1 //===-- PPCAsmPrinter.cpp - Print machine instrs to PowerPC assembly ------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains a printer that converts from our internal representation
11 // of machine-dependent LLVM code to PowerPC assembly language. This printer is
12 // the output mechanism used by `llc'.
13 //
14 // Documentation at http://developer.apple.com/documentation/DeveloperTools/
15 // Reference/Assembler/ASMIntroduction/chapter_1_section_1.html
16 //
17 //===----------------------------------------------------------------------===//
18 
19 #define DEBUG_TYPE "asmprinter"
20 #include "PPC.h"
21 #include "PPCTargetMachine.h"
22 #include "PPCSubtarget.h"
23 #include "InstPrinter/PPCInstPrinter.h"
24 #include "MCTargetDesc/PPCPredicates.h"
25 #include "llvm/Analysis/DebugInfo.h"
26 #include "llvm/Constants.h"
27 #include "llvm/DerivedTypes.h"
28 #include "llvm/Module.h"
29 #include "llvm/Assembly/Writer.h"
30 #include "llvm/CodeGen/AsmPrinter.h"
31 #include "llvm/CodeGen/MachineFunctionPass.h"
32 #include "llvm/CodeGen/MachineInstr.h"
33 #include "llvm/CodeGen/MachineInstrBuilder.h"
34 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
35 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
36 #include "llvm/MC/MCAsmInfo.h"
37 #include "llvm/MC/MCContext.h"
38 #include "llvm/MC/MCExpr.h"
39 #include "llvm/MC/MCInst.h"
40 #include "llvm/MC/MCSectionMachO.h"
41 #include "llvm/MC/MCStreamer.h"
42 #include "llvm/MC/MCSymbol.h"
43 #include "llvm/MC/MCSectionELF.h"
44 #include "llvm/Target/Mangler.h"
45 #include "llvm/Target/TargetRegisterInfo.h"
46 #include "llvm/Target/TargetInstrInfo.h"
47 #include "llvm/Target/TargetOptions.h"
48 #include "llvm/Support/CommandLine.h"
49 #include "llvm/Support/Debug.h"
50 #include "llvm/Support/MathExtras.h"
51 #include "llvm/Support/ErrorHandling.h"
52 #include "llvm/Support/TargetRegistry.h"
53 #include "llvm/Support/raw_ostream.h"
54 #include "llvm/Support/ELF.h"
55 #include "llvm/ADT/StringExtras.h"
56 #include "llvm/ADT/SmallString.h"
57 using namespace llvm;
58 
59 namespace {
60   class PPCAsmPrinter : public AsmPrinter {
61   protected:
62     DenseMap<MCSymbol*, MCSymbol*> TOC;
63     const PPCSubtarget &Subtarget;
64     uint64_t TOCLabelID;
65   public:
66     explicit PPCAsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
67       : AsmPrinter(TM, Streamer),
68         Subtarget(TM.getSubtarget<PPCSubtarget>()), TOCLabelID(0) {}
69 
70     virtual const char *getPassName() const {
71       return "PowerPC Assembly Printer";
72     }
73 
74 
75     virtual void EmitInstruction(const MachineInstr *MI);
76 
77     void printOperand(const MachineInstr *MI, unsigned OpNo, raw_ostream &O);
78 
79     bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
80                          unsigned AsmVariant, const char *ExtraCode,
81                          raw_ostream &O);
82     bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
83                                unsigned AsmVariant, const char *ExtraCode,
84                                raw_ostream &O);
85 
86     MachineLocation getDebugValueLocation(const MachineInstr *MI) const {
87       MachineLocation Location;
88       assert(MI->getNumOperands() == 4 && "Invalid no. of machine operands!");
89       // Frame address.  Currently handles register +- offset only.
90       if (MI->getOperand(0).isReg() && MI->getOperand(2).isImm())
91         Location.set(MI->getOperand(0).getReg(), MI->getOperand(2).getImm());
92       else {
93         DEBUG(dbgs() << "DBG_VALUE instruction ignored! " << *MI << "\n");
94       }
95       return Location;
96     }
97   };
98 
99   /// PPCLinuxAsmPrinter - PowerPC assembly printer, customized for Linux
100   class PPCLinuxAsmPrinter : public PPCAsmPrinter {
101   public:
102     explicit PPCLinuxAsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
103       : PPCAsmPrinter(TM, Streamer) {}
104 
105     virtual const char *getPassName() const {
106       return "Linux PPC Assembly Printer";
107     }
108 
109     bool doFinalization(Module &M);
110 
111     virtual void EmitFunctionEntryLabel();
112   };
113 
114   /// PPCDarwinAsmPrinter - PowerPC assembly printer, customized for Darwin/Mac
115   /// OS X
116   class PPCDarwinAsmPrinter : public PPCAsmPrinter {
117   public:
118     explicit PPCDarwinAsmPrinter(TargetMachine &TM, MCStreamer &Streamer)
119       : PPCAsmPrinter(TM, Streamer) {}
120 
121     virtual const char *getPassName() const {
122       return "Darwin PPC Assembly Printer";
123     }
124 
125     bool doFinalization(Module &M);
126     void EmitStartOfAsmFile(Module &M);
127 
128     void EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs);
129   };
130 } // end of anonymous namespace
131 
132 /// stripRegisterPrefix - This method strips the character prefix from a
133 /// register name so that only the number is left.  Used by for linux asm.
134 static const char *stripRegisterPrefix(const char *RegName) {
135   switch (RegName[0]) {
136     case 'r':
137     case 'f':
138     case 'v': return RegName + 1;
139     case 'c': if (RegName[1] == 'r') return RegName + 2;
140   }
141 
142   return RegName;
143 }
144 
145 void PPCAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
146                                  raw_ostream &O) {
147   const MachineOperand &MO = MI->getOperand(OpNo);
148 
149   switch (MO.getType()) {
150   case MachineOperand::MO_Register: {
151     const char *RegName = PPCInstPrinter::getRegisterName(MO.getReg());
152     // Linux assembler (Others?) does not take register mnemonics.
153     // FIXME - What about special registers used in mfspr/mtspr?
154     if (!Subtarget.isDarwin()) RegName = stripRegisterPrefix(RegName);
155     O << RegName;
156     return;
157   }
158   case MachineOperand::MO_Immediate:
159     O << MO.getImm();
160     return;
161 
162   case MachineOperand::MO_MachineBasicBlock:
163     O << *MO.getMBB()->getSymbol();
164     return;
165   case MachineOperand::MO_JumpTableIndex:
166     O << MAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
167       << '_' << MO.getIndex();
168     // FIXME: PIC relocation model
169     return;
170   case MachineOperand::MO_ConstantPoolIndex:
171     O << MAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber()
172       << '_' << MO.getIndex();
173     return;
174   case MachineOperand::MO_BlockAddress:
175     O << *GetBlockAddressSymbol(MO.getBlockAddress());
176     return;
177   case MachineOperand::MO_ExternalSymbol: {
178     // Computing the address of an external symbol, not calling it.
179     if (TM.getRelocationModel() == Reloc::Static) {
180       O << *GetExternalSymbolSymbol(MO.getSymbolName());
181       return;
182     }
183 
184     MCSymbol *NLPSym =
185       OutContext.GetOrCreateSymbol(StringRef(MAI->getGlobalPrefix())+
186                                    MO.getSymbolName()+"$non_lazy_ptr");
187     MachineModuleInfoImpl::StubValueTy &StubSym =
188       MMI->getObjFileInfo<MachineModuleInfoMachO>().getGVStubEntry(NLPSym);
189     if (StubSym.getPointer() == 0)
190       StubSym = MachineModuleInfoImpl::
191         StubValueTy(GetExternalSymbolSymbol(MO.getSymbolName()), true);
192 
193     O << *NLPSym;
194     return;
195   }
196   case MachineOperand::MO_GlobalAddress: {
197     // Computing the address of a global symbol, not calling it.
198     const GlobalValue *GV = MO.getGlobal();
199     MCSymbol *SymToPrint;
200 
201     // External or weakly linked global variables need non-lazily-resolved stubs
202     if (TM.getRelocationModel() != Reloc::Static &&
203         (GV->isDeclaration() || GV->isWeakForLinker())) {
204       if (!GV->hasHiddenVisibility()) {
205         SymToPrint = GetSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
206         MachineModuleInfoImpl::StubValueTy &StubSym =
207           MMI->getObjFileInfo<MachineModuleInfoMachO>()
208             .getGVStubEntry(SymToPrint);
209         if (StubSym.getPointer() == 0)
210           StubSym = MachineModuleInfoImpl::
211             StubValueTy(Mang->getSymbol(GV), !GV->hasInternalLinkage());
212       } else if (GV->isDeclaration() || GV->hasCommonLinkage() ||
213                  GV->hasAvailableExternallyLinkage()) {
214         SymToPrint = GetSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
215 
216         MachineModuleInfoImpl::StubValueTy &StubSym =
217           MMI->getObjFileInfo<MachineModuleInfoMachO>().
218                     getHiddenGVStubEntry(SymToPrint);
219         if (StubSym.getPointer() == 0)
220           StubSym = MachineModuleInfoImpl::
221             StubValueTy(Mang->getSymbol(GV), !GV->hasInternalLinkage());
222       } else {
223         SymToPrint = Mang->getSymbol(GV);
224       }
225     } else {
226       SymToPrint = Mang->getSymbol(GV);
227     }
228 
229     O << *SymToPrint;
230 
231     printOffset(MO.getOffset(), O);
232     return;
233   }
234 
235   default:
236     O << "<unknown operand type: " << MO.getType() << ">";
237     return;
238   }
239 }
240 
241 /// PrintAsmOperand - Print out an operand for an inline asm expression.
242 ///
243 bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
244                                     unsigned AsmVariant,
245                                     const char *ExtraCode, raw_ostream &O) {
246   // Does this asm operand have a single letter operand modifier?
247   if (ExtraCode && ExtraCode[0]) {
248     if (ExtraCode[1] != 0) return true; // Unknown modifier.
249 
250     switch (ExtraCode[0]) {
251     default: return true;  // Unknown modifier.
252     case 'c': // Don't print "$" before a global var name or constant.
253       break; // PPC never has a prefix.
254     case 'L': // Write second word of DImode reference.
255       // Verify that this operand has two consecutive registers.
256       if (!MI->getOperand(OpNo).isReg() ||
257           OpNo+1 == MI->getNumOperands() ||
258           !MI->getOperand(OpNo+1).isReg())
259         return true;
260       ++OpNo;   // Return the high-part.
261       break;
262     case 'I':
263       // Write 'i' if an integer constant, otherwise nothing.  Used to print
264       // addi vs add, etc.
265       if (MI->getOperand(OpNo).isImm())
266         O << "i";
267       return false;
268     }
269   }
270 
271   printOperand(MI, OpNo, O);
272   return false;
273 }
274 
275 // At the moment, all inline asm memory operands are a single register.
276 // In any case, the output of this routine should always be just one
277 // assembler operand.
278 
279 bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
280                                           unsigned AsmVariant,
281                                           const char *ExtraCode,
282                                           raw_ostream &O) {
283   if (ExtraCode && ExtraCode[0])
284     return true; // Unknown modifier.
285   assert(MI->getOperand(OpNo).isReg());
286   O << "0(";
287   printOperand(MI, OpNo, O);
288   O << ")";
289   return false;
290 }
291 
292 
293 /// EmitInstruction -- Print out a single PowerPC MI in Darwin syntax to
294 /// the current output stream.
295 ///
296 void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
297   MCInst TmpInst;
298 
299   // Lower multi-instruction pseudo operations.
300   switch (MI->getOpcode()) {
301   default: break;
302   case TargetOpcode::DBG_VALUE: {
303     if (!isVerbose() || !OutStreamer.hasRawTextSupport()) return;
304 
305     SmallString<32> Str;
306     raw_svector_ostream O(Str);
307     unsigned NOps = MI->getNumOperands();
308     assert(NOps==4);
309     O << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
310     // cast away const; DIetc do not take const operands for some reason.
311     DIVariable V(const_cast<MDNode *>(MI->getOperand(NOps-1).getMetadata()));
312     O << V.getName();
313     O << " <- ";
314     // Frame address.  Currently handles register +- offset only.
315     assert(MI->getOperand(0).isReg() && MI->getOperand(1).isImm());
316     O << '['; printOperand(MI, 0, O); O << '+'; printOperand(MI, 1, O);
317     O << ']';
318     O << "+";
319     printOperand(MI, NOps-2, O);
320     OutStreamer.EmitRawText(O.str());
321     return;
322   }
323 
324   case PPC::MovePCtoLR:
325   case PPC::MovePCtoLR8: {
326     // Transform %LR = MovePCtoLR
327     // Into this, where the label is the PIC base:
328     //     bl L1$pb
329     // L1$pb:
330     MCSymbol *PICBase = MF->getPICBaseSymbol();
331 
332     // Emit the 'bl'.
333     TmpInst.setOpcode(PPC::BL_Darwin); // Darwin vs SVR4 doesn't matter here.
334 
335 
336     // FIXME: We would like an efficient form for this, so we don't have to do
337     // a lot of extra uniquing.
338     TmpInst.addOperand(MCOperand::CreateExpr(MCSymbolRefExpr::
339                                              Create(PICBase, OutContext)));
340     OutStreamer.EmitInstruction(TmpInst);
341 
342     // Emit the label.
343     OutStreamer.EmitLabel(PICBase);
344     return;
345   }
346   case PPC::LDtoc: {
347     // Transform %X3 = LDtoc <ga:@min1>, %X2
348     LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
349 
350     // Change the opcode to LD, and the global address operand to be a
351     // reference to the TOC entry we will synthesize later.
352     TmpInst.setOpcode(PPC::LD);
353     const MachineOperand &MO = MI->getOperand(1);
354     assert(MO.isGlobal());
355 
356     // Map symbol -> label of TOC entry.
357     MCSymbol *&TOCEntry = TOC[Mang->getSymbol(MO.getGlobal())];
358     if (TOCEntry == 0)
359       TOCEntry = GetTempSymbol("C", TOCLabelID++);
360 
361     const MCExpr *Exp =
362       MCSymbolRefExpr::Create(TOCEntry, MCSymbolRefExpr::VK_PPC_TOC,
363                               OutContext);
364     TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
365     OutStreamer.EmitInstruction(TmpInst);
366     return;
367   }
368 
369   case PPC::MFCRpseud:
370   case PPC::MFCR8pseud:
371     // Transform: %R3 = MFCRpseud %CR7
372     // Into:      %R3 = MFCR      ;; cr7
373     OutStreamer.AddComment(PPCInstPrinter::
374                            getRegisterName(MI->getOperand(1).getReg()));
375     TmpInst.setOpcode(Subtarget.isPPC64() ? PPC::MFCR8 : PPC::MFCR);
376     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
377     OutStreamer.EmitInstruction(TmpInst);
378     return;
379   case PPC::SYNC:
380     // In Book E sync is called msync, handle this special case here...
381     if (Subtarget.isBookE()) {
382       OutStreamer.EmitRawText(StringRef("\tmsync"));
383       return;
384     }
385   }
386 
387   LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
388   OutStreamer.EmitInstruction(TmpInst);
389 }
390 
391 void PPCLinuxAsmPrinter::EmitFunctionEntryLabel() {
392   if (!Subtarget.isPPC64())  // linux/ppc32 - Normal entry label.
393     return AsmPrinter::EmitFunctionEntryLabel();
394 
395   // Emit an official procedure descriptor.
396   const MCSection *Current = OutStreamer.getCurrentSection();
397   const MCSectionELF *Section = OutStreamer.getContext().getELFSection(".opd",
398       ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC,
399       SectionKind::getReadOnly());
400   OutStreamer.SwitchSection(Section);
401   OutStreamer.EmitLabel(CurrentFnSym);
402   OutStreamer.EmitValueToAlignment(8);
403   MCSymbol *Symbol1 =
404     OutContext.GetOrCreateSymbol(".L." + Twine(CurrentFnSym->getName()));
405   MCSymbol *Symbol2 = OutContext.GetOrCreateSymbol(StringRef(".TOC.@tocbase"));
406   OutStreamer.EmitValue(MCSymbolRefExpr::Create(Symbol1, OutContext),
407                         Subtarget.isPPC64() ? 8 : 4/*size*/, 0/*addrspace*/);
408   OutStreamer.EmitValue(MCSymbolRefExpr::Create(Symbol2, OutContext),
409                         Subtarget.isPPC64() ? 8 : 4/*size*/, 0/*addrspace*/);
410   OutStreamer.SwitchSection(Current);
411 
412   MCSymbol *RealFnSym = OutContext.GetOrCreateSymbol(
413                           ".L." + Twine(CurrentFnSym->getName()));
414   OutStreamer.EmitLabel(RealFnSym);
415   CurrentFnSymForSize = RealFnSym;
416 }
417 
418 
419 bool PPCLinuxAsmPrinter::doFinalization(Module &M) {
420   const TargetData *TD = TM.getTargetData();
421 
422   bool isPPC64 = TD->getPointerSizeInBits() == 64;
423 
424   if (isPPC64 && !TOC.empty()) {
425     const MCSectionELF *Section = OutStreamer.getContext().getELFSection(".toc",
426         ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC,
427         SectionKind::getReadOnly());
428     OutStreamer.SwitchSection(Section);
429 
430     // FIXME: This is nondeterminstic!
431     for (DenseMap<MCSymbol*, MCSymbol*>::iterator I = TOC.begin(),
432          E = TOC.end(); I != E; ++I) {
433       OutStreamer.EmitLabel(I->second);
434       OutStreamer.EmitRawText("\t.tc " + Twine(I->first->getName()) +
435                               "[TC]," + I->first->getName());
436     }
437   }
438 
439   return AsmPrinter::doFinalization(M);
440 }
441 
442 void PPCDarwinAsmPrinter::EmitStartOfAsmFile(Module &M) {
443   static const char *const CPUDirectives[] = {
444     "",
445     "ppc",
446     "ppc440",
447     "ppc601",
448     "ppc602",
449     "ppc603",
450     "ppc7400",
451     "ppc750",
452     "ppc970",
453     "ppc64"
454   };
455 
456   unsigned Directive = Subtarget.getDarwinDirective();
457   if (Subtarget.isGigaProcessor() && Directive < PPC::DIR_970)
458     Directive = PPC::DIR_970;
459   if (Subtarget.hasAltivec() && Directive < PPC::DIR_7400)
460     Directive = PPC::DIR_7400;
461   if (Subtarget.isPPC64() && Directive < PPC::DIR_64)
462     Directive = PPC::DIR_64;
463   assert(Directive <= PPC::DIR_64 && "Directive out of range.");
464 
465   // FIXME: This is a total hack, finish mc'izing the PPC backend.
466   if (OutStreamer.hasRawTextSupport())
467     OutStreamer.EmitRawText("\t.machine " + Twine(CPUDirectives[Directive]));
468 
469   // Prime text sections so they are adjacent.  This reduces the likelihood a
470   // large data or debug section causes a branch to exceed 16M limit.
471   const TargetLoweringObjectFileMachO &TLOFMacho =
472     static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
473   OutStreamer.SwitchSection(TLOFMacho.getTextCoalSection());
474   if (TM.getRelocationModel() == Reloc::PIC_) {
475     OutStreamer.SwitchSection(
476            OutContext.getMachOSection("__TEXT", "__picsymbolstub1",
477                                       MCSectionMachO::S_SYMBOL_STUBS |
478                                       MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
479                                       32, SectionKind::getText()));
480   } else if (TM.getRelocationModel() == Reloc::DynamicNoPIC) {
481     OutStreamer.SwitchSection(
482            OutContext.getMachOSection("__TEXT","__symbol_stub1",
483                                       MCSectionMachO::S_SYMBOL_STUBS |
484                                       MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
485                                       16, SectionKind::getText()));
486   }
487   OutStreamer.SwitchSection(getObjFileLowering().getTextSection());
488 }
489 
490 static MCSymbol *GetLazyPtr(MCSymbol *Sym, MCContext &Ctx) {
491   // Remove $stub suffix, add $lazy_ptr.
492   SmallString<128> TmpStr(Sym->getName().begin(), Sym->getName().end()-5);
493   TmpStr += "$lazy_ptr";
494   return Ctx.GetOrCreateSymbol(TmpStr.str());
495 }
496 
497 static MCSymbol *GetAnonSym(MCSymbol *Sym, MCContext &Ctx) {
498   // Add $tmp suffix to $stub, yielding $stub$tmp.
499   SmallString<128> TmpStr(Sym->getName().begin(), Sym->getName().end());
500   TmpStr += "$tmp";
501   return Ctx.GetOrCreateSymbol(TmpStr.str());
502 }
503 
504 void PPCDarwinAsmPrinter::
505 EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs) {
506   bool isPPC64 = TM.getTargetData()->getPointerSizeInBits() == 64;
507 
508   const TargetLoweringObjectFileMachO &TLOFMacho =
509     static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
510 
511   // .lazy_symbol_pointer
512   const MCSection *LSPSection = TLOFMacho.getLazySymbolPointerSection();
513 
514   // Output stubs for dynamically-linked functions
515   if (TM.getRelocationModel() == Reloc::PIC_) {
516     const MCSection *StubSection =
517     OutContext.getMachOSection("__TEXT", "__picsymbolstub1",
518                                MCSectionMachO::S_SYMBOL_STUBS |
519                                MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
520                                32, SectionKind::getText());
521     for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
522       OutStreamer.SwitchSection(StubSection);
523       EmitAlignment(4);
524 
525       MCSymbol *Stub = Stubs[i].first;
526       MCSymbol *RawSym = Stubs[i].second.getPointer();
527       MCSymbol *LazyPtr = GetLazyPtr(Stub, OutContext);
528       MCSymbol *AnonSymbol = GetAnonSym(Stub, OutContext);
529 
530       OutStreamer.EmitLabel(Stub);
531       OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
532       // FIXME: MCize this.
533       OutStreamer.EmitRawText(StringRef("\tmflr r0"));
534       OutStreamer.EmitRawText("\tbcl 20,31," + Twine(AnonSymbol->getName()));
535       OutStreamer.EmitLabel(AnonSymbol);
536       OutStreamer.EmitRawText(StringRef("\tmflr r11"));
537       OutStreamer.EmitRawText("\taddis r11,r11,ha16("+Twine(LazyPtr->getName())+
538                               "-" + AnonSymbol->getName() + ")");
539       OutStreamer.EmitRawText(StringRef("\tmtlr r0"));
540 
541       if (isPPC64)
542         OutStreamer.EmitRawText("\tldu r12,lo16(" + Twine(LazyPtr->getName()) +
543                                 "-" + AnonSymbol->getName() + ")(r11)");
544       else
545         OutStreamer.EmitRawText("\tlwzu r12,lo16(" + Twine(LazyPtr->getName()) +
546                                 "-" + AnonSymbol->getName() + ")(r11)");
547       OutStreamer.EmitRawText(StringRef("\tmtctr r12"));
548       OutStreamer.EmitRawText(StringRef("\tbctr"));
549 
550       OutStreamer.SwitchSection(LSPSection);
551       OutStreamer.EmitLabel(LazyPtr);
552       OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
553 
554       if (isPPC64)
555         OutStreamer.EmitRawText(StringRef("\t.quad dyld_stub_binding_helper"));
556       else
557         OutStreamer.EmitRawText(StringRef("\t.long dyld_stub_binding_helper"));
558     }
559     OutStreamer.AddBlankLine();
560     return;
561   }
562 
563   const MCSection *StubSection =
564     OutContext.getMachOSection("__TEXT","__symbol_stub1",
565                                MCSectionMachO::S_SYMBOL_STUBS |
566                                MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
567                                16, SectionKind::getText());
568   for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
569     MCSymbol *Stub = Stubs[i].first;
570     MCSymbol *RawSym = Stubs[i].second.getPointer();
571     MCSymbol *LazyPtr = GetLazyPtr(Stub, OutContext);
572 
573     OutStreamer.SwitchSection(StubSection);
574     EmitAlignment(4);
575     OutStreamer.EmitLabel(Stub);
576     OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
577     OutStreamer.EmitRawText("\tlis r11,ha16(" + Twine(LazyPtr->getName()) +")");
578     if (isPPC64)
579       OutStreamer.EmitRawText("\tldu r12,lo16(" + Twine(LazyPtr->getName()) +
580                               ")(r11)");
581     else
582       OutStreamer.EmitRawText("\tlwzu r12,lo16(" + Twine(LazyPtr->getName()) +
583                               ")(r11)");
584     OutStreamer.EmitRawText(StringRef("\tmtctr r12"));
585     OutStreamer.EmitRawText(StringRef("\tbctr"));
586     OutStreamer.SwitchSection(LSPSection);
587     OutStreamer.EmitLabel(LazyPtr);
588     OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
589 
590     if (isPPC64)
591       OutStreamer.EmitRawText(StringRef("\t.quad dyld_stub_binding_helper"));
592     else
593       OutStreamer.EmitRawText(StringRef("\t.long dyld_stub_binding_helper"));
594   }
595 
596   OutStreamer.AddBlankLine();
597 }
598 
599 
600 bool PPCDarwinAsmPrinter::doFinalization(Module &M) {
601   bool isPPC64 = TM.getTargetData()->getPointerSizeInBits() == 64;
602 
603   // Darwin/PPC always uses mach-o.
604   const TargetLoweringObjectFileMachO &TLOFMacho =
605     static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
606   MachineModuleInfoMachO &MMIMacho =
607     MMI->getObjFileInfo<MachineModuleInfoMachO>();
608 
609   MachineModuleInfoMachO::SymbolListTy Stubs = MMIMacho.GetFnStubList();
610   if (!Stubs.empty())
611     EmitFunctionStubs(Stubs);
612 
613   if (MAI->doesSupportExceptionHandling() && MMI) {
614     // Add the (possibly multiple) personalities to the set of global values.
615     // Only referenced functions get into the Personalities list.
616     const std::vector<const Function*> &Personalities = MMI->getPersonalities();
617     for (std::vector<const Function*>::const_iterator I = Personalities.begin(),
618          E = Personalities.end(); I != E; ++I) {
619       if (*I) {
620         MCSymbol *NLPSym = GetSymbolWithGlobalValueBase(*I, "$non_lazy_ptr");
621         MachineModuleInfoImpl::StubValueTy &StubSym =
622           MMIMacho.getGVStubEntry(NLPSym);
623         StubSym = MachineModuleInfoImpl::StubValueTy(Mang->getSymbol(*I), true);
624       }
625     }
626   }
627 
628   // Output stubs for dynamically-linked functions.
629   Stubs = MMIMacho.GetGVStubList();
630 
631   // Output macho stubs for external and common global variables.
632   if (!Stubs.empty()) {
633     // Switch with ".non_lazy_symbol_pointer" directive.
634     OutStreamer.SwitchSection(TLOFMacho.getNonLazySymbolPointerSection());
635     EmitAlignment(isPPC64 ? 3 : 2);
636 
637     for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
638       // L_foo$stub:
639       OutStreamer.EmitLabel(Stubs[i].first);
640       //   .indirect_symbol _foo
641       MachineModuleInfoImpl::StubValueTy &MCSym = Stubs[i].second;
642       OutStreamer.EmitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol);
643 
644       if (MCSym.getInt())
645         // External to current translation unit.
646         OutStreamer.EmitIntValue(0, isPPC64 ? 8 : 4/*size*/, 0/*addrspace*/);
647       else
648         // Internal to current translation unit.
649         //
650         // When we place the LSDA into the TEXT section, the type info pointers
651         // need to be indirect and pc-rel. We accomplish this by using NLPs.
652         // However, sometimes the types are local to the file. So we need to
653         // fill in the value for the NLP in those cases.
654         OutStreamer.EmitValue(MCSymbolRefExpr::Create(MCSym.getPointer(),
655                                                       OutContext),
656                               isPPC64 ? 8 : 4/*size*/, 0/*addrspace*/);
657     }
658 
659     Stubs.clear();
660     OutStreamer.AddBlankLine();
661   }
662 
663   Stubs = MMIMacho.GetHiddenGVStubList();
664   if (!Stubs.empty()) {
665     OutStreamer.SwitchSection(getObjFileLowering().getDataSection());
666     EmitAlignment(isPPC64 ? 3 : 2);
667 
668     for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
669       // L_foo$stub:
670       OutStreamer.EmitLabel(Stubs[i].first);
671       //   .long _foo
672       OutStreamer.EmitValue(MCSymbolRefExpr::
673                             Create(Stubs[i].second.getPointer(),
674                                    OutContext),
675                             isPPC64 ? 8 : 4/*size*/, 0/*addrspace*/);
676     }
677 
678     Stubs.clear();
679     OutStreamer.AddBlankLine();
680   }
681 
682   // Funny Darwin hack: This flag tells the linker that no global symbols
683   // contain code that falls through to other global symbols (e.g. the obvious
684   // implementation of multiple entry points).  If this doesn't occur, the
685   // linker can safely perform dead code stripping.  Since LLVM never generates
686   // code that does this, it is always safe to set.
687   OutStreamer.EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
688 
689   return AsmPrinter::doFinalization(M);
690 }
691 
692 /// createPPCAsmPrinterPass - Returns a pass that prints the PPC assembly code
693 /// for a MachineFunction to the given output stream, in a format that the
694 /// Darwin assembler can deal with.
695 ///
696 static AsmPrinter *createPPCAsmPrinterPass(TargetMachine &tm,
697                                            MCStreamer &Streamer) {
698   const PPCSubtarget *Subtarget = &tm.getSubtarget<PPCSubtarget>();
699 
700   if (Subtarget->isDarwin())
701     return new PPCDarwinAsmPrinter(tm, Streamer);
702   return new PPCLinuxAsmPrinter(tm, Streamer);
703 }
704 
705 // Force static initialization.
706 extern "C" void LLVMInitializePowerPCAsmPrinter() {
707   TargetRegistry::RegisterAsmPrinter(ThePPC32Target, createPPCAsmPrinterPass);
708   TargetRegistry::RegisterAsmPrinter(ThePPC64Target, createPPCAsmPrinterPass);
709 }
710