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 "llvm/Assembly/Writer.h"
17 #include "llvm/DerivedTypes.h"
18 #include "llvm/Constants.h"
19 #include "llvm/Module.h"
20 #include "llvm/CodeGen/DwarfWriter.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/MachineJumpTableInfo.h"
26 #include "llvm/CodeGen/MachineLoopInfo.h"
27 #include "llvm/CodeGen/MachineModuleInfo.h"
28 #include "llvm/Analysis/ConstantFolding.h"
29 #include "llvm/Analysis/DebugInfo.h"
30 #include "llvm/MC/MCContext.h"
31 #include "llvm/MC/MCExpr.h"
32 #include "llvm/MC/MCInst.h"
33 #include "llvm/MC/MCSection.h"
34 #include "llvm/MC/MCStreamer.h"
35 #include "llvm/MC/MCSymbol.h"
36 #include "llvm/MC/MCAsmInfo.h"
37 #include "llvm/Target/Mangler.h"
38 #include "llvm/Target/TargetData.h"
39 #include "llvm/Target/TargetInstrInfo.h"
40 #include "llvm/Target/TargetLowering.h"
41 #include "llvm/Target/TargetLoweringObjectFile.h"
42 #include "llvm/Target/TargetOptions.h"
43 #include "llvm/Target/TargetRegisterInfo.h"
44 #include "llvm/ADT/SmallPtrSet.h"
45 #include "llvm/ADT/SmallString.h"
46 #include "llvm/ADT/Statistic.h"
47 #include "llvm/Support/CommandLine.h"
48 #include "llvm/Support/Debug.h"
49 #include "llvm/Support/ErrorHandling.h"
50 #include "llvm/Support/Format.h"
54 STATISTIC(EmittedInsts, "Number of machine instrs printed");
56 char AsmPrinter::ID = 0;
58 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
59 static gcp_map_type &getGCMap(void *&P) {
61 P = new gcp_map_type();
62 return *(gcp_map_type*)P;
66 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
67 : MachineFunctionPass(&ID),
68 TM(tm), MAI(tm.getMCAsmInfo()),
69 OutContext(Streamer.getContext()),
70 OutStreamer(Streamer),
71 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
73 GCMetadataPrinters = 0;
74 VerboseAsm = Streamer.isVerboseAsm();
77 AsmPrinter::~AsmPrinter() {
78 if (GCMetadataPrinters != 0) {
79 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
81 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
84 GCMetadataPrinters = 0;
90 /// getFunctionNumber - Return a unique ID for the current function.
92 unsigned AsmPrinter::getFunctionNumber() const {
93 return MF->getFunctionNumber();
96 TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
97 return TM.getTargetLowering()->getObjFileLowering();
100 /// getCurrentSection() - Return the current section we are emitting to.
101 const MCSection *AsmPrinter::getCurrentSection() const {
102 return OutStreamer.getCurrentSection();
106 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
107 AU.setPreservesAll();
108 MachineFunctionPass::getAnalysisUsage(AU);
109 AU.addRequired<MachineModuleInfo>();
110 AU.addRequired<GCModuleInfo>();
112 AU.addRequired<MachineLoopInfo>();
115 bool AsmPrinter::doInitialization(Module &M) {
116 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
117 MMI->AnalyzeModule(M);
119 // Initialize TargetLoweringObjectFile.
120 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
121 .Initialize(OutContext, TM);
123 Mang = new Mangler(OutContext, *TM.getTargetData());
125 // Allow the target to emit any magic that it wants at the start of the file.
126 EmitStartOfAsmFile(M);
128 // Very minimal debug info. It is ignored if we emit actual debug info. If we
129 // don't, this at least helps the user find where a global came from.
130 if (MAI->hasSingleParameterDotFile()) {
132 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
135 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
136 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
137 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
138 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
139 MP->beginAssembly(*this);
141 // Emit module-level inline asm if it exists.
142 if (!M.getModuleInlineAsm().empty()) {
143 OutStreamer.AddComment("Start of file scope inline assembly");
144 OutStreamer.AddBlankLine();
145 EmitInlineAsm(M.getModuleInlineAsm());
146 OutStreamer.AddComment("End of file scope inline assembly");
147 OutStreamer.AddBlankLine();
150 DW = getAnalysisIfAvailable<DwarfWriter>();
152 DW->BeginModule(&M, this);
157 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
158 switch ((GlobalValue::LinkageTypes)Linkage) {
159 case GlobalValue::CommonLinkage:
160 case GlobalValue::LinkOnceAnyLinkage:
161 case GlobalValue::LinkOnceODRLinkage:
162 case GlobalValue::WeakAnyLinkage:
163 case GlobalValue::WeakODRLinkage:
164 case GlobalValue::LinkerPrivateLinkage:
165 if (MAI->getWeakDefDirective() != 0) {
167 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
168 // .weak_definition _foo
169 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
170 } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
172 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
173 // FIXME: linkonce should be a section attribute, handled by COFF Section
175 // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
177 // FIXME: It would be nice to use .linkonce samesize for non-common
179 OutStreamer.EmitRawText(StringRef(LinkOnce));
182 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
185 case GlobalValue::DLLExportLinkage:
186 case GlobalValue::AppendingLinkage:
187 // FIXME: appending linkage variables should go into a section of
188 // their name or something. For now, just emit them as external.
189 case GlobalValue::ExternalLinkage:
190 // If external or appending, declare as a global symbol.
192 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
194 case GlobalValue::PrivateLinkage:
195 case GlobalValue::InternalLinkage:
198 llvm_unreachable("Unknown linkage type!");
203 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
204 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
205 if (!GV->hasInitializer()) // External globals require no code.
208 // Check to see if this is a special global used by LLVM, if so, emit it.
209 if (EmitSpecialLLVMGlobal(GV))
212 MCSymbol *GVSym = Mang->getSymbol(GV);
213 EmitVisibility(GVSym, GV->getVisibility());
215 if (MAI->hasDotTypeDotSizeDirective())
216 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
218 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
220 const TargetData *TD = TM.getTargetData();
221 unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
222 unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
224 // Handle common and BSS local symbols (.lcomm).
225 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
226 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
229 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
230 /*PrintType=*/false, GV->getParent());
231 OutStreamer.GetCommentOS() << '\n';
234 // Handle common symbols.
235 if (GVKind.isCommon()) {
237 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
241 // Handle local BSS symbols.
242 if (MAI->hasMachoZeroFillDirective()) {
243 const MCSection *TheSection =
244 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
245 // .zerofill __DATA, __bss, _foo, 400, 5
246 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
250 if (MAI->hasLCOMMDirective()) {
252 OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
257 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
259 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
263 const MCSection *TheSection =
264 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
266 // Handle the zerofill directive on darwin, which is a special form of BSS
268 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
270 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
271 // .zerofill __DATA, __common, _foo, 400, 5
272 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
276 OutStreamer.SwitchSection(TheSection);
278 EmitLinkage(GV->getLinkage(), GVSym);
279 EmitAlignment(AlignLog, GV);
282 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
283 /*PrintType=*/false, GV->getParent());
284 OutStreamer.GetCommentOS() << '\n';
286 OutStreamer.EmitLabel(GVSym);
288 EmitGlobalConstant(GV->getInitializer());
290 if (MAI->hasDotTypeDotSizeDirective())
292 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
294 OutStreamer.AddBlankLine();
297 /// EmitFunctionHeader - This method emits the header for the current
299 void AsmPrinter::EmitFunctionHeader() {
300 // Print out constants referenced by the function
303 // Print the 'header' of function.
304 const Function *F = MF->getFunction();
306 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
307 EmitVisibility(CurrentFnSym, F->getVisibility());
309 EmitLinkage(F->getLinkage(), CurrentFnSym);
310 EmitAlignment(MF->getAlignment(), F);
312 if (MAI->hasDotTypeDotSizeDirective())
313 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
316 WriteAsOperand(OutStreamer.GetCommentOS(), F,
317 /*PrintType=*/false, F->getParent());
318 OutStreamer.GetCommentOS() << '\n';
321 // Emit the CurrentFnSym. This is a virtual function to allow targets to
322 // do their wild and crazy things as required.
323 EmitFunctionEntryLabel();
325 // If the function had address-taken blocks that got deleted, then we have
326 // references to the dangling symbols. Emit them at the start of the function
327 // so that we don't get references to undefined symbols.
328 std::vector<MCSymbol*> DeadBlockSyms;
329 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
330 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
331 OutStreamer.AddComment("Address taken block that was later removed");
332 OutStreamer.EmitLabel(DeadBlockSyms[i]);
335 // Add some workaround for linkonce linkage on Cygwin\MinGW.
336 if (MAI->getLinkOnceDirective() != 0 &&
337 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
338 // FIXME: What is this?
340 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
341 CurrentFnSym->getName());
342 OutStreamer.EmitLabel(FakeStub);
345 // Emit pre-function debug and/or EH information.
346 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
347 DW->BeginFunction(MF);
350 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
351 /// function. This can be overridden by targets as required to do custom stuff.
352 void AsmPrinter::EmitFunctionEntryLabel() {
353 OutStreamer.EmitLabel(CurrentFnSym);
357 /// EmitComments - Pretty-print comments for instructions.
358 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
359 const MachineFunction *MF = MI.getParent()->getParent();
360 const TargetMachine &TM = MF->getTarget();
362 DebugLoc DL = MI.getDebugLoc();
363 if (!DL.isUnknown()) { // Print source line info.
364 DIScope Scope(DL.getScope(MF->getFunction()->getContext()));
365 // Omit the directory, because it's likely to be long and uninteresting.
367 CommentOS << Scope.getFilename();
369 CommentOS << "<unknown>";
370 CommentOS << ':' << DL.getLine();
371 if (DL.getCol() != 0)
372 CommentOS << ':' << DL.getCol();
376 // Check for spills and reloads
379 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
381 // We assume a single instruction only has a spill or reload, not
383 const MachineMemOperand *MMO;
384 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
385 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
386 MMO = *MI.memoperands_begin();
387 CommentOS << MMO->getSize() << "-byte Reload\n";
389 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
390 if (FrameInfo->isSpillSlotObjectIndex(FI))
391 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
392 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
393 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
394 MMO = *MI.memoperands_begin();
395 CommentOS << MMO->getSize() << "-byte Spill\n";
397 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
398 if (FrameInfo->isSpillSlotObjectIndex(FI))
399 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
402 // Check for spill-induced copies
403 unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
404 if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
405 SrcSubIdx, DstSubIdx)) {
406 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
407 CommentOS << " Reload Reuse\n";
413 /// EmitFunctionBody - This method emits the body and trailer for a
415 void AsmPrinter::EmitFunctionBody() {
416 // Emit target-specific gunk before the function body.
417 EmitFunctionBodyStart();
419 // Print out code for the function.
420 bool HasAnyRealCode = false;
421 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
423 // Print a label for the basic block.
424 EmitBasicBlockStart(I);
425 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
427 // Print the assembly for the instruction.
429 HasAnyRealCode = true;
433 // FIXME: Clean up processDebugLoc.
434 processDebugLoc(II, true);
437 EmitComments(*II, OutStreamer.GetCommentOS());
439 switch (II->getOpcode()) {
440 case TargetOpcode::DBG_LABEL:
441 case TargetOpcode::EH_LABEL:
442 case TargetOpcode::GC_LABEL:
443 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
445 case TargetOpcode::INLINEASM:
448 case TargetOpcode::IMPLICIT_DEF:
451 case TargetOpcode::KILL:
459 // FIXME: Clean up processDebugLoc.
460 processDebugLoc(II, false);
464 // If the function is empty and the object file uses .subsections_via_symbols,
465 // then we need to emit *something* to the function body to prevent the
466 // labels from collapsing together. Just emit a 0 byte.
467 if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
468 OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
470 // Emit target-specific gunk after the function body.
471 EmitFunctionBodyEnd();
473 // If the target wants a .size directive for the size of the function, emit
475 if (MAI->hasDotTypeDotSizeDirective()) {
476 // Create a symbol for the end of function, so we can get the size as
477 // difference between the function label and the temp label.
478 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
479 OutStreamer.EmitLabel(FnEndLabel);
481 const MCExpr *SizeExp =
482 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
483 MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
485 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
488 // Emit post-function debug information.
489 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
492 // Print out jump tables referenced by the function.
495 OutStreamer.AddBlankLine();
499 bool AsmPrinter::doFinalization(Module &M) {
500 // Emit global variables.
501 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
503 EmitGlobalVariable(I);
505 // Emit final debug information.
506 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
509 // If the target wants to know about weak references, print them all.
510 if (MAI->getWeakRefDirective()) {
511 // FIXME: This is not lazy, it would be nice to only print weak references
512 // to stuff that is actually used. Note that doing so would require targets
513 // to notice uses in operands (due to constant exprs etc). This should
514 // happen with the MC stuff eventually.
516 // Print out module-level global variables here.
517 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
519 if (!I->hasExternalWeakLinkage()) continue;
520 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
523 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
524 if (!I->hasExternalWeakLinkage()) continue;
525 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
529 if (MAI->hasSetDirective()) {
530 OutStreamer.AddBlankLine();
531 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
533 MCSymbol *Name = Mang->getSymbol(I);
535 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
536 MCSymbol *Target = Mang->getSymbol(GV);
538 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
539 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
540 else if (I->hasWeakLinkage())
541 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
543 assert(I->hasLocalLinkage() && "Invalid alias linkage");
545 EmitVisibility(Name, I->getVisibility());
547 // Emit the directives as assignments aka .set:
548 OutStreamer.EmitAssignment(Name,
549 MCSymbolRefExpr::Create(Target, OutContext));
553 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
554 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
555 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
556 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
557 MP->finishAssembly(*this);
559 // If we don't have any trampolines, then we don't require stack memory
560 // to be executable. Some targets have a directive to declare this.
561 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
562 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
563 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
564 OutStreamer.SwitchSection(S);
566 // Allow the target to emit any magic that it wants at the end of the file,
567 // after everything else has gone out.
570 delete Mang; Mang = 0;
573 OutStreamer.Finish();
577 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
579 // Get the function symbol.
580 CurrentFnSym = Mang->getSymbol(MF.getFunction());
583 LI = &getAnalysis<MachineLoopInfo>();
587 // SectionCPs - Keep track the alignment, constpool entries per Section.
591 SmallVector<unsigned, 4> CPEs;
592 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
596 /// EmitConstantPool - Print to the current output stream assembly
597 /// representations of the constants in the constant pool MCP. This is
598 /// used to print out constants which have been "spilled to memory" by
599 /// the code generator.
601 void AsmPrinter::EmitConstantPool() {
602 const MachineConstantPool *MCP = MF->getConstantPool();
603 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
604 if (CP.empty()) return;
606 // Calculate sections for constant pool entries. We collect entries to go into
607 // the same section together to reduce amount of section switch statements.
608 SmallVector<SectionCPs, 4> CPSections;
609 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
610 const MachineConstantPoolEntry &CPE = CP[i];
611 unsigned Align = CPE.getAlignment();
614 switch (CPE.getRelocationInfo()) {
615 default: llvm_unreachable("Unknown section kind");
616 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
618 Kind = SectionKind::getReadOnlyWithRelLocal();
621 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
622 case 4: Kind = SectionKind::getMergeableConst4(); break;
623 case 8: Kind = SectionKind::getMergeableConst8(); break;
624 case 16: Kind = SectionKind::getMergeableConst16();break;
625 default: Kind = SectionKind::getMergeableConst(); break;
629 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
631 // The number of sections are small, just do a linear search from the
632 // last section to the first.
634 unsigned SecIdx = CPSections.size();
635 while (SecIdx != 0) {
636 if (CPSections[--SecIdx].S == S) {
642 SecIdx = CPSections.size();
643 CPSections.push_back(SectionCPs(S, Align));
646 if (Align > CPSections[SecIdx].Alignment)
647 CPSections[SecIdx].Alignment = Align;
648 CPSections[SecIdx].CPEs.push_back(i);
651 // Now print stuff into the calculated sections.
652 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
653 OutStreamer.SwitchSection(CPSections[i].S);
654 EmitAlignment(Log2_32(CPSections[i].Alignment));
657 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
658 unsigned CPI = CPSections[i].CPEs[j];
659 MachineConstantPoolEntry CPE = CP[CPI];
661 // Emit inter-object padding for alignment.
662 unsigned AlignMask = CPE.getAlignment() - 1;
663 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
664 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
666 const Type *Ty = CPE.getType();
667 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
669 // Emit the label with a comment on it.
671 OutStreamer.GetCommentOS() << "constant pool ";
672 WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
673 MF->getFunction()->getParent());
674 OutStreamer.GetCommentOS() << '\n';
676 OutStreamer.EmitLabel(GetCPISymbol(CPI));
678 if (CPE.isMachineConstantPoolEntry())
679 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
681 EmitGlobalConstant(CPE.Val.ConstVal);
686 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
687 /// by the current function to the current output stream.
689 void AsmPrinter::EmitJumpTableInfo() {
690 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
691 if (MJTI == 0) return;
692 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
693 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
694 if (JT.empty()) return;
696 // Pick the directive to use to print the jump table entries, and switch to
697 // the appropriate section.
698 const Function *F = MF->getFunction();
699 bool JTInDiffSection = false;
700 if (// In PIC mode, we need to emit the jump table to the same section as the
701 // function body itself, otherwise the label differences won't make sense.
702 // FIXME: Need a better predicate for this: what about custom entries?
703 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
704 // We should also do if the section name is NULL or function is declared
705 // in discardable section
706 // FIXME: this isn't the right predicate, should be based on the MCSection
708 F->isWeakForLinker()) {
709 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
711 // Otherwise, drop it in the readonly section.
712 const MCSection *ReadOnlySection =
713 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
714 OutStreamer.SwitchSection(ReadOnlySection);
715 JTInDiffSection = true;
718 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
720 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
721 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
723 // If this jump table was deleted, ignore it.
724 if (JTBBs.empty()) continue;
726 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
727 // .set directive for each unique entry. This reduces the number of
728 // relocations the assembler will generate for the jump table.
729 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
730 MAI->hasSetDirective()) {
731 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
732 const TargetLowering *TLI = TM.getTargetLowering();
733 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
734 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
735 const MachineBasicBlock *MBB = JTBBs[ii];
736 if (!EmittedSets.insert(MBB)) continue;
738 // .set LJTSet, LBB32-base
740 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
741 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
742 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
746 // On some targets (e.g. Darwin) we want to emit two consequtive labels
747 // before each jump table. The first label is never referenced, but tells
748 // the assembler and linker the extents of the jump table object. The
749 // second label is actually referenced by the code.
750 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
751 // FIXME: This doesn't have to have any specific name, just any randomly
752 // named and numbered 'l' label would work. Simplify GetJTISymbol.
753 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
755 OutStreamer.EmitLabel(GetJTISymbol(JTI));
757 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
758 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
762 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
764 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
765 const MachineBasicBlock *MBB,
766 unsigned UID) const {
767 const MCExpr *Value = 0;
768 switch (MJTI->getEntryKind()) {
769 case MachineJumpTableInfo::EK_Inline:
770 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
771 case MachineJumpTableInfo::EK_Custom32:
772 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
775 case MachineJumpTableInfo::EK_BlockAddress:
776 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
778 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
780 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
781 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
782 // with a relocation as gp-relative, e.g.:
784 MCSymbol *MBBSym = MBB->getSymbol();
785 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
789 case MachineJumpTableInfo::EK_LabelDifference32: {
790 // EK_LabelDifference32 - Each entry is the address of the block minus
791 // the address of the jump table. This is used for PIC jump tables where
792 // gprel32 is not supported. e.g.:
793 // .word LBB123 - LJTI1_2
794 // If the .set directive is supported, this is emitted as:
795 // .set L4_5_set_123, LBB123 - LJTI1_2
796 // .word L4_5_set_123
798 // If we have emitted set directives for the jump table entries, print
799 // them rather than the entries themselves. If we're emitting PIC, then
800 // emit the table entries as differences between two text section labels.
801 if (MAI->hasSetDirective()) {
802 // If we used .set, reference the .set's symbol.
803 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
807 // Otherwise, use the difference as the jump table entry.
808 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
809 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
810 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
815 assert(Value && "Unknown entry kind!");
817 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
818 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
822 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
823 /// special global used by LLVM. If so, emit it and return true, otherwise
824 /// do nothing and return false.
825 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
826 if (GV->getName() == "llvm.used") {
827 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
828 EmitLLVMUsedList(GV->getInitializer());
832 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
833 if (GV->getSection() == "llvm.metadata" ||
834 GV->hasAvailableExternallyLinkage())
837 if (!GV->hasAppendingLinkage()) return false;
839 assert(GV->hasInitializer() && "Not a special LLVM global!");
841 const TargetData *TD = TM.getTargetData();
842 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
843 if (GV->getName() == "llvm.global_ctors") {
844 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
845 EmitAlignment(Align, 0);
846 EmitXXStructorList(GV->getInitializer());
848 if (TM.getRelocationModel() == Reloc::Static &&
849 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
850 StringRef Sym(".constructors_used");
851 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
857 if (GV->getName() == "llvm.global_dtors") {
858 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
859 EmitAlignment(Align, 0);
860 EmitXXStructorList(GV->getInitializer());
862 if (TM.getRelocationModel() == Reloc::Static &&
863 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
864 StringRef Sym(".destructors_used");
865 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
874 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
875 /// global in the specified llvm.used list for which emitUsedDirectiveFor
876 /// is true, as being used with this directive.
877 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
878 // Should be an array of 'i8*'.
879 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
880 if (InitList == 0) return;
882 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
883 const GlobalValue *GV =
884 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
885 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
886 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
890 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
891 /// function pointers, ignoring the init priority.
892 void AsmPrinter::EmitXXStructorList(Constant *List) {
893 // Should be an array of '{ int, void ()* }' structs. The first value is the
894 // init priority, which we ignore.
895 if (!isa<ConstantArray>(List)) return;
896 ConstantArray *InitList = cast<ConstantArray>(List);
897 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
898 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
899 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
901 if (CS->getOperand(1)->isNullValue())
902 return; // Found a null terminator, exit printing.
903 // Emit the function pointer.
904 EmitGlobalConstant(CS->getOperand(1));
908 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
909 void AsmPrinter::EmitInlineAsm(StringRef Str) const {
910 assert(!Str.empty() && "Can't emit empty inline asm block");
912 // If the output streamer is actually a .s file, just emit the blob textually.
913 // This is useful in case the asm parser doesn't handle something but the
914 // system assembler does.
915 if (OutStreamer.hasRawTextSupport()) {
916 OutStreamer.EmitRawText(Str);
920 errs() << "Inline asm not supported by this streamer!\n";
924 //===--------------------------------------------------------------------===//
925 // Emission and print routines
928 /// EmitInt8 - Emit a byte directive and value.
930 void AsmPrinter::EmitInt8(int Value) const {
931 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
934 /// EmitInt16 - Emit a short directive and value.
936 void AsmPrinter::EmitInt16(int Value) const {
937 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
940 /// EmitInt32 - Emit a long directive and value.
942 void AsmPrinter::EmitInt32(int Value) const {
943 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
946 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
947 /// in bytes of the directive is specified by Size and Hi/Lo specify the
948 /// labels. This implicitly uses .set if it is available.
949 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
950 unsigned Size) const {
951 // Get the Hi-Lo expression.
953 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
954 MCSymbolRefExpr::Create(Lo, OutContext),
957 if (!MAI->hasSetDirective()) {
958 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
962 // Otherwise, emit with .set (aka assignment).
964 OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
965 "set" + Twine(SetCounter++));
966 OutStreamer.EmitAssignment(SetLabel, Diff);
967 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
971 //===----------------------------------------------------------------------===//
973 // EmitAlignment - Emit an alignment directive to the specified power of
974 // two boundary. For example, if you pass in 3 here, you will get an 8
975 // byte alignment. If a global value is specified, and if that global has
976 // an explicit alignment requested, it will unconditionally override the
977 // alignment request. However, if ForcedAlignBits is specified, this value
978 // has final say: the ultimate alignment will be the max of ForcedAlignBits
979 // and the alignment computed with NumBits and the global.
983 // if (GV && GV->hasalignment) Align = GV->getalignment();
984 // Align = std::max(Align, ForcedAlignBits);
986 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
987 unsigned ForcedAlignBits,
988 bool UseFillExpr) const {
989 if (GV && GV->getAlignment())
990 NumBits = Log2_32(GV->getAlignment());
991 NumBits = std::max(NumBits, ForcedAlignBits);
993 if (NumBits == 0) return; // No need to emit alignment.
995 if (getCurrentSection()->getKind().isText())
996 OutStreamer.EmitCodeAlignment(1 << NumBits);
998 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1001 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1003 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1004 MCContext &Ctx = AP.OutContext;
1006 if (CV->isNullValue() || isa<UndefValue>(CV))
1007 return MCConstantExpr::Create(0, Ctx);
1009 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1010 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1012 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1013 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1014 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1015 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1017 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1019 llvm_unreachable("Unknown constant value to lower!");
1020 return MCConstantExpr::Create(0, Ctx);
1023 switch (CE->getOpcode()) {
1025 // If the code isn't optimized, there may be outstanding folding
1026 // opportunities. Attempt to fold the expression using TargetData as a
1027 // last resort before giving up.
1029 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1031 return LowerConstant(C, AP);
1035 llvm_unreachable("FIXME: Don't support this constant expr");
1036 case Instruction::GetElementPtr: {
1037 const TargetData &TD = *AP.TM.getTargetData();
1038 // Generate a symbolic expression for the byte address
1039 const Constant *PtrVal = CE->getOperand(0);
1040 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1041 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1044 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1048 // Truncate/sext the offset to the pointer size.
1049 if (TD.getPointerSizeInBits() != 64) {
1050 int SExtAmount = 64-TD.getPointerSizeInBits();
1051 Offset = (Offset << SExtAmount) >> SExtAmount;
1054 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1058 case Instruction::Trunc:
1059 // We emit the value and depend on the assembler to truncate the generated
1060 // expression properly. This is important for differences between
1061 // blockaddress labels. Since the two labels are in the same function, it
1062 // is reasonable to treat their delta as a 32-bit value.
1064 case Instruction::BitCast:
1065 return LowerConstant(CE->getOperand(0), AP);
1067 case Instruction::IntToPtr: {
1068 const TargetData &TD = *AP.TM.getTargetData();
1069 // Handle casts to pointers by changing them into casts to the appropriate
1070 // integer type. This promotes constant folding and simplifies this code.
1071 Constant *Op = CE->getOperand(0);
1072 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1074 return LowerConstant(Op, AP);
1077 case Instruction::PtrToInt: {
1078 const TargetData &TD = *AP.TM.getTargetData();
1079 // Support only foldable casts to/from pointers that can be eliminated by
1080 // changing the pointer to the appropriately sized integer type.
1081 Constant *Op = CE->getOperand(0);
1082 const Type *Ty = CE->getType();
1084 const MCExpr *OpExpr = LowerConstant(Op, AP);
1086 // We can emit the pointer value into this slot if the slot is an
1087 // integer slot equal to the size of the pointer.
1088 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1091 // Otherwise the pointer is smaller than the resultant integer, mask off
1092 // the high bits so we are sure to get a proper truncation if the input is
1094 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1095 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1096 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1099 // The MC library also has a right-shift operator, but it isn't consistently
1100 // signed or unsigned between different targets.
1101 case Instruction::Add:
1102 case Instruction::Sub:
1103 case Instruction::Mul:
1104 case Instruction::SDiv:
1105 case Instruction::SRem:
1106 case Instruction::Shl:
1107 case Instruction::And:
1108 case Instruction::Or:
1109 case Instruction::Xor: {
1110 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1111 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1112 switch (CE->getOpcode()) {
1113 default: llvm_unreachable("Unknown binary operator constant cast expr");
1114 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1115 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1116 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1117 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1118 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1119 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1120 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1121 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1122 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1128 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1130 if (AddrSpace != 0 || !CA->isString()) {
1131 // Not a string. Print the values in successive locations
1132 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1133 AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
1137 // Otherwise, it can be emitted as .ascii.
1138 SmallVector<char, 128> TmpVec;
1139 TmpVec.reserve(CA->getNumOperands());
1140 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1141 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1143 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1146 static void EmitGlobalConstantVector(const ConstantVector *CV,
1147 unsigned AddrSpace, AsmPrinter &AP) {
1148 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1149 AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1152 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1153 unsigned AddrSpace, AsmPrinter &AP) {
1154 // Print the fields in successive locations. Pad to align if needed!
1155 const TargetData *TD = AP.TM.getTargetData();
1156 unsigned Size = TD->getTypeAllocSize(CS->getType());
1157 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1158 uint64_t SizeSoFar = 0;
1159 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1160 const Constant *Field = CS->getOperand(i);
1162 // Check if padding is needed and insert one or more 0s.
1163 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1164 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1165 - Layout->getElementOffset(i)) - FieldSize;
1166 SizeSoFar += FieldSize + PadSize;
1168 // Now print the actual field value.
1169 AP.EmitGlobalConstant(Field, AddrSpace);
1171 // Insert padding - this may include padding to increase the size of the
1172 // current field up to the ABI size (if the struct is not packed) as well
1173 // as padding to ensure that the next field starts at the right offset.
1174 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1176 assert(SizeSoFar == Layout->getSizeInBytes() &&
1177 "Layout of constant struct may be incorrect!");
1180 static void EmitGlobalConstantUnion(const ConstantUnion *CU,
1181 unsigned AddrSpace, AsmPrinter &AP) {
1182 const TargetData *TD = AP.TM.getTargetData();
1183 unsigned Size = TD->getTypeAllocSize(CU->getType());
1185 const Constant *Contents = CU->getOperand(0);
1186 unsigned FilledSize = TD->getTypeAllocSize(Contents->getType());
1188 // Print the actually filled part
1189 AP.EmitGlobalConstant(Contents, AddrSpace);
1191 // And pad with enough zeroes
1192 AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace);
1195 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1197 // FP Constants are printed as integer constants to avoid losing
1199 if (CFP->getType()->isDoubleTy()) {
1200 if (AP.VerboseAsm) {
1201 double Val = CFP->getValueAPF().convertToDouble();
1202 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1205 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1206 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1210 if (CFP->getType()->isFloatTy()) {
1211 if (AP.VerboseAsm) {
1212 float Val = CFP->getValueAPF().convertToFloat();
1213 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1215 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1216 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1220 if (CFP->getType()->isX86_FP80Ty()) {
1221 // all long double variants are printed as hex
1222 // api needed to prevent premature destruction
1223 APInt API = CFP->getValueAPF().bitcastToAPInt();
1224 const uint64_t *p = API.getRawData();
1225 if (AP.VerboseAsm) {
1226 // Convert to double so we can print the approximate val as a comment.
1227 APFloat DoubleVal = CFP->getValueAPF();
1229 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1231 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1232 << DoubleVal.convertToDouble() << '\n';
1235 if (AP.TM.getTargetData()->isBigEndian()) {
1236 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1237 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1239 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1240 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1243 // Emit the tail padding for the long double.
1244 const TargetData &TD = *AP.TM.getTargetData();
1245 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1246 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1250 assert(CFP->getType()->isPPC_FP128Ty() &&
1251 "Floating point constant type not handled");
1252 // All long double variants are printed as hex api needed to prevent
1253 // premature destruction.
1254 APInt API = CFP->getValueAPF().bitcastToAPInt();
1255 const uint64_t *p = API.getRawData();
1256 if (AP.TM.getTargetData()->isBigEndian()) {
1257 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1258 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1260 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1261 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1265 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1266 unsigned AddrSpace, AsmPrinter &AP) {
1267 const TargetData *TD = AP.TM.getTargetData();
1268 unsigned BitWidth = CI->getBitWidth();
1269 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1271 // We don't expect assemblers to support integer data directives
1272 // for more than 64 bits, so we emit the data in at most 64-bit
1273 // quantities at a time.
1274 const uint64_t *RawData = CI->getValue().getRawData();
1275 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1276 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1277 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1281 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1282 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1283 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1284 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1285 if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef.
1286 return OutStreamer.EmitZeros(Size, AddrSpace);
1289 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1290 unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1297 OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1298 OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1301 EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1306 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1307 return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1309 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1310 return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1312 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1313 return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1315 if (isa<ConstantPointerNull>(CV)) {
1316 unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1317 OutStreamer.EmitIntValue(0, Size, AddrSpace);
1321 if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV))
1322 return EmitGlobalConstantUnion(CVU, AddrSpace, *this);
1324 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1325 return EmitGlobalConstantVector(V, AddrSpace, *this);
1327 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1328 // thread the streamer with EmitValue.
1329 OutStreamer.EmitValue(LowerConstant(CV, *this),
1330 TM.getTargetData()->getTypeAllocSize(CV->getType()),
1334 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1335 // Target doesn't support this yet!
1336 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1339 /// PrintSpecial - Print information related to the specified machine instr
1340 /// that is independent of the operand, and may be independent of the instr
1341 /// itself. This can be useful for portably encoding the comment character
1342 /// or other bits of target-specific knowledge into the asmstrings. The
1343 /// syntax used is ${:comment}. Targets can override this to add support
1344 /// for their own strange codes.
1345 void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
1346 const char *Code) const {
1347 if (!strcmp(Code, "private")) {
1348 OS << MAI->getPrivateGlobalPrefix();
1349 } else if (!strcmp(Code, "comment")) {
1350 OS << MAI->getCommentString();
1351 } else if (!strcmp(Code, "uid")) {
1352 // Comparing the address of MI isn't sufficient, because machineinstrs may
1353 // be allocated to the same address across functions.
1354 const Function *ThisF = MI->getParent()->getParent()->getFunction();
1356 // If this is a new LastFn instruction, bump the counter.
1357 if (LastMI != MI || LastFn != ThisF) {
1365 raw_string_ostream Msg(msg);
1366 Msg << "Unknown special formatter '" << Code
1367 << "' for machine instr: " << *MI;
1368 llvm_report_error(Msg.str());
1372 /// processDebugLoc - Processes the debug information of each machine
1373 /// instruction's DebugLoc.
1374 void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1375 bool BeforePrintingInsn) {
1376 if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1377 || !DW->ShouldEmitDwarfDebug())
1380 if (!BeforePrintingInsn)
1381 // After printing instruction
1388 /// EmitInlineAsm - This method formats and emits the specified machine
1389 /// instruction that is an inline asm.
1390 void AsmPrinter::EmitInlineAsm(const MachineInstr *MI) const {
1391 assert(MI->isInlineAsm() && "printInlineAsm only works on inline asms");
1393 unsigned NumOperands = MI->getNumOperands();
1395 // Count the number of register definitions to find the asm string.
1396 unsigned NumDefs = 0;
1397 for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1399 assert(NumDefs != NumOperands-1 && "No asm string?");
1401 assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1403 // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1404 const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1406 // If this asmstr is empty, just print the #APP/#NOAPP markers.
1407 // These are useful to see where empty asm's wound up.
1408 if (AsmStr[0] == 0) {
1409 if (!OutStreamer.hasRawTextSupport()) return;
1411 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1412 MAI->getInlineAsmStart());
1413 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1414 MAI->getInlineAsmEnd());
1418 // Emit the #APP start marker. This has to happen even if verbose-asm isn't
1419 // enabled, so we use EmitRawText.
1420 if (OutStreamer.hasRawTextSupport())
1421 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1422 MAI->getInlineAsmStart());
1424 // Emit the inline asm to a temporary string so we can emit it through
1426 SmallString<256> StringData;
1427 raw_svector_ostream OS(StringData);
1431 // The variant of the current asmprinter.
1432 int AsmPrinterVariant = MAI->getAssemblerDialect();
1434 int CurVariant = -1; // The number of the {.|.|.} region we are in.
1435 const char *LastEmitted = AsmStr; // One past the last character emitted.
1437 while (*LastEmitted) {
1438 switch (*LastEmitted) {
1440 // Not a special case, emit the string section literally.
1441 const char *LiteralEnd = LastEmitted+1;
1442 while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1443 *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1445 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1446 OS.write(LastEmitted, LiteralEnd-LastEmitted);
1447 LastEmitted = LiteralEnd;
1451 ++LastEmitted; // Consume newline character.
1452 OS << '\n'; // Indent code with newline.
1455 ++LastEmitted; // Consume '$' character.
1459 switch (*LastEmitted) {
1460 default: Done = false; break;
1461 case '$': // $$ -> $
1462 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1464 ++LastEmitted; // Consume second '$' character.
1466 case '(': // $( -> same as GCC's { character.
1467 ++LastEmitted; // Consume '(' character.
1468 if (CurVariant != -1) {
1469 llvm_report_error("Nested variants found in inline asm string: '"
1470 + std::string(AsmStr) + "'");
1472 CurVariant = 0; // We're in the first variant now.
1475 ++LastEmitted; // consume '|' character.
1476 if (CurVariant == -1)
1477 OS << '|'; // this is gcc's behavior for | outside a variant
1479 ++CurVariant; // We're in the next variant.
1481 case ')': // $) -> same as GCC's } char.
1482 ++LastEmitted; // consume ')' character.
1483 if (CurVariant == -1)
1484 OS << '}'; // this is gcc's behavior for } outside a variant
1491 bool HasCurlyBraces = false;
1492 if (*LastEmitted == '{') { // ${variable}
1493 ++LastEmitted; // Consume '{' character.
1494 HasCurlyBraces = true;
1497 // If we have ${:foo}, then this is not a real operand reference, it is a
1498 // "magic" string reference, just like in .td files. Arrange to call
1500 if (HasCurlyBraces && *LastEmitted == ':') {
1502 const char *StrStart = LastEmitted;
1503 const char *StrEnd = strchr(StrStart, '}');
1505 llvm_report_error(Twine("Unterminated ${:foo} operand in inline asm"
1506 " string: '") + Twine(AsmStr) + "'");
1508 std::string Val(StrStart, StrEnd);
1509 PrintSpecial(MI, OS, Val.c_str());
1510 LastEmitted = StrEnd+1;
1514 const char *IDStart = LastEmitted;
1517 long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1518 if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1519 llvm_report_error("Bad $ operand number in inline asm string: '"
1520 + std::string(AsmStr) + "'");
1522 LastEmitted = IDEnd;
1524 char Modifier[2] = { 0, 0 };
1526 if (HasCurlyBraces) {
1527 // If we have curly braces, check for a modifier character. This
1528 // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1529 if (*LastEmitted == ':') {
1530 ++LastEmitted; // Consume ':' character.
1531 if (*LastEmitted == 0) {
1532 llvm_report_error("Bad ${:} expression in inline asm string: '"
1533 + std::string(AsmStr) + "'");
1536 Modifier[0] = *LastEmitted;
1537 ++LastEmitted; // Consume modifier character.
1540 if (*LastEmitted != '}') {
1541 llvm_report_error("Bad ${} expression in inline asm string: '"
1542 + std::string(AsmStr) + "'");
1544 ++LastEmitted; // Consume '}' character.
1547 if ((unsigned)Val >= NumOperands-1) {
1548 llvm_report_error("Invalid $ operand number in inline asm string: '"
1549 + std::string(AsmStr) + "'");
1552 // Okay, we finally have a value number. Ask the target to print this
1554 if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1559 // Scan to find the machine operand number for the operand.
1560 for (; Val; --Val) {
1561 if (OpNo >= MI->getNumOperands()) break;
1562 unsigned OpFlags = MI->getOperand(OpNo).getImm();
1563 OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1566 if (OpNo >= MI->getNumOperands()) {
1569 unsigned OpFlags = MI->getOperand(OpNo).getImm();
1570 ++OpNo; // Skip over the ID number.
1572 if (Modifier[0] == 'l') // labels are target independent
1573 OS << *MI->getOperand(OpNo).getMBB()->getSymbol();
1575 AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1576 if ((OpFlags & 7) == 4) {
1577 Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1578 Modifier[0] ? Modifier : 0,
1581 Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1582 Modifier[0] ? Modifier : 0, OS);
1588 raw_string_ostream Msg(msg);
1589 Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1591 llvm_report_error(Msg.str());
1600 EmitInlineAsm(OS.str());
1602 // Emit the #NOAPP end marker. This has to happen even if verbose-asm isn't
1603 // enabled, so we use EmitRawText.
1604 if (OutStreamer.hasRawTextSupport())
1605 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1606 MAI->getInlineAsmEnd());
1609 /// EmitImplicitDef - This method emits the specified machine instruction
1610 /// that is an implicit def.
1611 void AsmPrinter::EmitImplicitDef(const MachineInstr *MI) const {
1612 if (!VerboseAsm) return;
1613 unsigned RegNo = MI->getOperand(0).getReg();
1614 OutStreamer.AddComment(Twine("implicit-def: ") +
1615 TM.getRegisterInfo()->getName(RegNo));
1616 OutStreamer.AddBlankLine();
1619 void AsmPrinter::EmitKill(const MachineInstr *MI) const {
1620 if (!VerboseAsm) return;
1622 std::string Str = "kill:";
1623 for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1624 const MachineOperand &Op = MI->getOperand(n);
1625 assert(Op.isReg() && "KILL instruction must have only register operands");
1627 Str += TM.getRegisterInfo()->getName(Op.getReg());
1628 Str += (Op.isDef() ? "<def>" : "<kill>");
1630 OutStreamer.AddComment(Str);
1631 OutStreamer.AddBlankLine();
1634 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1635 /// instruction, using the specified assembler variant. Targets should
1636 /// override this to format as appropriate.
1637 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1638 unsigned AsmVariant, const char *ExtraCode,
1640 // Target doesn't support this yet!
1644 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1645 unsigned AsmVariant,
1646 const char *ExtraCode, raw_ostream &O) {
1647 // Target doesn't support this yet!
1651 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1652 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1655 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1656 return MMI->getAddrLabelSymbol(BB);
1659 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1660 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1661 return OutContext.GetOrCreateSymbol
1662 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1663 + "_" + Twine(CPID));
1666 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1667 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1668 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1671 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1672 /// FIXME: privatize to AsmPrinter.
1673 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1674 return OutContext.GetOrCreateSymbol
1675 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1676 Twine(UID) + "_set_" + Twine(MBBID));
1679 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1680 /// global value name as its base, with the specified suffix, and where the
1681 /// symbol is forced to have private linkage if ForcePrivate is true.
1682 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1684 bool ForcePrivate) const {
1685 SmallString<60> NameStr;
1686 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1687 NameStr.append(Suffix.begin(), Suffix.end());
1688 return OutContext.GetOrCreateSymbol(NameStr.str());
1691 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1693 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1694 SmallString<60> NameStr;
1695 Mang->getNameWithPrefix(NameStr, Sym);
1696 return OutContext.GetOrCreateSymbol(NameStr.str());
1701 /// PrintParentLoopComment - Print comments about parent loops of this one.
1702 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1703 unsigned FunctionNumber) {
1704 if (Loop == 0) return;
1705 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1706 OS.indent(Loop->getLoopDepth()*2)
1707 << "Parent Loop BB" << FunctionNumber << "_"
1708 << Loop->getHeader()->getNumber()
1709 << " Depth=" << Loop->getLoopDepth() << '\n';
1713 /// PrintChildLoopComment - Print comments about child loops within
1714 /// the loop for this basic block, with nesting.
1715 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1716 unsigned FunctionNumber) {
1717 // Add child loop information
1718 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1719 OS.indent((*CL)->getLoopDepth()*2)
1720 << "Child Loop BB" << FunctionNumber << "_"
1721 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1723 PrintChildLoopComment(OS, *CL, FunctionNumber);
1727 /// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks.
1728 static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1729 const MachineLoopInfo *LI,
1730 const AsmPrinter &AP) {
1731 // Add loop depth information
1732 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1733 if (Loop == 0) return;
1735 MachineBasicBlock *Header = Loop->getHeader();
1736 assert(Header && "No header for loop");
1738 // If this block is not a loop header, just print out what is the loop header
1740 if (Header != &MBB) {
1741 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1742 Twine(AP.getFunctionNumber())+"_" +
1743 Twine(Loop->getHeader()->getNumber())+
1744 " Depth="+Twine(Loop->getLoopDepth()));
1748 // Otherwise, it is a loop header. Print out information about child and
1750 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1752 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1755 OS.indent(Loop->getLoopDepth()*2-2);
1760 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1762 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1766 /// EmitBasicBlockStart - This method prints the label for the specified
1767 /// MachineBasicBlock, an alignment (if present) and a comment describing
1768 /// it if appropriate.
1769 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1770 // Emit an alignment directive for this block, if needed.
1771 if (unsigned Align = MBB->getAlignment())
1772 EmitAlignment(Log2_32(Align));
1774 // If the block has its address taken, emit any labels that were used to
1775 // reference the block. It is possible that there is more than one label
1776 // here, because multiple LLVM BB's may have been RAUW'd to this block after
1777 // the references were generated.
1778 if (MBB->hasAddressTaken()) {
1779 const BasicBlock *BB = MBB->getBasicBlock();
1781 OutStreamer.AddComment("Block address taken");
1783 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1785 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1786 OutStreamer.EmitLabel(Syms[i]);
1789 // Print the main label for the block.
1790 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1791 if (VerboseAsm && OutStreamer.hasRawTextSupport()) {
1792 if (const BasicBlock *BB = MBB->getBasicBlock())
1794 OutStreamer.AddComment("%" + BB->getName());
1796 PrintBasicBlockLoopComments(*MBB, LI, *this);
1798 // NOTE: Want this comment at start of line, don't emit with AddComment.
1799 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1800 Twine(MBB->getNumber()) + ":");
1804 if (const BasicBlock *BB = MBB->getBasicBlock())
1806 OutStreamer.AddComment("%" + BB->getName());
1807 PrintBasicBlockLoopComments(*MBB, LI, *this);
1810 OutStreamer.EmitLabel(MBB->getSymbol());
1814 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1815 MCSymbolAttr Attr = MCSA_Invalid;
1817 switch (Visibility) {
1819 case GlobalValue::HiddenVisibility:
1820 Attr = MAI->getHiddenVisibilityAttr();
1822 case GlobalValue::ProtectedVisibility:
1823 Attr = MAI->getProtectedVisibilityAttr();
1827 if (Attr != MCSA_Invalid)
1828 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1831 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1833 OS << '+' << Offset;
1834 else if (Offset < 0)
1838 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1839 /// exactly one predecessor and the control transfer mechanism between
1840 /// the predecessor and this block is a fall-through.
1842 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1843 // If this is a landing pad, it isn't a fall through. If it has no preds,
1844 // then nothing falls through to it.
1845 if (MBB->isLandingPad() || MBB->pred_empty())
1848 // If there isn't exactly one predecessor, it can't be a fall through.
1849 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1851 if (PI2 != MBB->pred_end())
1854 // The predecessor has to be immediately before this block.
1855 const MachineBasicBlock *Pred = *PI;
1857 if (!Pred->isLayoutSuccessor(MBB))
1860 // If the block is completely empty, then it definitely does fall through.
1864 // Otherwise, check the last instruction.
1865 const MachineInstr &LastInst = Pred->back();
1866 return !LastInst.getDesc().isBarrier();
1871 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1872 if (!S->usesMetadata())
1875 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1876 gcp_map_type::iterator GCPI = GCMap.find(S);
1877 if (GCPI != GCMap.end())
1878 return GCPI->second;
1880 const char *Name = S->getName().c_str();
1882 for (GCMetadataPrinterRegistry::iterator
1883 I = GCMetadataPrinterRegistry::begin(),
1884 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1885 if (strcmp(Name, I->getName()) == 0) {
1886 GCMetadataPrinter *GMP = I->instantiate();
1888 GCMap.insert(std::make_pair(S, GMP));
1892 llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));