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 AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
59 : MachineFunctionPass(&ID),
60 TM(tm), MAI(tm.getMCAsmInfo()), TRI(tm.getRegisterInfo()),
61 OutContext(Streamer.getContext()),
62 OutStreamer(Streamer),
63 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
65 VerboseAsm = Streamer.isVerboseAsm();
68 AsmPrinter::~AsmPrinter() {
69 for (gcp_iterator I = GCMetadataPrinters.begin(),
70 E = GCMetadataPrinters.end(); I != E; ++I)
76 /// getFunctionNumber - Return a unique ID for the current function.
78 unsigned AsmPrinter::getFunctionNumber() const {
79 return MF->getFunctionNumber();
82 TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
83 return TM.getTargetLowering()->getObjFileLowering();
86 /// getCurrentSection() - Return the current section we are emitting to.
87 const MCSection *AsmPrinter::getCurrentSection() const {
88 return OutStreamer.getCurrentSection();
92 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
94 MachineFunctionPass::getAnalysisUsage(AU);
95 AU.addRequired<MachineModuleInfo>();
96 AU.addRequired<GCModuleInfo>();
98 AU.addRequired<MachineLoopInfo>();
101 bool AsmPrinter::doInitialization(Module &M) {
102 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
103 MMI->AnalyzeModule(M);
105 // Initialize TargetLoweringObjectFile.
106 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
107 .Initialize(OutContext, TM);
109 Mang = new Mangler(OutContext, *TM.getTargetData());
111 // Allow the target to emit any magic that it wants at the start of the file.
112 EmitStartOfAsmFile(M);
114 // Very minimal debug info. It is ignored if we emit actual debug info. If we
115 // don't, this at least helps the user find where a global came from.
116 if (MAI->hasSingleParameterDotFile()) {
118 OutStreamer.EmitFileDirective(M.getModuleIdentifier());
121 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
122 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
123 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
124 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
125 MP->beginAssembly(*this);
127 // Emit module-level inline asm if it exists.
128 if (!M.getModuleInlineAsm().empty()) {
129 OutStreamer.AddComment("Start of file scope inline assembly");
130 OutStreamer.AddBlankLine();
131 EmitInlineAsm(M.getModuleInlineAsm());
132 OutStreamer.AddComment("End of file scope inline assembly");
133 OutStreamer.AddBlankLine();
136 DW = getAnalysisIfAvailable<DwarfWriter>();
138 DW->BeginModule(&M, this);
143 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
144 switch ((GlobalValue::LinkageTypes)Linkage) {
145 case GlobalValue::CommonLinkage:
146 case GlobalValue::LinkOnceAnyLinkage:
147 case GlobalValue::LinkOnceODRLinkage:
148 case GlobalValue::WeakAnyLinkage:
149 case GlobalValue::WeakODRLinkage:
150 case GlobalValue::LinkerPrivateLinkage:
151 if (MAI->getWeakDefDirective() != 0) {
153 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
154 // .weak_definition _foo
155 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
156 } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
158 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
159 // FIXME: linkonce should be a section attribute, handled by COFF Section
161 // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
163 // FIXME: It would be nice to use .linkonce samesize for non-common
165 OutStreamer.EmitRawText(StringRef(LinkOnce));
168 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
171 case GlobalValue::DLLExportLinkage:
172 case GlobalValue::AppendingLinkage:
173 // FIXME: appending linkage variables should go into a section of
174 // their name or something. For now, just emit them as external.
175 case GlobalValue::ExternalLinkage:
176 // If external or appending, declare as a global symbol.
178 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
180 case GlobalValue::PrivateLinkage:
181 case GlobalValue::InternalLinkage:
184 llvm_unreachable("Unknown linkage type!");
189 /// EmitGlobalVariable - Emit the specified global variable to the .s file.
190 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
191 if (!GV->hasInitializer()) // External globals require no code.
194 // Check to see if this is a special global used by LLVM, if so, emit it.
195 if (EmitSpecialLLVMGlobal(GV))
198 MCSymbol *GVSym = Mang->getSymbol(GV);
199 EmitVisibility(GVSym, GV->getVisibility());
201 if (MAI->hasDotTypeDotSizeDirective())
202 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
204 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
206 const TargetData *TD = TM.getTargetData();
207 unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
208 unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
210 // Handle common and BSS local symbols (.lcomm).
211 if (GVKind.isCommon() || GVKind.isBSSLocal()) {
212 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
215 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
216 /*PrintType=*/false, GV->getParent());
217 OutStreamer.GetCommentOS() << '\n';
220 // Handle common symbols.
221 if (GVKind.isCommon()) {
223 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
227 // Handle local BSS symbols.
228 if (MAI->hasMachoZeroFillDirective()) {
229 const MCSection *TheSection =
230 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
231 // .zerofill __DATA, __bss, _foo, 400, 5
232 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
236 if (MAI->hasLCOMMDirective()) {
238 OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
243 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
245 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
249 const MCSection *TheSection =
250 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
252 // Handle the zerofill directive on darwin, which is a special form of BSS
254 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
256 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
257 // .zerofill __DATA, __common, _foo, 400, 5
258 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
262 OutStreamer.SwitchSection(TheSection);
264 EmitLinkage(GV->getLinkage(), GVSym);
265 EmitAlignment(AlignLog, GV);
268 WriteAsOperand(OutStreamer.GetCommentOS(), GV,
269 /*PrintType=*/false, GV->getParent());
270 OutStreamer.GetCommentOS() << '\n';
272 OutStreamer.EmitLabel(GVSym);
274 EmitGlobalConstant(GV->getInitializer());
276 if (MAI->hasDotTypeDotSizeDirective())
278 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
280 OutStreamer.AddBlankLine();
283 /// EmitFunctionHeader - This method emits the header for the current
285 void AsmPrinter::EmitFunctionHeader() {
286 // Print out constants referenced by the function
289 // Print the 'header' of function.
290 const Function *F = MF->getFunction();
292 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
293 EmitVisibility(CurrentFnSym, F->getVisibility());
295 EmitLinkage(F->getLinkage(), CurrentFnSym);
296 EmitAlignment(MF->getAlignment(), F);
298 if (MAI->hasDotTypeDotSizeDirective())
299 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
302 WriteAsOperand(OutStreamer.GetCommentOS(), F,
303 /*PrintType=*/false, F->getParent());
304 OutStreamer.GetCommentOS() << '\n';
307 // Emit the CurrentFnSym. This is a virtual function to allow targets to
308 // do their wild and crazy things as required.
309 EmitFunctionEntryLabel();
311 // If the function had address-taken blocks that got deleted, then we have
312 // references to the dangling symbols. Emit them at the start of the function
313 // so that we don't get references to undefined symbols.
314 std::vector<MCSymbol*> DeadBlockSyms;
315 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
316 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
317 OutStreamer.AddComment("Address taken block that was later removed");
318 OutStreamer.EmitLabel(DeadBlockSyms[i]);
321 // Add some workaround for linkonce linkage on Cygwin\MinGW.
322 if (MAI->getLinkOnceDirective() != 0 &&
323 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
324 // FIXME: What is this?
326 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
327 CurrentFnSym->getName());
328 OutStreamer.EmitLabel(FakeStub);
331 // Emit pre-function debug and/or EH information.
332 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
333 DW->BeginFunction(MF);
336 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
337 /// function. This can be overridden by targets as required to do custom stuff.
338 void AsmPrinter::EmitFunctionEntryLabel() {
339 OutStreamer.EmitLabel(CurrentFnSym);
343 /// EmitComments - Pretty-print comments for instructions.
344 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
345 const MachineFunction *MF = MI.getParent()->getParent();
346 const TargetMachine &TM = MF->getTarget();
348 DebugLoc DL = MI.getDebugLoc();
349 if (!DL.isUnknown()) { // Print source line info.
350 DIScope Scope(DL.getScope(MF->getFunction()->getContext()));
351 // Omit the directory, because it's likely to be long and uninteresting.
353 CommentOS << Scope.getFilename();
355 CommentOS << "<unknown>";
356 CommentOS << ':' << DL.getLine();
357 if (DL.getCol() != 0)
358 CommentOS << ':' << DL.getCol();
362 // Check for spills and reloads
365 const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
367 // We assume a single instruction only has a spill or reload, not
369 const MachineMemOperand *MMO;
370 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
371 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
372 MMO = *MI.memoperands_begin();
373 CommentOS << MMO->getSize() << "-byte Reload\n";
375 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
376 if (FrameInfo->isSpillSlotObjectIndex(FI))
377 CommentOS << MMO->getSize() << "-byte Folded Reload\n";
378 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
379 if (FrameInfo->isSpillSlotObjectIndex(FI)) {
380 MMO = *MI.memoperands_begin();
381 CommentOS << MMO->getSize() << "-byte Spill\n";
383 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
384 if (FrameInfo->isSpillSlotObjectIndex(FI))
385 CommentOS << MMO->getSize() << "-byte Folded Spill\n";
388 // Check for spill-induced copies
389 unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
390 if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
391 SrcSubIdx, DstSubIdx)) {
392 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
393 CommentOS << " Reload Reuse\n";
399 /// EmitFunctionBody - This method emits the body and trailer for a
401 void AsmPrinter::EmitFunctionBody() {
402 // Emit target-specific gunk before the function body.
403 EmitFunctionBodyStart();
405 // Print out code for the function.
406 bool HasAnyRealCode = false;
407 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
409 // Print a label for the basic block.
410 EmitBasicBlockStart(I);
411 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
413 // Print the assembly for the instruction.
415 HasAnyRealCode = true;
419 // FIXME: Clean up processDebugLoc.
420 processDebugLoc(II, true);
423 EmitComments(*II, OutStreamer.GetCommentOS());
425 switch (II->getOpcode()) {
426 case TargetOpcode::DBG_LABEL:
427 case TargetOpcode::EH_LABEL:
428 case TargetOpcode::GC_LABEL:
431 case TargetOpcode::INLINEASM:
434 case TargetOpcode::IMPLICIT_DEF:
435 printImplicitDef(II);
437 case TargetOpcode::KILL:
445 // FIXME: Clean up processDebugLoc.
446 processDebugLoc(II, false);
450 // If the function is empty and the object file uses .subsections_via_symbols,
451 // then we need to emit *something* to the function body to prevent the
452 // labels from collapsing together. Just emit a 0 byte.
453 if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
454 OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
456 // Emit target-specific gunk after the function body.
457 EmitFunctionBodyEnd();
459 // If the target wants a .size directive for the size of the function, emit
461 if (MAI->hasDotTypeDotSizeDirective()) {
462 // Create a symbol for the end of function, so we can get the size as
463 // difference between the function label and the temp label.
464 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
465 OutStreamer.EmitLabel(FnEndLabel);
467 const MCExpr *SizeExp =
468 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
469 MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
471 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
474 // Emit post-function debug information.
475 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
478 // Print out jump tables referenced by the function.
481 OutStreamer.AddBlankLine();
485 bool AsmPrinter::doFinalization(Module &M) {
486 // Emit global variables.
487 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
489 EmitGlobalVariable(I);
491 // Emit final debug information.
492 if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
495 // If the target wants to know about weak references, print them all.
496 if (MAI->getWeakRefDirective()) {
497 // FIXME: This is not lazy, it would be nice to only print weak references
498 // to stuff that is actually used. Note that doing so would require targets
499 // to notice uses in operands (due to constant exprs etc). This should
500 // happen with the MC stuff eventually.
502 // Print out module-level global variables here.
503 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
505 if (!I->hasExternalWeakLinkage()) continue;
506 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
509 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
510 if (!I->hasExternalWeakLinkage()) continue;
511 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
515 if (MAI->hasSetDirective()) {
516 OutStreamer.AddBlankLine();
517 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
519 MCSymbol *Name = Mang->getSymbol(I);
521 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
522 MCSymbol *Target = Mang->getSymbol(GV);
524 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
525 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
526 else if (I->hasWeakLinkage())
527 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
529 assert(I->hasLocalLinkage() && "Invalid alias linkage");
531 EmitVisibility(Name, I->getVisibility());
533 // Emit the directives as assignments aka .set:
534 OutStreamer.EmitAssignment(Name,
535 MCSymbolRefExpr::Create(Target, OutContext));
539 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
540 assert(MI && "AsmPrinter didn't require GCModuleInfo?");
541 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
542 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
543 MP->finishAssembly(*this);
545 // If we don't have any trampolines, then we don't require stack memory
546 // to be executable. Some targets have a directive to declare this.
547 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
548 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
549 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
550 OutStreamer.SwitchSection(S);
552 // Allow the target to emit any magic that it wants at the end of the file,
553 // after everything else has gone out.
556 delete Mang; Mang = 0;
559 OutStreamer.Finish();
563 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
565 // Get the function symbol.
566 CurrentFnSym = Mang->getSymbol(MF.getFunction());
569 LI = &getAnalysis<MachineLoopInfo>();
573 // SectionCPs - Keep track the alignment, constpool entries per Section.
577 SmallVector<unsigned, 4> CPEs;
578 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
582 /// EmitConstantPool - Print to the current output stream assembly
583 /// representations of the constants in the constant pool MCP. This is
584 /// used to print out constants which have been "spilled to memory" by
585 /// the code generator.
587 void AsmPrinter::EmitConstantPool() {
588 const MachineConstantPool *MCP = MF->getConstantPool();
589 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
590 if (CP.empty()) return;
592 // Calculate sections for constant pool entries. We collect entries to go into
593 // the same section together to reduce amount of section switch statements.
594 SmallVector<SectionCPs, 4> CPSections;
595 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
596 const MachineConstantPoolEntry &CPE = CP[i];
597 unsigned Align = CPE.getAlignment();
600 switch (CPE.getRelocationInfo()) {
601 default: llvm_unreachable("Unknown section kind");
602 case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
604 Kind = SectionKind::getReadOnlyWithRelLocal();
607 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
608 case 4: Kind = SectionKind::getMergeableConst4(); break;
609 case 8: Kind = SectionKind::getMergeableConst8(); break;
610 case 16: Kind = SectionKind::getMergeableConst16();break;
611 default: Kind = SectionKind::getMergeableConst(); break;
615 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
617 // The number of sections are small, just do a linear search from the
618 // last section to the first.
620 unsigned SecIdx = CPSections.size();
621 while (SecIdx != 0) {
622 if (CPSections[--SecIdx].S == S) {
628 SecIdx = CPSections.size();
629 CPSections.push_back(SectionCPs(S, Align));
632 if (Align > CPSections[SecIdx].Alignment)
633 CPSections[SecIdx].Alignment = Align;
634 CPSections[SecIdx].CPEs.push_back(i);
637 // Now print stuff into the calculated sections.
638 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
639 OutStreamer.SwitchSection(CPSections[i].S);
640 EmitAlignment(Log2_32(CPSections[i].Alignment));
643 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
644 unsigned CPI = CPSections[i].CPEs[j];
645 MachineConstantPoolEntry CPE = CP[CPI];
647 // Emit inter-object padding for alignment.
648 unsigned AlignMask = CPE.getAlignment() - 1;
649 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
650 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
652 const Type *Ty = CPE.getType();
653 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
655 // Emit the label with a comment on it.
657 OutStreamer.GetCommentOS() << "constant pool ";
658 WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
659 MF->getFunction()->getParent());
660 OutStreamer.GetCommentOS() << '\n';
662 OutStreamer.EmitLabel(GetCPISymbol(CPI));
664 if (CPE.isMachineConstantPoolEntry())
665 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
667 EmitGlobalConstant(CPE.Val.ConstVal);
672 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
673 /// by the current function to the current output stream.
675 void AsmPrinter::EmitJumpTableInfo() {
676 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
677 if (MJTI == 0) return;
678 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
679 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
680 if (JT.empty()) return;
682 // Pick the directive to use to print the jump table entries, and switch to
683 // the appropriate section.
684 const Function *F = MF->getFunction();
685 bool JTInDiffSection = false;
686 if (// In PIC mode, we need to emit the jump table to the same section as the
687 // function body itself, otherwise the label differences won't make sense.
688 // FIXME: Need a better predicate for this: what about custom entries?
689 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
690 // We should also do if the section name is NULL or function is declared
691 // in discardable section
692 // FIXME: this isn't the right predicate, should be based on the MCSection
694 F->isWeakForLinker()) {
695 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
697 // Otherwise, drop it in the readonly section.
698 const MCSection *ReadOnlySection =
699 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
700 OutStreamer.SwitchSection(ReadOnlySection);
701 JTInDiffSection = true;
704 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
706 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
707 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
709 // If this jump table was deleted, ignore it.
710 if (JTBBs.empty()) continue;
712 // For the EK_LabelDifference32 entry, if the target supports .set, emit a
713 // .set directive for each unique entry. This reduces the number of
714 // relocations the assembler will generate for the jump table.
715 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
716 MAI->hasSetDirective()) {
717 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
718 const TargetLowering *TLI = TM.getTargetLowering();
719 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
720 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
721 const MachineBasicBlock *MBB = JTBBs[ii];
722 if (!EmittedSets.insert(MBB)) continue;
724 // .set LJTSet, LBB32-base
726 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
727 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
728 MCBinaryExpr::CreateSub(LHS, Base, OutContext));
732 // On some targets (e.g. Darwin) we want to emit two consequtive labels
733 // before each jump table. The first label is never referenced, but tells
734 // the assembler and linker the extents of the jump table object. The
735 // second label is actually referenced by the code.
736 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
737 // FIXME: This doesn't have to have any specific name, just any randomly
738 // named and numbered 'l' label would work. Simplify GetJTISymbol.
739 OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
741 OutStreamer.EmitLabel(GetJTISymbol(JTI));
743 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
744 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
748 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
750 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
751 const MachineBasicBlock *MBB,
752 unsigned UID) const {
753 const MCExpr *Value = 0;
754 switch (MJTI->getEntryKind()) {
755 case MachineJumpTableInfo::EK_Inline:
756 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
757 case MachineJumpTableInfo::EK_Custom32:
758 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
761 case MachineJumpTableInfo::EK_BlockAddress:
762 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
764 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
766 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
767 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
768 // with a relocation as gp-relative, e.g.:
770 MCSymbol *MBBSym = MBB->getSymbol();
771 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
775 case MachineJumpTableInfo::EK_LabelDifference32: {
776 // EK_LabelDifference32 - Each entry is the address of the block minus
777 // the address of the jump table. This is used for PIC jump tables where
778 // gprel32 is not supported. e.g.:
779 // .word LBB123 - LJTI1_2
780 // If the .set directive is supported, this is emitted as:
781 // .set L4_5_set_123, LBB123 - LJTI1_2
782 // .word L4_5_set_123
784 // If we have emitted set directives for the jump table entries, print
785 // them rather than the entries themselves. If we're emitting PIC, then
786 // emit the table entries as differences between two text section labels.
787 if (MAI->hasSetDirective()) {
788 // If we used .set, reference the .set's symbol.
789 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
793 // Otherwise, use the difference as the jump table entry.
794 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
795 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
796 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
801 assert(Value && "Unknown entry kind!");
803 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
804 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
808 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
809 /// special global used by LLVM. If so, emit it and return true, otherwise
810 /// do nothing and return false.
811 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
812 if (GV->getName() == "llvm.used") {
813 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
814 EmitLLVMUsedList(GV->getInitializer());
818 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
819 if (GV->getSection() == "llvm.metadata" ||
820 GV->hasAvailableExternallyLinkage())
823 if (!GV->hasAppendingLinkage()) return false;
825 assert(GV->hasInitializer() && "Not a special LLVM global!");
827 const TargetData *TD = TM.getTargetData();
828 unsigned Align = Log2_32(TD->getPointerPrefAlignment());
829 if (GV->getName() == "llvm.global_ctors") {
830 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
831 EmitAlignment(Align, 0);
832 EmitXXStructorList(GV->getInitializer());
834 if (TM.getRelocationModel() == Reloc::Static &&
835 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
836 StringRef Sym(".constructors_used");
837 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
843 if (GV->getName() == "llvm.global_dtors") {
844 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
845 EmitAlignment(Align, 0);
846 EmitXXStructorList(GV->getInitializer());
848 if (TM.getRelocationModel() == Reloc::Static &&
849 MAI->hasStaticCtorDtorReferenceInStaticMode()) {
850 StringRef Sym(".destructors_used");
851 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
860 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
861 /// global in the specified llvm.used list for which emitUsedDirectiveFor
862 /// is true, as being used with this directive.
863 void AsmPrinter::EmitLLVMUsedList(Constant *List) {
864 // Should be an array of 'i8*'.
865 ConstantArray *InitList = dyn_cast<ConstantArray>(List);
866 if (InitList == 0) return;
868 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
869 const GlobalValue *GV =
870 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
871 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
872 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
876 /// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the
877 /// function pointers, ignoring the init priority.
878 void AsmPrinter::EmitXXStructorList(Constant *List) {
879 // Should be an array of '{ int, void ()* }' structs. The first value is the
880 // init priority, which we ignore.
881 if (!isa<ConstantArray>(List)) return;
882 ConstantArray *InitList = cast<ConstantArray>(List);
883 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
884 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
885 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs.
887 if (CS->getOperand(1)->isNullValue())
888 return; // Found a null terminator, exit printing.
889 // Emit the function pointer.
890 EmitGlobalConstant(CS->getOperand(1));
894 /// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
895 void AsmPrinter::EmitInlineAsm(StringRef Str) const {
896 assert(!Str.empty() && "Can't emit empty inline asm block");
898 // If the output streamer is actually a .s file, just emit the blob textually.
899 // This is useful in case the asm parser doesn't handle something but the
900 // system assembler does.
901 if (OutStreamer.hasRawTextSupport()) {
902 OutStreamer.EmitRawText(Str);
906 errs() << "Inline asm not supported by this streamer!\n";
910 //===--------------------------------------------------------------------===//
911 // Emission and print routines
914 /// EmitInt8 - Emit a byte directive and value.
916 void AsmPrinter::EmitInt8(int Value) const {
917 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
920 /// EmitInt16 - Emit a short directive and value.
922 void AsmPrinter::EmitInt16(int Value) const {
923 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
926 /// EmitInt32 - Emit a long directive and value.
928 void AsmPrinter::EmitInt32(int Value) const {
929 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
932 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
933 /// in bytes of the directive is specified by Size and Hi/Lo specify the
934 /// labels. This implicitly uses .set if it is available.
935 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
936 unsigned Size) const {
937 // Get the Hi-Lo expression.
939 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
940 MCSymbolRefExpr::Create(Lo, OutContext),
943 if (!MAI->hasSetDirective()) {
944 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
948 // Otherwise, emit with .set (aka assignment).
950 OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
951 "set" + Twine(SetCounter++));
952 OutStreamer.EmitAssignment(SetLabel, Diff);
953 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
957 //===----------------------------------------------------------------------===//
959 // EmitAlignment - Emit an alignment directive to the specified power of
960 // two boundary. For example, if you pass in 3 here, you will get an 8
961 // byte alignment. If a global value is specified, and if that global has
962 // an explicit alignment requested, it will unconditionally override the
963 // alignment request. However, if ForcedAlignBits is specified, this value
964 // has final say: the ultimate alignment will be the max of ForcedAlignBits
965 // and the alignment computed with NumBits and the global.
969 // if (GV && GV->hasalignment) Align = GV->getalignment();
970 // Align = std::max(Align, ForcedAlignBits);
972 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
973 unsigned ForcedAlignBits,
974 bool UseFillExpr) const {
975 if (GV && GV->getAlignment())
976 NumBits = Log2_32(GV->getAlignment());
977 NumBits = std::max(NumBits, ForcedAlignBits);
979 if (NumBits == 0) return; // No need to emit alignment.
981 if (getCurrentSection()->getKind().isText())
982 OutStreamer.EmitCodeAlignment(1 << NumBits);
984 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
987 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
989 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
990 MCContext &Ctx = AP.OutContext;
992 if (CV->isNullValue() || isa<UndefValue>(CV))
993 return MCConstantExpr::Create(0, Ctx);
995 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
996 return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
998 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
999 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1000 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1001 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1003 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1005 llvm_unreachable("Unknown constant value to lower!");
1006 return MCConstantExpr::Create(0, Ctx);
1009 switch (CE->getOpcode()) {
1011 // If the code isn't optimized, there may be outstanding folding
1012 // opportunities. Attempt to fold the expression using TargetData as a
1013 // last resort before giving up.
1015 ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1017 return LowerConstant(C, AP);
1021 llvm_unreachable("FIXME: Don't support this constant expr");
1022 case Instruction::GetElementPtr: {
1023 const TargetData &TD = *AP.TM.getTargetData();
1024 // Generate a symbolic expression for the byte address
1025 const Constant *PtrVal = CE->getOperand(0);
1026 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1027 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1030 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1034 // Truncate/sext the offset to the pointer size.
1035 if (TD.getPointerSizeInBits() != 64) {
1036 int SExtAmount = 64-TD.getPointerSizeInBits();
1037 Offset = (Offset << SExtAmount) >> SExtAmount;
1040 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1044 case Instruction::Trunc:
1045 // We emit the value and depend on the assembler to truncate the generated
1046 // expression properly. This is important for differences between
1047 // blockaddress labels. Since the two labels are in the same function, it
1048 // is reasonable to treat their delta as a 32-bit value.
1050 case Instruction::BitCast:
1051 return LowerConstant(CE->getOperand(0), AP);
1053 case Instruction::IntToPtr: {
1054 const TargetData &TD = *AP.TM.getTargetData();
1055 // Handle casts to pointers by changing them into casts to the appropriate
1056 // integer type. This promotes constant folding and simplifies this code.
1057 Constant *Op = CE->getOperand(0);
1058 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1060 return LowerConstant(Op, AP);
1063 case Instruction::PtrToInt: {
1064 const TargetData &TD = *AP.TM.getTargetData();
1065 // Support only foldable casts to/from pointers that can be eliminated by
1066 // changing the pointer to the appropriately sized integer type.
1067 Constant *Op = CE->getOperand(0);
1068 const Type *Ty = CE->getType();
1070 const MCExpr *OpExpr = LowerConstant(Op, AP);
1072 // We can emit the pointer value into this slot if the slot is an
1073 // integer slot equal to the size of the pointer.
1074 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1077 // Otherwise the pointer is smaller than the resultant integer, mask off
1078 // the high bits so we are sure to get a proper truncation if the input is
1080 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1081 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1082 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1085 // The MC library also has a right-shift operator, but it isn't consistently
1086 // signed or unsigned between different targets.
1087 case Instruction::Add:
1088 case Instruction::Sub:
1089 case Instruction::Mul:
1090 case Instruction::SDiv:
1091 case Instruction::SRem:
1092 case Instruction::Shl:
1093 case Instruction::And:
1094 case Instruction::Or:
1095 case Instruction::Xor: {
1096 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1097 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1098 switch (CE->getOpcode()) {
1099 default: llvm_unreachable("Unknown binary operator constant cast expr");
1100 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1101 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1102 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1103 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1104 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1105 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1106 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1107 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1108 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1114 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1116 if (AddrSpace != 0 || !CA->isString()) {
1117 // Not a string. Print the values in successive locations
1118 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1119 AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
1123 // Otherwise, it can be emitted as .ascii.
1124 SmallVector<char, 128> TmpVec;
1125 TmpVec.reserve(CA->getNumOperands());
1126 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1127 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1129 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1132 static void EmitGlobalConstantVector(const ConstantVector *CV,
1133 unsigned AddrSpace, AsmPrinter &AP) {
1134 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1135 AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1138 static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1139 unsigned AddrSpace, AsmPrinter &AP) {
1140 // Print the fields in successive locations. Pad to align if needed!
1141 const TargetData *TD = AP.TM.getTargetData();
1142 unsigned Size = TD->getTypeAllocSize(CS->getType());
1143 const StructLayout *Layout = TD->getStructLayout(CS->getType());
1144 uint64_t SizeSoFar = 0;
1145 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1146 const Constant *Field = CS->getOperand(i);
1148 // Check if padding is needed and insert one or more 0s.
1149 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1150 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1151 - Layout->getElementOffset(i)) - FieldSize;
1152 SizeSoFar += FieldSize + PadSize;
1154 // Now print the actual field value.
1155 AP.EmitGlobalConstant(Field, AddrSpace);
1157 // Insert padding - this may include padding to increase the size of the
1158 // current field up to the ABI size (if the struct is not packed) as well
1159 // as padding to ensure that the next field starts at the right offset.
1160 AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1162 assert(SizeSoFar == Layout->getSizeInBytes() &&
1163 "Layout of constant struct may be incorrect!");
1166 static void EmitGlobalConstantUnion(const ConstantUnion *CU,
1167 unsigned AddrSpace, AsmPrinter &AP) {
1168 const TargetData *TD = AP.TM.getTargetData();
1169 unsigned Size = TD->getTypeAllocSize(CU->getType());
1171 const Constant *Contents = CU->getOperand(0);
1172 unsigned FilledSize = TD->getTypeAllocSize(Contents->getType());
1174 // Print the actually filled part
1175 AP.EmitGlobalConstant(Contents, AddrSpace);
1177 // And pad with enough zeroes
1178 AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace);
1181 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1183 // FP Constants are printed as integer constants to avoid losing
1185 if (CFP->getType()->isDoubleTy()) {
1186 if (AP.VerboseAsm) {
1187 double Val = CFP->getValueAPF().convertToDouble();
1188 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1191 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1192 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1196 if (CFP->getType()->isFloatTy()) {
1197 if (AP.VerboseAsm) {
1198 float Val = CFP->getValueAPF().convertToFloat();
1199 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1201 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1202 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1206 if (CFP->getType()->isX86_FP80Ty()) {
1207 // all long double variants are printed as hex
1208 // api needed to prevent premature destruction
1209 APInt API = CFP->getValueAPF().bitcastToAPInt();
1210 const uint64_t *p = API.getRawData();
1211 if (AP.VerboseAsm) {
1212 // Convert to double so we can print the approximate val as a comment.
1213 APFloat DoubleVal = CFP->getValueAPF();
1215 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1217 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1218 << DoubleVal.convertToDouble() << '\n';
1221 if (AP.TM.getTargetData()->isBigEndian()) {
1222 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1223 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1225 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1226 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1229 // Emit the tail padding for the long double.
1230 const TargetData &TD = *AP.TM.getTargetData();
1231 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1232 TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1236 assert(CFP->getType()->isPPC_FP128Ty() &&
1237 "Floating point constant type not handled");
1238 // All long double variants are printed as hex api needed to prevent
1239 // premature destruction.
1240 APInt API = CFP->getValueAPF().bitcastToAPInt();
1241 const uint64_t *p = API.getRawData();
1242 if (AP.TM.getTargetData()->isBigEndian()) {
1243 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1244 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1246 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1247 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1251 static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1252 unsigned AddrSpace, AsmPrinter &AP) {
1253 const TargetData *TD = AP.TM.getTargetData();
1254 unsigned BitWidth = CI->getBitWidth();
1255 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1257 // We don't expect assemblers to support integer data directives
1258 // for more than 64 bits, so we emit the data in at most 64-bit
1259 // quantities at a time.
1260 const uint64_t *RawData = CI->getValue().getRawData();
1261 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1262 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1263 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1267 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1268 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1269 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1270 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1271 if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef.
1272 return OutStreamer.EmitZeros(Size, AddrSpace);
1275 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1276 unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1283 OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1284 OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1287 EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1292 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1293 return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1295 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1296 return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1298 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1299 return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1301 if (isa<ConstantPointerNull>(CV)) {
1302 unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1303 OutStreamer.EmitIntValue(0, Size, AddrSpace);
1307 if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV))
1308 return EmitGlobalConstantUnion(CVU, AddrSpace, *this);
1310 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1311 return EmitGlobalConstantVector(V, AddrSpace, *this);
1313 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
1314 // thread the streamer with EmitValue.
1315 OutStreamer.EmitValue(LowerConstant(CV, *this),
1316 TM.getTargetData()->getTypeAllocSize(CV->getType()),
1320 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1321 // Target doesn't support this yet!
1322 llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1325 /// PrintSpecial - Print information related to the specified machine instr
1326 /// that is independent of the operand, and may be independent of the instr
1327 /// itself. This can be useful for portably encoding the comment character
1328 /// or other bits of target-specific knowledge into the asmstrings. The
1329 /// syntax used is ${:comment}. Targets can override this to add support
1330 /// for their own strange codes.
1331 void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
1332 const char *Code) const {
1333 if (!strcmp(Code, "private")) {
1334 OS << MAI->getPrivateGlobalPrefix();
1335 } else if (!strcmp(Code, "comment")) {
1336 OS << MAI->getCommentString();
1337 } else if (!strcmp(Code, "uid")) {
1338 // Comparing the address of MI isn't sufficient, because machineinstrs may
1339 // be allocated to the same address across functions.
1340 const Function *ThisF = MI->getParent()->getParent()->getFunction();
1342 // If this is a new LastFn instruction, bump the counter.
1343 if (LastMI != MI || LastFn != ThisF) {
1351 raw_string_ostream Msg(msg);
1352 Msg << "Unknown special formatter '" << Code
1353 << "' for machine instr: " << *MI;
1354 llvm_report_error(Msg.str());
1358 /// processDebugLoc - Processes the debug information of each machine
1359 /// instruction's DebugLoc.
1360 void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1361 bool BeforePrintingInsn) {
1362 if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1363 || !DW->ShouldEmitDwarfDebug())
1366 if (!BeforePrintingInsn)
1367 // After printing instruction
1374 /// printInlineAsm - This method formats and prints the specified machine
1375 /// instruction that is an inline asm.
1376 void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1377 assert(MI->isInlineAsm() && "printInlineAsm only works on inline asms");
1379 unsigned NumOperands = MI->getNumOperands();
1381 // Count the number of register definitions to find the asm string.
1382 unsigned NumDefs = 0;
1383 for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1385 assert(NumDefs != NumOperands-1 && "No asm string?");
1387 assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1389 // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1390 const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1392 // If this asmstr is empty, just print the #APP/#NOAPP markers.
1393 // These are useful to see where empty asm's wound up.
1394 if (AsmStr[0] == 0) {
1395 if (!OutStreamer.hasRawTextSupport()) return;
1397 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1398 MAI->getInlineAsmStart());
1399 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1400 MAI->getInlineAsmEnd());
1404 // Emit the #APP start marker. This has to happen even if verbose-asm isn't
1405 // enabled, so we use EmitRawText.
1406 if (OutStreamer.hasRawTextSupport())
1407 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1408 MAI->getInlineAsmStart());
1410 // Emit the inline asm to a temporary string so we can emit it through
1412 SmallString<256> StringData;
1413 raw_svector_ostream OS(StringData);
1417 // The variant of the current asmprinter.
1418 int AsmPrinterVariant = MAI->getAssemblerDialect();
1420 int CurVariant = -1; // The number of the {.|.|.} region we are in.
1421 const char *LastEmitted = AsmStr; // One past the last character emitted.
1423 while (*LastEmitted) {
1424 switch (*LastEmitted) {
1426 // Not a special case, emit the string section literally.
1427 const char *LiteralEnd = LastEmitted+1;
1428 while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1429 *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1431 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1432 OS.write(LastEmitted, LiteralEnd-LastEmitted);
1433 LastEmitted = LiteralEnd;
1437 ++LastEmitted; // Consume newline character.
1438 OS << '\n'; // Indent code with newline.
1441 ++LastEmitted; // Consume '$' character.
1445 switch (*LastEmitted) {
1446 default: Done = false; break;
1447 case '$': // $$ -> $
1448 if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1450 ++LastEmitted; // Consume second '$' character.
1452 case '(': // $( -> same as GCC's { character.
1453 ++LastEmitted; // Consume '(' character.
1454 if (CurVariant != -1) {
1455 llvm_report_error("Nested variants found in inline asm string: '"
1456 + std::string(AsmStr) + "'");
1458 CurVariant = 0; // We're in the first variant now.
1461 ++LastEmitted; // consume '|' character.
1462 if (CurVariant == -1)
1463 OS << '|'; // this is gcc's behavior for | outside a variant
1465 ++CurVariant; // We're in the next variant.
1467 case ')': // $) -> same as GCC's } char.
1468 ++LastEmitted; // consume ')' character.
1469 if (CurVariant == -1)
1470 OS << '}'; // this is gcc's behavior for } outside a variant
1477 bool HasCurlyBraces = false;
1478 if (*LastEmitted == '{') { // ${variable}
1479 ++LastEmitted; // Consume '{' character.
1480 HasCurlyBraces = true;
1483 // If we have ${:foo}, then this is not a real operand reference, it is a
1484 // "magic" string reference, just like in .td files. Arrange to call
1486 if (HasCurlyBraces && *LastEmitted == ':') {
1488 const char *StrStart = LastEmitted;
1489 const char *StrEnd = strchr(StrStart, '}');
1491 llvm_report_error(Twine("Unterminated ${:foo} operand in inline asm"
1492 " string: '") + Twine(AsmStr) + "'");
1494 std::string Val(StrStart, StrEnd);
1495 PrintSpecial(MI, OS, Val.c_str());
1496 LastEmitted = StrEnd+1;
1500 const char *IDStart = LastEmitted;
1503 long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1504 if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1505 llvm_report_error("Bad $ operand number in inline asm string: '"
1506 + std::string(AsmStr) + "'");
1508 LastEmitted = IDEnd;
1510 char Modifier[2] = { 0, 0 };
1512 if (HasCurlyBraces) {
1513 // If we have curly braces, check for a modifier character. This
1514 // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1515 if (*LastEmitted == ':') {
1516 ++LastEmitted; // Consume ':' character.
1517 if (*LastEmitted == 0) {
1518 llvm_report_error("Bad ${:} expression in inline asm string: '"
1519 + std::string(AsmStr) + "'");
1522 Modifier[0] = *LastEmitted;
1523 ++LastEmitted; // Consume modifier character.
1526 if (*LastEmitted != '}') {
1527 llvm_report_error("Bad ${} expression in inline asm string: '"
1528 + std::string(AsmStr) + "'");
1530 ++LastEmitted; // Consume '}' character.
1533 if ((unsigned)Val >= NumOperands-1) {
1534 llvm_report_error("Invalid $ operand number in inline asm string: '"
1535 + std::string(AsmStr) + "'");
1538 // Okay, we finally have a value number. Ask the target to print this
1540 if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1545 // Scan to find the machine operand number for the operand.
1546 for (; Val; --Val) {
1547 if (OpNo >= MI->getNumOperands()) break;
1548 unsigned OpFlags = MI->getOperand(OpNo).getImm();
1549 OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1552 if (OpNo >= MI->getNumOperands()) {
1555 unsigned OpFlags = MI->getOperand(OpNo).getImm();
1556 ++OpNo; // Skip over the ID number.
1558 if (Modifier[0] == 'l') // labels are target independent
1559 OS << *MI->getOperand(OpNo).getMBB()->getSymbol();
1561 AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1562 if ((OpFlags & 7) == 4) {
1563 Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1564 Modifier[0] ? Modifier : 0,
1567 Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1568 Modifier[0] ? Modifier : 0, OS);
1574 raw_string_ostream Msg(msg);
1575 Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1577 llvm_report_error(Msg.str());
1586 EmitInlineAsm(OS.str());
1588 // Emit the #NOAPP end marker. This has to happen even if verbose-asm isn't
1589 // enabled, so we use EmitRawText.
1590 if (OutStreamer.hasRawTextSupport())
1591 OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1592 MAI->getInlineAsmEnd());
1595 /// printImplicitDef - This method prints the specified machine instruction
1596 /// that is an implicit def.
1597 void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1598 if (!VerboseAsm) return;
1599 OutStreamer.AddComment(Twine("implicit-def: ") +
1600 TRI->getName(MI->getOperand(0).getReg()));
1601 OutStreamer.AddBlankLine();
1604 void AsmPrinter::printKill(const MachineInstr *MI) const {
1605 if (!VerboseAsm) return;
1607 std::string Str = "kill:";
1608 for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1609 const MachineOperand &Op = MI->getOperand(n);
1610 assert(Op.isReg() && "KILL instruction must have only register operands");
1612 Str += TRI->getName(Op.getReg());
1613 Str += (Op.isDef() ? "<def>" : "<kill>");
1615 OutStreamer.AddComment(Str);
1616 OutStreamer.AddBlankLine();
1619 /// printLabel - This method prints a local label used by debug and
1620 /// exception handling tables.
1621 void AsmPrinter::printLabelInst(const MachineInstr *MI) const {
1622 OutStreamer.EmitLabel(MI->getOperand(0).getMCSymbol());
1625 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1626 /// instruction, using the specified assembler variant. Targets should
1627 /// override this to format as appropriate.
1628 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1629 unsigned AsmVariant, const char *ExtraCode,
1631 // Target doesn't support this yet!
1635 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1636 unsigned AsmVariant,
1637 const char *ExtraCode, raw_ostream &O) {
1638 // Target doesn't support this yet!
1642 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1643 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1646 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1647 return MMI->getAddrLabelSymbol(BB);
1650 /// GetCPISymbol - Return the symbol for the specified constant pool entry.
1651 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1652 return OutContext.GetOrCreateSymbol
1653 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1654 + "_" + Twine(CPID));
1657 /// GetJTISymbol - Return the symbol for the specified jump table entry.
1658 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1659 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1662 /// GetJTSetSymbol - Return the symbol for the specified jump table .set
1663 /// FIXME: privatize to AsmPrinter.
1664 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1665 return OutContext.GetOrCreateSymbol
1666 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1667 Twine(UID) + "_set_" + Twine(MBBID));
1670 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1671 /// global value name as its base, with the specified suffix, and where the
1672 /// symbol is forced to have private linkage if ForcePrivate is true.
1673 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1675 bool ForcePrivate) const {
1676 SmallString<60> NameStr;
1677 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1678 NameStr.append(Suffix.begin(), Suffix.end());
1679 return OutContext.GetOrCreateSymbol(NameStr.str());
1682 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1684 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1685 SmallString<60> NameStr;
1686 Mang->getNameWithPrefix(NameStr, Sym);
1687 return OutContext.GetOrCreateSymbol(NameStr.str());
1692 /// PrintParentLoopComment - Print comments about parent loops of this one.
1693 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1694 unsigned FunctionNumber) {
1695 if (Loop == 0) return;
1696 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1697 OS.indent(Loop->getLoopDepth()*2)
1698 << "Parent Loop BB" << FunctionNumber << "_"
1699 << Loop->getHeader()->getNumber()
1700 << " Depth=" << Loop->getLoopDepth() << '\n';
1704 /// PrintChildLoopComment - Print comments about child loops within
1705 /// the loop for this basic block, with nesting.
1706 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1707 unsigned FunctionNumber) {
1708 // Add child loop information
1709 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1710 OS.indent((*CL)->getLoopDepth()*2)
1711 << "Child Loop BB" << FunctionNumber << "_"
1712 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1714 PrintChildLoopComment(OS, *CL, FunctionNumber);
1718 /// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks.
1719 static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1720 const MachineLoopInfo *LI,
1721 const AsmPrinter &AP) {
1722 // Add loop depth information
1723 const MachineLoop *Loop = LI->getLoopFor(&MBB);
1724 if (Loop == 0) return;
1726 MachineBasicBlock *Header = Loop->getHeader();
1727 assert(Header && "No header for loop");
1729 // If this block is not a loop header, just print out what is the loop header
1731 if (Header != &MBB) {
1732 AP.OutStreamer.AddComment(" in Loop: Header=BB" +
1733 Twine(AP.getFunctionNumber())+"_" +
1734 Twine(Loop->getHeader()->getNumber())+
1735 " Depth="+Twine(Loop->getLoopDepth()));
1739 // Otherwise, it is a loop header. Print out information about child and
1741 raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1743 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1746 OS.indent(Loop->getLoopDepth()*2-2);
1751 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1753 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1757 /// EmitBasicBlockStart - This method prints the label for the specified
1758 /// MachineBasicBlock, an alignment (if present) and a comment describing
1759 /// it if appropriate.
1760 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1761 // Emit an alignment directive for this block, if needed.
1762 if (unsigned Align = MBB->getAlignment())
1763 EmitAlignment(Log2_32(Align));
1765 // If the block has its address taken, emit any labels that were used to
1766 // reference the block. It is possible that there is more than one label
1767 // here, because multiple LLVM BB's may have been RAUW'd to this block after
1768 // the references were generated.
1769 if (MBB->hasAddressTaken()) {
1770 const BasicBlock *BB = MBB->getBasicBlock();
1772 OutStreamer.AddComment("Block address taken");
1774 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1776 for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1777 OutStreamer.EmitLabel(Syms[i]);
1780 // Print the main label for the block.
1781 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1782 if (VerboseAsm && OutStreamer.hasRawTextSupport()) {
1783 if (const BasicBlock *BB = MBB->getBasicBlock())
1785 OutStreamer.AddComment("%" + BB->getName());
1787 PrintBasicBlockLoopComments(*MBB, LI, *this);
1789 // NOTE: Want this comment at start of line, don't emit with AddComment.
1790 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1791 Twine(MBB->getNumber()) + ":");
1795 if (const BasicBlock *BB = MBB->getBasicBlock())
1797 OutStreamer.AddComment("%" + BB->getName());
1798 PrintBasicBlockLoopComments(*MBB, LI, *this);
1801 OutStreamer.EmitLabel(MBB->getSymbol());
1805 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1806 MCSymbolAttr Attr = MCSA_Invalid;
1808 switch (Visibility) {
1810 case GlobalValue::HiddenVisibility:
1811 Attr = MAI->getHiddenVisibilityAttr();
1813 case GlobalValue::ProtectedVisibility:
1814 Attr = MAI->getProtectedVisibilityAttr();
1818 if (Attr != MCSA_Invalid)
1819 OutStreamer.EmitSymbolAttribute(Sym, Attr);
1822 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1824 OS << '+' << Offset;
1825 else if (Offset < 0)
1829 /// isBlockOnlyReachableByFallthough - Return true if the basic block has
1830 /// exactly one predecessor and the control transfer mechanism between
1831 /// the predecessor and this block is a fall-through.
1832 bool AsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB)
1834 // If this is a landing pad, it isn't a fall through. If it has no preds,
1835 // then nothing falls through to it.
1836 if (MBB->isLandingPad() || MBB->pred_empty())
1839 // If there isn't exactly one predecessor, it can't be a fall through.
1840 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1842 if (PI2 != MBB->pred_end())
1845 // The predecessor has to be immediately before this block.
1846 const MachineBasicBlock *Pred = *PI;
1848 if (!Pred->isLayoutSuccessor(MBB))
1851 // If the block is completely empty, then it definitely does fall through.
1855 // Otherwise, check the last instruction.
1856 const MachineInstr &LastInst = Pred->back();
1857 return !LastInst.getDesc().isBarrier();
1862 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1863 if (!S->usesMetadata())
1866 gcp_iterator GCPI = GCMetadataPrinters.find(S);
1867 if (GCPI != GCMetadataPrinters.end())
1868 return GCPI->second;
1870 const char *Name = S->getName().c_str();
1872 for (GCMetadataPrinterRegistry::iterator
1873 I = GCMetadataPrinterRegistry::begin(),
1874 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1875 if (strcmp(Name, I->getName()) == 0) {
1876 GCMetadataPrinter *GMP = I->instantiate();
1878 GCMetadataPrinters.insert(std::make_pair(S, GMP));
1882 llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));