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 #include "PPC.h"
20 #include "InstPrinter/PPCInstPrinter.h"
21 #include "MCTargetDesc/PPCMCExpr.h"
22 #include "MCTargetDesc/PPCPredicates.h"
23 #include "PPCMachineFunctionInfo.h"
24 #include "PPCSubtarget.h"
25 #include "PPCTargetMachine.h"
26 #include "PPCTargetStreamer.h"
27 #include "llvm/ADT/MapVector.h"
28 #include "llvm/ADT/SmallString.h"
29 #include "llvm/ADT/StringExtras.h"
30 #include "llvm/CodeGen/AsmPrinter.h"
31 #include "llvm/CodeGen/MachineConstantPool.h"
32 #include "llvm/CodeGen/MachineFunctionPass.h"
33 #include "llvm/CodeGen/MachineInstr.h"
34 #include "llvm/CodeGen/MachineInstrBuilder.h"
35 #include "llvm/CodeGen/MachineModuleInfoImpls.h"
36 #include "llvm/CodeGen/MachineRegisterInfo.h"
37 #include "llvm/CodeGen/StackMaps.h"
38 #include "llvm/CodeGen/TargetLoweringObjectFileImpl.h"
39 #include "llvm/IR/Constants.h"
40 #include "llvm/IR/DebugInfo.h"
41 #include "llvm/IR/DerivedTypes.h"
42 #include "llvm/IR/Mangler.h"
43 #include "llvm/IR/Module.h"
44 #include "llvm/MC/MCAsmInfo.h"
45 #include "llvm/MC/MCContext.h"
46 #include "llvm/MC/MCExpr.h"
47 #include "llvm/MC/MCInst.h"
48 #include "llvm/MC/MCInstBuilder.h"
49 #include "llvm/MC/MCSectionELF.h"
50 #include "llvm/MC/MCSectionMachO.h"
51 #include "llvm/MC/MCStreamer.h"
52 #include "llvm/MC/MCSymbol.h"
53 #include "llvm/Support/CommandLine.h"
54 #include "llvm/Support/Debug.h"
55 #include "llvm/Support/ELF.h"
56 #include "llvm/Support/ErrorHandling.h"
57 #include "llvm/Support/MathExtras.h"
58 #include "llvm/Support/TargetRegistry.h"
59 #include "llvm/Support/raw_ostream.h"
60 #include "llvm/Target/TargetInstrInfo.h"
61 #include "llvm/Target/TargetOptions.h"
62 #include "llvm/Target/TargetRegisterInfo.h"
63 using namespace llvm;
64 
65 #define DEBUG_TYPE "asmprinter"
66 
67 namespace {
68   class PPCAsmPrinter : public AsmPrinter {
69   protected:
70     MapVector<MCSymbol*, MCSymbol*> TOC;
71     const PPCSubtarget *Subtarget;
72     StackMaps SM;
73   public:
PPCAsmPrinter(TargetMachine & TM,std::unique_ptr<MCStreamer> Streamer)74     explicit PPCAsmPrinter(TargetMachine &TM,
75                            std::unique_ptr<MCStreamer> Streamer)
76         : AsmPrinter(TM, std::move(Streamer)), SM(*this) {}
77 
getPassName() const78     const char *getPassName() const override {
79       return "PowerPC Assembly Printer";
80     }
81 
82     MCSymbol *lookUpOrCreateTOCEntry(MCSymbol *Sym);
83 
84     void EmitInstruction(const MachineInstr *MI) override;
85 
86     void printOperand(const MachineInstr *MI, unsigned OpNo, raw_ostream &O);
87 
88     bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
89                          unsigned AsmVariant, const char *ExtraCode,
90                          raw_ostream &O) override;
91     bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
92                                unsigned AsmVariant, const char *ExtraCode,
93                                raw_ostream &O) override;
94 
95     void EmitEndOfAsmFile(Module &M) override;
96 
97     void LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
98                        const MachineInstr &MI);
99     void LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
100                          const MachineInstr &MI);
101     void EmitTlsCall(const MachineInstr *MI, MCSymbolRefExpr::VariantKind VK);
runOnMachineFunction(MachineFunction & MF)102     bool runOnMachineFunction(MachineFunction &MF) override {
103       Subtarget = &MF.getSubtarget<PPCSubtarget>();
104       return AsmPrinter::runOnMachineFunction(MF);
105     }
106   };
107 
108   /// PPCLinuxAsmPrinter - PowerPC assembly printer, customized for Linux
109   class PPCLinuxAsmPrinter : public PPCAsmPrinter {
110   public:
PPCLinuxAsmPrinter(TargetMachine & TM,std::unique_ptr<MCStreamer> Streamer)111     explicit PPCLinuxAsmPrinter(TargetMachine &TM,
112                                 std::unique_ptr<MCStreamer> Streamer)
113         : PPCAsmPrinter(TM, std::move(Streamer)) {}
114 
getPassName() const115     const char *getPassName() const override {
116       return "Linux PPC Assembly Printer";
117     }
118 
119     bool doFinalization(Module &M) override;
120     void EmitStartOfAsmFile(Module &M) override;
121 
122     void EmitFunctionEntryLabel() override;
123 
124     void EmitFunctionBodyStart() override;
125     void EmitFunctionBodyEnd() override;
126   };
127 
128   /// PPCDarwinAsmPrinter - PowerPC assembly printer, customized for Darwin/Mac
129   /// OS X
130   class PPCDarwinAsmPrinter : public PPCAsmPrinter {
131   public:
PPCDarwinAsmPrinter(TargetMachine & TM,std::unique_ptr<MCStreamer> Streamer)132     explicit PPCDarwinAsmPrinter(TargetMachine &TM,
133                                  std::unique_ptr<MCStreamer> Streamer)
134         : PPCAsmPrinter(TM, std::move(Streamer)) {}
135 
getPassName() const136     const char *getPassName() const override {
137       return "Darwin PPC Assembly Printer";
138     }
139 
140     bool doFinalization(Module &M) override;
141     void EmitStartOfAsmFile(Module &M) override;
142 
143     void EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs);
144   };
145 } // end of anonymous namespace
146 
147 /// stripRegisterPrefix - This method strips the character prefix from a
148 /// register name so that only the number is left.  Used by for linux asm.
stripRegisterPrefix(const char * RegName)149 static const char *stripRegisterPrefix(const char *RegName) {
150   switch (RegName[0]) {
151     case 'r':
152     case 'f':
153     case 'q': // for QPX
154     case 'v':
155       if (RegName[1] == 's')
156         return RegName + 2;
157       return RegName + 1;
158     case 'c': if (RegName[1] == 'r') return RegName + 2;
159   }
160 
161   return RegName;
162 }
163 
printOperand(const MachineInstr * MI,unsigned OpNo,raw_ostream & O)164 void PPCAsmPrinter::printOperand(const MachineInstr *MI, unsigned OpNo,
165                                  raw_ostream &O) {
166   const DataLayout *DL = TM.getDataLayout();
167   const MachineOperand &MO = MI->getOperand(OpNo);
168 
169   switch (MO.getType()) {
170   case MachineOperand::MO_Register: {
171     const char *RegName = PPCInstPrinter::getRegisterName(MO.getReg());
172     // Linux assembler (Others?) does not take register mnemonics.
173     // FIXME - What about special registers used in mfspr/mtspr?
174     if (!Subtarget->isDarwin())
175       RegName = stripRegisterPrefix(RegName);
176     O << RegName;
177     return;
178   }
179   case MachineOperand::MO_Immediate:
180     O << MO.getImm();
181     return;
182 
183   case MachineOperand::MO_MachineBasicBlock:
184     O << *MO.getMBB()->getSymbol();
185     return;
186   case MachineOperand::MO_ConstantPoolIndex:
187     O << DL->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber()
188       << '_' << MO.getIndex();
189     return;
190   case MachineOperand::MO_BlockAddress:
191     O << *GetBlockAddressSymbol(MO.getBlockAddress());
192     return;
193   case MachineOperand::MO_GlobalAddress: {
194     // Computing the address of a global symbol, not calling it.
195     const GlobalValue *GV = MO.getGlobal();
196     MCSymbol *SymToPrint;
197 
198     // External or weakly linked global variables need non-lazily-resolved stubs
199     if (TM.getRelocationModel() != Reloc::Static &&
200         (GV->isDeclaration() || GV->isWeakForLinker())) {
201       if (!GV->hasHiddenVisibility()) {
202         SymToPrint = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
203         MachineModuleInfoImpl::StubValueTy &StubSym =
204           MMI->getObjFileInfo<MachineModuleInfoMachO>()
205             .getGVStubEntry(SymToPrint);
206         if (!StubSym.getPointer())
207           StubSym = MachineModuleInfoImpl::
208             StubValueTy(getSymbol(GV), !GV->hasInternalLinkage());
209       } else if (GV->isDeclaration() || GV->hasCommonLinkage() ||
210                  GV->hasAvailableExternallyLinkage()) {
211         SymToPrint = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr");
212 
213         MachineModuleInfoImpl::StubValueTy &StubSym =
214           MMI->getObjFileInfo<MachineModuleInfoMachO>().
215                     getHiddenGVStubEntry(SymToPrint);
216         if (!StubSym.getPointer())
217           StubSym = MachineModuleInfoImpl::
218             StubValueTy(getSymbol(GV), !GV->hasInternalLinkage());
219       } else {
220         SymToPrint = getSymbol(GV);
221       }
222     } else {
223       SymToPrint = getSymbol(GV);
224     }
225 
226     O << *SymToPrint;
227 
228     printOffset(MO.getOffset(), O);
229     return;
230   }
231 
232   default:
233     O << "<unknown operand type: " << (unsigned)MO.getType() << ">";
234     return;
235   }
236 }
237 
238 /// PrintAsmOperand - Print out an operand for an inline asm expression.
239 ///
PrintAsmOperand(const MachineInstr * MI,unsigned OpNo,unsigned AsmVariant,const char * ExtraCode,raw_ostream & O)240 bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
241                                     unsigned AsmVariant,
242                                     const char *ExtraCode, raw_ostream &O) {
243   // Does this asm operand have a single letter operand modifier?
244   if (ExtraCode && ExtraCode[0]) {
245     if (ExtraCode[1] != 0) return true; // Unknown modifier.
246 
247     switch (ExtraCode[0]) {
248     default:
249       // See if this is a generic print operand
250       return AsmPrinter::PrintAsmOperand(MI, OpNo, AsmVariant, ExtraCode, O);
251     case 'c': // Don't print "$" before a global var name or constant.
252       break; // PPC never has a prefix.
253     case 'L': // Write second word of DImode reference.
254       // Verify that this operand has two consecutive registers.
255       if (!MI->getOperand(OpNo).isReg() ||
256           OpNo+1 == MI->getNumOperands() ||
257           !MI->getOperand(OpNo+1).isReg())
258         return true;
259       ++OpNo;   // Return the high-part.
260       break;
261     case 'I':
262       // Write 'i' if an integer constant, otherwise nothing.  Used to print
263       // addi vs add, etc.
264       if (MI->getOperand(OpNo).isImm())
265         O << "i";
266       return false;
267     }
268   }
269 
270   printOperand(MI, OpNo, O);
271   return false;
272 }
273 
274 // At the moment, all inline asm memory operands are a single register.
275 // In any case, the output of this routine should always be just one
276 // assembler operand.
277 
PrintAsmMemoryOperand(const MachineInstr * MI,unsigned OpNo,unsigned AsmVariant,const char * ExtraCode,raw_ostream & O)278 bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
279                                           unsigned AsmVariant,
280                                           const char *ExtraCode,
281                                           raw_ostream &O) {
282   if (ExtraCode && ExtraCode[0]) {
283     if (ExtraCode[1] != 0) return true; // Unknown modifier.
284 
285     switch (ExtraCode[0]) {
286     default: return true;  // Unknown modifier.
287     case 'y': // A memory reference for an X-form instruction
288       {
289         const char *RegName = "r0";
290         if (!Subtarget->isDarwin())
291           RegName = stripRegisterPrefix(RegName);
292         O << RegName << ", ";
293         printOperand(MI, OpNo, O);
294         return false;
295       }
296     case 'U': // Print 'u' for update form.
297     case 'X': // Print 'x' for indexed form.
298       {
299 	// FIXME: Currently for PowerPC memory operands are always loaded
300 	// into a register, so we never get an update or indexed form.
301 	// This is bad even for offset forms, since even if we know we
302 	// have a value in -16(r1), we will generate a load into r<n>
303 	// and then load from 0(r<n>).  Until that issue is fixed,
304 	// tolerate 'U' and 'X' but don't output anything.
305 	assert(MI->getOperand(OpNo).isReg());
306 	return false;
307       }
308     }
309   }
310 
311   assert(MI->getOperand(OpNo).isReg());
312   O << "0(";
313   printOperand(MI, OpNo, O);
314   O << ")";
315   return false;
316 }
317 
318 
319 /// lookUpOrCreateTOCEntry -- Given a symbol, look up whether a TOC entry
320 /// exists for it.  If not, create one.  Then return a symbol that references
321 /// the TOC entry.
lookUpOrCreateTOCEntry(MCSymbol * Sym)322 MCSymbol *PPCAsmPrinter::lookUpOrCreateTOCEntry(MCSymbol *Sym) {
323   MCSymbol *&TOCEntry = TOC[Sym];
324   if (!TOCEntry)
325     TOCEntry = createTempSymbol("C");
326   return TOCEntry;
327 }
328 
EmitEndOfAsmFile(Module & M)329 void PPCAsmPrinter::EmitEndOfAsmFile(Module &M) {
330   SM.serializeToStackMapSection();
331 }
332 
LowerSTACKMAP(MCStreamer & OutStreamer,StackMaps & SM,const MachineInstr & MI)333 void PPCAsmPrinter::LowerSTACKMAP(MCStreamer &OutStreamer, StackMaps &SM,
334                                   const MachineInstr &MI) {
335   unsigned NumNOPBytes = MI.getOperand(1).getImm();
336 
337   SM.recordStackMap(MI);
338   assert(NumNOPBytes % 4 == 0 && "Invalid number of NOP bytes requested!");
339 
340   // Scan ahead to trim the shadow.
341   const MachineBasicBlock &MBB = *MI.getParent();
342   MachineBasicBlock::const_iterator MII(MI);
343   ++MII;
344   while (NumNOPBytes > 0) {
345     if (MII == MBB.end() || MII->isCall() ||
346         MII->getOpcode() == PPC::DBG_VALUE ||
347         MII->getOpcode() == TargetOpcode::PATCHPOINT ||
348         MII->getOpcode() == TargetOpcode::STACKMAP)
349       break;
350     ++MII;
351     NumNOPBytes -= 4;
352   }
353 
354   // Emit nops.
355   for (unsigned i = 0; i < NumNOPBytes; i += 4)
356     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::NOP));
357 }
358 
359 // Lower a patchpoint of the form:
360 // [<def>], <id>, <numBytes>, <target>, <numArgs>
LowerPATCHPOINT(MCStreamer & OutStreamer,StackMaps & SM,const MachineInstr & MI)361 void PPCAsmPrinter::LowerPATCHPOINT(MCStreamer &OutStreamer, StackMaps &SM,
362                                     const MachineInstr &MI) {
363   SM.recordPatchPoint(MI);
364   PatchPointOpers Opers(&MI);
365 
366   int64_t CallTarget = Opers.getMetaOper(PatchPointOpers::TargetPos).getImm();
367   unsigned EncodedBytes = 0;
368   if (CallTarget) {
369     assert((CallTarget & 0xFFFFFFFFFFFF) == CallTarget &&
370            "High 16 bits of call target should be zero.");
371     unsigned ScratchReg = MI.getOperand(Opers.getNextScratchIdx()).getReg();
372     EncodedBytes = 6*4;
373     // Materialize the jump address:
374     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LI8)
375                                     .addReg(ScratchReg)
376                                     .addImm((CallTarget >> 32) & 0xFFFF));
377     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::RLDIC)
378                                     .addReg(ScratchReg)
379                                     .addReg(ScratchReg)
380                                     .addImm(32).addImm(16));
381     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ORIS8)
382                                     .addReg(ScratchReg)
383                                     .addReg(ScratchReg)
384                                     .addImm((CallTarget >> 16) & 0xFFFF));
385     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ORI8)
386                                     .addReg(ScratchReg)
387                                     .addReg(ScratchReg)
388                                     .addImm(CallTarget & 0xFFFF));
389 
390     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MTCTR8).addReg(ScratchReg));
391     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BCTRL8));
392   }
393 
394   // Emit padding.
395   unsigned NumBytes = Opers.getMetaOper(PatchPointOpers::NBytesPos).getImm();
396   assert(NumBytes >= EncodedBytes &&
397          "Patchpoint can't request size less than the length of a call.");
398   assert((NumBytes - EncodedBytes) % 4 == 0 &&
399          "Invalid number of NOP bytes requested!");
400   for (unsigned i = EncodedBytes; i < NumBytes; i += 4)
401     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::NOP));
402 }
403 
404 /// EmitTlsCall -- Given a GETtls[ld]ADDR[32] instruction, print a
405 /// call to __tls_get_addr to the current output stream.
EmitTlsCall(const MachineInstr * MI,MCSymbolRefExpr::VariantKind VK)406 void PPCAsmPrinter::EmitTlsCall(const MachineInstr *MI,
407                                 MCSymbolRefExpr::VariantKind VK) {
408   StringRef Name = "__tls_get_addr";
409   MCSymbol *TlsGetAddr = OutContext.GetOrCreateSymbol(Name);
410   MCSymbolRefExpr::VariantKind Kind = MCSymbolRefExpr::VK_None;
411 
412   assert(MI->getOperand(0).isReg() &&
413          ((Subtarget->isPPC64() && MI->getOperand(0).getReg() == PPC::X3) ||
414           (!Subtarget->isPPC64() && MI->getOperand(0).getReg() == PPC::R3)) &&
415          "GETtls[ld]ADDR[32] must define GPR3");
416   assert(MI->getOperand(1).isReg() &&
417          ((Subtarget->isPPC64() && MI->getOperand(1).getReg() == PPC::X3) ||
418           (!Subtarget->isPPC64() && MI->getOperand(1).getReg() == PPC::R3)) &&
419          "GETtls[ld]ADDR[32] must read GPR3");
420 
421   if (!Subtarget->isPPC64() && !Subtarget->isDarwin() &&
422       TM.getRelocationModel() == Reloc::PIC_)
423     Kind = MCSymbolRefExpr::VK_PLT;
424   const MCSymbolRefExpr *TlsRef =
425     MCSymbolRefExpr::Create(TlsGetAddr, Kind, OutContext);
426   const MachineOperand &MO = MI->getOperand(2);
427   const GlobalValue *GValue = MO.getGlobal();
428   MCSymbol *MOSymbol = getSymbol(GValue);
429   const MCExpr *SymVar = MCSymbolRefExpr::Create(MOSymbol, VK, OutContext);
430   EmitToStreamer(OutStreamer,
431                  MCInstBuilder(Subtarget->isPPC64() ?
432                                PPC::BL8_NOP_TLS : PPC::BL_TLS)
433                  .addExpr(TlsRef)
434                  .addExpr(SymVar));
435 }
436 
437 /// EmitInstruction -- Print out a single PowerPC MI in Darwin syntax to
438 /// the current output stream.
439 ///
EmitInstruction(const MachineInstr * MI)440 void PPCAsmPrinter::EmitInstruction(const MachineInstr *MI) {
441   MCInst TmpInst;
442   bool isPPC64 = Subtarget->isPPC64();
443   bool isDarwin = Triple(TM.getTargetTriple()).isOSDarwin();
444   const Module *M = MF->getFunction()->getParent();
445   PICLevel::Level PL = M->getPICLevel();
446 
447   // Lower multi-instruction pseudo operations.
448   switch (MI->getOpcode()) {
449   default: break;
450   case TargetOpcode::DBG_VALUE:
451     llvm_unreachable("Should be handled target independently");
452   case TargetOpcode::STACKMAP:
453     return LowerSTACKMAP(OutStreamer, SM, *MI);
454   case TargetOpcode::PATCHPOINT:
455     return LowerPATCHPOINT(OutStreamer, SM, *MI);
456 
457   case PPC::MoveGOTtoLR: {
458     // Transform %LR = MoveGOTtoLR
459     // Into this: bl _GLOBAL_OFFSET_TABLE_@local-4
460     // _GLOBAL_OFFSET_TABLE_@local-4 (instruction preceding
461     // _GLOBAL_OFFSET_TABLE_) has exactly one instruction:
462     //      blrl
463     // This will return the pointer to _GLOBAL_OFFSET_TABLE_@local
464     MCSymbol *GOTSymbol =
465       OutContext.GetOrCreateSymbol(StringRef("_GLOBAL_OFFSET_TABLE_"));
466     const MCExpr *OffsExpr =
467       MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(GOTSymbol,
468                                                       MCSymbolRefExpr::VK_PPC_LOCAL,
469                                                       OutContext),
470                               MCConstantExpr::Create(4, OutContext),
471                               OutContext);
472 
473     // Emit the 'bl'.
474     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BL).addExpr(OffsExpr));
475     return;
476   }
477   case PPC::MovePCtoLR:
478   case PPC::MovePCtoLR8: {
479     // Transform %LR = MovePCtoLR
480     // Into this, where the label is the PIC base:
481     //     bl L1$pb
482     // L1$pb:
483     MCSymbol *PICBase = MF->getPICBaseSymbol();
484 
485     // Emit the 'bl'.
486     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BL)
487       // FIXME: We would like an efficient form for this, so we don't have to do
488       // a lot of extra uniquing.
489       .addExpr(MCSymbolRefExpr::Create(PICBase, OutContext)));
490 
491     // Emit the label.
492     OutStreamer.EmitLabel(PICBase);
493     return;
494   }
495   case PPC::UpdateGBR: {
496     // Transform %Rd = UpdateGBR(%Rt, %Ri)
497     // Into: lwz %Rt, .L0$poff - .L0$pb(%Ri)
498     //       add %Rd, %Rt, %Ri
499     // Get the offset from the GOT Base Register to the GOT
500     LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
501     MCSymbol *PICOffset =
502       MF->getInfo<PPCFunctionInfo>()->getPICOffsetSymbol();
503     TmpInst.setOpcode(PPC::LWZ);
504     const MCExpr *Exp =
505       MCSymbolRefExpr::Create(PICOffset, MCSymbolRefExpr::VK_None, OutContext);
506     const MCExpr *PB =
507       MCSymbolRefExpr::Create(MF->getPICBaseSymbol(),
508                               MCSymbolRefExpr::VK_None,
509                               OutContext);
510     const MCOperand TR = TmpInst.getOperand(1);
511     const MCOperand PICR = TmpInst.getOperand(0);
512 
513     // Step 1: lwz %Rt, .L$poff - .L$pb(%Ri)
514     TmpInst.getOperand(1) =
515         MCOperand::CreateExpr(MCBinaryExpr::CreateSub(Exp, PB, OutContext));
516     TmpInst.getOperand(0) = TR;
517     TmpInst.getOperand(2) = PICR;
518     EmitToStreamer(OutStreamer, TmpInst);
519 
520     TmpInst.setOpcode(PPC::ADD4);
521     TmpInst.getOperand(0) = PICR;
522     TmpInst.getOperand(1) = TR;
523     TmpInst.getOperand(2) = PICR;
524     EmitToStreamer(OutStreamer, TmpInst);
525     return;
526   }
527   case PPC::LWZtoc: {
528     // Transform %R3 = LWZtoc <ga:@min1>, %R2
529     LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
530 
531     // Change the opcode to LWZ, and the global address operand to be a
532     // reference to the GOT entry we will synthesize later.
533     TmpInst.setOpcode(PPC::LWZ);
534     const MachineOperand &MO = MI->getOperand(1);
535 
536     // Map symbol -> label of TOC entry
537     assert(MO.isGlobal() || MO.isCPI() || MO.isJTI() || MO.isBlockAddress());
538     MCSymbol *MOSymbol = nullptr;
539     if (MO.isGlobal())
540       MOSymbol = getSymbol(MO.getGlobal());
541     else if (MO.isCPI())
542       MOSymbol = GetCPISymbol(MO.getIndex());
543     else if (MO.isJTI())
544       MOSymbol = GetJTISymbol(MO.getIndex());
545     else if (MO.isBlockAddress())
546       MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
547 
548     if (PL == PICLevel::Small) {
549       const MCExpr *Exp =
550         MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_GOT,
551                                 OutContext);
552       TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
553     } else {
554       MCSymbol *TOCEntry = lookUpOrCreateTOCEntry(MOSymbol);
555 
556       const MCExpr *Exp =
557         MCSymbolRefExpr::Create(TOCEntry, MCSymbolRefExpr::VK_None,
558                                 OutContext);
559       const MCExpr *PB =
560         MCSymbolRefExpr::Create(OutContext.GetOrCreateSymbol(Twine(".LTOC")),
561                                                              OutContext);
562       Exp = MCBinaryExpr::CreateSub(Exp, PB, OutContext);
563       TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
564     }
565     EmitToStreamer(OutStreamer, TmpInst);
566     return;
567   }
568   case PPC::LDtocJTI:
569   case PPC::LDtocCPT:
570   case PPC::LDtocBA:
571   case PPC::LDtoc: {
572     // Transform %X3 = LDtoc <ga:@min1>, %X2
573     LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
574 
575     // Change the opcode to LD, and the global address operand to be a
576     // reference to the TOC entry we will synthesize later.
577     TmpInst.setOpcode(PPC::LD);
578     const MachineOperand &MO = MI->getOperand(1);
579 
580     // Map symbol -> label of TOC entry
581     assert(MO.isGlobal() || MO.isCPI() || MO.isJTI() || MO.isBlockAddress());
582     MCSymbol *MOSymbol = nullptr;
583     if (MO.isGlobal())
584       MOSymbol = getSymbol(MO.getGlobal());
585     else if (MO.isCPI())
586       MOSymbol = GetCPISymbol(MO.getIndex());
587     else if (MO.isJTI())
588       MOSymbol = GetJTISymbol(MO.getIndex());
589     else if (MO.isBlockAddress())
590       MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
591 
592     MCSymbol *TOCEntry = lookUpOrCreateTOCEntry(MOSymbol);
593 
594     const MCExpr *Exp =
595       MCSymbolRefExpr::Create(TOCEntry, MCSymbolRefExpr::VK_PPC_TOC,
596                               OutContext);
597     TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
598     EmitToStreamer(OutStreamer, TmpInst);
599     return;
600   }
601 
602   case PPC::ADDIStocHA: {
603     // Transform %Xd = ADDIStocHA %X2, <ga:@sym>
604     LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
605 
606     // Change the opcode to ADDIS8.  If the global address is external, has
607     // common linkage, is a non-local function address, or is a jump table
608     // address, then generate a TOC entry and reference that.  Otherwise
609     // reference the symbol directly.
610     TmpInst.setOpcode(PPC::ADDIS8);
611     const MachineOperand &MO = MI->getOperand(2);
612     assert((MO.isGlobal() || MO.isCPI() || MO.isJTI() ||
613             MO.isBlockAddress()) &&
614            "Invalid operand for ADDIStocHA!");
615     MCSymbol *MOSymbol = nullptr;
616     bool IsExternal = false;
617     bool IsNonLocalFunction = false;
618     bool IsCommon = false;
619     bool IsAvailExt = false;
620 
621     if (MO.isGlobal()) {
622       const GlobalValue *GV = MO.getGlobal();
623       MOSymbol = getSymbol(GV);
624       IsExternal = GV->isDeclaration();
625       IsCommon = GV->hasCommonLinkage();
626       IsNonLocalFunction = GV->getType()->getElementType()->isFunctionTy() &&
627         (GV->isDeclaration() || GV->isWeakForLinker());
628       IsAvailExt = GV->hasAvailableExternallyLinkage();
629     } else if (MO.isCPI())
630       MOSymbol = GetCPISymbol(MO.getIndex());
631     else if (MO.isJTI())
632       MOSymbol = GetJTISymbol(MO.getIndex());
633     else if (MO.isBlockAddress())
634       MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
635 
636     if (IsExternal || IsNonLocalFunction || IsCommon || IsAvailExt ||
637         MO.isJTI() || MO.isBlockAddress() ||
638         TM.getCodeModel() == CodeModel::Large)
639       MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
640 
641     const MCExpr *Exp =
642       MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TOC_HA,
643                               OutContext);
644     TmpInst.getOperand(2) = MCOperand::CreateExpr(Exp);
645     EmitToStreamer(OutStreamer, TmpInst);
646     return;
647   }
648   case PPC::LDtocL: {
649     // Transform %Xd = LDtocL <ga:@sym>, %Xs
650     LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
651 
652     // Change the opcode to LD.  If the global address is external, has
653     // common linkage, or is a jump table address, then reference the
654     // associated TOC entry.  Otherwise reference the symbol directly.
655     TmpInst.setOpcode(PPC::LD);
656     const MachineOperand &MO = MI->getOperand(1);
657     assert((MO.isGlobal() || MO.isCPI() || MO.isJTI() ||
658             MO.isBlockAddress()) &&
659            "Invalid operand for LDtocL!");
660     MCSymbol *MOSymbol = nullptr;
661 
662     if (MO.isJTI())
663       MOSymbol = lookUpOrCreateTOCEntry(GetJTISymbol(MO.getIndex()));
664     else if (MO.isBlockAddress()) {
665       MOSymbol = GetBlockAddressSymbol(MO.getBlockAddress());
666       MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
667     }
668     else if (MO.isCPI()) {
669       MOSymbol = GetCPISymbol(MO.getIndex());
670       if (TM.getCodeModel() == CodeModel::Large)
671         MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
672     }
673     else if (MO.isGlobal()) {
674       const GlobalValue *GValue = MO.getGlobal();
675       MOSymbol = getSymbol(GValue);
676       if (GValue->getType()->getElementType()->isFunctionTy() ||
677           GValue->isDeclaration() || GValue->hasCommonLinkage() ||
678           GValue->hasAvailableExternallyLinkage() ||
679           TM.getCodeModel() == CodeModel::Large)
680         MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
681     }
682 
683     const MCExpr *Exp =
684       MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TOC_LO,
685                               OutContext);
686     TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
687     EmitToStreamer(OutStreamer, TmpInst);
688     return;
689   }
690   case PPC::ADDItocL: {
691     // Transform %Xd = ADDItocL %Xs, <ga:@sym>
692     LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
693 
694     // Change the opcode to ADDI8.  If the global address is external, then
695     // generate a TOC entry and reference that.  Otherwise reference the
696     // symbol directly.
697     TmpInst.setOpcode(PPC::ADDI8);
698     const MachineOperand &MO = MI->getOperand(2);
699     assert((MO.isGlobal() || MO.isCPI()) && "Invalid operand for ADDItocL");
700     MCSymbol *MOSymbol = nullptr;
701     bool IsExternal = false;
702     bool IsNonLocalFunction = false;
703 
704     if (MO.isGlobal()) {
705       const GlobalValue *GV = MO.getGlobal();
706       MOSymbol = getSymbol(GV);
707       IsExternal = GV->isDeclaration();
708       IsNonLocalFunction = GV->getType()->getElementType()->isFunctionTy() &&
709         (GV->isDeclaration() || GV->isWeakForLinker());
710     } else if (MO.isCPI())
711       MOSymbol = GetCPISymbol(MO.getIndex());
712 
713     if (IsNonLocalFunction || IsExternal ||
714         TM.getCodeModel() == CodeModel::Large)
715       MOSymbol = lookUpOrCreateTOCEntry(MOSymbol);
716 
717     const MCExpr *Exp =
718       MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_TOC_LO,
719                               OutContext);
720     TmpInst.getOperand(2) = MCOperand::CreateExpr(Exp);
721     EmitToStreamer(OutStreamer, TmpInst);
722     return;
723   }
724   case PPC::ADDISgotTprelHA: {
725     // Transform: %Xd = ADDISgotTprelHA %X2, <ga:@sym>
726     // Into:      %Xd = ADDIS8 %X2, sym@got@tlsgd@ha
727     assert(Subtarget->isPPC64() && "Not supported for 32-bit PowerPC");
728     const MachineOperand &MO = MI->getOperand(2);
729     const GlobalValue *GValue = MO.getGlobal();
730     MCSymbol *MOSymbol = getSymbol(GValue);
731     const MCExpr *SymGotTprel =
732       MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TPREL_HA,
733                               OutContext);
734     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS8)
735                                 .addReg(MI->getOperand(0).getReg())
736                                 .addReg(MI->getOperand(1).getReg())
737                                 .addExpr(SymGotTprel));
738     return;
739   }
740   case PPC::LDgotTprelL:
741   case PPC::LDgotTprelL32: {
742     // Transform %Xd = LDgotTprelL <ga:@sym>, %Xs
743     LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
744 
745     // Change the opcode to LD.
746     TmpInst.setOpcode(isPPC64 ? PPC::LD : PPC::LWZ);
747     const MachineOperand &MO = MI->getOperand(1);
748     const GlobalValue *GValue = MO.getGlobal();
749     MCSymbol *MOSymbol = getSymbol(GValue);
750     const MCExpr *Exp =
751       MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TPREL_LO,
752                               OutContext);
753     TmpInst.getOperand(1) = MCOperand::CreateExpr(Exp);
754     EmitToStreamer(OutStreamer, TmpInst);
755     return;
756   }
757 
758   case PPC::PPC32PICGOT: {
759     MCSymbol *GOTSymbol = OutContext.GetOrCreateSymbol(StringRef("_GLOBAL_OFFSET_TABLE_"));
760     MCSymbol *GOTRef = OutContext.CreateTempSymbol();
761     MCSymbol *NextInstr = OutContext.CreateTempSymbol();
762 
763     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BL)
764       // FIXME: We would like an efficient form for this, so we don't have to do
765       // a lot of extra uniquing.
766       .addExpr(MCSymbolRefExpr::Create(NextInstr, OutContext)));
767     const MCExpr *OffsExpr =
768       MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(GOTSymbol, OutContext),
769                                 MCSymbolRefExpr::Create(GOTRef, OutContext),
770         OutContext);
771     OutStreamer.EmitLabel(GOTRef);
772     OutStreamer.EmitValue(OffsExpr, 4);
773     OutStreamer.EmitLabel(NextInstr);
774     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MFLR)
775                                 .addReg(MI->getOperand(0).getReg()));
776     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LWZ)
777                                 .addReg(MI->getOperand(1).getReg())
778                                 .addImm(0)
779                                 .addReg(MI->getOperand(0).getReg()));
780     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADD4)
781                                 .addReg(MI->getOperand(0).getReg())
782                                 .addReg(MI->getOperand(1).getReg())
783                                 .addReg(MI->getOperand(0).getReg()));
784     return;
785   }
786   case PPC::PPC32GOT: {
787     MCSymbol *GOTSymbol = OutContext.GetOrCreateSymbol(StringRef("_GLOBAL_OFFSET_TABLE_"));
788     const MCExpr *SymGotTlsL =
789       MCSymbolRefExpr::Create(GOTSymbol, MCSymbolRefExpr::VK_PPC_LO,
790                               OutContext);
791     const MCExpr *SymGotTlsHA =
792       MCSymbolRefExpr::Create(GOTSymbol, MCSymbolRefExpr::VK_PPC_HA,
793                               OutContext);
794     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LI)
795                                 .addReg(MI->getOperand(0).getReg())
796                                 .addExpr(SymGotTlsL));
797     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS)
798                                 .addReg(MI->getOperand(0).getReg())
799                                 .addReg(MI->getOperand(0).getReg())
800                                 .addExpr(SymGotTlsHA));
801     return;
802   }
803   case PPC::ADDIStlsgdHA: {
804     // Transform: %Xd = ADDIStlsgdHA %X2, <ga:@sym>
805     // Into:      %Xd = ADDIS8 %X2, sym@got@tlsgd@ha
806     assert(Subtarget->isPPC64() && "Not supported for 32-bit PowerPC");
807     const MachineOperand &MO = MI->getOperand(2);
808     const GlobalValue *GValue = MO.getGlobal();
809     MCSymbol *MOSymbol = getSymbol(GValue);
810     const MCExpr *SymGotTlsGD =
811       MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TLSGD_HA,
812                               OutContext);
813     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS8)
814                                 .addReg(MI->getOperand(0).getReg())
815                                 .addReg(MI->getOperand(1).getReg())
816                                 .addExpr(SymGotTlsGD));
817     return;
818   }
819   case PPC::ADDItlsgdL:
820     // Transform: %Xd = ADDItlsgdL %Xs, <ga:@sym>
821     // Into:      %Xd = ADDI8 %Xs, sym@got@tlsgd@l
822   case PPC::ADDItlsgdL32: {
823     // Transform: %Rd = ADDItlsgdL32 %Rs, <ga:@sym>
824     // Into:      %Rd = ADDI %Rs, sym@got@tlsgd
825     const MachineOperand &MO = MI->getOperand(2);
826     const GlobalValue *GValue = MO.getGlobal();
827     MCSymbol *MOSymbol = getSymbol(GValue);
828     const MCExpr *SymGotTlsGD = MCSymbolRefExpr::Create(
829         MOSymbol, Subtarget->isPPC64() ? MCSymbolRefExpr::VK_PPC_GOT_TLSGD_LO
830                                        : MCSymbolRefExpr::VK_PPC_GOT_TLSGD,
831         OutContext);
832     EmitToStreamer(OutStreamer,
833                    MCInstBuilder(Subtarget->isPPC64() ? PPC::ADDI8 : PPC::ADDI)
834                    .addReg(MI->getOperand(0).getReg())
835                    .addReg(MI->getOperand(1).getReg())
836                    .addExpr(SymGotTlsGD));
837     return;
838   }
839   case PPC::GETtlsADDR:
840     // Transform: %X3 = GETtlsADDR %X3, <ga:@sym>
841     // Into: BL8_NOP_TLS __tls_get_addr(sym at tlsgd)
842   case PPC::GETtlsADDR32: {
843     // Transform: %R3 = GETtlsADDR32 %R3, <ga:@sym>
844     // Into: BL_TLS __tls_get_addr(sym at tlsgd)@PLT
845     EmitTlsCall(MI, MCSymbolRefExpr::VK_PPC_TLSGD);
846     return;
847   }
848   case PPC::ADDIStlsldHA: {
849     // Transform: %Xd = ADDIStlsldHA %X2, <ga:@sym>
850     // Into:      %Xd = ADDIS8 %X2, sym@got@tlsld@ha
851     assert(Subtarget->isPPC64() && "Not supported for 32-bit PowerPC");
852     const MachineOperand &MO = MI->getOperand(2);
853     const GlobalValue *GValue = MO.getGlobal();
854     MCSymbol *MOSymbol = getSymbol(GValue);
855     const MCExpr *SymGotTlsLD =
856       MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_GOT_TLSLD_HA,
857                               OutContext);
858     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS8)
859                                 .addReg(MI->getOperand(0).getReg())
860                                 .addReg(MI->getOperand(1).getReg())
861                                 .addExpr(SymGotTlsLD));
862     return;
863   }
864   case PPC::ADDItlsldL:
865     // Transform: %Xd = ADDItlsldL %Xs, <ga:@sym>
866     // Into:      %Xd = ADDI8 %Xs, sym@got@tlsld@l
867   case PPC::ADDItlsldL32: {
868     // Transform: %Rd = ADDItlsldL32 %Rs, <ga:@sym>
869     // Into:      %Rd = ADDI %Rs, sym@got@tlsld
870     const MachineOperand &MO = MI->getOperand(2);
871     const GlobalValue *GValue = MO.getGlobal();
872     MCSymbol *MOSymbol = getSymbol(GValue);
873     const MCExpr *SymGotTlsLD = MCSymbolRefExpr::Create(
874         MOSymbol, Subtarget->isPPC64() ? MCSymbolRefExpr::VK_PPC_GOT_TLSLD_LO
875                                        : MCSymbolRefExpr::VK_PPC_GOT_TLSLD,
876         OutContext);
877     EmitToStreamer(OutStreamer,
878                    MCInstBuilder(Subtarget->isPPC64() ? PPC::ADDI8 : PPC::ADDI)
879                        .addReg(MI->getOperand(0).getReg())
880                        .addReg(MI->getOperand(1).getReg())
881                        .addExpr(SymGotTlsLD));
882     return;
883   }
884   case PPC::GETtlsldADDR:
885     // Transform: %X3 = GETtlsldADDR %X3, <ga:@sym>
886     // Into: BL8_NOP_TLS __tls_get_addr(sym at tlsld)
887   case PPC::GETtlsldADDR32: {
888     // Transform: %R3 = GETtlsldADDR32 %R3, <ga:@sym>
889     // Into: BL_TLS __tls_get_addr(sym at tlsld)@PLT
890     EmitTlsCall(MI, MCSymbolRefExpr::VK_PPC_TLSLD);
891     return;
892   }
893   case PPC::ADDISdtprelHA:
894     // Transform: %Xd = ADDISdtprelHA %X3, <ga:@sym>
895     // Into:      %Xd = ADDIS8 %X3, sym@dtprel@ha
896   case PPC::ADDISdtprelHA32: {
897     // Transform: %Rd = ADDISdtprelHA32 %R3, <ga:@sym>
898     // Into:      %Rd = ADDIS %R3, sym@dtprel@ha
899     const MachineOperand &MO = MI->getOperand(2);
900     const GlobalValue *GValue = MO.getGlobal();
901     MCSymbol *MOSymbol = getSymbol(GValue);
902     const MCExpr *SymDtprel =
903       MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_DTPREL_HA,
904                               OutContext);
905     EmitToStreamer(
906         OutStreamer,
907         MCInstBuilder(Subtarget->isPPC64() ? PPC::ADDIS8 : PPC::ADDIS)
908             .addReg(MI->getOperand(0).getReg())
909             .addReg(Subtarget->isPPC64() ? PPC::X3 : PPC::R3)
910             .addExpr(SymDtprel));
911     return;
912   }
913   case PPC::ADDIdtprelL:
914     // Transform: %Xd = ADDIdtprelL %Xs, <ga:@sym>
915     // Into:      %Xd = ADDI8 %Xs, sym@dtprel@l
916   case PPC::ADDIdtprelL32: {
917     // Transform: %Rd = ADDIdtprelL32 %Rs, <ga:@sym>
918     // Into:      %Rd = ADDI %Rs, sym@dtprel@l
919     const MachineOperand &MO = MI->getOperand(2);
920     const GlobalValue *GValue = MO.getGlobal();
921     MCSymbol *MOSymbol = getSymbol(GValue);
922     const MCExpr *SymDtprel =
923       MCSymbolRefExpr::Create(MOSymbol, MCSymbolRefExpr::VK_PPC_DTPREL_LO,
924                               OutContext);
925     EmitToStreamer(OutStreamer,
926                    MCInstBuilder(Subtarget->isPPC64() ? PPC::ADDI8 : PPC::ADDI)
927                        .addReg(MI->getOperand(0).getReg())
928                        .addReg(MI->getOperand(1).getReg())
929                        .addExpr(SymDtprel));
930     return;
931   }
932   case PPC::MFOCRF:
933   case PPC::MFOCRF8:
934     if (!Subtarget->hasMFOCRF()) {
935       // Transform: %R3 = MFOCRF %CR7
936       // Into:      %R3 = MFCR   ;; cr7
937       unsigned NewOpcode =
938         MI->getOpcode() == PPC::MFOCRF ? PPC::MFCR : PPC::MFCR8;
939       OutStreamer.AddComment(PPCInstPrinter::
940                              getRegisterName(MI->getOperand(1).getReg()));
941       EmitToStreamer(OutStreamer, MCInstBuilder(NewOpcode)
942                                   .addReg(MI->getOperand(0).getReg()));
943       return;
944     }
945     break;
946   case PPC::MTOCRF:
947   case PPC::MTOCRF8:
948     if (!Subtarget->hasMFOCRF()) {
949       // Transform: %CR7 = MTOCRF %R3
950       // Into:      MTCRF mask, %R3 ;; cr7
951       unsigned NewOpcode =
952         MI->getOpcode() == PPC::MTOCRF ? PPC::MTCRF : PPC::MTCRF8;
953       unsigned Mask = 0x80 >> OutContext.getRegisterInfo()
954                               ->getEncodingValue(MI->getOperand(0).getReg());
955       OutStreamer.AddComment(PPCInstPrinter::
956                              getRegisterName(MI->getOperand(0).getReg()));
957       EmitToStreamer(OutStreamer, MCInstBuilder(NewOpcode)
958                                   .addImm(Mask)
959                                   .addReg(MI->getOperand(1).getReg()));
960       return;
961     }
962     break;
963   case PPC::LD:
964   case PPC::STD:
965   case PPC::LWA_32:
966   case PPC::LWA: {
967     // Verify alignment is legal, so we don't create relocations
968     // that can't be supported.
969     // FIXME:  This test is currently disabled for Darwin.  The test
970     // suite shows a handful of test cases that fail this check for
971     // Darwin.  Those need to be investigated before this sanity test
972     // can be enabled for those subtargets.
973     if (!Subtarget->isDarwin()) {
974       unsigned OpNum = (MI->getOpcode() == PPC::STD) ? 2 : 1;
975       const MachineOperand &MO = MI->getOperand(OpNum);
976       if (MO.isGlobal() && MO.getGlobal()->getAlignment() < 4)
977         llvm_unreachable("Global must be word-aligned for LD, STD, LWA!");
978     }
979     // Now process the instruction normally.
980     break;
981   }
982   }
983 
984   LowerPPCMachineInstrToMCInst(MI, TmpInst, *this, isDarwin);
985   EmitToStreamer(OutStreamer, TmpInst);
986 }
987 
EmitStartOfAsmFile(Module & M)988 void PPCLinuxAsmPrinter::EmitStartOfAsmFile(Module &M) {
989   if (static_cast<const PPCTargetMachine &>(TM).isELFv2ABI()) {
990     PPCTargetStreamer *TS =
991       static_cast<PPCTargetStreamer *>(OutStreamer.getTargetStreamer());
992 
993     if (TS)
994       TS->emitAbiVersion(2);
995   }
996 
997   if (static_cast<const PPCTargetMachine &>(TM).isPPC64() ||
998       TM.getRelocationModel() != Reloc::PIC_)
999     return AsmPrinter::EmitStartOfAsmFile(M);
1000 
1001   if (M.getPICLevel() == PICLevel::Small)
1002     return AsmPrinter::EmitStartOfAsmFile(M);
1003 
1004   OutStreamer.SwitchSection(OutContext.getELFSection(
1005       ".got2", ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC));
1006 
1007   MCSymbol *TOCSym = OutContext.GetOrCreateSymbol(Twine(".LTOC"));
1008   MCSymbol *CurrentPos = OutContext.CreateTempSymbol();
1009 
1010   OutStreamer.EmitLabel(CurrentPos);
1011 
1012   // The GOT pointer points to the middle of the GOT, in order to reference the
1013   // entire 64kB range.  0x8000 is the midpoint.
1014   const MCExpr *tocExpr =
1015     MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(CurrentPos, OutContext),
1016                             MCConstantExpr::Create(0x8000, OutContext),
1017                             OutContext);
1018 
1019   OutStreamer.EmitAssignment(TOCSym, tocExpr);
1020 
1021   OutStreamer.SwitchSection(getObjFileLowering().getTextSection());
1022 }
1023 
EmitFunctionEntryLabel()1024 void PPCLinuxAsmPrinter::EmitFunctionEntryLabel() {
1025   // linux/ppc32 - Normal entry label.
1026   if (!Subtarget->isPPC64() &&
1027       (TM.getRelocationModel() != Reloc::PIC_ ||
1028        MF->getFunction()->getParent()->getPICLevel() == PICLevel::Small))
1029     return AsmPrinter::EmitFunctionEntryLabel();
1030 
1031   if (!Subtarget->isPPC64()) {
1032     const PPCFunctionInfo *PPCFI = MF->getInfo<PPCFunctionInfo>();
1033   	if (PPCFI->usesPICBase()) {
1034       MCSymbol *RelocSymbol = PPCFI->getPICOffsetSymbol();
1035       MCSymbol *PICBase = MF->getPICBaseSymbol();
1036       OutStreamer.EmitLabel(RelocSymbol);
1037 
1038       const MCExpr *OffsExpr =
1039         MCBinaryExpr::CreateSub(
1040           MCSymbolRefExpr::Create(OutContext.GetOrCreateSymbol(Twine(".LTOC")),
1041                                                                OutContext),
1042                                   MCSymbolRefExpr::Create(PICBase, OutContext),
1043           OutContext);
1044       OutStreamer.EmitValue(OffsExpr, 4);
1045       OutStreamer.EmitLabel(CurrentFnSym);
1046       return;
1047     } else
1048       return AsmPrinter::EmitFunctionEntryLabel();
1049   }
1050 
1051   // ELFv2 ABI - Normal entry label.
1052   if (Subtarget->isELFv2ABI())
1053     return AsmPrinter::EmitFunctionEntryLabel();
1054 
1055   // Emit an official procedure descriptor.
1056   MCSectionSubPair Current = OutStreamer.getCurrentSection();
1057   const MCSectionELF *Section = OutStreamer.getContext().getELFSection(
1058       ".opd", ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
1059   OutStreamer.SwitchSection(Section);
1060   OutStreamer.EmitLabel(CurrentFnSym);
1061   OutStreamer.EmitValueToAlignment(8);
1062   MCSymbol *Symbol1 = CurrentFnSymForSize;
1063   // Generates a R_PPC64_ADDR64 (from FK_DATA_8) relocation for the function
1064   // entry point.
1065   OutStreamer.EmitValue(MCSymbolRefExpr::Create(Symbol1, OutContext),
1066 			8 /*size*/);
1067   MCSymbol *Symbol2 = OutContext.GetOrCreateSymbol(StringRef(".TOC."));
1068   // Generates a R_PPC64_TOC relocation for TOC base insertion.
1069   OutStreamer.EmitValue(MCSymbolRefExpr::Create(Symbol2,
1070                         MCSymbolRefExpr::VK_PPC_TOCBASE, OutContext),
1071                         8/*size*/);
1072   // Emit a null environment pointer.
1073   OutStreamer.EmitIntValue(0, 8 /* size */);
1074   OutStreamer.SwitchSection(Current.first, Current.second);
1075 }
1076 
1077 
doFinalization(Module & M)1078 bool PPCLinuxAsmPrinter::doFinalization(Module &M) {
1079   const DataLayout *TD = TM.getDataLayout();
1080 
1081   bool isPPC64 = TD->getPointerSizeInBits() == 64;
1082 
1083   PPCTargetStreamer &TS =
1084       static_cast<PPCTargetStreamer &>(*OutStreamer.getTargetStreamer());
1085 
1086   if (!TOC.empty()) {
1087     const MCSectionELF *Section;
1088 
1089     if (isPPC64)
1090       Section = OutStreamer.getContext().getELFSection(
1091           ".toc", ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
1092         else
1093           Section = OutStreamer.getContext().getELFSection(
1094               ".got2", ELF::SHT_PROGBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
1095     OutStreamer.SwitchSection(Section);
1096 
1097     for (MapVector<MCSymbol*, MCSymbol*>::iterator I = TOC.begin(),
1098          E = TOC.end(); I != E; ++I) {
1099       OutStreamer.EmitLabel(I->second);
1100       MCSymbol *S = I->first;
1101       if (isPPC64)
1102         TS.emitTCEntry(*S);
1103       else
1104         OutStreamer.EmitSymbolValue(S, 4);
1105     }
1106   }
1107 
1108   return AsmPrinter::doFinalization(M);
1109 }
1110 
1111 /// EmitFunctionBodyStart - Emit a global entry point prefix for ELFv2.
EmitFunctionBodyStart()1112 void PPCLinuxAsmPrinter::EmitFunctionBodyStart() {
1113   // In the ELFv2 ABI, in functions that use the TOC register, we need to
1114   // provide two entry points.  The ABI guarantees that when calling the
1115   // local entry point, r2 is set up by the caller to contain the TOC base
1116   // for this function, and when calling the global entry point, r12 is set
1117   // up by the caller to hold the address of the global entry point.  We
1118   // thus emit a prefix sequence along the following lines:
1119   //
1120   // func:
1121   //         # global entry point
1122   //         addis r2,r12,(.TOC.-func)@ha
1123   //         addi  r2,r2,(.TOC.-func)@l
1124   //         .localentry func, .-func
1125   //         # local entry point, followed by function body
1126   //
1127   // This ensures we have r2 set up correctly while executing the function
1128   // body, no matter which entry point is called.
1129   if (Subtarget->isELFv2ABI()
1130       // Only do all that if the function uses r2 in the first place.
1131       && !MF->getRegInfo().use_empty(PPC::X2)) {
1132 
1133     MCSymbol *GlobalEntryLabel = OutContext.CreateTempSymbol();
1134     OutStreamer.EmitLabel(GlobalEntryLabel);
1135     const MCSymbolRefExpr *GlobalEntryLabelExp =
1136       MCSymbolRefExpr::Create(GlobalEntryLabel, OutContext);
1137 
1138     MCSymbol *TOCSymbol = OutContext.GetOrCreateSymbol(StringRef(".TOC."));
1139     const MCExpr *TOCDeltaExpr =
1140       MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(TOCSymbol, OutContext),
1141                               GlobalEntryLabelExp, OutContext);
1142 
1143     const MCExpr *TOCDeltaHi =
1144       PPCMCExpr::CreateHa(TOCDeltaExpr, false, OutContext);
1145     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS)
1146                                 .addReg(PPC::X2)
1147                                 .addReg(PPC::X12)
1148                                 .addExpr(TOCDeltaHi));
1149 
1150     const MCExpr *TOCDeltaLo =
1151       PPCMCExpr::CreateLo(TOCDeltaExpr, false, OutContext);
1152     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDI)
1153                                 .addReg(PPC::X2)
1154                                 .addReg(PPC::X2)
1155                                 .addExpr(TOCDeltaLo));
1156 
1157     MCSymbol *LocalEntryLabel = OutContext.CreateTempSymbol();
1158     OutStreamer.EmitLabel(LocalEntryLabel);
1159     const MCSymbolRefExpr *LocalEntryLabelExp =
1160        MCSymbolRefExpr::Create(LocalEntryLabel, OutContext);
1161     const MCExpr *LocalOffsetExp =
1162       MCBinaryExpr::CreateSub(LocalEntryLabelExp,
1163                               GlobalEntryLabelExp, OutContext);
1164 
1165     PPCTargetStreamer *TS =
1166       static_cast<PPCTargetStreamer *>(OutStreamer.getTargetStreamer());
1167 
1168     if (TS)
1169       TS->emitLocalEntry(CurrentFnSym, LocalOffsetExp);
1170   }
1171 }
1172 
1173 /// EmitFunctionBodyEnd - Print the traceback table before the .size
1174 /// directive.
1175 ///
EmitFunctionBodyEnd()1176 void PPCLinuxAsmPrinter::EmitFunctionBodyEnd() {
1177   // Only the 64-bit target requires a traceback table.  For now,
1178   // we only emit the word of zeroes that GDB requires to find
1179   // the end of the function, and zeroes for the eight-byte
1180   // mandatory fields.
1181   // FIXME: We should fill in the eight-byte mandatory fields as described in
1182   // the PPC64 ELF ABI (this is a low-priority item because GDB does not
1183   // currently make use of these fields).
1184   if (Subtarget->isPPC64()) {
1185     OutStreamer.EmitIntValue(0, 4/*size*/);
1186     OutStreamer.EmitIntValue(0, 8/*size*/);
1187   }
1188 }
1189 
EmitStartOfAsmFile(Module & M)1190 void PPCDarwinAsmPrinter::EmitStartOfAsmFile(Module &M) {
1191   static const char *const CPUDirectives[] = {
1192     "",
1193     "ppc",
1194     "ppc440",
1195     "ppc601",
1196     "ppc602",
1197     "ppc603",
1198     "ppc7400",
1199     "ppc750",
1200     "ppc970",
1201     "ppcA2",
1202     "ppce500mc",
1203     "ppce5500",
1204     "power3",
1205     "power4",
1206     "power5",
1207     "power5x",
1208     "power6",
1209     "power6x",
1210     "power7",
1211     "ppc64",
1212     "ppc64le"
1213   };
1214 
1215   // Get the numerically largest directive.
1216   // FIXME: How should we merge darwin directives?
1217   unsigned Directive = PPC::DIR_NONE;
1218   for (const Function &F : M) {
1219     const PPCSubtarget &STI = TM.getSubtarget<PPCSubtarget>(F);
1220     unsigned FDir = STI.getDarwinDirective();
1221     Directive = Directive > FDir ? FDir : STI.getDarwinDirective();
1222     if (STI.hasMFOCRF() && Directive < PPC::DIR_970)
1223       Directive = PPC::DIR_970;
1224     if (STI.hasAltivec() && Directive < PPC::DIR_7400)
1225       Directive = PPC::DIR_7400;
1226     if (STI.isPPC64() && Directive < PPC::DIR_64)
1227       Directive = PPC::DIR_64;
1228   }
1229 
1230   assert(Directive <= PPC::DIR_64 && "Directive out of range.");
1231 
1232   assert(Directive < array_lengthof(CPUDirectives) &&
1233          "CPUDirectives[] might not be up-to-date!");
1234   PPCTargetStreamer &TStreamer =
1235       *static_cast<PPCTargetStreamer *>(OutStreamer.getTargetStreamer());
1236   TStreamer.emitMachine(CPUDirectives[Directive]);
1237 
1238   // Prime text sections so they are adjacent.  This reduces the likelihood a
1239   // large data or debug section causes a branch to exceed 16M limit.
1240   const TargetLoweringObjectFileMachO &TLOFMacho =
1241     static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
1242   OutStreamer.SwitchSection(TLOFMacho.getTextCoalSection());
1243   if (TM.getRelocationModel() == Reloc::PIC_) {
1244     OutStreamer.SwitchSection(
1245            OutContext.getMachOSection("__TEXT", "__picsymbolstub1",
1246                                       MachO::S_SYMBOL_STUBS |
1247                                       MachO::S_ATTR_PURE_INSTRUCTIONS,
1248                                       32, SectionKind::getText()));
1249   } else if (TM.getRelocationModel() == Reloc::DynamicNoPIC) {
1250     OutStreamer.SwitchSection(
1251            OutContext.getMachOSection("__TEXT","__symbol_stub1",
1252                                       MachO::S_SYMBOL_STUBS |
1253                                       MachO::S_ATTR_PURE_INSTRUCTIONS,
1254                                       16, SectionKind::getText()));
1255   }
1256   OutStreamer.SwitchSection(getObjFileLowering().getTextSection());
1257 }
1258 
GetLazyPtr(MCSymbol * Sym,MCContext & Ctx)1259 static MCSymbol *GetLazyPtr(MCSymbol *Sym, MCContext &Ctx) {
1260   // Remove $stub suffix, add $lazy_ptr.
1261   StringRef NoStub = Sym->getName().substr(0, Sym->getName().size()-5);
1262   return Ctx.GetOrCreateSymbol(NoStub + "$lazy_ptr");
1263 }
1264 
GetAnonSym(MCSymbol * Sym,MCContext & Ctx)1265 static MCSymbol *GetAnonSym(MCSymbol *Sym, MCContext &Ctx) {
1266   // Add $tmp suffix to $stub, yielding $stub$tmp.
1267   return Ctx.GetOrCreateSymbol(Sym->getName() + "$tmp");
1268 }
1269 
1270 void PPCDarwinAsmPrinter::
EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy & Stubs)1271 EmitFunctionStubs(const MachineModuleInfoMachO::SymbolListTy &Stubs) {
1272   bool isPPC64 = TM.getDataLayout()->getPointerSizeInBits() == 64;
1273 
1274   // Construct a local MCSubtargetInfo and shadow EmitToStreamer here.
1275   // This is because the MachineFunction won't exist (but have not yet been
1276   // freed) and since we're at the global level we can use the default
1277   // constructed subtarget.
1278   std::unique_ptr<MCSubtargetInfo> STI(TM.getTarget().createMCSubtargetInfo(
1279       TM.getTargetTriple(), TM.getTargetCPU(), TM.getTargetFeatureString()));
1280   auto EmitToStreamer = [&STI] (MCStreamer &S, const MCInst &Inst) {
1281     S.EmitInstruction(Inst, *STI);
1282   };
1283 
1284   const TargetLoweringObjectFileMachO &TLOFMacho =
1285     static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
1286 
1287   // .lazy_symbol_pointer
1288   const MCSection *LSPSection = TLOFMacho.getLazySymbolPointerSection();
1289 
1290   // Output stubs for dynamically-linked functions
1291   if (TM.getRelocationModel() == Reloc::PIC_) {
1292     const MCSection *StubSection =
1293     OutContext.getMachOSection("__TEXT", "__picsymbolstub1",
1294                                MachO::S_SYMBOL_STUBS |
1295                                MachO::S_ATTR_PURE_INSTRUCTIONS,
1296                                32, SectionKind::getText());
1297     for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
1298       OutStreamer.SwitchSection(StubSection);
1299       EmitAlignment(4);
1300 
1301       MCSymbol *Stub = Stubs[i].first;
1302       MCSymbol *RawSym = Stubs[i].second.getPointer();
1303       MCSymbol *LazyPtr = GetLazyPtr(Stub, OutContext);
1304       MCSymbol *AnonSymbol = GetAnonSym(Stub, OutContext);
1305 
1306       OutStreamer.EmitLabel(Stub);
1307       OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
1308 
1309       const MCExpr *Anon = MCSymbolRefExpr::Create(AnonSymbol, OutContext);
1310       const MCExpr *LazyPtrExpr = MCSymbolRefExpr::Create(LazyPtr, OutContext);
1311       const MCExpr *Sub =
1312         MCBinaryExpr::CreateSub(LazyPtrExpr, Anon, OutContext);
1313 
1314       // mflr r0
1315       EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MFLR).addReg(PPC::R0));
1316       // bcl 20, 31, AnonSymbol
1317       EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BCLalways).addExpr(Anon));
1318       OutStreamer.EmitLabel(AnonSymbol);
1319       // mflr r11
1320       EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MFLR).addReg(PPC::R11));
1321       // addis r11, r11, ha16(LazyPtr - AnonSymbol)
1322       const MCExpr *SubHa16 = PPCMCExpr::CreateHa(Sub, true, OutContext);
1323       EmitToStreamer(OutStreamer, MCInstBuilder(PPC::ADDIS)
1324         .addReg(PPC::R11)
1325         .addReg(PPC::R11)
1326         .addExpr(SubHa16));
1327       // mtlr r0
1328       EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MTLR).addReg(PPC::R0));
1329 
1330       // ldu r12, lo16(LazyPtr - AnonSymbol)(r11)
1331       // lwzu r12, lo16(LazyPtr - AnonSymbol)(r11)
1332       const MCExpr *SubLo16 = PPCMCExpr::CreateLo(Sub, true, OutContext);
1333       EmitToStreamer(OutStreamer, MCInstBuilder(isPPC64 ? PPC::LDU : PPC::LWZU)
1334         .addReg(PPC::R12)
1335         .addExpr(SubLo16).addExpr(SubLo16)
1336         .addReg(PPC::R11));
1337       // mtctr r12
1338       EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MTCTR).addReg(PPC::R12));
1339       // bctr
1340       EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BCTR));
1341 
1342       OutStreamer.SwitchSection(LSPSection);
1343       OutStreamer.EmitLabel(LazyPtr);
1344       OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
1345 
1346       MCSymbol *DyldStubBindingHelper =
1347         OutContext.GetOrCreateSymbol(StringRef("dyld_stub_binding_helper"));
1348       if (isPPC64) {
1349         // .quad dyld_stub_binding_helper
1350         OutStreamer.EmitSymbolValue(DyldStubBindingHelper, 8);
1351       } else {
1352         // .long dyld_stub_binding_helper
1353         OutStreamer.EmitSymbolValue(DyldStubBindingHelper, 4);
1354       }
1355     }
1356     OutStreamer.AddBlankLine();
1357     return;
1358   }
1359 
1360   const MCSection *StubSection =
1361     OutContext.getMachOSection("__TEXT","__symbol_stub1",
1362                                MachO::S_SYMBOL_STUBS |
1363                                MachO::S_ATTR_PURE_INSTRUCTIONS,
1364                                16, SectionKind::getText());
1365   for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
1366     MCSymbol *Stub = Stubs[i].first;
1367     MCSymbol *RawSym = Stubs[i].second.getPointer();
1368     MCSymbol *LazyPtr = GetLazyPtr(Stub, OutContext);
1369     const MCExpr *LazyPtrExpr = MCSymbolRefExpr::Create(LazyPtr, OutContext);
1370 
1371     OutStreamer.SwitchSection(StubSection);
1372     EmitAlignment(4);
1373     OutStreamer.EmitLabel(Stub);
1374     OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
1375 
1376     // lis r11, ha16(LazyPtr)
1377     const MCExpr *LazyPtrHa16 =
1378       PPCMCExpr::CreateHa(LazyPtrExpr, true, OutContext);
1379     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::LIS)
1380       .addReg(PPC::R11)
1381       .addExpr(LazyPtrHa16));
1382 
1383     // ldu r12, lo16(LazyPtr)(r11)
1384     // lwzu r12, lo16(LazyPtr)(r11)
1385     const MCExpr *LazyPtrLo16 =
1386       PPCMCExpr::CreateLo(LazyPtrExpr, true, OutContext);
1387     EmitToStreamer(OutStreamer, MCInstBuilder(isPPC64 ? PPC::LDU : PPC::LWZU)
1388       .addReg(PPC::R12)
1389       .addExpr(LazyPtrLo16).addExpr(LazyPtrLo16)
1390       .addReg(PPC::R11));
1391 
1392     // mtctr r12
1393     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::MTCTR).addReg(PPC::R12));
1394     // bctr
1395     EmitToStreamer(OutStreamer, MCInstBuilder(PPC::BCTR));
1396 
1397     OutStreamer.SwitchSection(LSPSection);
1398     OutStreamer.EmitLabel(LazyPtr);
1399     OutStreamer.EmitSymbolAttribute(RawSym, MCSA_IndirectSymbol);
1400 
1401     MCSymbol *DyldStubBindingHelper =
1402       OutContext.GetOrCreateSymbol(StringRef("dyld_stub_binding_helper"));
1403     if (isPPC64) {
1404       // .quad dyld_stub_binding_helper
1405       OutStreamer.EmitSymbolValue(DyldStubBindingHelper, 8);
1406     } else {
1407       // .long dyld_stub_binding_helper
1408       OutStreamer.EmitSymbolValue(DyldStubBindingHelper, 4);
1409     }
1410   }
1411 
1412   OutStreamer.AddBlankLine();
1413 }
1414 
1415 
doFinalization(Module & M)1416 bool PPCDarwinAsmPrinter::doFinalization(Module &M) {
1417   bool isPPC64 = TM.getDataLayout()->getPointerSizeInBits() == 64;
1418 
1419   // Darwin/PPC always uses mach-o.
1420   const TargetLoweringObjectFileMachO &TLOFMacho =
1421     static_cast<const TargetLoweringObjectFileMachO &>(getObjFileLowering());
1422   MachineModuleInfoMachO &MMIMacho =
1423     MMI->getObjFileInfo<MachineModuleInfoMachO>();
1424 
1425   MachineModuleInfoMachO::SymbolListTy Stubs = MMIMacho.GetFnStubList();
1426   if (!Stubs.empty())
1427     EmitFunctionStubs(Stubs);
1428 
1429   if (MAI->doesSupportExceptionHandling() && MMI) {
1430     // Add the (possibly multiple) personalities to the set of global values.
1431     // Only referenced functions get into the Personalities list.
1432     const std::vector<const Function*> &Personalities = MMI->getPersonalities();
1433     for (std::vector<const Function*>::const_iterator I = Personalities.begin(),
1434          E = Personalities.end(); I != E; ++I) {
1435       if (*I) {
1436         MCSymbol *NLPSym = getSymbolWithGlobalValueBase(*I, "$non_lazy_ptr");
1437         MachineModuleInfoImpl::StubValueTy &StubSym =
1438           MMIMacho.getGVStubEntry(NLPSym);
1439         StubSym = MachineModuleInfoImpl::StubValueTy(getSymbol(*I), true);
1440       }
1441     }
1442   }
1443 
1444   // Output stubs for dynamically-linked functions.
1445   Stubs = MMIMacho.GetGVStubList();
1446 
1447   // Output macho stubs for external and common global variables.
1448   if (!Stubs.empty()) {
1449     // Switch with ".non_lazy_symbol_pointer" directive.
1450     OutStreamer.SwitchSection(TLOFMacho.getNonLazySymbolPointerSection());
1451     EmitAlignment(isPPC64 ? 3 : 2);
1452 
1453     for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
1454       // L_foo$stub:
1455       OutStreamer.EmitLabel(Stubs[i].first);
1456       //   .indirect_symbol _foo
1457       MachineModuleInfoImpl::StubValueTy &MCSym = Stubs[i].second;
1458       OutStreamer.EmitSymbolAttribute(MCSym.getPointer(), MCSA_IndirectSymbol);
1459 
1460       if (MCSym.getInt())
1461         // External to current translation unit.
1462         OutStreamer.EmitIntValue(0, isPPC64 ? 8 : 4/*size*/);
1463       else
1464         // Internal to current translation unit.
1465         //
1466         // When we place the LSDA into the TEXT section, the type info pointers
1467         // need to be indirect and pc-rel. We accomplish this by using NLPs.
1468         // However, sometimes the types are local to the file. So we need to
1469         // fill in the value for the NLP in those cases.
1470         OutStreamer.EmitValue(MCSymbolRefExpr::Create(MCSym.getPointer(),
1471                                                       OutContext),
1472                               isPPC64 ? 8 : 4/*size*/);
1473     }
1474 
1475     Stubs.clear();
1476     OutStreamer.AddBlankLine();
1477   }
1478 
1479   Stubs = MMIMacho.GetHiddenGVStubList();
1480   if (!Stubs.empty()) {
1481     OutStreamer.SwitchSection(getObjFileLowering().getDataSection());
1482     EmitAlignment(isPPC64 ? 3 : 2);
1483 
1484     for (unsigned i = 0, e = Stubs.size(); i != e; ++i) {
1485       // L_foo$stub:
1486       OutStreamer.EmitLabel(Stubs[i].first);
1487       //   .long _foo
1488       OutStreamer.EmitValue(MCSymbolRefExpr::
1489                             Create(Stubs[i].second.getPointer(),
1490                                    OutContext),
1491                             isPPC64 ? 8 : 4/*size*/);
1492     }
1493 
1494     Stubs.clear();
1495     OutStreamer.AddBlankLine();
1496   }
1497 
1498   // Funny Darwin hack: This flag tells the linker that no global symbols
1499   // contain code that falls through to other global symbols (e.g. the obvious
1500   // implementation of multiple entry points).  If this doesn't occur, the
1501   // linker can safely perform dead code stripping.  Since LLVM never generates
1502   // code that does this, it is always safe to set.
1503   OutStreamer.EmitAssemblerFlag(MCAF_SubsectionsViaSymbols);
1504 
1505   return AsmPrinter::doFinalization(M);
1506 }
1507 
1508 /// createPPCAsmPrinterPass - Returns a pass that prints the PPC assembly code
1509 /// for a MachineFunction to the given output stream, in a format that the
1510 /// Darwin assembler can deal with.
1511 ///
1512 static AsmPrinter *
createPPCAsmPrinterPass(TargetMachine & tm,std::unique_ptr<MCStreamer> && Streamer)1513 createPPCAsmPrinterPass(TargetMachine &tm,
1514                         std::unique_ptr<MCStreamer> &&Streamer) {
1515   if (Triple(tm.getTargetTriple()).isMacOSX())
1516     return new PPCDarwinAsmPrinter(tm, std::move(Streamer));
1517   return new PPCLinuxAsmPrinter(tm, std::move(Streamer));
1518 }
1519 
1520 // Force static initialization.
LLVMInitializePowerPCAsmPrinter()1521 extern "C" void LLVMInitializePowerPCAsmPrinter() {
1522   TargetRegistry::RegisterAsmPrinter(ThePPC32Target, createPPCAsmPrinterPass);
1523   TargetRegistry::RegisterAsmPrinter(ThePPC64Target, createPPCAsmPrinterPass);
1524   TargetRegistry::RegisterAsmPrinter(ThePPC64LETarget, createPPCAsmPrinterPass);
1525 }
1526