) emitImplicitDef(II);
785 case TargetOpcode::KILL:
786 if (isVerbose()) emitKill(II, *this);
793 if (ShouldPrintDebugScopes) {
794 for (unsigned III = 0, EEE = Handlers.size(); III != EEE; ++III) {
795 const HandlerInfo &OI = Handlers[III];
796 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName,
797 TimePassesIsEnabled);
798 OI.Handler->endInstruction();
804 // If the last instruction was a prolog label, then we have a situation where
805 // we emitted a prolog but no function body. This results in the ending prolog
806 // label equaling the end of function label and an invalid "row" in the
807 // FDE. We need to emit a noop in this situation so that the FDE's rows are
809 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
811 // If the function is empty and the object file uses .subsections_via_symbols,
812 // then we need to emit *something* to the function body to prevent the
813 // labels from collapsing together. Just emit a noop.
814 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
816 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
817 if (Noop.getOpcode()) {
818 OutStreamer.AddComment("avoids zero-length function");
819 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
820 } else // Target not mc-ized yet.
821 OutStreamer.EmitRawText(StringRef("\tnop\n"));
824 const Function *F = MF->getFunction();
825 for (Function::const_iterator i = F->begin(), e = F->end(); i != e; ++i) {
826 const BasicBlock *BB = i;
827 if (!BB->hasAddressTaken())
829 MCSymbol *Sym = GetBlockAddressSymbol(BB);
830 if (Sym->isDefined())
832 OutStreamer.AddComment("Address of block that was removed by CodeGen");
833 OutStreamer.EmitLabel(Sym);
836 // Emit target-specific gunk after the function body.
837 EmitFunctionBodyEnd();
839 // If the target wants a .size directive for the size of the function, emit
841 if (MAI->hasDotTypeDotSizeDirective()) {
842 // Create a symbol for the end of function, so we can get the size as
843 // difference between the function label and the temp label.
844 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
845 OutStreamer.EmitLabel(FnEndLabel);
847 const MCExpr *SizeExp =
848 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
849 MCSymbolRefExpr::Create(CurrentFnSymForSize,
852 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
855 // Emit post-function debug and/or EH information.
856 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
857 const HandlerInfo &OI = Handlers[I];
858 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, TimePassesIsEnabled);
859 OI.Handler->endFunction(MF);
863 // Print out jump tables referenced by the function.
866 OutStreamer.AddBlankLine();
869 /// EmitDwarfRegOp - Emit dwarf register operation.
870 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc,
871 bool Indirect) const {
872 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
873 int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
874 bool isSubRegister = Reg < 0;
877 for (MCSuperRegIterator SR(MLoc.getReg(), TRI); SR.isValid() && Reg < 0;
879 Reg = TRI->getDwarfRegNum(*SR, false);
881 Idx = TRI->getSubRegIndex(*SR, MLoc.getReg());
884 // FIXME: Handle cases like a super register being encoded as
885 // DW_OP_reg 32 DW_OP_piece 4 DW_OP_reg 33
887 // FIXME: We have no reasonable way of handling errors in here. The
888 // caller might be in the middle of an dwarf expression. We should
889 // probably assert that Reg >= 0 once debug info generation is more mature.
891 OutStreamer.AddComment("nop (invalid dwarf register number)");
892 EmitInt8(dwarf::DW_OP_nop);
896 if (MLoc.isIndirect() || Indirect) {
898 OutStreamer.AddComment(
899 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg));
900 EmitInt8(dwarf::DW_OP_breg0 + Reg);
902 OutStreamer.AddComment("DW_OP_bregx");
903 EmitInt8(dwarf::DW_OP_bregx);
904 OutStreamer.AddComment(Twine(Reg));
907 EmitSLEB128(!MLoc.isIndirect() ? 0 : MLoc.getOffset());
908 if (MLoc.isIndirect() && Indirect)
909 EmitInt8(dwarf::DW_OP_deref);
912 OutStreamer.AddComment(
913 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
914 EmitInt8(dwarf::DW_OP_reg0 + Reg);
916 OutStreamer.AddComment("DW_OP_regx");
917 EmitInt8(dwarf::DW_OP_regx);
918 OutStreamer.AddComment(Twine(Reg));
925 unsigned Size = TRI->getSubRegIdxSize(Idx);
926 unsigned Offset = TRI->getSubRegIdxOffset(Idx);
928 OutStreamer.AddComment("DW_OP_bit_piece");
929 EmitInt8(dwarf::DW_OP_bit_piece);
930 OutStreamer.AddComment(Twine(Size));
932 OutStreamer.AddComment(Twine(Offset));
935 OutStreamer.AddComment("DW_OP_piece");
936 EmitInt8(dwarf::DW_OP_piece);
937 unsigned ByteSize = Size / 8; // Assuming 8 bits per byte.
938 OutStreamer.AddComment(Twine(ByteSize));
939 EmitULEB128(ByteSize);
944 bool AsmPrinter::doFinalization(Module &M) {
945 // Emit global variables.
946 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
948 EmitGlobalVariable(I);
950 // Emit visibility info for declarations
951 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
952 const Function &F = *I;
953 if (!F.isDeclaration())
955 GlobalValue::VisibilityTypes V = F.getVisibility();
956 if (V == GlobalValue::DefaultVisibility)
959 MCSymbol *Name = getSymbol(&F);
960 EmitVisibility(Name, V, false);
963 // Emit module flags.
964 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
965 M.getModuleFlagsMetadata(ModuleFlags);
966 if (!ModuleFlags.empty())
967 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM);
969 // Make sure we wrote out everything we need.
972 // Finalize debug and EH information.
973 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
974 const HandlerInfo &OI = Handlers[I];
975 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName,
976 TimePassesIsEnabled);
977 OI.Handler->endModule();
983 // If the target wants to know about weak references, print them all.
984 if (MAI->getWeakRefDirective()) {
985 // FIXME: This is not lazy, it would be nice to only print weak references
986 // to stuff that is actually used. Note that doing so would require targets
987 // to notice uses in operands (due to constant exprs etc). This should
988 // happen with the MC stuff eventually.
990 // Print out module-level global variables here.
991 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
993 if (!I->hasExternalWeakLinkage()) continue;
994 OutStreamer.EmitSymbolAttribute(getSymbol(I), MCSA_WeakReference);
997 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
998 if (!I->hasExternalWeakLinkage()) continue;
999 OutStreamer.EmitSymbolAttribute(getSymbol(I), MCSA_WeakReference);
1003 if (MAI->hasSetDirective()) {
1004 OutStreamer.AddBlankLine();
1005 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
1007 MCSymbol *Name = getSymbol(I);
1009 const GlobalValue *GV = I->getAliasedGlobal();
1010 if (GV->isDeclaration()) {
1011 report_fatal_error(Name->getName() +
1012 ": Target doesn't support aliases to declarations");
1015 MCSymbol *Target = getSymbol(GV);
1017 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
1018 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
1019 else if (I->hasWeakLinkage() || I->hasLinkOnceLinkage())
1020 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
1022 assert(I->hasLocalLinkage() && "Invalid alias linkage");
1024 EmitVisibility(Name, I->getVisibility());
1026 // Emit the directives as assignments aka .set:
1027 OutStreamer.EmitAssignment(Name,
1028 MCSymbolRefExpr::Create(Target, OutContext));
1032 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1033 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1034 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1035 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
1036 MP->finishAssembly(*this);
1038 // Emit llvm.ident metadata in an '.ident' directive.
1039 EmitModuleIdents(M);
1041 // If we don't have any trampolines, then we don't require stack memory
1042 // to be executable. Some targets have a directive to declare this.
1043 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1044 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1045 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1046 OutStreamer.SwitchSection(S);
1048 // Allow the target to emit any magic that it wants at the end of the file,
1049 // after everything else has gone out.
1050 EmitEndOfAsmFile(M);
1052 delete Mang; Mang = 0;
1055 OutStreamer.Finish();
1056 OutStreamer.reset();
1061 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1063 // Get the function symbol.
1064 CurrentFnSym = getSymbol(MF.getFunction());
1065 CurrentFnSymForSize = CurrentFnSym;
1068 LI = &getAnalysis<MachineLoopInfo>();
1072 // SectionCPs - Keep track the alignment, constpool entries per Section.
1076 SmallVector<unsigned, 4> CPEs;
1077 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1081 /// EmitConstantPool - Print to the current output stream assembly
1082 /// representations of the constants in the constant pool MCP. This is
1083 /// used to print out constants which have been "spilled to memory" by
1084 /// the code generator.
1086 void AsmPrinter::EmitConstantPool() {
1087 const MachineConstantPool *MCP = MF->getConstantPool();
1088 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1089 if (CP.empty()) return;
1091 // Calculate sections for constant pool entries. We collect entries to go into
1092 // the same section together to reduce amount of section switch statements.
1093 SmallVector<SectionCPs, 4> CPSections;
1094 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1095 const MachineConstantPoolEntry &CPE = CP[i];
1096 unsigned Align = CPE.getAlignment();
1099 switch (CPE.getRelocationInfo()) {
1100 default: llvm_unreachable("Unknown section kind");
1101 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
1103 Kind = SectionKind::getReadOnlyWithRelLocal();
1106 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) {
1107 case 4: Kind = SectionKind::getMergeableConst4(); break;
1108 case 8: Kind = SectionKind::getMergeableConst8(); break;
1109 case 16: Kind = SectionKind::getMergeableConst16();break;
1110 default: Kind = SectionKind::getMergeableConst(); break;
1114 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
1116 // The number of sections are small, just do a linear search from the
1117 // last section to the first.
1119 unsigned SecIdx = CPSections.size();
1120 while (SecIdx != 0) {
1121 if (CPSections[--SecIdx].S == S) {
1127 SecIdx = CPSections.size();
1128 CPSections.push_back(SectionCPs(S, Align));
1131 if (Align > CPSections[SecIdx].Alignment)
1132 CPSections[SecIdx].Alignment = Align;
1133 CPSections[SecIdx].CPEs.push_back(i);
1136 // Now print stuff into the calculated sections.
1137 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1138 OutStreamer.SwitchSection(CPSections[i].S);
1139 EmitAlignment(Log2_32(CPSections[i].Alignment));
1141 unsigned Offset = 0;
1142 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1143 unsigned CPI = CPSections[i].CPEs[j];
1144 MachineConstantPoolEntry CPE = CP[CPI];
1146 // Emit inter-object padding for alignment.
1147 unsigned AlignMask = CPE.getAlignment() - 1;
1148 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1149 OutStreamer.EmitZeros(NewOffset - Offset);
1151 Type *Ty = CPE.getType();
1152 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty);
1153 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1155 if (CPE.isMachineConstantPoolEntry())
1156 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1158 EmitGlobalConstant(CPE.Val.ConstVal);
1163 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1164 /// by the current function to the current output stream.
1166 void AsmPrinter::EmitJumpTableInfo() {
1167 const DataLayout *DL = MF->getTarget().getDataLayout();
1168 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1169 if (MJTI == 0) return;
1170 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1171 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1172 if (JT.empty()) return;
1174 // Pick the directive to use to print the jump table entries, and switch to
1175 // the appropriate section.
1176 const Function *F = MF->getFunction();
1177 bool JTInDiffSection = false;
1178 if (// In PIC mode, we need to emit the jump table to the same section as the
1179 // function body itself, otherwise the label differences won't make sense.
1180 // FIXME: Need a better predicate for this: what about custom entries?
1181 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1182 // We should also do if the section name is NULL or function is declared
1183 // in discardable section
1184 // FIXME: this isn't the right predicate, should be based on the MCSection
1185 // for the function.
1186 F->isWeakForLinker()) {
1187 OutStreamer.SwitchSection(
1188 getObjFileLowering().SectionForGlobal(F, *Mang, TM));
1190 // Otherwise, drop it in the readonly section.
1191 const MCSection *ReadOnlySection =
1192 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1193 OutStreamer.SwitchSection(ReadOnlySection);
1194 JTInDiffSection = true;
1197 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout())));
1199 // Jump tables in code sections are marked with a data_region directive
1200 // where that's supported.
1201 if (!JTInDiffSection)
1202 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1204 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1205 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1207 // If this jump table was deleted, ignore it.
1208 if (JTBBs.empty()) continue;
1210 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1211 // .set directive for each unique entry. This reduces the number of
1212 // relocations the assembler will generate for the jump table.
1213 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1214 MAI->hasSetDirective()) {
1215 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1216 const TargetLowering *TLI = TM.getTargetLowering();
1217 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1218 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1219 const MachineBasicBlock *MBB = JTBBs[ii];
1220 if (!EmittedSets.insert(MBB)) continue;
1222 // .set LJTSet, LBB32-base
1224 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1225 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1226 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1230 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1231 // before each jump table. The first label is never referenced, but tells
1232 // the assembler and linker the extents of the jump table object. The
1233 // second label is actually referenced by the code.
1234 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1235 // FIXME: This doesn't have to have any specific name, just any randomly
1236 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1237 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1239 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1241 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1242 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1244 if (!JTInDiffSection)
1245 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1248 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1250 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1251 const MachineBasicBlock *MBB,
1252 unsigned UID) const {
1253 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1254 const MCExpr *Value = 0;
1255 switch (MJTI->getEntryKind()) {
1256 case MachineJumpTableInfo::EK_Inline:
1257 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1258 case MachineJumpTableInfo::EK_Custom32:
1259 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1262 case MachineJumpTableInfo::EK_BlockAddress:
1263 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1265 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1267 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1268 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1269 // with a relocation as gp-relative, e.g.:
1271 MCSymbol *MBBSym = MBB->getSymbol();
1272 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1276 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1277 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1278 // with a relocation as gp-relative, e.g.:
1280 MCSymbol *MBBSym = MBB->getSymbol();
1281 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1285 case MachineJumpTableInfo::EK_LabelDifference32: {
1286 // EK_LabelDifference32 - Each entry is the address of the block minus
1287 // the address of the jump table. This is used for PIC jump tables where
1288 // gprel32 is not supported. e.g.:
1289 // .word LBB123 - LJTI1_2
1290 // If the .set directive is supported, this is emitted as:
1291 // .set L4_5_set_123, LBB123 - LJTI1_2
1292 // .word L4_5_set_123
1294 // If we have emitted set directives for the jump table entries, print
1295 // them rather than the entries themselves. If we're emitting PIC, then
1296 // emit the table entries as differences between two text section labels.
1297 if (MAI->hasSetDirective()) {
1298 // If we used .set, reference the .set's symbol.
1299 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1303 // Otherwise, use the difference as the jump table entry.
1304 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1305 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1306 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1311 assert(Value && "Unknown entry kind!");
1313 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout());
1314 OutStreamer.EmitValue(Value, EntrySize);
1318 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1319 /// special global used by LLVM. If so, emit it and return true, otherwise
1320 /// do nothing and return false.
1321 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1322 if (GV->getName() == "llvm.used") {
1323 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1324 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1328 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1329 if (GV->getSection() == "llvm.metadata" ||
1330 GV->hasAvailableExternallyLinkage())
1333 if (!GV->hasAppendingLinkage()) return false;
1335 assert(GV->hasInitializer() && "Not a special LLVM global!");
1337 if (GV->getName() == "llvm.global_ctors") {
1338 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1340 if (TM.getRelocationModel() == Reloc::Static &&
1341 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1342 StringRef Sym(".constructors_used");
1343 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1349 if (GV->getName() == "llvm.global_dtors") {
1350 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1352 if (TM.getRelocationModel() == Reloc::Static &&
1353 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1354 StringRef Sym(".destructors_used");
1355 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1364 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1365 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1366 /// is true, as being used with this directive.
1367 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1368 // Should be an array of 'i8*'.
1369 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1370 const GlobalValue *GV =
1371 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1372 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, *Mang))
1373 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1377 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1379 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1380 // Should be an array of '{ int, void ()* }' structs. The first value is the
1382 if (!isa<ConstantArray>(List)) return;
1384 // Sanity check the structors list.
1385 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1386 if (!InitList) return; // Not an array!
1387 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1388 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs!
1389 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1390 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1392 // Gather the structors in a form that's convenient for sorting by priority.
1393 typedef std::pair<unsigned, Constant *> Structor;
1394 SmallVector<Structor, 8> Structors;
1395 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1396 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i));
1397 if (!CS) continue; // Malformed.
1398 if (CS->getOperand(1)->isNullValue())
1399 break; // Found a null terminator, skip the rest.
1400 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1401 if (!Priority) continue; // Malformed.
1402 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535),
1403 CS->getOperand(1)));
1406 // Emit the function pointers in the target-specific order
1407 const DataLayout *DL = TM.getDataLayout();
1408 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1409 std::stable_sort(Structors.begin(), Structors.end(), less_first());
1410 for (unsigned i = 0, e = Structors.size(); i != e; ++i) {
1411 const MCSection *OutputSection =
1413 getObjFileLowering().getStaticCtorSection(Structors[i].first) :
1414 getObjFileLowering().getStaticDtorSection(Structors[i].first));
1415 OutStreamer.SwitchSection(OutputSection);
1416 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1417 EmitAlignment(Align);
1418 EmitXXStructor(Structors[i].second);
1422 void AsmPrinter::EmitModuleIdents(Module &M) {
1423 if (!MAI->hasIdentDirective())
1426 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1427 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1428 const MDNode *N = NMD->getOperand(i);
1429 assert(N->getNumOperands() == 1 &&
1430 "llvm.ident metadata entry can have only one operand");
1431 const MDString *S = cast<MDString>(N->getOperand(0));
1432 OutStreamer.EmitIdent(S->getString());
1437 //===--------------------------------------------------------------------===//
1438 // Emission and print routines
1441 /// EmitInt8 - Emit a byte directive and value.
1443 void AsmPrinter::EmitInt8(int Value) const {
1444 OutStreamer.EmitIntValue(Value, 1);
1447 /// EmitInt16 - Emit a short directive and value.
1449 void AsmPrinter::EmitInt16(int Value) const {
1450 OutStreamer.EmitIntValue(Value, 2);
1453 /// EmitInt32 - Emit a long directive and value.
1455 void AsmPrinter::EmitInt32(int Value) const {
1456 OutStreamer.EmitIntValue(Value, 4);
1459 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1460 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1461 /// labels. This implicitly uses .set if it is available.
1462 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1463 unsigned Size) const {
1464 // Get the Hi-Lo expression.
1465 const MCExpr *Diff =
1466 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1467 MCSymbolRefExpr::Create(Lo, OutContext),
1470 if (!MAI->hasSetDirective()) {
1471 OutStreamer.EmitValue(Diff, Size);
1475 // Otherwise, emit with .set (aka assignment).
1476 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1477 OutStreamer.EmitAssignment(SetLabel, Diff);
1478 OutStreamer.EmitSymbolValue(SetLabel, Size);
1481 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1482 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1483 /// specify the labels. This implicitly uses .set if it is available.
1484 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1486 unsigned Size) const {
1488 // Emit Hi+Offset - Lo
1489 // Get the Hi+Offset expression.
1490 const MCExpr *Plus =
1491 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1492 MCConstantExpr::Create(Offset, OutContext),
1495 // Get the Hi+Offset-Lo expression.
1496 const MCExpr *Diff =
1497 MCBinaryExpr::CreateSub(Plus,
1498 MCSymbolRefExpr::Create(Lo, OutContext),
1501 if (!MAI->hasSetDirective())
1502 OutStreamer.EmitValue(Diff, Size);
1504 // Otherwise, emit with .set (aka assignment).
1505 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1506 OutStreamer.EmitAssignment(SetLabel, Diff);
1507 OutStreamer.EmitSymbolValue(SetLabel, Size);
1511 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1512 /// where the size in bytes of the directive is specified by Size and Label
1513 /// specifies the label. This implicitly uses .set if it is available.
1514 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1516 bool IsSectionRelative) const {
1517 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1518 OutStreamer.EmitCOFFSecRel32(Label);
1522 // Emit Label+Offset (or just Label if Offset is zero)
1523 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1525 Expr = MCBinaryExpr::CreateAdd(
1526 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1528 OutStreamer.EmitValue(Expr, Size);
1531 //===----------------------------------------------------------------------===//
1533 // EmitAlignment - Emit an alignment directive to the specified power of
1534 // two boundary. For example, if you pass in 3 here, you will get an 8
1535 // byte alignment. If a global value is specified, and if that global has
1536 // an explicit alignment requested, it will override the alignment request
1537 // if required for correctness.
1539 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1540 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits);
1542 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1544 if (getCurrentSection()->getKind().isText())
1545 OutStreamer.EmitCodeAlignment(1 << NumBits);
1547 OutStreamer.EmitValueToAlignment(1 << NumBits);
1550 //===----------------------------------------------------------------------===//
1551 // Constant emission.
1552 //===----------------------------------------------------------------------===//
1554 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1556 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1557 MCContext &Ctx = AP.OutContext;
1559 if (CV->isNullValue() || isa<UndefValue>(CV))
1560 return MCConstantExpr::Create(0, Ctx);
1562 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1563 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1565 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1566 return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx);
1568 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1569 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1571 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1573 llvm_unreachable("Unknown constant value to lower!");
1576 if (const MCExpr *RelocExpr =
1577 AP.getObjFileLowering().getExecutableRelativeSymbol(CE, *AP.Mang))
1580 switch (CE->getOpcode()) {
1582 // If the code isn't optimized, there may be outstanding folding
1583 // opportunities. Attempt to fold the expression using DataLayout as a
1584 // last resort before giving up.
1586 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout()))
1588 return lowerConstant(C, AP);
1590 // Otherwise report the problem to the user.
1593 raw_string_ostream OS(S);
1594 OS << "Unsupported expression in static initializer: ";
1595 CE->printAsOperand(OS, /*PrintType=*/false,
1596 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1597 report_fatal_error(OS.str());
1599 case Instruction::GetElementPtr: {
1600 const DataLayout &DL = *AP.TM.getDataLayout();
1601 // Generate a symbolic expression for the byte address
1602 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1603 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1605 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1609 int64_t Offset = OffsetAI.getSExtValue();
1610 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1614 case Instruction::Trunc:
1615 // We emit the value and depend on the assembler to truncate the generated
1616 // expression properly. This is important for differences between
1617 // blockaddress labels. Since the two labels are in the same function, it
1618 // is reasonable to treat their delta as a 32-bit value.
1620 case Instruction::BitCast:
1621 return lowerConstant(CE->getOperand(0), AP);
1623 case Instruction::IntToPtr: {
1624 const DataLayout &DL = *AP.TM.getDataLayout();
1625 // Handle casts to pointers by changing them into casts to the appropriate
1626 // integer type. This promotes constant folding and simplifies this code.
1627 Constant *Op = CE->getOperand(0);
1628 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1630 return lowerConstant(Op, AP);
1633 case Instruction::PtrToInt: {
1634 const DataLayout &DL = *AP.TM.getDataLayout();
1635 // Support only foldable casts to/from pointers that can be eliminated by
1636 // changing the pointer to the appropriately sized integer type.
1637 Constant *Op = CE->getOperand(0);
1638 Type *Ty = CE->getType();
1640 const MCExpr *OpExpr = lowerConstant(Op, AP);
1642 // We can emit the pointer value into this slot if the slot is an
1643 // integer slot equal to the size of the pointer.
1644 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1647 // Otherwise the pointer is smaller than the resultant integer, mask off
1648 // the high bits so we are sure to get a proper truncation if the input is
1650 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1651 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1652 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1655 // The MC library also has a right-shift operator, but it isn't consistently
1656 // signed or unsigned between different targets.
1657 case Instruction::Add:
1658 case Instruction::Sub:
1659 case Instruction::Mul:
1660 case Instruction::SDiv:
1661 case Instruction::SRem:
1662 case Instruction::Shl:
1663 case Instruction::And:
1664 case Instruction::Or:
1665 case Instruction::Xor: {
1666 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1667 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1668 switch (CE->getOpcode()) {
1669 default: llvm_unreachable("Unknown binary operator constant cast expr");
1670 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1671 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1672 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1673 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1674 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1675 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1676 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1677 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1678 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1684 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1686 /// isRepeatedByteSequence - Determine whether the given value is
1687 /// composed of a repeated sequence of identical bytes and return the
1688 /// byte value. If it is not a repeated sequence, return -1.
1689 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1690 StringRef Data = V->getRawDataValues();
1691 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1693 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1694 if (Data[i] != C) return -1;
1695 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1699 /// isRepeatedByteSequence - Determine whether the given value is
1700 /// composed of a repeated sequence of identical bytes and return the
1701 /// byte value. If it is not a repeated sequence, return -1.
1702 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1704 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1705 if (CI->getBitWidth() > 64) return -1;
1707 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType());
1708 uint64_t Value = CI->getZExtValue();
1710 // Make sure the constant is at least 8 bits long and has a power
1711 // of 2 bit width. This guarantees the constant bit width is
1712 // always a multiple of 8 bits, avoiding issues with padding out
1713 // to Size and other such corner cases.
1714 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1716 uint8_t Byte = static_cast<uint8_t>(Value);
1718 for (unsigned i = 1; i < Size; ++i) {
1720 if (static_cast<uint8_t>(Value) != Byte) return -1;
1724 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1725 // Make sure all array elements are sequences of the same repeated
1727 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1728 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1729 if (Byte == -1) return -1;
1731 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1732 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1733 if (ThisByte == -1) return -1;
1734 if (Byte != ThisByte) return -1;
1739 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1740 return isRepeatedByteSequence(CDS);
1745 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1748 // See if we can aggregate this into a .fill, if so, emit it as such.
1749 int Value = isRepeatedByteSequence(CDS, AP.TM);
1751 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType());
1752 // Don't emit a 1-byte object as a .fill.
1754 return AP.OutStreamer.EmitFill(Bytes, Value);
1757 // If this can be emitted with .ascii/.asciz, emit it as such.
1758 if (CDS->isString())
1759 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1761 // Otherwise, emit the values in successive locations.
1762 unsigned ElementByteSize = CDS->getElementByteSize();
1763 if (isa<IntegerType>(CDS->getElementType())) {
1764 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1766 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1767 CDS->getElementAsInteger(i));
1768 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1771 } else if (ElementByteSize == 4) {
1772 // FP Constants are printed as integer constants to avoid losing
1774 assert(CDS->getElementType()->isFloatTy());
1775 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1781 F = CDS->getElementAsFloat(i);
1783 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1784 AP.OutStreamer.EmitIntValue(I, 4);
1787 assert(CDS->getElementType()->isDoubleTy());
1788 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1794 F = CDS->getElementAsDouble(i);
1796 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1797 AP.OutStreamer.EmitIntValue(I, 8);
1801 const DataLayout &DL = *AP.TM.getDataLayout();
1802 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1803 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1804 CDS->getNumElements();
1805 if (unsigned Padding = Size - EmittedSize)
1806 AP.OutStreamer.EmitZeros(Padding);
1810 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1811 // See if we can aggregate some values. Make sure it can be
1812 // represented as a series of bytes of the constant value.
1813 int Value = isRepeatedByteSequence(CA, AP.TM);
1816 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType());
1817 AP.OutStreamer.EmitFill(Bytes, Value);
1820 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1821 emitGlobalConstantImpl(CA->getOperand(i), AP);
1825 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1826 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1827 emitGlobalConstantImpl(CV->getOperand(i), AP);
1829 const DataLayout &DL = *AP.TM.getDataLayout();
1830 unsigned Size = DL.getTypeAllocSize(CV->getType());
1831 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1832 CV->getType()->getNumElements();
1833 if (unsigned Padding = Size - EmittedSize)
1834 AP.OutStreamer.EmitZeros(Padding);
1837 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1838 // Print the fields in successive locations. Pad to align if needed!
1839 const DataLayout *DL = AP.TM.getDataLayout();
1840 unsigned Size = DL->getTypeAllocSize(CS->getType());
1841 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1842 uint64_t SizeSoFar = 0;
1843 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1844 const Constant *Field = CS->getOperand(i);
1846 // Check if padding is needed and insert one or more 0s.
1847 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1848 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1849 - Layout->getElementOffset(i)) - FieldSize;
1850 SizeSoFar += FieldSize + PadSize;
1852 // Now print the actual field value.
1853 emitGlobalConstantImpl(Field, AP);
1855 // Insert padding - this may include padding to increase the size of the
1856 // current field up to the ABI size (if the struct is not packed) as well
1857 // as padding to ensure that the next field starts at the right offset.
1858 AP.OutStreamer.EmitZeros(PadSize);
1860 assert(SizeSoFar == Layout->getSizeInBytes() &&
1861 "Layout of constant struct may be incorrect!");
1864 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1865 APInt API = CFP->getValueAPF().bitcastToAPInt();
1867 // First print a comment with what we think the original floating-point value
1868 // should have been.
1869 if (AP.isVerbose()) {
1870 SmallString<8> StrVal;
1871 CFP->getValueAPF().toString(StrVal);
1873 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1874 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1877 // Now iterate through the APInt chunks, emitting them in endian-correct
1878 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1880 unsigned NumBytes = API.getBitWidth() / 8;
1881 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1882 const uint64_t *p = API.getRawData();
1884 // PPC's long double has odd notions of endianness compared to how LLVM
1885 // handles it: p[0] goes first for *big* endian on PPC.
1886 if (AP.TM.getDataLayout()->isBigEndian() != CFP->getType()->isPPC_FP128Ty()) {
1887 int Chunk = API.getNumWords() - 1;
1890 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1892 for (; Chunk >= 0; --Chunk)
1893 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1896 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1897 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1900 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1903 // Emit the tail padding for the long double.
1904 const DataLayout &DL = *AP.TM.getDataLayout();
1905 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1906 DL.getTypeStoreSize(CFP->getType()));
1909 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1910 const DataLayout *DL = AP.TM.getDataLayout();
1911 unsigned BitWidth = CI->getBitWidth();
1913 // Copy the value as we may massage the layout for constants whose bit width
1914 // is not a multiple of 64-bits.
1915 APInt Realigned(CI->getValue());
1916 uint64_t ExtraBits = 0;
1917 unsigned ExtraBitsSize = BitWidth & 63;
1919 if (ExtraBitsSize) {
1920 // The bit width of the data is not a multiple of 64-bits.
1921 // The extra bits are expected to be at the end of the chunk of the memory.
1923 // * Nothing to be done, just record the extra bits to emit.
1925 // * Record the extra bits to emit.
1926 // * Realign the raw data to emit the chunks of 64-bits.
1927 if (DL->isBigEndian()) {
1928 // Basically the structure of the raw data is a chunk of 64-bits cells:
1929 // 0 1 BitWidth / 64
1930 // [chunk1][chunk2] ... [chunkN].
1931 // The most significant chunk is chunkN and it should be emitted first.
1932 // However, due to the alignment issue chunkN contains useless bits.
1933 // Realign the chunks so that they contain only useless information:
1934 // ExtraBits 0 1 (BitWidth / 64) - 1
1935 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1936 ExtraBits = Realigned.getRawData()[0] &
1937 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1938 Realigned = Realigned.lshr(ExtraBitsSize);
1940 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1943 // We don't expect assemblers to support integer data directives
1944 // for more than 64 bits, so we emit the data in at most 64-bit
1945 // quantities at a time.
1946 const uint64_t *RawData = Realigned.getRawData();
1947 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1948 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1949 AP.OutStreamer.EmitIntValue(Val, 8);
1952 if (ExtraBitsSize) {
1953 // Emit the extra bits after the 64-bits chunks.
1955 // Emit a directive that fills the expected size.
1956 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(CI->getType());
1957 Size -= (BitWidth / 64) * 8;
1958 assert(Size && Size * 8 >= ExtraBitsSize &&
1959 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1960 == ExtraBits && "Directive too small for extra bits.");
1961 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1965 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1966 const DataLayout *DL = AP.TM.getDataLayout();
1967 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1968 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1969 return AP.OutStreamer.EmitZeros(Size);
1971 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1978 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1979 CI->getZExtValue());
1980 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1983 emitGlobalConstantLargeInt(CI, AP);
1988 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1989 return emitGlobalConstantFP(CFP, AP);
1991 if (isa<ConstantPointerNull>(CV)) {
1992 AP.OutStreamer.EmitIntValue(0, Size);
1996 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1997 return emitGlobalConstantDataSequential(CDS, AP);
1999 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2000 return emitGlobalConstantArray(CVA, AP);
2002 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2003 return emitGlobalConstantStruct(CVS, AP);
2005 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2006 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2008 if (CE->getOpcode() == Instruction::BitCast)
2009 return emitGlobalConstantImpl(CE->getOperand(0), AP);
2012 // If the constant expression's size is greater than 64-bits, then we have
2013 // to emit the value in chunks. Try to constant fold the value and emit it
2015 Constant *New = ConstantFoldConstantExpression(CE, DL);
2016 if (New && New != CE)
2017 return emitGlobalConstantImpl(New, AP);
2021 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2022 return emitGlobalConstantVector(V, AP);
2024 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2025 // thread the streamer with EmitValue.
2026 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
2029 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2030 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2031 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType());
2033 emitGlobalConstantImpl(CV, *this);
2034 else if (MAI->hasSubsectionsViaSymbols()) {
2035 // If the global has zero size, emit a single byte so that two labels don't
2036 // look like they are at the same location.
2037 OutStreamer.EmitIntValue(0, 1);
2041 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2042 // Target doesn't support this yet!
2043 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2046 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2048 OS << '+' << Offset;
2049 else if (Offset < 0)
2053 //===----------------------------------------------------------------------===//
2054 // Symbol Lowering Routines.
2055 //===----------------------------------------------------------------------===//
2057 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2058 /// temporary label with the specified stem and unique ID.
2059 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
2060 const DataLayout *DL = TM.getDataLayout();
2061 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2065 /// GetTempSymbol - Return an assembler temporary label with the specified
2067 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
2068 const DataLayout *DL = TM.getDataLayout();
2069 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2074 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2075 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2078 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2079 return MMI->getAddrLabelSymbol(BB);
2082 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2083 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2084 const DataLayout *DL = TM.getDataLayout();
2085 return OutContext.GetOrCreateSymbol
2086 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2087 + "_" + Twine(CPID));
2090 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2091 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2092 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2095 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2096 /// FIXME: privatize to AsmPrinter.
2097 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2098 const DataLayout *DL = TM.getDataLayout();
2099 return OutContext.GetOrCreateSymbol
2100 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2101 Twine(UID) + "_set_" + Twine(MBBID));
2104 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2105 StringRef Suffix) const {
2106 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang);
2109 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2111 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2112 SmallString<60> NameStr;
2113 Mang->getNameWithPrefix(NameStr, Sym);
2114 return OutContext.GetOrCreateSymbol(NameStr.str());
2119 /// PrintParentLoopComment - Print comments about parent loops of this one.
2120 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2121 unsigned FunctionNumber) {
2122 if (Loop == 0) return;
2123 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2124 OS.indent(Loop->getLoopDepth()*2)
2125 << "Parent Loop BB" << FunctionNumber << "_"
2126 << Loop->getHeader()->getNumber()
2127 << " Depth=" << Loop->getLoopDepth() << '\n';
2131 /// PrintChildLoopComment - Print comments about child loops within
2132 /// the loop for this basic block, with nesting.
2133 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2134 unsigned FunctionNumber) {
2135 // Add child loop information
2136 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
2137 OS.indent((*CL)->getLoopDepth()*2)
2138 << "Child Loop BB" << FunctionNumber << "_"
2139 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
2141 PrintChildLoopComment(OS, *CL, FunctionNumber);
2145 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2146 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2147 const MachineLoopInfo *LI,
2148 const AsmPrinter &AP) {
2149 // Add loop depth information
2150 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2151 if (Loop == 0) return;
2153 MachineBasicBlock *Header = Loop->getHeader();
2154 assert(Header && "No header for loop");
2156 // If this block is not a loop header, just print out what is the loop header
2158 if (Header != &MBB) {
2159 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2160 Twine(AP.getFunctionNumber())+"_" +
2161 Twine(Loop->getHeader()->getNumber())+
2162 " Depth="+Twine(Loop->getLoopDepth()));
2166 // Otherwise, it is a loop header. Print out information about child and
2168 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2170 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2173 OS.indent(Loop->getLoopDepth()*2-2);
2178 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2180 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2184 /// EmitBasicBlockStart - This method prints the label for the specified
2185 /// MachineBasicBlock, an alignment (if present) and a comment describing
2186 /// it if appropriate.
2187 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
2188 // Emit an alignment directive for this block, if needed.
2189 if (unsigned Align = MBB->getAlignment())
2190 EmitAlignment(Align);
2192 // If the block has its address taken, emit any labels that were used to
2193 // reference the block. It is possible that there is more than one label
2194 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2195 // the references were generated.
2196 if (MBB->hasAddressTaken()) {
2197 const BasicBlock *BB = MBB->getBasicBlock();
2199 OutStreamer.AddComment("Block address taken");
2201 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
2203 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
2204 OutStreamer.EmitLabel(Syms[i]);
2207 // Print some verbose block comments.
2209 if (const BasicBlock *BB = MBB->getBasicBlock())
2211 OutStreamer.AddComment("%" + BB->getName());
2212 emitBasicBlockLoopComments(*MBB, LI, *this);
2215 // Print the main label for the block.
2216 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
2218 // NOTE: Want this comment at start of line, don't emit with AddComment.
2219 OutStreamer.emitRawComment(" BB#" + Twine(MBB->getNumber()) + ":", false);
2222 OutStreamer.EmitLabel(MBB->getSymbol());
2226 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2227 bool IsDefinition) const {
2228 MCSymbolAttr Attr = MCSA_Invalid;
2230 switch (Visibility) {
2232 case GlobalValue::HiddenVisibility:
2234 Attr = MAI->getHiddenVisibilityAttr();
2236 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2238 case GlobalValue::ProtectedVisibility:
2239 Attr = MAI->getProtectedVisibilityAttr();
2243 if (Attr != MCSA_Invalid)
2244 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2247 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2248 /// exactly one predecessor and the control transfer mechanism between
2249 /// the predecessor and this block is a fall-through.
2251 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2252 // If this is a landing pad, it isn't a fall through. If it has no preds,
2253 // then nothing falls through to it.
2254 if (MBB->isLandingPad() || MBB->pred_empty())
2257 // If there isn't exactly one predecessor, it can't be a fall through.
2258 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
2260 if (PI2 != MBB->pred_end())
2263 // The predecessor has to be immediately before this block.
2264 MachineBasicBlock *Pred = *PI;
2266 if (!Pred->isLayoutSuccessor(MBB))
2269 // If the block is completely empty, then it definitely does fall through.
2273 // Check the terminators in the previous blocks
2274 for (MachineBasicBlock::iterator II = Pred->getFirstTerminator(),
2275 IE = Pred->end(); II != IE; ++II) {
2276 MachineInstr &MI = *II;
2278 // If it is not a simple branch, we are in a table somewhere.
2279 if (!MI.isBranch() || MI.isIndirectBranch())
2282 // If we are the operands of one of the branches, this is not a fall
2283 // through. Note that targets with delay slots will usually bundle
2284 // terminators with the delay slot instruction.
2285 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2288 if (OP->isMBB() && OP->getMBB() == MBB)
2298 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
2299 if (!S->usesMetadata())
2302 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2303 gcp_map_type::iterator GCPI = GCMap.find(S);
2304 if (GCPI != GCMap.end())
2305 return GCPI->second;
2307 const char *Name = S->getName().c_str();
2309 for (GCMetadataPrinterRegistry::iterator
2310 I = GCMetadataPrinterRegistry::begin(),
2311 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2312 if (strcmp(Name, I->getName()) == 0) {
2313 GCMetadataPrinter *GMP = I->instantiate();
2315 GCMap.insert(std::make_pair(S, GMP));
2319 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2322 /// Pin vtable to this file.
2323 AsmPrinterHandler::~AsmPrinterHandler() {}