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