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/Constants.h"
26 #include "llvm/DebugInfo.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, "$non_lazy_ptr");
215 
216         MachineModuleInfoImpl::StubValueTy &StubSym =
217           MMI->getObjFileInfo<MachineModuleInfoMachO>().
218                     getHiddenGVStubEntry(SymToPrint);
219         if (StubSym.getPointer() == 0)
220           StubSym = MachineModuleInfoImpl::
221             StubValueTy(Mang->getSymbol(GV), !GV->hasInternalLinkage());
222       } else {
223         SymToPrint = Mang->getSymbol(GV);
224       }
225     } else {
226       SymToPrint = Mang->getSymbol(GV);
227     }
228 
229     O << *SymToPrint;
230 
231     printOffset(MO.getOffset(), O);
232     return;
233   }
234 
235   default:
236     O << "<unknown operand type: " << MO.getType() << ">";
237     return;
238   }
239 }
240 
241 /// PrintAsmOperand - Print out an operand for an inline asm expression.
242 ///
243 bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
244                                     unsigned AsmVariant,
245                                     const char *ExtraCode, raw_ostream &O) {
246   // Does this asm operand have a single letter operand modifier?
247   if (ExtraCode && ExtraCode[0]) {
248     if (ExtraCode[1] != 0) return true; // Unknown modifier.
249 
250     switch (ExtraCode[0]) {
251     default:
252       // See if this is a generic print operand
253       return AsmPrinter::PrintAsmOperand(MI, OpNo, AsmVariant, ExtraCode, O);
254     case 'c': // Don't print "$" before a global var name or constant.
255       break; // PPC never has a prefix.
256     case 'L': // Write second word of DImode reference.
257       // Verify that this operand has two consecutive registers.
258       if (!MI->getOperand(OpNo).isReg() ||
259           OpNo+1 == MI->getNumOperands() ||
260           !MI->getOperand(OpNo+1).isReg())
261         return true;
262       ++OpNo;   // Return the high-part.
263       break;
264     case 'I':
265       // Write 'i' if an integer constant, otherwise nothing.  Used to print
266       // addi vs add, etc.
267       if (MI->getOperand(OpNo).isImm())
268         O << "i";
269       return false;
270     }
271   }
272 
273   printOperand(MI, OpNo, O);
274   return false;
275 }
276 
277 // At the moment, all inline asm memory operands are a single register.
278 // In any case, the output of this routine should always be just one
279 // assembler operand.
280 
281 bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
282                                           unsigned AsmVariant,
283                                           const char *ExtraCode,
284                                           raw_ostream &O) {
285   if (ExtraCode && ExtraCode[0])
286     return true; // Unknown modifier.
287   assert(MI->getOperand(OpNo).isReg());
288   O << "0(";
289   printOperand(MI, OpNo, O);
290   O << ")";
291   return false;
292 }
293 
294 
295 /// EmitInstruction -- Print out a single PowerPC MI in Darwin syntax to
296 /// the current output stream.
297 ///
298 void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
299   MCInst TmpInst;
300 
301   // Lower multi-instruction pseudo operations.
302   switch (MI->getOpcode()) {
303   default: break;
304   case TargetOpcode::DBG_VALUE: {
305     if (!isVerbose() || !OutStreamer.hasRawTextSupport()) return;
306 
307     SmallString<32> Str;
308     raw_svector_ostream O(Str);
309     unsigned NOps = MI->getNumOperands();
310     assert(NOps==4);
311     O << '\t' << MAI->getCommentString() << "DEBUG_VALUE: ";
312     // cast away const; DIetc do not take const operands for some reason.
313     DIVariable V(const_cast<MDNode *>(MI->getOperand(NOps-1).getMetadata()));
314     O << V.getName();
315     O << " <- ";
316     // Frame address.  Currently handles register +- offset only.
317     assert(MI->getOperand(0).isReg() && MI->getOperand(1).isImm());
318     O << '['; printOperand(MI, 0, O); O << '+'; printOperand(MI, 1, O);
319     O << ']';
320     O << "+";
321     printOperand(MI, NOps-2, O);
322     OutStreamer.EmitRawText(O.str());
323     return;
324   }
325 
326   case PPC::MovePCtoLR:
327   case PPC::MovePCtoLR8: {
328     // Transform %LR = MovePCtoLR
329     // Into this, where the label is the PIC base:
330     //     bl L1$pb
331     // L1$pb:
332     MCSymbol *PICBase = MF->getPICBaseSymbol();
333 
334     // Emit the 'bl'.
335     TmpInst.setOpcode(PPC::BL_Darwin); // Darwin vs SVR4 doesn't matter here.
336 
337 
338     // FIXME: We would like an efficient form for this, so we don't have to do
339     // a lot of extra uniquing.
340     TmpInst.addOperand(MCOperand::CreateExpr(MCSymbolRefExpr::
341                                              Create(PICBase, OutContext)));
342     OutStreamer.EmitInstruction(TmpInst);
343 
344     // Emit the label.
345     OutStreamer.EmitLabel(PICBase);
346     return;
347   }
348   case PPC::LDtoc: {
349     // Transform %X3 = LDtoc <ga:@min1>, %X2
350     LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
351 
352     // Change the opcode to LD, and the global address operand to be a
353     // reference to the TOC entry we will synthesize later.
354     TmpInst.setOpcode(PPC::LD);
355     const MachineOperand &MO = MI->getOperand(1);
356     assert(MO.isGlobal());
357 
358     // Map symbol -> label of TOC entry.
359     MCSymbol *&TOCEntry = TOC[Mang->getSymbol(MO.getGlobal())];
360     if (TOCEntry == 0)
361       TOCEntry = GetTempSymbol("C", TOCLabelID++);
362 
363     const MCExpr *Exp =
364       MCSymbolRefExpr::Create(TOCEntry, MCSymbolRefExpr::VK_PPC_TOC,
365                               OutContext);
366     TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
367     OutStreamer.EmitInstruction(TmpInst);
368     return;
369   }
370 
371   case PPC::MFCRpseud:
372   case PPC::MFCR8pseud:
373     // Transform: %R3 = MFCRpseud %CR7
374     // Into:      %R3 = MFCR      ;; cr7
375     OutStreamer.AddComment(PPCInstPrinter::
376                            getRegisterName(MI->getOperand(1).getReg()));
377     TmpInst.setOpcode(Subtarget.isPPC64() ? PPC::MFCR8 : PPC::MFCR);
378     TmpInst.addOperand(MCOperand::CreateReg(MI->getOperand(0).getReg()));
379     OutStreamer.EmitInstruction(TmpInst);
380     return;
381   case PPC::SYNC:
382     // In Book E sync is called msync, handle this special case here...
383     if (Subtarget.isBookE()) {
384       OutStreamer.EmitRawText(StringRef("\tmsync"));
385       return;
386     }
387   }
388 
389   LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, Subtarget.isDarwin());
390   OutStreamer.EmitInstruction(TmpInst);
391 }
392 
393 void PPCLinuxAsmPrinter::EmitFunctionEntryLabel() {
394   if (!Subtarget.isPPC64())  // linux/ppc32 - Normal entry label.
395     return AsmPrinter::EmitFunctionEntryLabel();
396 
397   // Emit an official procedure descriptor.
398   const MCSection *Current = OutStreamer.getCurrentSection();
399   const MCSectionELF *Section = OutStreamer.getContext().getELFSection(".opd",
400       ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC,
401       SectionKind::getReadOnly());
402   OutStreamer.SwitchSection(Section);
403   OutStreamer.EmitLabel(CurrentFnSym);
404   OutStreamer.EmitValueToAlignment(8);
405   MCSymbol *Symbol1 =
406     OutContext.GetOrCreateSymbol(".L." + Twine(CurrentFnSym->getName()));
407   MCSymbol *Symbol2 = OutContext.GetOrCreateSymbol(StringRef(".TOC.@tocbase"));
408   OutStreamer.EmitValue(MCSymbolRefExpr::Create(Symbol1, OutContext),
409                         Subtarget.isPPC64() ? 8 : 4/*size*/, 0/*addrspace*/);
410   OutStreamer.EmitValue(MCSymbolRefExpr::Create(Symbol2, OutContext),
411                         Subtarget.isPPC64() ? 8 : 4/*size*/, 0/*addrspace*/);
412   OutStreamer.SwitchSection(Current);
413 
414   MCSymbol *RealFnSym = OutContext.GetOrCreateSymbol(
415                           ".L." + Twine(CurrentFnSym->getName()));
416   OutStreamer.EmitLabel(RealFnSym);
417   CurrentFnSymForSize = RealFnSym;
418 }
419 
420 
421 bool PPCLinuxAsmPrinter::doFinalization(Module &M) {
422   const TargetData *TD = TM.getTargetData();
423 
424   bool isPPC64 = TD->getPointerSizeInBits() == 64;
425 
426   if (isPPC64 && !TOC.empty()) {
427     const MCSectionELF *Section = OutStreamer.getContext().getELFSection(".toc",
428         ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC,
429         SectionKind::getReadOnly());
430     OutStreamer.SwitchSection(Section);
431 
432     // FIXME: This is nondeterminstic!
433     for (DenseMap<MCSymbol*, MCSymbol*>::iterator I = TOC.begin(),
434          E = TOC.end(); I != E; ++I) {
435       OutStreamer.EmitLabel(I->second);
436       OutStreamer.EmitRawText("\t.tc " + Twine(I->first->getName()) +
437                               "[TC]," + I->first->getName());
438     }
439   }
440 
441   return AsmPrinter::doFinalization(M);
442 }
443 
444 void PPCDarwinAsmPrinter::EmitStartOfAsmFile(Module &M) {
445   static const char *const CPUDirectives[] = {
446     "",
447     "ppc",
448     "ppc440",
449     "ppc601",
450     "ppc602",
451     "ppc603",
452     "ppc7400",
453     "ppc750",
454     "ppc970",
455     "ppcA2",
456     "power6",
457     "power7",
458     "ppc64"
459   };
460 
461   unsigned Directive = Subtarget.getDarwinDirective();
462   if (Subtarget.hasMFOCRF() && Directive < PPC::DIR_970)
463     Directive = PPC::DIR_970;
464   if (Subtarget.hasAltivec() && Directive < PPC::DIR_7400)
465     Directive = PPC::DIR_7400;
466   if (Subtarget.isPPC64() && Directive < PPC::DIR_64)
467     Directive = PPC::DIR_64;
468   assert(Directive <= PPC::DIR_64 && "Directive out of range.");
469 
470   // FIXME: This is a total hack, finish mc'izing the PPC backend.
471   if (OutStreamer.hasRawTextSupport())
472     OutStreamer.EmitRawText("\t.machine " + Twine(CPUDirectives[Directive]));
473 
474   // Prime text sections so they are adjacent.  This reduces the likelihood a
475   // large data or debug section causes a branch to exceed 16M limit.
476   const TargetLoweringObjectFileMachO &TLOFMacho =
477     static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
478   OutStreamer.SwitchSection(TLOFMacho.getTextCoalSection());
479   if (TM.getRelocationModel() == Reloc::PIC_) {
480     OutStreamer.SwitchSection(
481            OutContext.getMachOSection("__TEXT", "__picsymbolstub1",
482                                       MCSectionMachO::S_SYMBOL_STUBS |
483                                       MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
484                                       32, SectionKind::getText()));
485   } else if (TM.getRelocationModel() == Reloc::DynamicNoPIC) {
486     OutStreamer.SwitchSection(
487            OutContext.getMachOSection("__TEXT","__symbol_stub1",
488                                       MCSectionMachO::S_SYMBOL_STUBS |
489                                       MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
490                                       16, SectionKind::getText()));
491   }
492   OutStreamer.SwitchSection(getObjFileLowering().getTextSection());
493 }
494 
495 static MCSymbol *GetLazyPtr(MCSymbol *Sym, MCContext &Ctx) {
496   // Remove $stub suffix, add $lazy_ptr.
497   SmallString<128> TmpStr(Sym->getName().begin(), Sym->getName().end()-5);
498   TmpStr += "$lazy_ptr";
499   return Ctx.GetOrCreateSymbol(TmpStr.str());
500 }
501 
502 static MCSymbol *GetAnonSym(MCSymbol *Sym, MCContext &Ctx) {
503   // Add $tmp suffix to $stub, yielding $stub$tmp.
504   SmallString<128> TmpStr(Sym->getName().begin(), Sym->getName().end());
505   TmpStr += "$tmp";
506   return Ctx.GetOrCreateSymbol(TmpStr.str());
507 }
508 
509 void PPCDarwinAsmPrinter::
510 EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs) {
511   bool isPPC64 = TM.getTargetData()->getPointerSizeInBits() == 64;
512 
513   const TargetLoweringObjectFileMachO &TLOFMacho =
514     static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
515 
516   // .lazy_symbol_pointer
517   const MCSection *LSPSection = TLOFMacho.getLazySymbolPointerSection();
518 
519   // Output stubs for dynamically-linked functions
520   if (TM.getRelocationModel() == Reloc::PIC_) {
521     const MCSection *StubSection =
522     OutContext.getMachOSection("__TEXT", "__picsymbolstub1",
523                                MCSectionMachO::S_SYMBOL_STUBS |
524                                MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
525                                32, SectionKind::getText());
526     for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
527       OutStreamer.SwitchSection(StubSection);
528       EmitAlignment(4);
529 
530       MCSymbol *Stub = Stubs[i].first;
531       MCSymbol *RawSym = Stubs[i].second.getPointer();
532       MCSymbol *LazyPtr = GetLazyPtr(Stub, OutContext);
533       MCSymbol *AnonSymbol = GetAnonSym(Stub, OutContext);
534 
535       OutStreamer.EmitLabel(Stub);
536       OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
537       // FIXME: MCize this.
538       OutStreamer.EmitRawText(StringRef("\tmflr r0"));
539       OutStreamer.EmitRawText("\tbcl 20,31," + Twine(AnonSymbol->getName()));
540       OutStreamer.EmitLabel(AnonSymbol);
541       OutStreamer.EmitRawText(StringRef("\tmflr r11"));
542       OutStreamer.EmitRawText("\taddis r11,r11,ha16("+Twine(LazyPtr->getName())+
543                               "-" + AnonSymbol->getName() + ")");
544       OutStreamer.EmitRawText(StringRef("\tmtlr r0"));
545 
546       if (isPPC64)
547         OutStreamer.EmitRawText("\tldu r12,lo16(" + Twine(LazyPtr->getName()) +
548                                 "-" + AnonSymbol->getName() + ")(r11)");
549       else
550         OutStreamer.EmitRawText("\tlwzu r12,lo16(" + Twine(LazyPtr->getName()) +
551                                 "-" + AnonSymbol->getName() + ")(r11)");
552       OutStreamer.EmitRawText(StringRef("\tmtctr r12"));
553       OutStreamer.EmitRawText(StringRef("\tbctr"));
554 
555       OutStreamer.SwitchSection(LSPSection);
556       OutStreamer.EmitLabel(LazyPtr);
557       OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
558 
559       if (isPPC64)
560         OutStreamer.EmitRawText(StringRef("\t.quad dyld_stub_binding_helper"));
561       else
562         OutStreamer.EmitRawText(StringRef("\t.long dyld_stub_binding_helper"));
563     }
564     OutStreamer.AddBlankLine();
565     return;
566   }
567 
568   const MCSection *StubSection =
569     OutContext.getMachOSection("__TEXT","__symbol_stub1",
570                                MCSectionMachO::S_SYMBOL_STUBS |
571                                MCSectionMachO::S_ATTR_PURE_INSTRUCTIONS,
572                                16, SectionKind::getText());
573   for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
574     MCSymbol *Stub = Stubs[i].first;
575     MCSymbol *RawSym = Stubs[i].second.getPointer();
576     MCSymbol *LazyPtr = GetLazyPtr(Stub, OutContext);
577 
578     OutStreamer.SwitchSection(StubSection);
579     EmitAlignment(4);
580     OutStreamer.EmitLabel(Stub);
581     OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
582     OutStreamer.EmitRawText("\tlis r11,ha16(" + Twine(LazyPtr->getName()) +")");
583     if (isPPC64)
584       OutStreamer.EmitRawText("\tldu r12,lo16(" + Twine(LazyPtr->getName()) +
585                               ")(r11)");
586     else
587       OutStreamer.EmitRawText("\tlwzu r12,lo16(" + Twine(LazyPtr->getName()) +
588                               ")(r11)");
589     OutStreamer.EmitRawText(StringRef("\tmtctr r12"));
590     OutStreamer.EmitRawText(StringRef("\tbctr"));
591     OutStreamer.SwitchSection(LSPSection);
592     OutStreamer.EmitLabel(LazyPtr);
593     OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
594 
595     if (isPPC64)
596       OutStreamer.EmitRawText(StringRef("\t.quad dyld_stub_binding_helper"));
597     else
598       OutStreamer.EmitRawText(StringRef("\t.long dyld_stub_binding_helper"));
599   }
600 
601   OutStreamer.AddBlankLine();
602 }
603 
604 
605 bool PPCDarwinAsmPrinter::doFinalization(Module &M) {
606   bool isPPC64 = TM.getTargetData()->getPointerSizeInBits() == 64;
607 
608   // Darwin/PPC always uses mach-o.
609   const TargetLoweringObjectFileMachO &TLOFMacho =
610     static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
611   MachineModuleInfoMachO &MMIMacho =
612     MMI->getObjFileInfo<MachineModuleInfoMachO>();
613 
614   MachineModuleInfoMachO::SymbolListTy Stubs = MMIMacho.GetFnStubList();
615   if (!Stubs.empty())
616     EmitFunctionStubs(Stubs);
617 
618   if (MAI->doesSupportExceptionHandling() && MMI) {
619     // Add the (possibly multiple) personalities to the set of global values.
620     // Only referenced functions get into the Personalities list.
621     const std::vector<const Function*> &Personalities = MMI->getPersonalities();
622     for (std::vector<const Function*>::const_iterator I = Personalities.begin(),
623          E = Personalities.end(); I != E; ++I) {
624       if (*I) {
625         MCSymbol *NLPSym = GetSymbolWithGlobalValueBase(*I, "$non_lazy_ptr");
626         MachineModuleInfoImpl::StubValueTy &StubSym =
627           MMIMacho.getGVStubEntry(NLPSym);
628         StubSym = MachineModuleInfoImpl::StubValueTy(Mang->getSymbol(*I), true);
629       }
630     }
631   }
632 
633   // Output stubs for dynamically-linked functions.
634   Stubs = MMIMacho.GetGVStubList();
635 
636   // Output macho stubs for external and common global variables.
637   if (!Stubs.empty()) {
638     // Switch with ".non_lazy_symbol_pointer" directive.
639     OutStreamer.SwitchSection(TLOFMacho.getNonLazySymbolPointerSection());
640     EmitAlignment(isPPC64 ? 3 : 2);
641 
642     for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
643       // L_foo$stub:
644       OutStreamer.EmitLabel(Stubs[i].first);
645       //   .indirect_symbol _foo
646       MachineModuleInfoImpl::StubValueTy &MCSym = Stubs[i].second;
647       OutStreamer.EmitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol);
648 
649       if (MCSym.getInt())
650         // External to current translation unit.
651         OutStreamer.EmitIntValue(0, isPPC64 ? 8 : 4/*size*/, 0/*addrspace*/);
652       else
653         // Internal to current translation unit.
654         //
655         // When we place the LSDA into the TEXT section, the type info pointers
656         // need to be indirect and pc-rel. We accomplish this by using NLPs.
657         // However, sometimes the types are local to the file. So we need to
658         // fill in the value for the NLP in those cases.
659         OutStreamer.EmitValue(MCSymbolRefExpr::Create(MCSym.getPointer(),
660                                                       OutContext),
661                               isPPC64 ? 8 : 4/*size*/, 0/*addrspace*/);
662     }
663 
664     Stubs.clear();
665     OutStreamer.AddBlankLine();
666   }
667 
668   Stubs = MMIMacho.GetHiddenGVStubList();
669   if (!Stubs.empty()) {
670     OutStreamer.SwitchSection(getObjFileLowering().getDataSection());
671     EmitAlignment(isPPC64 ? 3 : 2);
672 
673     for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
674       // L_foo$stub:
675       OutStreamer.EmitLabel(Stubs[i].first);
676       //   .long _foo
677       OutStreamer.EmitValue(MCSymbolRefExpr::
678                             Create(Stubs[i].second.getPointer(),
679                                    OutContext),
680                             isPPC64 ? 8 : 4/*size*/, 0/*addrspace*/);
681     }
682 
683     Stubs.clear();
684     OutStreamer.AddBlankLine();
685   }
686 
687   // Funny Darwin hack: This flag tells the linker that no global symbols
688   // contain code that falls through to other global symbols (e.g. the obvious
689   // implementation of multiple entry points).  If this doesn't occur, the
690   // linker can safely perform dead code stripping.  Since LLVM never generates
691   // code that does this, it is always safe to set.
692   OutStreamer.EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
693 
694   return AsmPrinter::doFinalization(M);
695 }
696 
697 /// createPPCAsmPrinterPass - Returns a pass that prints the PPC assembly code
698 /// for a MachineFunction to the given output stream, in a format that the
699 /// Darwin assembler can deal with.
700 ///
701 static AsmPrinter *createPPCAsmPrinterPass(TargetMachine &tm,
702                                            MCStreamer &Streamer) {
703   const PPCSubtarget *Subtarget = &tm.getSubtarget<PPCSubtarget>();
704 
705   if (Subtarget->isDarwin())
706     return new PPCDarwinAsmPrinter(tm, Streamer);
707   return new PPCLinuxAsmPrinter(tm, Streamer);
708 }
709 
710 // Force static initialization.
711 extern "C" void LLVMInitializePowerPCAsmPrinter() {
712   TargetRegistry::RegisterAsmPrinter(ThePPC32Target, createPPCAsmPrinterPass);
713   TargetRegistry::RegisterAsmPrinter(ThePPC64Target, createPPCAsmPrinterPass);
714 }
715