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(*Mang, GV);
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(getObjFileLowering().SectionForGlobal(F, Mang, TM));
496 EmitVisibility(CurrentFnSym, F->getVisibility());
498 EmitLinkage(F, CurrentFnSym);
499 EmitAlignment(MF->getAlignment(), F);
501 if (MAI->hasDotTypeDotSizeDirective())
502 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
505 F->printAsOperand(OutStreamer.GetCommentOS(),
506 /*PrintType=*/false, F->getParent());
507 OutStreamer.GetCommentOS() << '\n';
510 // Emit the CurrentFnSym. This is a virtual function to allow targets to
511 // do their wild and crazy things as required.
512 EmitFunctionEntryLabel();
514 // If the function had address-taken blocks that got deleted, then we have
515 // references to the dangling symbols. Emit them at the start of the function
516 // so that we don't get references to undefined symbols.
517 std::vector<MCSymbol*> DeadBlockSyms;
518 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
519 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
520 OutStreamer.AddComment("Address taken block that was later removed");
521 OutStreamer.EmitLabel(DeadBlockSyms[i]);
524 // Emit pre-function debug and/or EH information.
525 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
526 const HandlerInfo &OI = Handlers[I];
527 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, TimePassesIsEnabled);
528 OI.Handler->beginFunction(MF);
531 // Emit the prefix data.
532 if (F->hasPrefixData())
533 EmitGlobalConstant(F->getPrefixData());
536 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
537 /// function. This can be overridden by targets as required to do custom stuff.
538 void AsmPrinter::EmitFunctionEntryLabel() {
539 // The function label could have already been emitted if two symbols end up
540 // conflicting due to asm renaming. Detect this and emit an error.
541 if (CurrentFnSym->isUndefined())
542 return OutStreamer.EmitLabel(CurrentFnSym);
544 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
545 "' label emitted multiple times to assembly file");
548 /// emitComments - Pretty-print comments for instructions.
549 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
550 const MachineFunction *MF = MI.getParent()->getParent();
551 const TargetMachine &TM = MF->getTarget();
553 // Check for spills and reloads
556 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
558 // We assume a single instruction only has a spill or reload, not
560 const MachineMemOperand *MMO;
561 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
562 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
563 MMO = *MI.memoperands_begin();
564 CommentOS << MMO->getSize() << "-byte Reload\n";
566 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
567 if (FrameInfo->isSpillSlotObjectIndex(FI))
568 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
569 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
570 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
571 MMO = *MI.memoperands_begin();
572 CommentOS << MMO->getSize() << "-byte Spill\n";
574 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
575 if (FrameInfo->isSpillSlotObjectIndex(FI))
576 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
579 // Check for spill-induced copies
580 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
581 CommentOS << " Reload Reuse\n";
584 /// emitImplicitDef - This method emits the specified machine instruction
585 /// that is an implicit def.
586 void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
587 unsigned RegNo = MI->getOperand(0).getReg();
588 OutStreamer.AddComment(Twine("implicit-def: ") +
589 TM.getRegisterInfo()->getName(RegNo));
590 OutStreamer.AddBlankLine();
593 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
594 std::string Str = "kill:";
595 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
596 const MachineOperand &Op = MI->getOperand(i);
597 assert(Op.isReg() && "KILL instruction must have only register operands");
599 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
600 Str += (Op.isDef() ? "<def>" : "<kill>");
602 AP.OutStreamer.AddComment(Str);
603 AP.OutStreamer.AddBlankLine();
606 /// emitDebugValueComment - This method handles the target-independent form
607 /// of DBG_VALUE, returning true if it was able to do so. A false return
608 /// means the target will need to handle MI in EmitInstruction.
609 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
610 // This code handles only the 3-operand target-independent form.
611 if (MI->getNumOperands() != 3)
614 SmallString<128> Str;
615 raw_svector_ostream OS(Str);
616 OS << "DEBUG_VALUE: ";
618 DIVariable V(MI->getOperand(2).getMetadata());
619 if (V.getContext().isSubprogram()) {
620 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
624 OS << V.getName() << " <- ";
626 // The second operand is only an offset if it's an immediate.
627 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
628 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
630 // Register or immediate value. Register 0 means undef.
631 if (MI->getOperand(0).isFPImm()) {
632 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
633 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
634 OS << (double)APF.convertToFloat();
635 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
636 OS << APF.convertToDouble();
638 // There is no good way to print long double. Convert a copy to
639 // double. Ah well, it's only a comment.
641 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
643 OS << "(long double) " << APF.convertToDouble();
645 } else if (MI->getOperand(0).isImm()) {
646 OS << MI->getOperand(0).getImm();
647 } else if (MI->getOperand(0).isCImm()) {
648 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
651 if (MI->getOperand(0).isReg()) {
652 Reg = MI->getOperand(0).getReg();
654 assert(MI->getOperand(0).isFI() && "Unknown operand type");
655 const TargetFrameLowering *TFI = AP.TM.getFrameLowering();
656 Offset += TFI->getFrameIndexReference(*AP.MF,
657 MI->getOperand(0).getIndex(), Reg);
661 // Suppress offset, it is not meaningful here.
663 // NOTE: Want this comment at start of line, don't emit with AddComment.
664 AP.OutStreamer.emitRawComment(OS.str());
669 OS << AP.TM.getRegisterInfo()->getName(Reg);
673 OS << '+' << Offset << ']';
675 // NOTE: Want this comment at start of line, don't emit with AddComment.
676 AP.OutStreamer.emitRawComment(OS.str());
680 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
681 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
682 MF->getFunction()->needsUnwindTableEntry())
685 if (MMI->hasDebugInfo())
691 bool AsmPrinter::needsSEHMoves() {
692 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 &&
693 MF->getFunction()->needsUnwindTableEntry();
696 void AsmPrinter::emitPrologLabel(const MachineInstr &MI) {
697 const MCSymbol *Label = MI.getOperand(0).getMCSymbol();
699 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
702 if (needsCFIMoves() == CFI_M_None)
705 if (MMI->getCompactUnwindEncoding() != 0)
706 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding());
708 const MachineModuleInfo &MMI = MF->getMMI();
709 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
710 bool FoundOne = false;
712 for (std::vector<MCCFIInstruction>::const_iterator I = Instrs.begin(),
713 E = Instrs.end(); I != E; ++I) {
714 if (I->getLabel() == Label) {
715 emitCFIInstruction(*I);
722 /// EmitFunctionBody - This method emits the body and trailer for a
724 void AsmPrinter::EmitFunctionBody() {
725 // Emit target-specific gunk before the function body.
726 EmitFunctionBodyStart();
728 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
730 // Print out code for the function.
731 bool HasAnyRealCode = false;
732 const MachineInstr *LastMI = 0;
733 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
735 // Print a label for the basic block.
736 EmitBasicBlockStart(I);
737 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
741 // Print the assembly for the instruction.
742 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
743 !II->isDebugValue()) {
744 HasAnyRealCode = true;
748 if (ShouldPrintDebugScopes) {
749 for (unsigned III = 0, EEE = Handlers.size(); III != EEE; ++III) {
750 const HandlerInfo &OI = Handlers[III];
751 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName,
752 TimePassesIsEnabled);
753 OI.Handler->beginInstruction(II);
758 emitComments(*II, OutStreamer.GetCommentOS());
760 switch (II->getOpcode()) {
761 case TargetOpcode::PROLOG_LABEL:
762 emitPrologLabel(*II);
765 case TargetOpcode::EH_LABEL:
766 case TargetOpcode::GC_LABEL:
767 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
769 case TargetOpcode::INLINEASM:
772 case TargetOpcode::DBG_VALUE:
774 if (!emitDebugValueComment(II, *this))
778 case TargetOpcode::IMPLICIT_DEF:
779 if (isVerbose()) emitImplicitDef(II);
781 case TargetOpcode::KILL:
782 if (isVerbose()) emitKill(II, *this);
789 if (ShouldPrintDebugScopes) {
790 for (unsigned III = 0, EEE = Handlers.size(); III != EEE; ++III) {
791 const HandlerInfo &OI = Handlers[III];
792 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName,
793 TimePassesIsEnabled);
794 OI.Handler->endInstruction();
800 // If the last instruction was a prolog label, then we have a situation where
801 // we emitted a prolog but no function body. This results in the ending prolog
802 // label equaling the end of function label and an invalid "row" in the
803 // FDE. We need to emit a noop in this situation so that the FDE's rows are
805 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
807 // If the function is empty and the object file uses .subsections_via_symbols,
808 // then we need to emit *something* to the function body to prevent the
809 // labels from collapsing together. Just emit a noop.
810 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
812 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
813 if (Noop.getOpcode()) {
814 OutStreamer.AddComment("avoids zero-length function");
815 OutStreamer.EmitInstruction(Noop, getSubtargetInfo());
816 } else // Target not mc-ized yet.
817 OutStreamer.EmitRawText(StringRef("\tnop\n"));
820 const Function *F = MF->getFunction();
821 for (Function::const_iterator i = F->begin(), e = F->end(); i != e; ++i) {
822 const BasicBlock *BB = i;
823 if (!BB->hasAddressTaken())
825 MCSymbol *Sym = GetBlockAddressSymbol(BB);
826 if (Sym->isDefined())
828 OutStreamer.AddComment("Address of block that was removed by CodeGen");
829 OutStreamer.EmitLabel(Sym);
832 // Emit target-specific gunk after the function body.
833 EmitFunctionBodyEnd();
835 // If the target wants a .size directive for the size of the function, emit
837 if (MAI->hasDotTypeDotSizeDirective()) {
838 // Create a symbol for the end of function, so we can get the size as
839 // difference between the function label and the temp label.
840 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
841 OutStreamer.EmitLabel(FnEndLabel);
843 const MCExpr *SizeExp =
844 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
845 MCSymbolRefExpr::Create(CurrentFnSymForSize,
848 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
851 // Emit post-function debug and/or EH information.
852 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
853 const HandlerInfo &OI = Handlers[I];
854 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, TimePassesIsEnabled);
855 OI.Handler->endFunction(MF);
859 // Print out jump tables referenced by the function.
862 OutStreamer.AddBlankLine();
865 /// EmitDwarfRegOp - Emit dwarf register operation.
866 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc,
867 bool Indirect) const {
868 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
869 int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
871 for (MCSuperRegIterator SR(MLoc.getReg(), TRI); SR.isValid() && Reg < 0;
873 Reg = TRI->getDwarfRegNum(*SR, false);
874 // FIXME: Get the bit range this register uses of the superregister
875 // so that we can produce a DW_OP_bit_piece
878 // FIXME: Handle cases like a super register being encoded as
879 // DW_OP_reg 32 DW_OP_piece 4 DW_OP_reg 33
881 // FIXME: We have no reasonable way of handling errors in here. The
882 // caller might be in the middle of an dwarf expression. We should
883 // probably assert that Reg >= 0 once debug info generation is more mature.
885 if (MLoc.isIndirect() || Indirect) {
887 OutStreamer.AddComment(
888 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg));
889 EmitInt8(dwarf::DW_OP_breg0 + Reg);
891 OutStreamer.AddComment("DW_OP_bregx");
892 EmitInt8(dwarf::DW_OP_bregx);
893 OutStreamer.AddComment(Twine(Reg));
896 EmitSLEB128(!MLoc.isIndirect() ? 0 : MLoc.getOffset());
897 if (MLoc.isIndirect() && Indirect)
898 EmitInt8(dwarf::DW_OP_deref);
901 OutStreamer.AddComment(
902 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
903 EmitInt8(dwarf::DW_OP_reg0 + Reg);
905 OutStreamer.AddComment("DW_OP_regx");
906 EmitInt8(dwarf::DW_OP_regx);
907 OutStreamer.AddComment(Twine(Reg));
912 // FIXME: Produce a DW_OP_bit_piece if we used a superregister
915 bool AsmPrinter::doFinalization(Module &M) {
916 // Emit global variables.
917 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
919 EmitGlobalVariable(I);
921 // Emit visibility info for declarations
922 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
923 const Function &F = *I;
924 if (!F.isDeclaration())
926 GlobalValue::VisibilityTypes V = F.getVisibility();
927 if (V == GlobalValue::DefaultVisibility)
930 MCSymbol *Name = getSymbol(&F);
931 EmitVisibility(Name, V, false);
934 // Emit module flags.
935 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
936 M.getModuleFlagsMetadata(ModuleFlags);
937 if (!ModuleFlags.empty())
938 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, Mang, TM);
940 // Make sure we wrote out everything we need.
943 // Finalize debug and EH information.
944 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) {
945 const HandlerInfo &OI = Handlers[I];
946 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName,
947 TimePassesIsEnabled);
948 OI.Handler->endModule();
954 // If the target wants to know about weak references, print them all.
955 if (MAI->getWeakRefDirective()) {
956 // FIXME: This is not lazy, it would be nice to only print weak references
957 // to stuff that is actually used. Note that doing so would require targets
958 // to notice uses in operands (due to constant exprs etc). This should
959 // happen with the MC stuff eventually.
961 // Print out module-level global variables here.
962 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
964 if (!I->hasExternalWeakLinkage()) continue;
965 OutStreamer.EmitSymbolAttribute(getSymbol(I), MCSA_WeakReference);
968 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
969 if (!I->hasExternalWeakLinkage()) continue;
970 OutStreamer.EmitSymbolAttribute(getSymbol(I), MCSA_WeakReference);
974 if (MAI->hasSetDirective()) {
975 OutStreamer.AddBlankLine();
976 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
978 MCSymbol *Name = getSymbol(I);
980 const GlobalValue *GV = I->getAliasedGlobal();
981 if (GV->isDeclaration()) {
982 report_fatal_error(Name->getName() +
983 ": Target doesn't support aliases to declarations");
986 MCSymbol *Target = getSymbol(GV);
988 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
989 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
990 else if (I->hasWeakLinkage() || I->hasLinkOnceLinkage())
991 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
993 assert(I->hasLocalLinkage() && "Invalid alias linkage");
995 EmitVisibility(Name, I->getVisibility());
997 // Emit the directives as assignments aka .set:
998 OutStreamer.EmitAssignment(Name,
999 MCSymbolRefExpr::Create(Target, OutContext));
1003 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1004 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
1005 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1006 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
1007 MP->finishAssembly(*this);
1009 // Emit llvm.ident metadata in an '.ident' directive.
1010 EmitModuleIdents(M);
1012 // If we don't have any trampolines, then we don't require stack memory
1013 // to be executable. Some targets have a directive to declare this.
1014 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1015 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1016 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1017 OutStreamer.SwitchSection(S);
1019 // Allow the target to emit any magic that it wants at the end of the file,
1020 // after everything else has gone out.
1021 EmitEndOfAsmFile(M);
1023 delete Mang; Mang = 0;
1026 OutStreamer.Finish();
1027 OutStreamer.reset();
1032 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1034 // Get the function symbol.
1035 CurrentFnSym = getSymbol(MF.getFunction());
1036 CurrentFnSymForSize = CurrentFnSym;
1039 LI = &getAnalysis<MachineLoopInfo>();
1043 // SectionCPs - Keep track the alignment, constpool entries per Section.
1047 SmallVector<unsigned, 4> CPEs;
1048 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
1052 /// EmitConstantPool - Print to the current output stream assembly
1053 /// representations of the constants in the constant pool MCP. This is
1054 /// used to print out constants which have been "spilled to memory" by
1055 /// the code generator.
1057 void AsmPrinter::EmitConstantPool() {
1058 const MachineConstantPool *MCP = MF->getConstantPool();
1059 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1060 if (CP.empty()) return;
1062 // Calculate sections for constant pool entries. We collect entries to go into
1063 // the same section together to reduce amount of section switch statements.
1064 SmallVector<SectionCPs, 4> CPSections;
1065 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1066 const MachineConstantPoolEntry &CPE = CP[i];
1067 unsigned Align = CPE.getAlignment();
1070 switch (CPE.getRelocationInfo()) {
1071 default: llvm_unreachable("Unknown section kind");
1072 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
1074 Kind = SectionKind::getReadOnlyWithRelLocal();
1077 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) {
1078 case 4: Kind = SectionKind::getMergeableConst4(); break;
1079 case 8: Kind = SectionKind::getMergeableConst8(); break;
1080 case 16: Kind = SectionKind::getMergeableConst16();break;
1081 default: Kind = SectionKind::getMergeableConst(); break;
1085 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
1087 // The number of sections are small, just do a linear search from the
1088 // last section to the first.
1090 unsigned SecIdx = CPSections.size();
1091 while (SecIdx != 0) {
1092 if (CPSections[--SecIdx].S == S) {
1098 SecIdx = CPSections.size();
1099 CPSections.push_back(SectionCPs(S, Align));
1102 if (Align > CPSections[SecIdx].Alignment)
1103 CPSections[SecIdx].Alignment = Align;
1104 CPSections[SecIdx].CPEs.push_back(i);
1107 // Now print stuff into the calculated sections.
1108 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1109 OutStreamer.SwitchSection(CPSections[i].S);
1110 EmitAlignment(Log2_32(CPSections[i].Alignment));
1112 unsigned Offset = 0;
1113 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1114 unsigned CPI = CPSections[i].CPEs[j];
1115 MachineConstantPoolEntry CPE = CP[CPI];
1117 // Emit inter-object padding for alignment.
1118 unsigned AlignMask = CPE.getAlignment() - 1;
1119 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1120 OutStreamer.EmitZeros(NewOffset - Offset);
1122 Type *Ty = CPE.getType();
1123 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty);
1124 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1126 if (CPE.isMachineConstantPoolEntry())
1127 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1129 EmitGlobalConstant(CPE.Val.ConstVal);
1134 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1135 /// by the current function to the current output stream.
1137 void AsmPrinter::EmitJumpTableInfo() {
1138 const DataLayout *DL = MF->getTarget().getDataLayout();
1139 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1140 if (MJTI == 0) return;
1141 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1142 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1143 if (JT.empty()) return;
1145 // Pick the directive to use to print the jump table entries, and switch to
1146 // the appropriate section.
1147 const Function *F = MF->getFunction();
1148 bool JTInDiffSection = false;
1149 if (// In PIC mode, we need to emit the jump table to the same section as the
1150 // function body itself, otherwise the label differences won't make sense.
1151 // FIXME: Need a better predicate for this: what about custom entries?
1152 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1153 // We should also do if the section name is NULL or function is declared
1154 // in discardable section
1155 // FIXME: this isn't the right predicate, should be based on the MCSection
1156 // for the function.
1157 F->isWeakForLinker()) {
1158 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
1160 // Otherwise, drop it in the readonly section.
1161 const MCSection *ReadOnlySection =
1162 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1163 OutStreamer.SwitchSection(ReadOnlySection);
1164 JTInDiffSection = true;
1167 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout())));
1169 // Jump tables in code sections are marked with a data_region directive
1170 // where that's supported.
1171 if (!JTInDiffSection)
1172 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1174 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1175 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1177 // If this jump table was deleted, ignore it.
1178 if (JTBBs.empty()) continue;
1180 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1181 // .set directive for each unique entry. This reduces the number of
1182 // relocations the assembler will generate for the jump table.
1183 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1184 MAI->hasSetDirective()) {
1185 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1186 const TargetLowering *TLI = TM.getTargetLowering();
1187 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1188 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1189 const MachineBasicBlock *MBB = JTBBs[ii];
1190 if (!EmittedSets.insert(MBB)) continue;
1192 // .set LJTSet, LBB32-base
1194 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1195 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1196 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1200 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1201 // before each jump table. The first label is never referenced, but tells
1202 // the assembler and linker the extents of the jump table object. The
1203 // second label is actually referenced by the code.
1204 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix())
1205 // FIXME: This doesn't have to have any specific name, just any randomly
1206 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1207 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1209 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1211 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1212 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1214 if (!JTInDiffSection)
1215 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1218 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1220 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1221 const MachineBasicBlock *MBB,
1222 unsigned UID) const {
1223 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1224 const MCExpr *Value = 0;
1225 switch (MJTI->getEntryKind()) {
1226 case MachineJumpTableInfo::EK_Inline:
1227 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1228 case MachineJumpTableInfo::EK_Custom32:
1229 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1232 case MachineJumpTableInfo::EK_BlockAddress:
1233 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1235 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1237 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1238 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1239 // with a relocation as gp-relative, e.g.:
1241 MCSymbol *MBBSym = MBB->getSymbol();
1242 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1246 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1247 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1248 // with a relocation as gp-relative, e.g.:
1250 MCSymbol *MBBSym = MBB->getSymbol();
1251 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1255 case MachineJumpTableInfo::EK_LabelDifference32: {
1256 // EK_LabelDifference32 - Each entry is the address of the block minus
1257 // the address of the jump table. This is used for PIC jump tables where
1258 // gprel32 is not supported. e.g.:
1259 // .word LBB123 - LJTI1_2
1260 // If the .set directive is supported, this is emitted as:
1261 // .set L4_5_set_123, LBB123 - LJTI1_2
1262 // .word L4_5_set_123
1264 // If we have emitted set directives for the jump table entries, print
1265 // them rather than the entries themselves. If we're emitting PIC, then
1266 // emit the table entries as differences between two text section labels.
1267 if (MAI->hasSetDirective()) {
1268 // If we used .set, reference the .set's symbol.
1269 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1273 // Otherwise, use the difference as the jump table entry.
1274 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1275 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1276 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1281 assert(Value && "Unknown entry kind!");
1283 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout());
1284 OutStreamer.EmitValue(Value, EntrySize);
1288 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1289 /// special global used by LLVM. If so, emit it and return true, otherwise
1290 /// do nothing and return false.
1291 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1292 if (GV->getName() == "llvm.used") {
1293 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1294 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1298 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1299 if (GV->getSection() == "llvm.metadata" ||
1300 GV->hasAvailableExternallyLinkage())
1303 if (!GV->hasAppendingLinkage()) return false;
1305 assert(GV->hasInitializer() && "Not a special LLVM global!");
1307 if (GV->getName() == "llvm.global_ctors") {
1308 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1310 if (TM.getRelocationModel() == Reloc::Static &&
1311 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1312 StringRef Sym(".constructors_used");
1313 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1319 if (GV->getName() == "llvm.global_dtors") {
1320 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1322 if (TM.getRelocationModel() == Reloc::Static &&
1323 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1324 StringRef Sym(".destructors_used");
1325 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1334 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1335 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1336 /// is true, as being used with this directive.
1337 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1338 // Should be an array of 'i8*'.
1339 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1340 const GlobalValue *GV =
1341 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1342 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1343 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1347 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1349 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1350 // Should be an array of '{ int, void ()* }' structs. The first value is the
1352 if (!isa<ConstantArray>(List)) return;
1354 // Sanity check the structors list.
1355 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1356 if (!InitList) return; // Not an array!
1357 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1358 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs!
1359 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1360 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1362 // Gather the structors in a form that's convenient for sorting by priority.
1363 typedef std::pair<unsigned, Constant *> Structor;
1364 SmallVector<Structor, 8> Structors;
1365 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1366 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i));
1367 if (!CS) continue; // Malformed.
1368 if (CS->getOperand(1)->isNullValue())
1369 break; // Found a null terminator, skip the rest.
1370 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1371 if (!Priority) continue; // Malformed.
1372 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535),
1373 CS->getOperand(1)));
1376 // Emit the function pointers in the target-specific order
1377 const DataLayout *DL = TM.getDataLayout();
1378 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1379 std::stable_sort(Structors.begin(), Structors.end(), less_first());
1380 for (unsigned i = 0, e = Structors.size(); i != e; ++i) {
1381 const MCSection *OutputSection =
1383 getObjFileLowering().getStaticCtorSection(Structors[i].first) :
1384 getObjFileLowering().getStaticDtorSection(Structors[i].first));
1385 OutStreamer.SwitchSection(OutputSection);
1386 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1387 EmitAlignment(Align);
1388 EmitXXStructor(Structors[i].second);
1392 void AsmPrinter::EmitModuleIdents(Module &M) {
1393 if (!MAI->hasIdentDirective())
1396 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1397 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1398 const MDNode *N = NMD->getOperand(i);
1399 assert(N->getNumOperands() == 1 &&
1400 "llvm.ident metadata entry can have only one operand");
1401 const MDString *S = cast<MDString>(N->getOperand(0));
1402 OutStreamer.EmitIdent(S->getString());
1407 //===--------------------------------------------------------------------===//
1408 // Emission and print routines
1411 /// EmitInt8 - Emit a byte directive and value.
1413 void AsmPrinter::EmitInt8(int Value) const {
1414 OutStreamer.EmitIntValue(Value, 1);
1417 /// EmitInt16 - Emit a short directive and value.
1419 void AsmPrinter::EmitInt16(int Value) const {
1420 OutStreamer.EmitIntValue(Value, 2);
1423 /// EmitInt32 - Emit a long directive and value.
1425 void AsmPrinter::EmitInt32(int Value) const {
1426 OutStreamer.EmitIntValue(Value, 4);
1429 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1430 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1431 /// labels. This implicitly uses .set if it is available.
1432 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1433 unsigned Size) const {
1434 // Get the Hi-Lo expression.
1435 const MCExpr *Diff =
1436 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1437 MCSymbolRefExpr::Create(Lo, OutContext),
1440 if (!MAI->hasSetDirective()) {
1441 OutStreamer.EmitValue(Diff, Size);
1445 // Otherwise, emit with .set (aka assignment).
1446 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1447 OutStreamer.EmitAssignment(SetLabel, Diff);
1448 OutStreamer.EmitSymbolValue(SetLabel, Size);
1451 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1452 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1453 /// specify the labels. This implicitly uses .set if it is available.
1454 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1456 unsigned Size) const {
1458 // Emit Hi+Offset - Lo
1459 // Get the Hi+Offset expression.
1460 const MCExpr *Plus =
1461 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1462 MCConstantExpr::Create(Offset, OutContext),
1465 // Get the Hi+Offset-Lo expression.
1466 const MCExpr *Diff =
1467 MCBinaryExpr::CreateSub(Plus,
1468 MCSymbolRefExpr::Create(Lo, OutContext),
1471 if (!MAI->hasSetDirective())
1472 OutStreamer.EmitValue(Diff, Size);
1474 // Otherwise, emit with .set (aka assignment).
1475 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1476 OutStreamer.EmitAssignment(SetLabel, Diff);
1477 OutStreamer.EmitSymbolValue(SetLabel, Size);
1481 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1482 /// where the size in bytes of the directive is specified by Size and Label
1483 /// specifies the label. This implicitly uses .set if it is available.
1484 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1486 bool IsSectionRelative) const {
1487 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1488 OutStreamer.EmitCOFFSecRel32(Label);
1492 // Emit Label+Offset (or just Label if Offset is zero)
1493 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1495 Expr = MCBinaryExpr::CreateAdd(
1496 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext);
1498 OutStreamer.EmitValue(Expr, Size);
1501 //===----------------------------------------------------------------------===//
1503 // EmitAlignment - Emit an alignment directive to the specified power of
1504 // two boundary. For example, if you pass in 3 here, you will get an 8
1505 // byte alignment. If a global value is specified, and if that global has
1506 // an explicit alignment requested, it will override the alignment request
1507 // if required for correctness.
1509 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1510 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits);
1512 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1514 if (getCurrentSection()->getKind().isText())
1515 OutStreamer.EmitCodeAlignment(1 << NumBits);
1517 OutStreamer.EmitValueToAlignment(1 << NumBits);
1520 //===----------------------------------------------------------------------===//
1521 // Constant emission.
1522 //===----------------------------------------------------------------------===//
1524 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1526 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1527 MCContext &Ctx = AP.OutContext;
1529 if (CV->isNullValue() || isa<UndefValue>(CV))
1530 return MCConstantExpr::Create(0, Ctx);
1532 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1533 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1535 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1536 return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx);
1538 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1539 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1541 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1543 llvm_unreachable("Unknown constant value to lower!");
1546 if (const MCExpr *RelocExpr =
1547 AP.getObjFileLowering().getExecutableRelativeSymbol(CE, AP.Mang))
1550 switch (CE->getOpcode()) {
1552 // If the code isn't optimized, there may be outstanding folding
1553 // opportunities. Attempt to fold the expression using DataLayout as a
1554 // last resort before giving up.
1556 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout()))
1558 return lowerConstant(C, AP);
1560 // Otherwise report the problem to the user.
1563 raw_string_ostream OS(S);
1564 OS << "Unsupported expression in static initializer: ";
1565 CE->printAsOperand(OS, /*PrintType=*/false,
1566 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1567 report_fatal_error(OS.str());
1569 case Instruction::GetElementPtr: {
1570 const DataLayout &DL = *AP.TM.getDataLayout();
1571 // Generate a symbolic expression for the byte address
1572 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0);
1573 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1575 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1579 int64_t Offset = OffsetAI.getSExtValue();
1580 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1584 case Instruction::Trunc:
1585 // We emit the value and depend on the assembler to truncate the generated
1586 // expression properly. This is important for differences between
1587 // blockaddress labels. Since the two labels are in the same function, it
1588 // is reasonable to treat their delta as a 32-bit value.
1590 case Instruction::BitCast:
1591 return lowerConstant(CE->getOperand(0), AP);
1593 case Instruction::IntToPtr: {
1594 const DataLayout &DL = *AP.TM.getDataLayout();
1595 // Handle casts to pointers by changing them into casts to the appropriate
1596 // integer type. This promotes constant folding and simplifies this code.
1597 Constant *Op = CE->getOperand(0);
1598 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
1600 return lowerConstant(Op, AP);
1603 case Instruction::PtrToInt: {
1604 const DataLayout &DL = *AP.TM.getDataLayout();
1605 // Support only foldable casts to/from pointers that can be eliminated by
1606 // changing the pointer to the appropriately sized integer type.
1607 Constant *Op = CE->getOperand(0);
1608 Type *Ty = CE->getType();
1610 const MCExpr *OpExpr = lowerConstant(Op, AP);
1612 // We can emit the pointer value into this slot if the slot is an
1613 // integer slot equal to the size of the pointer.
1614 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1617 // Otherwise the pointer is smaller than the resultant integer, mask off
1618 // the high bits so we are sure to get a proper truncation if the input is
1620 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1621 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1622 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1625 // The MC library also has a right-shift operator, but it isn't consistently
1626 // signed or unsigned between different targets.
1627 case Instruction::Add:
1628 case Instruction::Sub:
1629 case Instruction::Mul:
1630 case Instruction::SDiv:
1631 case Instruction::SRem:
1632 case Instruction::Shl:
1633 case Instruction::And:
1634 case Instruction::Or:
1635 case Instruction::Xor: {
1636 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1637 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1638 switch (CE->getOpcode()) {
1639 default: llvm_unreachable("Unknown binary operator constant cast expr");
1640 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1641 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1642 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1643 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1644 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1645 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1646 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1647 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1648 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1654 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1656 /// isRepeatedByteSequence - Determine whether the given value is
1657 /// composed of a repeated sequence of identical bytes and return the
1658 /// byte value. If it is not a repeated sequence, return -1.
1659 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1660 StringRef Data = V->getRawDataValues();
1661 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1663 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1664 if (Data[i] != C) return -1;
1665 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1669 /// isRepeatedByteSequence - Determine whether the given value is
1670 /// composed of a repeated sequence of identical bytes and return the
1671 /// byte value. If it is not a repeated sequence, return -1.
1672 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1674 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1675 if (CI->getBitWidth() > 64) return -1;
1677 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType());
1678 uint64_t Value = CI->getZExtValue();
1680 // Make sure the constant is at least 8 bits long and has a power
1681 // of 2 bit width. This guarantees the constant bit width is
1682 // always a multiple of 8 bits, avoiding issues with padding out
1683 // to Size and other such corner cases.
1684 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1686 uint8_t Byte = static_cast<uint8_t>(Value);
1688 for (unsigned i = 1; i < Size; ++i) {
1690 if (static_cast<uint8_t>(Value) != Byte) return -1;
1694 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1695 // Make sure all array elements are sequences of the same repeated
1697 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1698 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1699 if (Byte == -1) return -1;
1701 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1702 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1703 if (ThisByte == -1) return -1;
1704 if (Byte != ThisByte) return -1;
1709 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1710 return isRepeatedByteSequence(CDS);
1715 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1718 // See if we can aggregate this into a .fill, if so, emit it as such.
1719 int Value = isRepeatedByteSequence(CDS, AP.TM);
1721 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType());
1722 // Don't emit a 1-byte object as a .fill.
1724 return AP.OutStreamer.EmitFill(Bytes, Value);
1727 // If this can be emitted with .ascii/.asciz, emit it as such.
1728 if (CDS->isString())
1729 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1731 // Otherwise, emit the values in successive locations.
1732 unsigned ElementByteSize = CDS->getElementByteSize();
1733 if (isa<IntegerType>(CDS->getElementType())) {
1734 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1736 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1737 CDS->getElementAsInteger(i));
1738 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1741 } else if (ElementByteSize == 4) {
1742 // FP Constants are printed as integer constants to avoid losing
1744 assert(CDS->getElementType()->isFloatTy());
1745 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1751 F = CDS->getElementAsFloat(i);
1753 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1754 AP.OutStreamer.EmitIntValue(I, 4);
1757 assert(CDS->getElementType()->isDoubleTy());
1758 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1764 F = CDS->getElementAsDouble(i);
1766 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1767 AP.OutStreamer.EmitIntValue(I, 8);
1771 const DataLayout &DL = *AP.TM.getDataLayout();
1772 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1773 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1774 CDS->getNumElements();
1775 if (unsigned Padding = Size - EmittedSize)
1776 AP.OutStreamer.EmitZeros(Padding);
1780 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1781 // See if we can aggregate some values. Make sure it can be
1782 // represented as a series of bytes of the constant value.
1783 int Value = isRepeatedByteSequence(CA, AP.TM);
1786 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType());
1787 AP.OutStreamer.EmitFill(Bytes, Value);
1790 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1791 emitGlobalConstantImpl(CA->getOperand(i), AP);
1795 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1796 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1797 emitGlobalConstantImpl(CV->getOperand(i), AP);
1799 const DataLayout &DL = *AP.TM.getDataLayout();
1800 unsigned Size = DL.getTypeAllocSize(CV->getType());
1801 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1802 CV->getType()->getNumElements();
1803 if (unsigned Padding = Size - EmittedSize)
1804 AP.OutStreamer.EmitZeros(Padding);
1807 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1808 // Print the fields in successive locations. Pad to align if needed!
1809 const DataLayout *DL = AP.TM.getDataLayout();
1810 unsigned Size = DL->getTypeAllocSize(CS->getType());
1811 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1812 uint64_t SizeSoFar = 0;
1813 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1814 const Constant *Field = CS->getOperand(i);
1816 // Check if padding is needed and insert one or more 0s.
1817 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1818 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1819 - Layout->getElementOffset(i)) - FieldSize;
1820 SizeSoFar += FieldSize + PadSize;
1822 // Now print the actual field value.
1823 emitGlobalConstantImpl(Field, AP);
1825 // Insert padding - this may include padding to increase the size of the
1826 // current field up to the ABI size (if the struct is not packed) as well
1827 // as padding to ensure that the next field starts at the right offset.
1828 AP.OutStreamer.EmitZeros(PadSize);
1830 assert(SizeSoFar == Layout->getSizeInBytes() &&
1831 "Layout of constant struct may be incorrect!");
1834 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1835 APInt API = CFP->getValueAPF().bitcastToAPInt();
1837 // First print a comment with what we think the original floating-point value
1838 // should have been.
1839 if (AP.isVerbose()) {
1840 SmallString<8> StrVal;
1841 CFP->getValueAPF().toString(StrVal);
1843 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1844 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1847 // Now iterate through the APInt chunks, emitting them in endian-correct
1848 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1850 unsigned NumBytes = API.getBitWidth() / 8;
1851 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1852 const uint64_t *p = API.getRawData();
1854 // PPC's long double has odd notions of endianness compared to how LLVM
1855 // handles it: p[0] goes first for *big* endian on PPC.
1856 if (AP.TM.getDataLayout()->isBigEndian() != CFP->getType()->isPPC_FP128Ty()) {
1857 int Chunk = API.getNumWords() - 1;
1860 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1862 for (; Chunk >= 0; --Chunk)
1863 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1866 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1867 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1870 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1873 // Emit the tail padding for the long double.
1874 const DataLayout &DL = *AP.TM.getDataLayout();
1875 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1876 DL.getTypeStoreSize(CFP->getType()));
1879 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1880 const DataLayout *DL = AP.TM.getDataLayout();
1881 unsigned BitWidth = CI->getBitWidth();
1883 // Copy the value as we may massage the layout for constants whose bit width
1884 // is not a multiple of 64-bits.
1885 APInt Realigned(CI->getValue());
1886 uint64_t ExtraBits = 0;
1887 unsigned ExtraBitsSize = BitWidth & 63;
1889 if (ExtraBitsSize) {
1890 // The bit width of the data is not a multiple of 64-bits.
1891 // The extra bits are expected to be at the end of the chunk of the memory.
1893 // * Nothing to be done, just record the extra bits to emit.
1895 // * Record the extra bits to emit.
1896 // * Realign the raw data to emit the chunks of 64-bits.
1897 if (DL->isBigEndian()) {
1898 // Basically the structure of the raw data is a chunk of 64-bits cells:
1899 // 0 1 BitWidth / 64
1900 // [chunk1][chunk2] ... [chunkN].
1901 // The most significant chunk is chunkN and it should be emitted first.
1902 // However, due to the alignment issue chunkN contains useless bits.
1903 // Realign the chunks so that they contain only useless information:
1904 // ExtraBits 0 1 (BitWidth / 64) - 1
1905 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1906 ExtraBits = Realigned.getRawData()[0] &
1907 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1908 Realigned = Realigned.lshr(ExtraBitsSize);
1910 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1913 // We don't expect assemblers to support integer data directives
1914 // for more than 64 bits, so we emit the data in at most 64-bit
1915 // quantities at a time.
1916 const uint64_t *RawData = Realigned.getRawData();
1917 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1918 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1919 AP.OutStreamer.EmitIntValue(Val, 8);
1922 if (ExtraBitsSize) {
1923 // Emit the extra bits after the 64-bits chunks.
1925 // Emit a directive that fills the expected size.
1926 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(CI->getType());
1927 Size -= (BitWidth / 64) * 8;
1928 assert(Size && Size * 8 >= ExtraBitsSize &&
1929 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1930 == ExtraBits && "Directive too small for extra bits.");
1931 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1935 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1936 const DataLayout *DL = AP.TM.getDataLayout();
1937 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1938 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1939 return AP.OutStreamer.EmitZeros(Size);
1941 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1948 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1949 CI->getZExtValue());
1950 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1953 emitGlobalConstantLargeInt(CI, AP);
1958 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1959 return emitGlobalConstantFP(CFP, AP);
1961 if (isa<ConstantPointerNull>(CV)) {
1962 AP.OutStreamer.EmitIntValue(0, Size);
1966 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1967 return emitGlobalConstantDataSequential(CDS, AP);
1969 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1970 return emitGlobalConstantArray(CVA, AP);
1972 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1973 return emitGlobalConstantStruct(CVS, AP);
1975 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
1976 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
1978 if (CE->getOpcode() == Instruction::BitCast)
1979 return emitGlobalConstantImpl(CE->getOperand(0), AP);
1982 // If the constant expression's size is greater than 64-bits, then we have
1983 // to emit the value in chunks. Try to constant fold the value and emit it
1985 Constant *New = ConstantFoldConstantExpression(CE, DL);
1986 if (New && New != CE)
1987 return emitGlobalConstantImpl(New, AP);
1991 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1992 return emitGlobalConstantVector(V, AP);
1994 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1995 // thread the streamer with EmitValue.
1996 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
1999 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2000 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
2001 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType());
2003 emitGlobalConstantImpl(CV, *this);
2004 else if (MAI->hasSubsectionsViaSymbols()) {
2005 // If the global has zero size, emit a single byte so that two labels don't
2006 // look like they are at the same location.
2007 OutStreamer.EmitIntValue(0, 1);
2011 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2012 // Target doesn't support this yet!
2013 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
2016 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2018 OS << '+' << Offset;
2019 else if (Offset < 0)
2023 //===----------------------------------------------------------------------===//
2024 // Symbol Lowering Routines.
2025 //===----------------------------------------------------------------------===//
2027 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
2028 /// temporary label with the specified stem and unique ID.
2029 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
2030 const DataLayout *DL = TM.getDataLayout();
2031 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) +
2035 /// GetTempSymbol - Return an assembler temporary label with the specified
2037 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
2038 const DataLayout *DL = TM.getDataLayout();
2039 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+
2044 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2045 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2048 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2049 return MMI->getAddrLabelSymbol(BB);
2052 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
2053 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2054 const DataLayout *DL = TM.getDataLayout();
2055 return OutContext.GetOrCreateSymbol
2056 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
2057 + "_" + Twine(CPID));
2060 /// GetJTISymbol - Return the symbol for the specified jump table entry.
2061 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2062 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2065 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
2066 /// FIXME: privatize to AsmPrinter.
2067 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2068 const DataLayout *DL = TM.getDataLayout();
2069 return OutContext.GetOrCreateSymbol
2070 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
2071 Twine(UID) + "_set_" + Twine(MBBID));
2074 MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2075 StringRef Suffix) const {
2076 return getObjFileLowering().getSymbolWithGlobalValueBase(*Mang, GV, Suffix);
2079 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2081 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2082 SmallString<60> NameStr;
2083 Mang->getNameWithPrefix(NameStr, Sym);
2084 return OutContext.GetOrCreateSymbol(NameStr.str());
2089 /// PrintParentLoopComment - Print comments about parent loops of this one.
2090 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2091 unsigned FunctionNumber) {
2092 if (Loop == 0) return;
2093 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2094 OS.indent(Loop->getLoopDepth()*2)
2095 << "Parent Loop BB" << FunctionNumber << "_"
2096 << Loop->getHeader()->getNumber()
2097 << " Depth=" << Loop->getLoopDepth() << '\n';
2101 /// PrintChildLoopComment - Print comments about child loops within
2102 /// the loop for this basic block, with nesting.
2103 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2104 unsigned FunctionNumber) {
2105 // Add child loop information
2106 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
2107 OS.indent((*CL)->getLoopDepth()*2)
2108 << "Child Loop BB" << FunctionNumber << "_"
2109 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
2111 PrintChildLoopComment(OS, *CL, FunctionNumber);
2115 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2116 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2117 const MachineLoopInfo *LI,
2118 const AsmPrinter &AP) {
2119 // Add loop depth information
2120 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2121 if (Loop == 0) return;
2123 MachineBasicBlock *Header = Loop->getHeader();
2124 assert(Header && "No header for loop");
2126 // If this block is not a loop header, just print out what is the loop header
2128 if (Header != &MBB) {
2129 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2130 Twine(AP.getFunctionNumber())+"_" +
2131 Twine(Loop->getHeader()->getNumber())+
2132 " Depth="+Twine(Loop->getLoopDepth()));
2136 // Otherwise, it is a loop header. Print out information about child and
2138 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2140 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2143 OS.indent(Loop->getLoopDepth()*2-2);
2148 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2150 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2154 /// EmitBasicBlockStart - This method prints the label for the specified
2155 /// MachineBasicBlock, an alignment (if present) and a comment describing
2156 /// it if appropriate.
2157 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
2158 // Emit an alignment directive for this block, if needed.
2159 if (unsigned Align = MBB->getAlignment())
2160 EmitAlignment(Align);
2162 // If the block has its address taken, emit any labels that were used to
2163 // reference the block. It is possible that there is more than one label
2164 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2165 // the references were generated.
2166 if (MBB->hasAddressTaken()) {
2167 const BasicBlock *BB = MBB->getBasicBlock();
2169 OutStreamer.AddComment("Block address taken");
2171 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
2173 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
2174 OutStreamer.EmitLabel(Syms[i]);
2177 // Print some verbose block comments.
2179 if (const BasicBlock *BB = MBB->getBasicBlock())
2181 OutStreamer.AddComment("%" + BB->getName());
2182 emitBasicBlockLoopComments(*MBB, LI, *this);
2185 // Print the main label for the block.
2186 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
2188 // NOTE: Want this comment at start of line, don't emit with AddComment.
2189 OutStreamer.emitRawComment(" BB#" + Twine(MBB->getNumber()) + ":", false);
2192 OutStreamer.EmitLabel(MBB->getSymbol());
2196 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2197 bool IsDefinition) const {
2198 MCSymbolAttr Attr = MCSA_Invalid;
2200 switch (Visibility) {
2202 case GlobalValue::HiddenVisibility:
2204 Attr = MAI->getHiddenVisibilityAttr();
2206 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2208 case GlobalValue::ProtectedVisibility:
2209 Attr = MAI->getProtectedVisibilityAttr();
2213 if (Attr != MCSA_Invalid)
2214 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2217 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2218 /// exactly one predecessor and the control transfer mechanism between
2219 /// the predecessor and this block is a fall-through.
2221 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2222 // If this is a landing pad, it isn't a fall through. If it has no preds,
2223 // then nothing falls through to it.
2224 if (MBB->isLandingPad() || MBB->pred_empty())
2227 // If there isn't exactly one predecessor, it can't be a fall through.
2228 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
2230 if (PI2 != MBB->pred_end())
2233 // The predecessor has to be immediately before this block.
2234 MachineBasicBlock *Pred = *PI;
2236 if (!Pred->isLayoutSuccessor(MBB))
2239 // If the block is completely empty, then it definitely does fall through.
2243 // Check the terminators in the previous blocks
2244 for (MachineBasicBlock::iterator II = Pred->getFirstTerminator(),
2245 IE = Pred->end(); II != IE; ++II) {
2246 MachineInstr &MI = *II;
2248 // If it is not a simple branch, we are in a table somewhere.
2249 if (!MI.isBranch() || MI.isIndirectBranch())
2252 // If we are the operands of one of the branches, this is not a fall
2253 // through. Note that targets with delay slots will usually bundle
2254 // terminators with the delay slot instruction.
2255 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) {
2258 if (OP->isMBB() && OP->getMBB() == MBB)
2268 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
2269 if (!S->usesMetadata())
2272 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2273 gcp_map_type::iterator GCPI = GCMap.find(S);
2274 if (GCPI != GCMap.end())
2275 return GCPI->second;
2277 const char *Name = S->getName().c_str();
2279 for (GCMetadataPrinterRegistry::iterator
2280 I = GCMetadataPrinterRegistry::begin(),
2281 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2282 if (strcmp(Name, I->getName()) == 0) {
2283 GCMetadataPrinter *GMP = I->instantiate();
2285 GCMap.insert(std::make_pair(S, GMP));
2289 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2292 /// Pin vtable to this file.
2293 AsmPrinterHandler::~AsmPrinterHandler() {}