1 //===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the AsmPrinter class.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "asm-printer"
15 #include "llvm/CodeGen/AsmPrinter.h"
16 #include "DwarfDebug.h"
17 #include "DwarfException.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/Statistic.h"
20 #include "llvm/Analysis/ConstantFolding.h"
21 #include "llvm/Assembly/Writer.h"
22 #include "llvm/CodeGen/GCMetadataPrinter.h"
23 #include "llvm/CodeGen/MachineConstantPool.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineJumpTableInfo.h"
27 #include "llvm/CodeGen/MachineLoopInfo.h"
28 #include "llvm/CodeGen/MachineModuleInfo.h"
29 #include "llvm/DebugInfo.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/Module.h"
32 #include "llvm/IR/Operator.h"
33 #include "llvm/MC/MCAsmInfo.h"
34 #include "llvm/MC/MCContext.h"
35 #include "llvm/MC/MCExpr.h"
36 #include "llvm/MC/MCInst.h"
37 #include "llvm/MC/MCSection.h"
38 #include "llvm/MC/MCStreamer.h"
39 #include "llvm/MC/MCSymbol.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/Format.h"
42 #include "llvm/Support/MathExtras.h"
43 #include "llvm/Support/Timer.h"
44 #include "llvm/Target/Mangler.h"
45 #include "llvm/Target/TargetFrameLowering.h"
46 #include "llvm/Target/TargetInstrInfo.h"
47 #include "llvm/Target/TargetLowering.h"
48 #include "llvm/Target/TargetLoweringObjectFile.h"
49 #include "llvm/Target/TargetOptions.h"
50 #include "llvm/Target/TargetRegisterInfo.h"
53 static const char *const DWARFGroupName = "DWARF Emission";
54 static const char *const DbgTimerName = "DWARF Debug Writer";
55 static const char *const EHTimerName = "DWARF Exception Writer";
57 STATISTIC(EmittedInsts, "Number of machine instrs printed");
59 char AsmPrinter::ID = 0;
61 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
62 static gcp_map_type &getGCMap(void *&P) {
64 P = new gcp_map_type();
65 return *(gcp_map_type*)P;
69 /// getGVAlignmentLog2 - Return the alignment to use for the specified global
70 /// value in log2 form. This rounds up to the preferred alignment if possible
72 static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD,
73 unsigned InBits = 0) {
75 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
76 NumBits = TD.getPreferredAlignmentLog(GVar);
78 // If InBits is specified, round it to it.
82 // If the GV has a specified alignment, take it into account.
83 if (GV->getAlignment() == 0)
86 unsigned GVAlign = Log2_32(GV->getAlignment());
88 // If the GVAlign is larger than NumBits, or if we are required to obey
89 // NumBits because the GV has an assigned section, obey it.
90 if (GVAlign > NumBits || GV->hasSection())
95 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
96 : MachineFunctionPass(ID),
97 TM(tm), MAI(tm.getMCAsmInfo()), MII(tm.getInstrInfo()),
98 OutContext(Streamer.getContext()),
99 OutStreamer(Streamer),
100 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
101 DD = 0; DE = 0; MMI = 0; LI = 0; MF = 0;
102 CurrentFnSym = CurrentFnSymForSize = 0;
103 GCMetadataPrinters = 0;
104 VerboseAsm = Streamer.isVerboseAsm();
107 AsmPrinter::~AsmPrinter() {
108 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized");
110 if (GCMetadataPrinters != 0) {
111 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
113 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
116 GCMetadataPrinters = 0;
122 /// getFunctionNumber - Return a unique ID for the current function.
124 unsigned AsmPrinter::getFunctionNumber() const {
125 return MF->getFunctionNumber();
128 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
129 return TM.getTargetLowering()->getObjFileLowering();
132 /// getDataLayout - Return information about data layout.
133 const DataLayout &AsmPrinter::getDataLayout() const {
134 return *TM.getDataLayout();
137 StringRef AsmPrinter::getTargetTriple() const {
138 return TM.getTargetTriple();
141 /// getCurrentSection() - Return the current section we are emitting to.
142 const MCSection *AsmPrinter::getCurrentSection() const {
143 return OutStreamer.getCurrentSection().first;
148 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
149 AU.setPreservesAll();
150 MachineFunctionPass::getAnalysisUsage(AU);
151 AU.addRequired<MachineModuleInfo>();
152 AU.addRequired<GCModuleInfo>();
154 AU.addRequired<MachineLoopInfo>();
157 bool AsmPrinter::doInitialization(Module &M) {
158 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
159 MMI->AnalyzeModule(M);
161 // Initialize TargetLoweringObjectFile.
162 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
163 .Initialize(OutContext, TM);
165 OutStreamer.InitStreamer();
167 Mang = new Mangler(OutContext, &TM);
169 // Allow the target to emit any magic that it wants at the start of the file.
170 EmitStartOfAsmFile(M);
172 // Very minimal debug info. It is ignored if we emit actual debug info. If we
173 // don't, this at least helps the user find where a global came from.
174 if (MAI->hasSingleParameterDotFile()) {
176 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
179 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
180 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
181 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
182 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
183 MP->beginAssembly(*this);
185 // Emit module-level inline asm if it exists.
186 if (!M.getModuleInlineAsm().empty()) {
187 OutStreamer.AddComment("Start of file scope inline assembly");
188 OutStreamer.AddBlankLine();
189 EmitInlineAsm(M.getModuleInlineAsm()+"\n");
190 OutStreamer.AddComment("End of file scope inline assembly");
191 OutStreamer.AddBlankLine();
194 if (MAI->doesSupportDebugInformation())
195 DD = new DwarfDebug(this, &M);
197 switch (MAI->getExceptionHandlingType()) {
198 case ExceptionHandling::None:
200 case ExceptionHandling::SjLj:
201 case ExceptionHandling::DwarfCFI:
202 DE = new DwarfCFIException(this);
204 case ExceptionHandling::ARM:
205 DE = new ARMException(this);
207 case ExceptionHandling::Win64:
208 DE = new Win64Exception(this);
212 llvm_unreachable("Unknown exception type.");
215 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
216 switch ((GlobalValue::LinkageTypes)Linkage) {
217 case GlobalValue::CommonLinkage:
218 case GlobalValue::LinkOnceAnyLinkage:
219 case GlobalValue::LinkOnceODRLinkage:
220 case GlobalValue::LinkOnceODRAutoHideLinkage:
221 case GlobalValue::WeakAnyLinkage:
222 case GlobalValue::WeakODRLinkage:
223 case GlobalValue::LinkerPrivateWeakLinkage:
224 if (MAI->getWeakDefDirective() != 0) {
226 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
228 if ((GlobalValue::LinkageTypes)Linkage !=
229 GlobalValue::LinkOnceODRAutoHideLinkage)
230 // .weak_definition _foo
231 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
233 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
234 } else if (MAI->getLinkOnceDirective() != 0) {
236 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
237 //NOTE: linkonce is handled by the section the symbol was assigned to.
240 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
243 case GlobalValue::DLLExportLinkage:
244 case GlobalValue::AppendingLinkage:
245 // FIXME: appending linkage variables should go into a section of
246 // their name or something. For now, just emit them as external.
247 case GlobalValue::ExternalLinkage:
248 // If external or appending, declare as a global symbol.
250 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
252 case GlobalValue::PrivateLinkage:
253 case GlobalValue::InternalLinkage:
254 case GlobalValue::LinkerPrivateLinkage:
257 llvm_unreachable("Unknown linkage type!");
262 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
263 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
264 if (GV->hasInitializer()) {
265 // Check to see if this is a special global used by LLVM, if so, emit it.
266 if (EmitSpecialLLVMGlobal(GV))
270 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
271 /*PrintType=*/false, GV->getParent());
272 OutStreamer.GetCommentOS() << '\n';
276 MCSymbol *GVSym = Mang->getSymbol(GV);
277 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration());
279 if (!GV->hasInitializer()) // External globals require no extra code.
282 if (MAI->hasDotTypeDotSizeDirective())
283 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
285 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
287 const DataLayout *DL = TM.getDataLayout();
288 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType());
290 // If the alignment is specified, we *must* obey it. Overaligning a global
291 // with a specified alignment is a prompt way to break globals emitted to
292 // sections and expected to be contiguous (e.g. ObjC metadata).
293 unsigned AlignLog = getGVAlignmentLog2(GV, *DL);
296 DD->setSymbolSize(GVSym, Size);
298 // Handle common and BSS local symbols (.lcomm).
299 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
300 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
301 unsigned Align = 1 << AlignLog;
303 // Handle common symbols.
304 if (GVKind.isCommon()) {
305 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
309 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
313 // Handle local BSS symbols.
314 if (MAI->hasMachoZeroFillDirective()) {
315 const MCSection *TheSection =
316 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
317 // .zerofill __DATA, __bss, _foo, 400, 5
318 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align);
322 // Use .lcomm only if it supports user-specified alignment.
323 // Otherwise, while it would still be correct to use .lcomm in some
324 // cases (e.g. when Align == 1), the external assembler might enfore
325 // some -unknown- default alignment behavior, which could cause
326 // spurious differences between external and integrated assembler.
327 // Prefer to simply fall back to .local / .comm in this case.
328 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
330 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align);
334 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
338 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
340 OutStreamer.EmitCommonSymbol(GVSym, Size, Align);
344 const MCSection *TheSection =
345 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
347 // Handle the zerofill directive on darwin, which is a special form of BSS
349 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
350 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined.
353 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
354 // .zerofill __DATA, __common, _foo, 400, 5
355 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
359 // Handle thread local data for mach-o which requires us to output an
360 // additional structure of data and mangle the original symbol so that we
361 // can reference it later.
363 // TODO: This should become an "emit thread local global" method on TLOF.
364 // All of this macho specific stuff should be sunk down into TLOFMachO and
365 // stuff like "TLSExtraDataSection" should no longer be part of the parent
366 // TLOF class. This will also make it more obvious that stuff like
367 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
369 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
370 // Emit the .tbss symbol
372 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
374 if (GVKind.isThreadBSS()) {
375 TheSection = getObjFileLowering().getTLSBSSSection();
376 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
377 } else if (GVKind.isThreadData()) {
378 OutStreamer.SwitchSection(TheSection);
380 EmitAlignment(AlignLog, GV);
381 OutStreamer.EmitLabel(MangSym);
383 EmitGlobalConstant(GV->getInitializer());
386 OutStreamer.AddBlankLine();
388 // Emit the variable struct for the runtime.
389 const MCSection *TLVSect
390 = getObjFileLowering().getTLSExtraDataSection();
392 OutStreamer.SwitchSection(TLVSect);
393 // Emit the linkage here.
394 EmitLinkage(GV->getLinkage(), GVSym);
395 OutStreamer.EmitLabel(GVSym);
397 // Three pointers in size:
398 // - __tlv_bootstrap - used to make sure support exists
399 // - spare pointer, used when mapped by the runtime
400 // - pointer to mangled symbol above with initializer
401 unsigned PtrSize = DL->getPointerSizeInBits()/8;
402 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
404 OutStreamer.EmitIntValue(0, PtrSize);
405 OutStreamer.EmitSymbolValue(MangSym, PtrSize);
407 OutStreamer.AddBlankLine();
411 OutStreamer.SwitchSection(TheSection);
413 EmitLinkage(GV->getLinkage(), GVSym);
414 EmitAlignment(AlignLog, GV);
416 OutStreamer.EmitLabel(GVSym);
418 EmitGlobalConstant(GV->getInitializer());
420 if (MAI->hasDotTypeDotSizeDirective())
422 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
424 OutStreamer.AddBlankLine();
427 /// EmitFunctionHeader - This method emits the header for the current
429 void AsmPrinter::EmitFunctionHeader() {
430 // Print out constants referenced by the function
433 // Print the 'header' of function.
434 const Function *F = MF->getFunction();
436 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
437 EmitVisibility(CurrentFnSym, F->getVisibility());
439 EmitLinkage(F->getLinkage(), CurrentFnSym);
440 EmitAlignment(MF->getAlignment(), F);
442 if (MAI->hasDotTypeDotSizeDirective())
443 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
446 WriteAsOperand(OutStreamer.GetCommentOS(), F,
447 /*PrintType=*/false, F->getParent());
448 OutStreamer.GetCommentOS() << '\n';
451 // Emit the CurrentFnSym. This is a virtual function to allow targets to
452 // do their wild and crazy things as required.
453 EmitFunctionEntryLabel();
455 // If the function had address-taken blocks that got deleted, then we have
456 // references to the dangling symbols. Emit them at the start of the function
457 // so that we don't get references to undefined symbols.
458 std::vector<MCSymbol*> DeadBlockSyms;
459 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
460 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
461 OutStreamer.AddComment("Address taken block that was later removed");
462 OutStreamer.EmitLabel(DeadBlockSyms[i]);
465 // Emit the prefix data.
466 if (F->hasPrefixData())
467 EmitGlobalConstant(F->getPrefixData());
469 // Emit pre-function debug and/or EH information.
471 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
472 DE->BeginFunction(MF);
475 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
476 DD->beginFunction(MF);
480 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
481 /// function. This can be overridden by targets as required to do custom stuff.
482 void AsmPrinter::EmitFunctionEntryLabel() {
483 // The function label could have already been emitted if two symbols end up
484 // conflicting due to asm renaming. Detect this and emit an error.
485 if (CurrentFnSym->isUndefined())
486 return OutStreamer.EmitLabel(CurrentFnSym);
488 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
489 "' label emitted multiple times to assembly file");
492 /// emitComments - Pretty-print comments for instructions.
493 static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
494 const MachineFunction *MF = MI.getParent()->getParent();
495 const TargetMachine &TM = MF->getTarget();
497 // Check for spills and reloads
500 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
502 // We assume a single instruction only has a spill or reload, not
504 const MachineMemOperand *MMO;
505 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
506 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
507 MMO = *MI.memoperands_begin();
508 CommentOS << MMO->getSize() << "-byte Reload\n";
510 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
511 if (FrameInfo->isSpillSlotObjectIndex(FI))
512 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
513 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
514 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
515 MMO = *MI.memoperands_begin();
516 CommentOS << MMO->getSize() << "-byte Spill\n";
518 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
519 if (FrameInfo->isSpillSlotObjectIndex(FI))
520 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
523 // Check for spill-induced copies
524 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
525 CommentOS << " Reload Reuse\n";
528 /// emitImplicitDef - This method emits the specified machine instruction
529 /// that is an implicit def.
530 static void emitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
531 unsigned RegNo = MI->getOperand(0).getReg();
532 AP.OutStreamer.AddComment(Twine("implicit-def: ") +
533 AP.TM.getRegisterInfo()->getName(RegNo));
534 AP.OutStreamer.AddBlankLine();
537 static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
538 std::string Str = "kill:";
539 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
540 const MachineOperand &Op = MI->getOperand(i);
541 assert(Op.isReg() && "KILL instruction must have only register operands");
543 Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
544 Str += (Op.isDef() ? "<def>" : "<kill>");
546 AP.OutStreamer.AddComment(Str);
547 AP.OutStreamer.AddBlankLine();
550 /// emitDebugValueComment - This method handles the target-independent form
551 /// of DBG_VALUE, returning true if it was able to do so. A false return
552 /// means the target will need to handle MI in EmitInstruction.
553 static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
554 // This code handles only the 3-operand target-independent form.
555 if (MI->getNumOperands() != 3)
558 SmallString<128> Str;
559 raw_svector_ostream OS(Str);
560 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
562 // cast away const; DIetc do not take const operands for some reason.
563 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
564 if (V.getContext().isSubprogram()) {
565 StringRef Name = DISubprogram(V.getContext()).getDisplayName();
569 OS << V.getName() << " <- ";
571 // The second operand is only an offset if it's an immediate.
572 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
573 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0;
575 // Register or immediate value. Register 0 means undef.
576 if (MI->getOperand(0).isFPImm()) {
577 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
578 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
579 OS << (double)APF.convertToFloat();
580 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
581 OS << APF.convertToDouble();
583 // There is no good way to print long double. Convert a copy to
584 // double. Ah well, it's only a comment.
586 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
588 OS << "(long double) " << APF.convertToDouble();
590 } else if (MI->getOperand(0).isImm()) {
591 OS << MI->getOperand(0).getImm();
592 } else if (MI->getOperand(0).isCImm()) {
593 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
596 if (MI->getOperand(0).isReg()) {
597 Reg = MI->getOperand(0).getReg();
599 assert(MI->getOperand(0).isFI() && "Unknown operand type");
600 const TargetFrameLowering *TFI = AP.TM.getFrameLowering();
601 Offset += TFI->getFrameIndexReference(*AP.MF,
602 MI->getOperand(0).getIndex(), Reg);
606 // Suppress offset, it is not meaningful here.
608 // NOTE: Want this comment at start of line, don't emit with AddComment.
609 AP.OutStreamer.EmitRawText(OS.str());
614 OS << AP.TM.getRegisterInfo()->getName(Reg);
618 OS << '+' << Offset << ']';
620 // NOTE: Want this comment at start of line, don't emit with AddComment.
621 AP.OutStreamer.EmitRawText(OS.str());
625 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() {
626 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
627 MF->getFunction()->needsUnwindTableEntry())
630 if (MMI->hasDebugInfo())
636 bool AsmPrinter::needsSEHMoves() {
637 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 &&
638 MF->getFunction()->needsUnwindTableEntry();
641 bool AsmPrinter::needsRelocationsForDwarfStringPool() const {
642 return MAI->doesDwarfUseRelocationsAcrossSections();
645 void AsmPrinter::emitPrologLabel(const MachineInstr &MI) {
646 const MCSymbol *Label = MI.getOperand(0).getMCSymbol();
648 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
651 if (needsCFIMoves() == CFI_M_None)
654 if (MMI->getCompactUnwindEncoding() != 0)
655 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding());
657 const MachineModuleInfo &MMI = MF->getMMI();
658 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions();
659 bool FoundOne = false;
661 for (std::vector<MCCFIInstruction>::const_iterator I = Instrs.begin(),
662 E = Instrs.end(); I != E; ++I) {
663 if (I->getLabel() == Label) {
664 emitCFIInstruction(*I);
671 /// EmitFunctionBody - This method emits the body and trailer for a
673 void AsmPrinter::EmitFunctionBody() {
674 // Emit target-specific gunk before the function body.
675 EmitFunctionBodyStart();
677 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
679 // Print out code for the function.
680 bool HasAnyRealCode = false;
681 const MachineInstr *LastMI = 0;
682 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
684 // Print a label for the basic block.
685 EmitBasicBlockStart(I);
686 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
690 // Print the assembly for the instruction.
691 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
692 !II->isDebugValue()) {
693 HasAnyRealCode = true;
697 if (ShouldPrintDebugScopes) {
698 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
699 DD->beginInstruction(II);
703 emitComments(*II, OutStreamer.GetCommentOS());
705 switch (II->getOpcode()) {
706 case TargetOpcode::PROLOG_LABEL:
707 emitPrologLabel(*II);
710 case TargetOpcode::EH_LABEL:
711 case TargetOpcode::GC_LABEL:
712 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
714 case TargetOpcode::INLINEASM:
717 case TargetOpcode::DBG_VALUE:
719 if (!emitDebugValueComment(II, *this))
723 case TargetOpcode::IMPLICIT_DEF:
724 if (isVerbose()) emitImplicitDef(II, *this);
726 case TargetOpcode::KILL:
727 if (isVerbose()) emitKill(II, *this);
730 if (!TM.hasMCUseLoc())
731 MCLineEntry::Make(&OutStreamer, getCurrentSection());
737 if (ShouldPrintDebugScopes) {
738 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
739 DD->endInstruction(II);
744 // If the last instruction was a prolog label, then we have a situation where
745 // we emitted a prolog but no function body. This results in the ending prolog
746 // label equaling the end of function label and an invalid "row" in the
747 // FDE. We need to emit a noop in this situation so that the FDE's rows are
749 bool RequiresNoop = LastMI && LastMI->isPrologLabel();
751 // If the function is empty and the object file uses .subsections_via_symbols,
752 // then we need to emit *something* to the function body to prevent the
753 // labels from collapsing together. Just emit a noop.
754 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) {
756 TM.getInstrInfo()->getNoopForMachoTarget(Noop);
757 if (Noop.getOpcode()) {
758 OutStreamer.AddComment("avoids zero-length function");
759 OutStreamer.EmitInstruction(Noop);
760 } else // Target not mc-ized yet.
761 OutStreamer.EmitRawText(StringRef("\tnop\n"));
764 const Function *F = MF->getFunction();
765 for (Function::const_iterator i = F->begin(), e = F->end(); i != e; ++i) {
766 const BasicBlock *BB = i;
767 if (!BB->hasAddressTaken())
769 MCSymbol *Sym = GetBlockAddressSymbol(BB);
770 if (Sym->isDefined())
772 OutStreamer.AddComment("Address of block that was removed by CodeGen");
773 OutStreamer.EmitLabel(Sym);
776 // Emit target-specific gunk after the function body.
777 EmitFunctionBodyEnd();
779 // If the target wants a .size directive for the size of the function, emit
781 if (MAI->hasDotTypeDotSizeDirective()) {
782 // Create a symbol for the end of function, so we can get the size as
783 // difference between the function label and the temp label.
784 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
785 OutStreamer.EmitLabel(FnEndLabel);
787 const MCExpr *SizeExp =
788 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
789 MCSymbolRefExpr::Create(CurrentFnSymForSize,
792 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
795 // Emit post-function debug information.
797 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
801 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
806 // Print out jump tables referenced by the function.
809 OutStreamer.AddBlankLine();
812 /// EmitDwarfRegOp - Emit dwarf register operation.
813 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc,
814 bool Indirect) const {
815 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
816 int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false);
818 for (MCSuperRegIterator SR(MLoc.getReg(), TRI); SR.isValid() && Reg < 0;
820 Reg = TRI->getDwarfRegNum(*SR, false);
821 // FIXME: Get the bit range this register uses of the superregister
822 // so that we can produce a DW_OP_bit_piece
825 // FIXME: Handle cases like a super register being encoded as
826 // DW_OP_reg 32 DW_OP_piece 4 DW_OP_reg 33
828 // FIXME: We have no reasonable way of handling errors in here. The
829 // caller might be in the middle of an dwarf expression. We should
830 // probably assert that Reg >= 0 once debug info generation is more mature.
832 if (MLoc.isIndirect() || Indirect) {
834 OutStreamer.AddComment(
835 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg));
836 EmitInt8(dwarf::DW_OP_breg0 + Reg);
838 OutStreamer.AddComment("DW_OP_bregx");
839 EmitInt8(dwarf::DW_OP_bregx);
840 OutStreamer.AddComment(Twine(Reg));
843 EmitSLEB128(!MLoc.isIndirect() ? 0 : MLoc.getOffset());
844 if (MLoc.isIndirect() && Indirect)
845 EmitInt8(dwarf::DW_OP_deref);
848 OutStreamer.AddComment(
849 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg));
850 EmitInt8(dwarf::DW_OP_reg0 + Reg);
852 OutStreamer.AddComment("DW_OP_regx");
853 EmitInt8(dwarf::DW_OP_regx);
854 OutStreamer.AddComment(Twine(Reg));
859 // FIXME: Produce a DW_OP_bit_piece if we used a superregister
862 bool AsmPrinter::doFinalization(Module &M) {
863 // Emit global variables.
864 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
866 EmitGlobalVariable(I);
868 // Emit visibility info for declarations
869 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
870 const Function &F = *I;
871 if (!F.isDeclaration())
873 GlobalValue::VisibilityTypes V = F.getVisibility();
874 if (V == GlobalValue::DefaultVisibility)
877 MCSymbol *Name = Mang->getSymbol(&F);
878 EmitVisibility(Name, V, false);
881 // Emit module flags.
882 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags;
883 M.getModuleFlagsMetadata(ModuleFlags);
884 if (!ModuleFlags.empty())
885 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, Mang, TM);
887 // Make sure we wrote out everything we need.
890 // Finalize debug and EH information.
893 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled);
900 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
906 // If the target wants to know about weak references, print them all.
907 if (MAI->getWeakRefDirective()) {
908 // FIXME: This is not lazy, it would be nice to only print weak references
909 // to stuff that is actually used. Note that doing so would require targets
910 // to notice uses in operands (due to constant exprs etc). This should
911 // happen with the MC stuff eventually.
913 // Print out module-level global variables here.
914 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
916 if (!I->hasExternalWeakLinkage()) continue;
917 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
920 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
921 if (!I->hasExternalWeakLinkage()) continue;
922 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
926 if (MAI->hasSetDirective()) {
927 OutStreamer.AddBlankLine();
928 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
930 MCSymbol *Name = Mang->getSymbol(I);
932 const GlobalValue *GV = I->getAliasedGlobal();
933 MCSymbol *Target = Mang->getSymbol(GV);
935 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
936 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
937 else if (I->hasWeakLinkage())
938 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
940 assert(I->hasLocalLinkage() && "Invalid alias linkage");
942 EmitVisibility(Name, I->getVisibility());
944 // Emit the directives as assignments aka .set:
945 OutStreamer.EmitAssignment(Name,
946 MCSymbolRefExpr::Create(Target, OutContext));
950 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
951 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
952 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
953 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
954 MP->finishAssembly(*this);
956 // If we don't have any trampolines, then we don't require stack memory
957 // to be executable. Some targets have a directive to declare this.
958 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
959 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
960 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
961 OutStreamer.SwitchSection(S);
963 // Allow the target to emit any magic that it wants at the end of the file,
964 // after everything else has gone out.
967 delete Mang; Mang = 0;
970 OutStreamer.Finish();
976 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
978 // Get the function symbol.
979 CurrentFnSym = Mang->getSymbol(MF.getFunction());
980 CurrentFnSymForSize = CurrentFnSym;
983 LI = &getAnalysis<MachineLoopInfo>();
987 // SectionCPs - Keep track the alignment, constpool entries per Section.
991 SmallVector<unsigned, 4> CPEs;
992 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
996 /// EmitConstantPool - Print to the current output stream assembly
997 /// representations of the constants in the constant pool MCP. This is
998 /// used to print out constants which have been "spilled to memory" by
999 /// the code generator.
1001 void AsmPrinter::EmitConstantPool() {
1002 const MachineConstantPool *MCP = MF->getConstantPool();
1003 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1004 if (CP.empty()) return;
1006 // Calculate sections for constant pool entries. We collect entries to go into
1007 // the same section together to reduce amount of section switch statements.
1008 SmallVector<SectionCPs, 4> CPSections;
1009 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1010 const MachineConstantPoolEntry &CPE = CP[i];
1011 unsigned Align = CPE.getAlignment();
1014 switch (CPE.getRelocationInfo()) {
1015 default: llvm_unreachable("Unknown section kind");
1016 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
1018 Kind = SectionKind::getReadOnlyWithRelLocal();
1021 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) {
1022 case 4: Kind = SectionKind::getMergeableConst4(); break;
1023 case 8: Kind = SectionKind::getMergeableConst8(); break;
1024 case 16: Kind = SectionKind::getMergeableConst16();break;
1025 default: Kind = SectionKind::getMergeableConst(); break;
1029 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
1031 // The number of sections are small, just do a linear search from the
1032 // last section to the first.
1034 unsigned SecIdx = CPSections.size();
1035 while (SecIdx != 0) {
1036 if (CPSections[--SecIdx].S == S) {
1042 SecIdx = CPSections.size();
1043 CPSections.push_back(SectionCPs(S, Align));
1046 if (Align > CPSections[SecIdx].Alignment)
1047 CPSections[SecIdx].Alignment = Align;
1048 CPSections[SecIdx].CPEs.push_back(i);
1051 // Now print stuff into the calculated sections.
1052 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1053 OutStreamer.SwitchSection(CPSections[i].S);
1054 EmitAlignment(Log2_32(CPSections[i].Alignment));
1056 unsigned Offset = 0;
1057 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1058 unsigned CPI = CPSections[i].CPEs[j];
1059 MachineConstantPoolEntry CPE = CP[CPI];
1061 // Emit inter-object padding for alignment.
1062 unsigned AlignMask = CPE.getAlignment() - 1;
1063 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1064 OutStreamer.EmitZeros(NewOffset - Offset);
1066 Type *Ty = CPE.getType();
1067 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty);
1068 OutStreamer.EmitLabel(GetCPISymbol(CPI));
1070 if (CPE.isMachineConstantPoolEntry())
1071 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1073 EmitGlobalConstant(CPE.Val.ConstVal);
1078 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
1079 /// by the current function to the current output stream.
1081 void AsmPrinter::EmitJumpTableInfo() {
1082 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1083 if (MJTI == 0) return;
1084 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1085 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1086 if (JT.empty()) return;
1088 // Pick the directive to use to print the jump table entries, and switch to
1089 // the appropriate section.
1090 const Function *F = MF->getFunction();
1091 bool JTInDiffSection = false;
1092 if (// In PIC mode, we need to emit the jump table to the same section as the
1093 // function body itself, otherwise the label differences won't make sense.
1094 // FIXME: Need a better predicate for this: what about custom entries?
1095 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
1096 // We should also do if the section name is NULL or function is declared
1097 // in discardable section
1098 // FIXME: this isn't the right predicate, should be based on the MCSection
1099 // for the function.
1100 F->isWeakForLinker()) {
1101 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
1103 // Otherwise, drop it in the readonly section.
1104 const MCSection *ReadOnlySection =
1105 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
1106 OutStreamer.SwitchSection(ReadOnlySection);
1107 JTInDiffSection = true;
1110 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout())));
1112 // Jump tables in code sections are marked with a data_region directive
1113 // where that's supported.
1114 if (!JTInDiffSection)
1115 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32);
1117 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1118 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1120 // If this jump table was deleted, ignore it.
1121 if (JTBBs.empty()) continue;
1123 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
1124 // .set directive for each unique entry. This reduces the number of
1125 // relocations the assembler will generate for the jump table.
1126 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1127 MAI->hasSetDirective()) {
1128 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1129 const TargetLowering *TLI = TM.getTargetLowering();
1130 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1131 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1132 const MachineBasicBlock *MBB = JTBBs[ii];
1133 if (!EmittedSets.insert(MBB)) continue;
1135 // .set LJTSet, LBB32-base
1137 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1138 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1139 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
1143 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1144 // before each jump table. The first label is never referenced, but tells
1145 // the assembler and linker the extents of the jump table object. The
1146 // second label is actually referenced by the code.
1147 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
1148 // FIXME: This doesn't have to have any specific name, just any randomly
1149 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1150 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
1152 OutStreamer.EmitLabel(GetJTISymbol(JTI));
1154 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1155 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1157 if (!JTInDiffSection)
1158 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd);
1161 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1163 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1164 const MachineBasicBlock *MBB,
1165 unsigned UID) const {
1166 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block");
1167 const MCExpr *Value = 0;
1168 switch (MJTI->getEntryKind()) {
1169 case MachineJumpTableInfo::EK_Inline:
1170 llvm_unreachable("Cannot emit EK_Inline jump table entry");
1171 case MachineJumpTableInfo::EK_Custom32:
1172 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1175 case MachineJumpTableInfo::EK_BlockAddress:
1176 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1178 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1180 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1181 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1182 // with a relocation as gp-relative, e.g.:
1184 MCSymbol *MBBSym = MBB->getSymbol();
1185 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1189 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1190 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1191 // with a relocation as gp-relative, e.g.:
1193 MCSymbol *MBBSym = MBB->getSymbol();
1194 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1198 case MachineJumpTableInfo::EK_LabelDifference32: {
1199 // EK_LabelDifference32 - Each entry is the address of the block minus
1200 // the address of the jump table. This is used for PIC jump tables where
1201 // gprel32 is not supported. e.g.:
1202 // .word LBB123 - LJTI1_2
1203 // If the .set directive is supported, this is emitted as:
1204 // .set L4_5_set_123, LBB123 - LJTI1_2
1205 // .word L4_5_set_123
1207 // If we have emitted set directives for the jump table entries, print
1208 // them rather than the entries themselves. If we're emitting PIC, then
1209 // emit the table entries as differences between two text section labels.
1210 if (MAI->hasSetDirective()) {
1211 // If we used .set, reference the .set's symbol.
1212 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1216 // Otherwise, use the difference as the jump table entry.
1217 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1218 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1219 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1224 assert(Value && "Unknown entry kind!");
1226 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout());
1227 OutStreamer.EmitValue(Value, EntrySize);
1231 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1232 /// special global used by LLVM. If so, emit it and return true, otherwise
1233 /// do nothing and return false.
1234 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1235 if (GV->getName() == "llvm.used") {
1236 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1237 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1241 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1242 if (GV->getSection() == "llvm.metadata" ||
1243 GV->hasAvailableExternallyLinkage())
1246 if (!GV->hasAppendingLinkage()) return false;
1248 assert(GV->hasInitializer() && "Not a special LLVM global!");
1250 if (GV->getName() == "llvm.global_ctors") {
1251 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true);
1253 if (TM.getRelocationModel() == Reloc::Static &&
1254 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1255 StringRef Sym(".constructors_used");
1256 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1262 if (GV->getName() == "llvm.global_dtors") {
1263 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false);
1265 if (TM.getRelocationModel() == Reloc::Static &&
1266 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1267 StringRef Sym(".destructors_used");
1268 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1277 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1278 /// global in the specified llvm.used list for which emitUsedDirectiveFor
1279 /// is true, as being used with this directive.
1280 void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1281 // Should be an array of 'i8*'.
1282 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1283 const GlobalValue *GV =
1284 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1285 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1286 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1290 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1292 void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) {
1293 // Should be an array of '{ int, void ()* }' structs. The first value is the
1295 if (!isa<ConstantArray>(List)) return;
1297 // Sanity check the structors list.
1298 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1299 if (!InitList) return; // Not an array!
1300 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1301 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs!
1302 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1303 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1305 // Gather the structors in a form that's convenient for sorting by priority.
1306 typedef std::pair<unsigned, Constant *> Structor;
1307 SmallVector<Structor, 8> Structors;
1308 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1309 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i));
1310 if (!CS) continue; // Malformed.
1311 if (CS->getOperand(1)->isNullValue())
1312 break; // Found a null terminator, skip the rest.
1313 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1314 if (!Priority) continue; // Malformed.
1315 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535),
1316 CS->getOperand(1)));
1319 // Emit the function pointers in the target-specific order
1320 const DataLayout *DL = TM.getDataLayout();
1321 unsigned Align = Log2_32(DL->getPointerPrefAlignment());
1322 std::stable_sort(Structors.begin(), Structors.end(), less_first());
1323 for (unsigned i = 0, e = Structors.size(); i != e; ++i) {
1324 const MCSection *OutputSection =
1326 getObjFileLowering().getStaticCtorSection(Structors[i].first) :
1327 getObjFileLowering().getStaticDtorSection(Structors[i].first));
1328 OutStreamer.SwitchSection(OutputSection);
1329 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection())
1330 EmitAlignment(Align);
1331 EmitXXStructor(Structors[i].second);
1335 //===--------------------------------------------------------------------===//
1336 // Emission and print routines
1339 /// EmitInt8 - Emit a byte directive and value.
1341 void AsmPrinter::EmitInt8(int Value) const {
1342 OutStreamer.EmitIntValue(Value, 1);
1345 /// EmitInt16 - Emit a short directive and value.
1347 void AsmPrinter::EmitInt16(int Value) const {
1348 OutStreamer.EmitIntValue(Value, 2);
1351 /// EmitInt32 - Emit a long directive and value.
1353 void AsmPrinter::EmitInt32(int Value) const {
1354 OutStreamer.EmitIntValue(Value, 4);
1357 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1358 /// in bytes of the directive is specified by Size and Hi/Lo specify the
1359 /// labels. This implicitly uses .set if it is available.
1360 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1361 unsigned Size) const {
1362 // Get the Hi-Lo expression.
1363 const MCExpr *Diff =
1364 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1365 MCSymbolRefExpr::Create(Lo, OutContext),
1368 if (!MAI->hasSetDirective()) {
1369 OutStreamer.EmitValue(Diff, Size);
1373 // Otherwise, emit with .set (aka assignment).
1374 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1375 OutStreamer.EmitAssignment(SetLabel, Diff);
1376 OutStreamer.EmitSymbolValue(SetLabel, Size);
1379 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1380 /// where the size in bytes of the directive is specified by Size and Hi/Lo
1381 /// specify the labels. This implicitly uses .set if it is available.
1382 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1383 const MCSymbol *Lo, unsigned Size)
1386 // Emit Hi+Offset - Lo
1387 // Get the Hi+Offset expression.
1388 const MCExpr *Plus =
1389 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1390 MCConstantExpr::Create(Offset, OutContext),
1393 // Get the Hi+Offset-Lo expression.
1394 const MCExpr *Diff =
1395 MCBinaryExpr::CreateSub(Plus,
1396 MCSymbolRefExpr::Create(Lo, OutContext),
1399 if (!MAI->hasSetDirective())
1400 OutStreamer.EmitValue(Diff, 4);
1402 // Otherwise, emit with .set (aka assignment).
1403 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1404 OutStreamer.EmitAssignment(SetLabel, Diff);
1405 OutStreamer.EmitSymbolValue(SetLabel, 4);
1409 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1410 /// where the size in bytes of the directive is specified by Size and Label
1411 /// specifies the label. This implicitly uses .set if it is available.
1412 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1413 unsigned Size, bool IsSectionRelative)
1415 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1416 OutStreamer.EmitCOFFSecRel32(Label);
1420 // Emit Label+Offset (or just Label if Offset is zero)
1421 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext);
1423 Expr = MCBinaryExpr::CreateAdd(Expr,
1424 MCConstantExpr::Create(Offset, OutContext),
1427 OutStreamer.EmitValue(Expr, Size);
1431 //===----------------------------------------------------------------------===//
1433 // EmitAlignment - Emit an alignment directive to the specified power of
1434 // two boundary. For example, if you pass in 3 here, you will get an 8
1435 // byte alignment. If a global value is specified, and if that global has
1436 // an explicit alignment requested, it will override the alignment request
1437 // if required for correctness.
1439 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1440 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits);
1442 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1444 if (getCurrentSection()->getKind().isText())
1445 OutStreamer.EmitCodeAlignment(1 << NumBits);
1447 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1450 //===----------------------------------------------------------------------===//
1451 // Constant emission.
1452 //===----------------------------------------------------------------------===//
1454 /// lowerConstant - Lower the specified LLVM Constant to an MCExpr.
1456 static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) {
1457 MCContext &Ctx = AP.OutContext;
1459 if (CV->isNullValue() || isa<UndefValue>(CV))
1460 return MCConstantExpr::Create(0, Ctx);
1462 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1463 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1465 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1466 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1468 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1469 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1471 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1473 llvm_unreachable("Unknown constant value to lower!");
1476 switch (CE->getOpcode()) {
1478 // If the code isn't optimized, there may be outstanding folding
1479 // opportunities. Attempt to fold the expression using DataLayout as a
1480 // last resort before giving up.
1482 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout()))
1484 return lowerConstant(C, AP);
1486 // Otherwise report the problem to the user.
1489 raw_string_ostream OS(S);
1490 OS << "Unsupported expression in static initializer: ";
1491 WriteAsOperand(OS, CE, /*PrintType=*/false,
1492 !AP.MF ? 0 : AP.MF->getFunction()->getParent());
1493 report_fatal_error(OS.str());
1495 case Instruction::GetElementPtr: {
1496 const DataLayout &DL = *AP.TM.getDataLayout();
1497 // Generate a symbolic expression for the byte address
1498 APInt OffsetAI(DL.getPointerSizeInBits(), 0);
1499 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI);
1501 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP);
1505 int64_t Offset = OffsetAI.getSExtValue();
1506 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1510 case Instruction::Trunc:
1511 // We emit the value and depend on the assembler to truncate the generated
1512 // expression properly. This is important for differences between
1513 // blockaddress labels. Since the two labels are in the same function, it
1514 // is reasonable to treat their delta as a 32-bit value.
1516 case Instruction::BitCast:
1517 return lowerConstant(CE->getOperand(0), AP);
1519 case Instruction::IntToPtr: {
1520 const DataLayout &DL = *AP.TM.getDataLayout();
1521 // Handle casts to pointers by changing them into casts to the appropriate
1522 // integer type. This promotes constant folding and simplifies this code.
1523 Constant *Op = CE->getOperand(0);
1524 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getContext()),
1526 return lowerConstant(Op, AP);
1529 case Instruction::PtrToInt: {
1530 const DataLayout &DL = *AP.TM.getDataLayout();
1531 // Support only foldable casts to/from pointers that can be eliminated by
1532 // changing the pointer to the appropriately sized integer type.
1533 Constant *Op = CE->getOperand(0);
1534 Type *Ty = CE->getType();
1536 const MCExpr *OpExpr = lowerConstant(Op, AP);
1538 // We can emit the pointer value into this slot if the slot is an
1539 // integer slot equal to the size of the pointer.
1540 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
1543 // Otherwise the pointer is smaller than the resultant integer, mask off
1544 // the high bits so we are sure to get a proper truncation if the input is
1546 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
1547 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1548 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1551 // The MC library also has a right-shift operator, but it isn't consistently
1552 // signed or unsigned between different targets.
1553 case Instruction::Add:
1554 case Instruction::Sub:
1555 case Instruction::Mul:
1556 case Instruction::SDiv:
1557 case Instruction::SRem:
1558 case Instruction::Shl:
1559 case Instruction::And:
1560 case Instruction::Or:
1561 case Instruction::Xor: {
1562 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP);
1563 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP);
1564 switch (CE->getOpcode()) {
1565 default: llvm_unreachable("Unknown binary operator constant cast expr");
1566 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1567 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1568 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1569 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1570 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1571 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1572 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1573 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1574 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1580 static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP);
1582 /// isRepeatedByteSequence - Determine whether the given value is
1583 /// composed of a repeated sequence of identical bytes and return the
1584 /// byte value. If it is not a repeated sequence, return -1.
1585 static int isRepeatedByteSequence(const ConstantDataSequential *V) {
1586 StringRef Data = V->getRawDataValues();
1587 assert(!Data.empty() && "Empty aggregates should be CAZ node");
1589 for (unsigned i = 1, e = Data.size(); i != e; ++i)
1590 if (Data[i] != C) return -1;
1591 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
1595 /// isRepeatedByteSequence - Determine whether the given value is
1596 /// composed of a repeated sequence of identical bytes and return the
1597 /// byte value. If it is not a repeated sequence, return -1.
1598 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) {
1600 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
1601 if (CI->getBitWidth() > 64) return -1;
1603 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType());
1604 uint64_t Value = CI->getZExtValue();
1606 // Make sure the constant is at least 8 bits long and has a power
1607 // of 2 bit width. This guarantees the constant bit width is
1608 // always a multiple of 8 bits, avoiding issues with padding out
1609 // to Size and other such corner cases.
1610 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1;
1612 uint8_t Byte = static_cast<uint8_t>(Value);
1614 for (unsigned i = 1; i < Size; ++i) {
1616 if (static_cast<uint8_t>(Value) != Byte) return -1;
1620 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
1621 // Make sure all array elements are sequences of the same repeated
1623 assert(CA->getNumOperands() != 0 && "Should be a CAZ");
1624 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM);
1625 if (Byte == -1) return -1;
1627 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) {
1628 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM);
1629 if (ThisByte == -1) return -1;
1630 if (Byte != ThisByte) return -1;
1635 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
1636 return isRepeatedByteSequence(CDS);
1641 static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS,
1644 // See if we can aggregate this into a .fill, if so, emit it as such.
1645 int Value = isRepeatedByteSequence(CDS, AP.TM);
1647 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType());
1648 // Don't emit a 1-byte object as a .fill.
1650 return AP.OutStreamer.EmitFill(Bytes, Value);
1653 // If this can be emitted with .ascii/.asciz, emit it as such.
1654 if (CDS->isString())
1655 return AP.OutStreamer.EmitBytes(CDS->getAsString());
1657 // Otherwise, emit the values in successive locations.
1658 unsigned ElementByteSize = CDS->getElementByteSize();
1659 if (isa<IntegerType>(CDS->getElementType())) {
1660 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1662 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1663 CDS->getElementAsInteger(i));
1664 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i),
1667 } else if (ElementByteSize == 4) {
1668 // FP Constants are printed as integer constants to avoid losing
1670 assert(CDS->getElementType()->isFloatTy());
1671 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1677 F = CDS->getElementAsFloat(i);
1679 AP.OutStreamer.GetCommentOS() << "float " << F << '\n';
1680 AP.OutStreamer.EmitIntValue(I, 4);
1683 assert(CDS->getElementType()->isDoubleTy());
1684 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1690 F = CDS->getElementAsDouble(i);
1692 AP.OutStreamer.GetCommentOS() << "double " << F << '\n';
1693 AP.OutStreamer.EmitIntValue(I, 8);
1697 const DataLayout &DL = *AP.TM.getDataLayout();
1698 unsigned Size = DL.getTypeAllocSize(CDS->getType());
1699 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
1700 CDS->getNumElements();
1701 if (unsigned Padding = Size - EmittedSize)
1702 AP.OutStreamer.EmitZeros(Padding);
1706 static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) {
1707 // See if we can aggregate some values. Make sure it can be
1708 // represented as a series of bytes of the constant value.
1709 int Value = isRepeatedByteSequence(CA, AP.TM);
1712 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType());
1713 AP.OutStreamer.EmitFill(Bytes, Value);
1716 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1717 emitGlobalConstantImpl(CA->getOperand(i), AP);
1721 static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) {
1722 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1723 emitGlobalConstantImpl(CV->getOperand(i), AP);
1725 const DataLayout &DL = *AP.TM.getDataLayout();
1726 unsigned Size = DL.getTypeAllocSize(CV->getType());
1727 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
1728 CV->getType()->getNumElements();
1729 if (unsigned Padding = Size - EmittedSize)
1730 AP.OutStreamer.EmitZeros(Padding);
1733 static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) {
1734 // Print the fields in successive locations. Pad to align if needed!
1735 const DataLayout *DL = AP.TM.getDataLayout();
1736 unsigned Size = DL->getTypeAllocSize(CS->getType());
1737 const StructLayout *Layout = DL->getStructLayout(CS->getType());
1738 uint64_t SizeSoFar = 0;
1739 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1740 const Constant *Field = CS->getOperand(i);
1742 // Check if padding is needed and insert one or more 0s.
1743 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType());
1744 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1745 - Layout->getElementOffset(i)) - FieldSize;
1746 SizeSoFar += FieldSize + PadSize;
1748 // Now print the actual field value.
1749 emitGlobalConstantImpl(Field, AP);
1751 // Insert padding - this may include padding to increase the size of the
1752 // current field up to the ABI size (if the struct is not packed) as well
1753 // as padding to ensure that the next field starts at the right offset.
1754 AP.OutStreamer.EmitZeros(PadSize);
1756 assert(SizeSoFar == Layout->getSizeInBytes() &&
1757 "Layout of constant struct may be incorrect!");
1760 static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
1761 APInt API = CFP->getValueAPF().bitcastToAPInt();
1763 // First print a comment with what we think the original floating-point value
1764 // should have been.
1765 if (AP.isVerbose()) {
1766 SmallString<8> StrVal;
1767 CFP->getValueAPF().toString(StrVal);
1769 CFP->getType()->print(AP.OutStreamer.GetCommentOS());
1770 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n';
1773 // Now iterate through the APInt chunks, emitting them in endian-correct
1774 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
1776 unsigned NumBytes = API.getBitWidth() / 8;
1777 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
1778 const uint64_t *p = API.getRawData();
1780 // PPC's long double has odd notions of endianness compared to how LLVM
1781 // handles it: p[0] goes first for *big* endian on PPC.
1782 if (AP.TM.getDataLayout()->isBigEndian() != CFP->getType()->isPPC_FP128Ty()) {
1783 int Chunk = API.getNumWords() - 1;
1786 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes);
1788 for (; Chunk >= 0; --Chunk)
1789 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1792 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
1793 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t));
1796 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes);
1799 // Emit the tail padding for the long double.
1800 const DataLayout &DL = *AP.TM.getDataLayout();
1801 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) -
1802 DL.getTypeStoreSize(CFP->getType()));
1805 static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
1806 const DataLayout *DL = AP.TM.getDataLayout();
1807 unsigned BitWidth = CI->getBitWidth();
1809 // Copy the value as we may massage the layout for constants whose bit width
1810 // is not a multiple of 64-bits.
1811 APInt Realigned(CI->getValue());
1812 uint64_t ExtraBits = 0;
1813 unsigned ExtraBitsSize = BitWidth & 63;
1815 if (ExtraBitsSize) {
1816 // The bit width of the data is not a multiple of 64-bits.
1817 // The extra bits are expected to be at the end of the chunk of the memory.
1819 // * Nothing to be done, just record the extra bits to emit.
1821 // * Record the extra bits to emit.
1822 // * Realign the raw data to emit the chunks of 64-bits.
1823 if (DL->isBigEndian()) {
1824 // Basically the structure of the raw data is a chunk of 64-bits cells:
1825 // 0 1 BitWidth / 64
1826 // [chunk1][chunk2] ... [chunkN].
1827 // The most significant chunk is chunkN and it should be emitted first.
1828 // However, due to the alignment issue chunkN contains useless bits.
1829 // Realign the chunks so that they contain only useless information:
1830 // ExtraBits 0 1 (BitWidth / 64) - 1
1831 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
1832 ExtraBits = Realigned.getRawData()[0] &
1833 (((uint64_t)-1) >> (64 - ExtraBitsSize));
1834 Realigned = Realigned.lshr(ExtraBitsSize);
1836 ExtraBits = Realigned.getRawData()[BitWidth / 64];
1839 // We don't expect assemblers to support integer data directives
1840 // for more than 64 bits, so we emit the data in at most 64-bit
1841 // quantities at a time.
1842 const uint64_t *RawData = Realigned.getRawData();
1843 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1844 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1845 AP.OutStreamer.EmitIntValue(Val, 8);
1848 if (ExtraBitsSize) {
1849 // Emit the extra bits after the 64-bits chunks.
1851 // Emit a directive that fills the expected size.
1852 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(CI->getType());
1853 Size -= (BitWidth / 64) * 8;
1854 assert(Size && Size * 8 >= ExtraBitsSize &&
1855 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))
1856 == ExtraBits && "Directive too small for extra bits.");
1857 AP.OutStreamer.EmitIntValue(ExtraBits, Size);
1861 static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) {
1862 const DataLayout *DL = AP.TM.getDataLayout();
1863 uint64_t Size = DL->getTypeAllocSize(CV->getType());
1864 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
1865 return AP.OutStreamer.EmitZeros(Size);
1867 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1874 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n",
1875 CI->getZExtValue());
1876 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size);
1879 emitGlobalConstantLargeInt(CI, AP);
1884 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1885 return emitGlobalConstantFP(CFP, AP);
1887 if (isa<ConstantPointerNull>(CV)) {
1888 AP.OutStreamer.EmitIntValue(0, Size);
1892 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
1893 return emitGlobalConstantDataSequential(CDS, AP);
1895 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1896 return emitGlobalConstantArray(CVA, AP);
1898 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1899 return emitGlobalConstantStruct(CVS, AP);
1901 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
1902 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
1904 if (CE->getOpcode() == Instruction::BitCast)
1905 return emitGlobalConstantImpl(CE->getOperand(0), AP);
1908 // If the constant expression's size is greater than 64-bits, then we have
1909 // to emit the value in chunks. Try to constant fold the value and emit it
1911 Constant *New = ConstantFoldConstantExpression(CE, DL);
1912 if (New && New != CE)
1913 return emitGlobalConstantImpl(New, AP);
1917 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1918 return emitGlobalConstantVector(V, AP);
1920 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1921 // thread the streamer with EmitValue.
1922 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size);
1925 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1926 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
1927 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType());
1929 emitGlobalConstantImpl(CV, *this);
1930 else if (MAI->hasSubsectionsViaSymbols()) {
1931 // If the global has zero size, emit a single byte so that two labels don't
1932 // look like they are at the same location.
1933 OutStreamer.EmitIntValue(0, 1);
1937 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1938 // Target doesn't support this yet!
1939 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1942 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1944 OS << '+' << Offset;
1945 else if (Offset < 0)
1949 //===----------------------------------------------------------------------===//
1950 // Symbol Lowering Routines.
1951 //===----------------------------------------------------------------------===//
1953 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1954 /// temporary label with the specified stem and unique ID.
1955 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1956 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1960 /// GetTempSymbol - Return an assembler temporary label with the specified
1962 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1963 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1968 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1969 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1972 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1973 return MMI->getAddrLabelSymbol(BB);
1976 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1977 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1978 return OutContext.GetOrCreateSymbol
1979 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1980 + "_" + Twine(CPID));
1983 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1984 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1985 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1988 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1989 /// FIXME: privatize to AsmPrinter.
1990 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1991 return OutContext.GetOrCreateSymbol
1992 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1993 Twine(UID) + "_set_" + Twine(MBBID));
1996 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1997 /// global value name as its base, with the specified suffix, and where the
1998 /// symbol is forced to have private linkage if ForcePrivate is true.
1999 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
2001 bool ForcePrivate) const {
2002 SmallString<60> NameStr;
2003 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
2004 NameStr.append(Suffix.begin(), Suffix.end());
2005 return OutContext.GetOrCreateSymbol(NameStr.str());
2008 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
2010 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2011 SmallString<60> NameStr;
2012 Mang->getNameWithPrefix(NameStr, Sym);
2013 return OutContext.GetOrCreateSymbol(NameStr.str());
2018 /// PrintParentLoopComment - Print comments about parent loops of this one.
2019 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2020 unsigned FunctionNumber) {
2021 if (Loop == 0) return;
2022 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2023 OS.indent(Loop->getLoopDepth()*2)
2024 << "Parent Loop BB" << FunctionNumber << "_"
2025 << Loop->getHeader()->getNumber()
2026 << " Depth=" << Loop->getLoopDepth() << '\n';
2030 /// PrintChildLoopComment - Print comments about child loops within
2031 /// the loop for this basic block, with nesting.
2032 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2033 unsigned FunctionNumber) {
2034 // Add child loop information
2035 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
2036 OS.indent((*CL)->getLoopDepth()*2)
2037 << "Child Loop BB" << FunctionNumber << "_"
2038 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
2040 PrintChildLoopComment(OS, *CL, FunctionNumber);
2044 /// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2045 static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2046 const MachineLoopInfo *LI,
2047 const AsmPrinter &AP) {
2048 // Add loop depth information
2049 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2050 if (Loop == 0) return;
2052 MachineBasicBlock *Header = Loop->getHeader();
2053 assert(Header && "No header for loop");
2055 // If this block is not a loop header, just print out what is the loop header
2057 if (Header != &MBB) {
2058 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
2059 Twine(AP.getFunctionNumber())+"_" +
2060 Twine(Loop->getHeader()->getNumber())+
2061 " Depth="+Twine(Loop->getLoopDepth()));
2065 // Otherwise, it is a loop header. Print out information about child and
2067 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
2069 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2072 OS.indent(Loop->getLoopDepth()*2-2);
2077 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2079 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2083 /// EmitBasicBlockStart - This method prints the label for the specified
2084 /// MachineBasicBlock, an alignment (if present) and a comment describing
2085 /// it if appropriate.
2086 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
2087 // Emit an alignment directive for this block, if needed.
2088 if (unsigned Align = MBB->getAlignment())
2089 EmitAlignment(Align);
2091 // If the block has its address taken, emit any labels that were used to
2092 // reference the block. It is possible that there is more than one label
2093 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2094 // the references were generated.
2095 if (MBB->hasAddressTaken()) {
2096 const BasicBlock *BB = MBB->getBasicBlock();
2098 OutStreamer.AddComment("Block address taken");
2100 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
2102 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
2103 OutStreamer.EmitLabel(Syms[i]);
2106 // Print some verbose block comments.
2108 if (const BasicBlock *BB = MBB->getBasicBlock())
2110 OutStreamer.AddComment("%" + BB->getName());
2111 emitBasicBlockLoopComments(*MBB, LI, *this);
2114 // Print the main label for the block.
2115 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
2116 if (isVerbose() && OutStreamer.hasRawTextSupport()) {
2117 // NOTE: Want this comment at start of line, don't emit with AddComment.
2118 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
2119 Twine(MBB->getNumber()) + ":");
2122 OutStreamer.EmitLabel(MBB->getSymbol());
2126 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2127 bool IsDefinition) const {
2128 MCSymbolAttr Attr = MCSA_Invalid;
2130 switch (Visibility) {
2132 case GlobalValue::HiddenVisibility:
2134 Attr = MAI->getHiddenVisibilityAttr();
2136 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2138 case GlobalValue::ProtectedVisibility:
2139 Attr = MAI->getProtectedVisibilityAttr();
2143 if (Attr != MCSA_Invalid)
2144 OutStreamer.EmitSymbolAttribute(Sym, Attr);
2147 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
2148 /// exactly one predecessor and the control transfer mechanism between
2149 /// the predecessor and this block is a fall-through.
2151 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2152 // If this is a landing pad, it isn't a fall through. If it has no preds,
2153 // then nothing falls through to it.
2154 if (MBB->isLandingPad() || MBB->pred_empty())
2157 // If there isn't exactly one predecessor, it can't be a fall through.
2158 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
2160 if (PI2 != MBB->pred_end())
2163 // The predecessor has to be immediately before this block.
2164 MachineBasicBlock *Pred = *PI;
2166 if (!Pred->isLayoutSuccessor(MBB))
2169 // If the block is completely empty, then it definitely does fall through.
2173 // Check the terminators in the previous blocks
2174 for (MachineBasicBlock::iterator II = Pred->getFirstTerminator(),
2175 IE = Pred->end(); II != IE; ++II) {
2176 MachineInstr &MI = *II;
2178 // If it is not a simple branch, we are in a table somewhere.
2179 if (!MI.isBranch() || MI.isIndirectBranch())
2182 // If we are the operands of one of the branches, this is not
2184 for (MachineInstr::mop_iterator OI = MI.operands_begin(),
2185 OE = MI.operands_end(); OI != OE; ++OI) {
2186 const MachineOperand& OP = *OI;
2189 if (OP.isMBB() && OP.getMBB() == MBB)
2199 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
2200 if (!S->usesMetadata())
2203 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2204 gcp_map_type::iterator GCPI = GCMap.find(S);
2205 if (GCPI != GCMap.end())
2206 return GCPI->second;
2208 const char *Name = S->getName().c_str();
2210 for (GCMetadataPrinterRegistry::iterator
2211 I = GCMetadataPrinterRegistry::begin(),
2212 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2213 if (strcmp(Name, I->getName()) == 0) {
2214 GCMetadataPrinter *GMP = I->instantiate();
2216 GCMap.insert(std::make_pair(S, GMP));
2220 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));