PPCAsmPrinter.cpp revision ba4733d901b1c2b994f66707657342b8c81c92bc 
1//===-- PPCAsmPrinter.cpp - Print machine instrs to PowerPC assembly --------=//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source 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 "llvm/Constants.h"
24#include "llvm/DerivedTypes.h"
25#include "llvm/Module.h"
26#include "llvm/Assembly/Writer.h"
27#include "llvm/CodeGen/AsmPrinter.h"
28#include "llvm/CodeGen/DwarfWriter.h"
29#include "llvm/CodeGen/MachineDebugInfo.h"
30#include "llvm/CodeGen/MachineFunctionPass.h"
31#include "llvm/CodeGen/MachineInstr.h"
32#include "llvm/Support/Mangler.h"
33#include "llvm/Support/MathExtras.h"
34#include "llvm/Support/CommandLine.h"
35#include "llvm/Support/Debug.h"
36#include "llvm/Support/Visibility.h"
37#include "llvm/Target/MRegisterInfo.h"
38#include "llvm/Target/TargetInstrInfo.h"
39#include "llvm/Target/TargetOptions.h"
40#include "llvm/ADT/Statistic.h"
41#include "llvm/ADT/StringExtras.h"
42#include <iostream>
43#include <set>
44using namespace llvm;
45
46namespace {
47  Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
48
49  class VISIBILITY_HIDDEN PPCAsmPrinter : public AsmPrinter {
50  public:
51    std::set<std::string> FnStubs, GVStubs;
52
53    PPCAsmPrinter(std::ostream &O, TargetMachine &TM)
54      : AsmPrinter(O, TM) {}
55
56    virtual const char *getPassName() const {
57      return "PowerPC Assembly Printer";
58    }
59
60    PPCTargetMachine &getTM() {
61      return static_cast<PPCTargetMachine&>(TM);
62    }
63
64    unsigned enumRegToMachineReg(unsigned enumReg) {
65      switch (enumReg) {
66      default: assert(0 && "Unhandled register!"); break;
67      case PPC::CR0:  return  0;
68      case PPC::CR1:  return  1;
69      case PPC::CR2:  return  2;
70      case PPC::CR3:  return  3;
71      case PPC::CR4:  return  4;
72      case PPC::CR5:  return  5;
73      case PPC::CR6:  return  6;
74      case PPC::CR7:  return  7;
75      }
76      abort();
77    }
78
79    /// printInstruction - This method is automatically generated by tablegen
80    /// from the instruction set description.  This method returns true if the
81    /// machine instruction was sufficiently described to print it, otherwise it
82    /// returns false.
83    bool printInstruction(const MachineInstr *MI);
84
85    void printMachineInstruction(const MachineInstr *MI);
86    void printOp(const MachineOperand &MO);
87
88    void printOperand(const MachineInstr *MI, unsigned OpNo) {
89      const MachineOperand &MO = MI->getOperand(OpNo);
90      if (MO.isRegister()) {
91        assert(MRegisterInfo::isPhysicalRegister(MO.getReg())&&"Not physreg??");
92        O << TM.getRegisterInfo()->get(MO.getReg()).Name;
93      } else if (MO.isImmediate()) {
94        O << MO.getImmedValue();
95      } else {
96        printOp(MO);
97      }
98    }
99
100    bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
101                         unsigned AsmVariant, const char *ExtraCode);
102    bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
103                               unsigned AsmVariant, const char *ExtraCode);
104
105
106    void printS5ImmOperand(const MachineInstr *MI, unsigned OpNo) {
107      char value = MI->getOperand(OpNo).getImmedValue();
108      value = (value << (32-5)) >> (32-5);
109      O << (int)value;
110    }
111    void printU5ImmOperand(const MachineInstr *MI, unsigned OpNo) {
112      unsigned char value = MI->getOperand(OpNo).getImmedValue();
113      assert(value <= 31 && "Invalid u5imm argument!");
114      O << (unsigned int)value;
115    }
116    void printU6ImmOperand(const MachineInstr *MI, unsigned OpNo) {
117      unsigned char value = MI->getOperand(OpNo).getImmedValue();
118      assert(value <= 63 && "Invalid u6imm argument!");
119      O << (unsigned int)value;
120    }
121    void printS16ImmOperand(const MachineInstr *MI, unsigned OpNo) {
122      O << (short)MI->getOperand(OpNo).getImmedValue();
123    }
124    void printU16ImmOperand(const MachineInstr *MI, unsigned OpNo) {
125      O << (unsigned short)MI->getOperand(OpNo).getImmedValue();
126    }
127    void printS16X4ImmOperand(const MachineInstr *MI, unsigned OpNo) {
128      O << (short)(MI->getOperand(OpNo).getImmedValue()*4);
129    }
130    void printBranchOperand(const MachineInstr *MI, unsigned OpNo) {
131      // Branches can take an immediate operand.  This is used by the branch
132      // selection pass to print $+8, an eight byte displacement from the PC.
133      if (MI->getOperand(OpNo).isImmediate()) {
134        O << "$+" << MI->getOperand(OpNo).getImmedValue();
135      } else {
136        printOp(MI->getOperand(OpNo));
137      }
138    }
139    void printCallOperand(const MachineInstr *MI, unsigned OpNo) {
140      const MachineOperand &MO = MI->getOperand(OpNo);
141      if (TM.getRelocationModel() != Reloc::Static) {
142        if (MO.getType() == MachineOperand::MO_GlobalAddress) {
143          GlobalValue *GV = MO.getGlobal();
144          if (((GV->isExternal() || GV->hasWeakLinkage() ||
145                GV->hasLinkOnceLinkage()))) {
146            // Dynamically-resolved functions need a stub for the function.
147            std::string Name = Mang->getValueName(GV);
148            FnStubs.insert(Name);
149            O << "L" << Name << "$stub";
150            return;
151          }
152        }
153        if (MO.getType() == MachineOperand::MO_ExternalSymbol) {
154          std::string Name(GlobalPrefix); Name += MO.getSymbolName();
155          FnStubs.insert(Name);
156          O << "L" << Name << "$stub";
157          return;
158        }
159      }
160
161      printOp(MI->getOperand(OpNo));
162    }
163    void printAbsAddrOperand(const MachineInstr *MI, unsigned OpNo) {
164     O << (int)MI->getOperand(OpNo).getImmedValue()*4;
165    }
166    void printPICLabel(const MachineInstr *MI, unsigned OpNo) {
167      O << "\"L" << getFunctionNumber() << "$pb\"\n";
168      O << "\"L" << getFunctionNumber() << "$pb\":";
169    }
170    void printSymbolHi(const MachineInstr *MI, unsigned OpNo) {
171      if (MI->getOperand(OpNo).isImmediate()) {
172        printS16ImmOperand(MI, OpNo);
173      } else {
174        O << "ha16(";
175        printOp(MI->getOperand(OpNo));
176        if (TM.getRelocationModel() == Reloc::PIC)
177          O << "-\"L" << getFunctionNumber() << "$pb\")";
178        else
179          O << ')';
180      }
181    }
182    void printSymbolLo(const MachineInstr *MI, unsigned OpNo) {
183      if (MI->getOperand(OpNo).isImmediate()) {
184        printS16ImmOperand(MI, OpNo);
185      } else {
186        O << "lo16(";
187        printOp(MI->getOperand(OpNo));
188        if (TM.getRelocationModel() == Reloc::PIC)
189          O << "-\"L" << getFunctionNumber() << "$pb\")";
190        else
191          O << ')';
192      }
193    }
194    void printcrbitm(const MachineInstr *MI, unsigned OpNo) {
195      unsigned CCReg = MI->getOperand(OpNo).getReg();
196      unsigned RegNo = enumRegToMachineReg(CCReg);
197      O << (0x80 >> RegNo);
198    }
199    // The new addressing mode printers.
200    void printMemRegImm(const MachineInstr *MI, unsigned OpNo) {
201      printSymbolLo(MI, OpNo);
202      O << '(';
203      if (MI->getOperand(OpNo+1).isRegister() &&
204          MI->getOperand(OpNo+1).getReg() == PPC::R0)
205        O << "0";
206      else
207        printOperand(MI, OpNo+1);
208      O << ')';
209    }
210    void printMemRegImmShifted(const MachineInstr *MI, unsigned OpNo) {
211      if (MI->getOperand(OpNo).isImmediate())
212        printS16X4ImmOperand(MI, OpNo);
213      else
214        printSymbolLo(MI, OpNo);
215      O << '(';
216      if (MI->getOperand(OpNo+1).isRegister() &&
217          MI->getOperand(OpNo+1).getReg() == PPC::R0)
218        O << "0";
219      else
220        printOperand(MI, OpNo+1);
221      O << ')';
222    }
223
224    void printMemRegReg(const MachineInstr *MI, unsigned OpNo) {
225      // When used as the base register, r0 reads constant zero rather than
226      // the value contained in the register.  For this reason, the darwin
227      // assembler requires that we print r0 as 0 (no r) when used as the base.
228      const MachineOperand &MO = MI->getOperand(OpNo);
229      if (MO.getReg() == PPC::R0)
230        O << '0';
231      else
232        O << TM.getRegisterInfo()->get(MO.getReg()).Name;
233      O << ", ";
234      printOperand(MI, OpNo+1);
235    }
236
237    virtual bool runOnMachineFunction(MachineFunction &F) = 0;
238    virtual bool doFinalization(Module &M) = 0;
239
240  };
241
242  /// DarwinDwarfWriter - Dwarf debug info writer customized for Darwin/Mac OS X
243  ///
244  struct VISIBILITY_HIDDEN DarwinDwarfWriter : public DwarfWriter {
245    // Ctor.
246    DarwinDwarfWriter(std::ostream &o, AsmPrinter *ap)
247    : DwarfWriter(o, ap)
248    {
249      needsSet = true;
250      DwarfAbbrevSection = ".section __DWARF,__debug_abbrev";
251      DwarfInfoSection = ".section __DWARF,__debug_info";
252      DwarfLineSection = ".section __DWARF,__debug_line";
253      DwarfFrameSection = ".section __DWARF,__debug_frame";
254      DwarfPubNamesSection = ".section __DWARF,__debug_pubnames";
255      DwarfPubTypesSection = ".section __DWARF,__debug_pubtypes";
256      DwarfStrSection = ".section __DWARF,__debug_str";
257      DwarfLocSection = ".section __DWARF,__debug_loc";
258      DwarfARangesSection = ".section __DWARF,__debug_aranges";
259      DwarfRangesSection = ".section __DWARF,__debug_ranges";
260      DwarfMacInfoSection = ".section __DWARF,__debug_macinfo";
261      TextSection = ".text";
262      DataSection = ".data";
263    }
264  };
265
266  /// DarwinAsmPrinter - PowerPC assembly printer, customized for Darwin/Mac OS
267  /// X
268  struct VISIBILITY_HIDDEN DarwinAsmPrinter : public PPCAsmPrinter {
269
270    DarwinDwarfWriter DW;
271
272    DarwinAsmPrinter(std::ostream &O, PPCTargetMachine &TM)
273      : PPCAsmPrinter(O, TM), DW(O, this) {
274      bool isPPC64 = TM.getSubtargetImpl()->isPPC64();
275      CommentString = ";";
276      GlobalPrefix = "_";
277      PrivateGlobalPrefix = "L";     // Marker for constant pool idxs
278      ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
279      if (isPPC64)
280        Data64bitsDirective = ".quad\t";       // we can't emit a 64-bit unit
281      else
282        Data64bitsDirective = 0;       // we can't emit a 64-bit unit
283      AlignmentIsInBytes = false;    // Alignment is by power of 2.
284      ConstantPoolSection = "\t.const\t";
285      // FIXME: Conditionalize jump table section based on PIC
286      JumpTableSection = ".const";
287      LCOMMDirective = "\t.lcomm\t";
288      StaticCtorsSection = ".mod_init_func";
289      StaticDtorsSection = ".mod_term_func";
290      InlineAsmStart = "# InlineAsm Start";
291      InlineAsmEnd = "# InlineAsm End";
292    }
293
294    virtual const char *getPassName() const {
295      return "Darwin PPC Assembly Printer";
296    }
297
298    bool runOnMachineFunction(MachineFunction &F);
299    bool doInitialization(Module &M);
300    bool doFinalization(Module &M);
301
302    void getAnalysisUsage(AnalysisUsage &AU) const {
303      AU.setPreservesAll();
304      AU.addRequired<MachineDebugInfo>();
305      PPCAsmPrinter::getAnalysisUsage(AU);
306    }
307
308  };
309} // end of anonymous namespace
310
311/// createDarwinAsmPrinterPass - Returns a pass that prints the PPC assembly
312/// code for a MachineFunction to the given output stream, in a format that the
313/// Darwin assembler can deal with.
314///
315FunctionPass *llvm::createDarwinAsmPrinter(std::ostream &o,
316                                           PPCTargetMachine &tm) {
317  return new DarwinAsmPrinter(o, tm);
318}
319
320// Include the auto-generated portion of the assembly writer
321#include "PPCGenAsmWriter.inc"
322
323void PPCAsmPrinter::printOp(const MachineOperand &MO) {
324  switch (MO.getType()) {
325  case MachineOperand::MO_Immediate:
326    std::cerr << "printOp() does not handle immediate values\n";
327    abort();
328    return;
329
330  case MachineOperand::MO_MachineBasicBlock:
331    printBasicBlockLabel(MO.getMachineBasicBlock());
332    return;
333  case MachineOperand::MO_JumpTableIndex:
334    O << PrivateGlobalPrefix << "JTI" << getFunctionNumber()
335      << '_' << MO.getJumpTableIndex();
336    // FIXME: PIC relocation model
337    return;
338  case MachineOperand::MO_ConstantPoolIndex:
339    O << PrivateGlobalPrefix << "CPI" << getFunctionNumber()
340      << '_' << MO.getConstantPoolIndex();
341    return;
342  case MachineOperand::MO_ExternalSymbol:
343    // Computing the address of an external symbol, not calling it.
344    if (TM.getRelocationModel() != Reloc::Static) {
345      std::string Name(GlobalPrefix); Name += MO.getSymbolName();
346      GVStubs.insert(Name);
347      O << "L" << Name << "$non_lazy_ptr";
348      return;
349    }
350    O << GlobalPrefix << MO.getSymbolName();
351    return;
352  case MachineOperand::MO_GlobalAddress: {
353    // Computing the address of a global symbol, not calling it.
354    GlobalValue *GV = MO.getGlobal();
355    std::string Name = Mang->getValueName(GV);
356    int offset = MO.getOffset();
357
358    // External or weakly linked global variables need non-lazily-resolved stubs
359    if (TM.getRelocationModel() != Reloc::Static) {
360      if (((GV->isExternal() || GV->hasWeakLinkage() ||
361            GV->hasLinkOnceLinkage()))) {
362        GVStubs.insert(Name);
363        O << "L" << Name << "$non_lazy_ptr";
364        return;
365      }
366    }
367
368    O << Name;
369    return;
370  }
371
372  default:
373    O << "<unknown operand type: " << MO.getType() << ">";
374    return;
375  }
376}
377
378/// PrintAsmOperand - Print out an operand for an inline asm expression.
379///
380bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
381                                    unsigned AsmVariant,
382                                    const char *ExtraCode) {
383  // Does this asm operand have a single letter operand modifier?
384  if (ExtraCode && ExtraCode[0]) {
385    if (ExtraCode[1] != 0) return true; // Unknown modifier.
386
387    switch (ExtraCode[0]) {
388    default: return true;  // Unknown modifier.
389    case 'L': // Write second word of DImode reference.
390      // Verify that this operand has two consecutive registers.
391      if (!MI->getOperand(OpNo).isRegister() ||
392          OpNo+1 == MI->getNumOperands() ||
393          !MI->getOperand(OpNo+1).isRegister())
394        return true;
395      ++OpNo;   // Return the high-part.
396      break;
397    }
398  }
399
400  printOperand(MI, OpNo);
401  return false;
402}
403
404bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
405                                          unsigned AsmVariant,
406                                          const char *ExtraCode) {
407  if (ExtraCode && ExtraCode[0])
408    return true; // Unknown modifier.
409  printMemRegReg(MI, OpNo);
410  return false;
411}
412
413/// printMachineInstruction -- Print out a single PowerPC MI in Darwin syntax to
414/// the current output stream.
415///
416void PPCAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
417  ++EmittedInsts;
418
419  // Check for slwi/srwi mnemonics.
420  if (MI->getOpcode() == PPC::RLWINM) {
421    bool FoundMnemonic = false;
422    unsigned char SH = MI->getOperand(2).getImmedValue();
423    unsigned char MB = MI->getOperand(3).getImmedValue();
424    unsigned char ME = MI->getOperand(4).getImmedValue();
425    if (SH <= 31 && MB == 0 && ME == (31-SH)) {
426      O << "slwi "; FoundMnemonic = true;
427    }
428    if (SH <= 31 && MB == (32-SH) && ME == 31) {
429      O << "srwi "; FoundMnemonic = true;
430      SH = 32-SH;
431    }
432    if (FoundMnemonic) {
433      printOperand(MI, 0);
434      O << ", ";
435      printOperand(MI, 1);
436      O << ", " << (unsigned int)SH << "\n";
437      return;
438    }
439  } else if (MI->getOpcode() == PPC::OR || MI->getOpcode() == PPC::OR8) {
440    if (MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
441      O << "mr ";
442      printOperand(MI, 0);
443      O << ", ";
444      printOperand(MI, 1);
445      O << "\n";
446      return;
447    }
448  }
449
450  if (printInstruction(MI))
451    return; // Printer was automatically generated
452
453  assert(0 && "Unhandled instruction in asm writer!");
454  abort();
455  return;
456}
457
458/// runOnMachineFunction - This uses the printMachineInstruction()
459/// method to print assembly for each instruction.
460///
461bool DarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
462  DW.SetDebugInfo(&getAnalysis<MachineDebugInfo>());
463
464  SetupMachineFunction(MF);
465  O << "\n\n";
466
467  // Print out constants referenced by the function
468  EmitConstantPool(MF.getConstantPool());
469
470  // Print out jump tables referenced by the function
471  EmitJumpTableInfo(MF.getJumpTableInfo());
472
473  // Print out labels for the function.
474  const Function *F = MF.getFunction();
475  switch (F->getLinkage()) {
476  default: assert(0 && "Unknown linkage type!");
477  case Function::InternalLinkage:  // Symbols default to internal.
478    SwitchToTextSection("\t.text", F);
479    break;
480  case Function::ExternalLinkage:
481    SwitchToTextSection("\t.text", F);
482    O << "\t.globl\t" << CurrentFnName << "\n";
483    break;
484  case Function::WeakLinkage:
485  case Function::LinkOnceLinkage:
486    SwitchToTextSection(
487                ".section __TEXT,__textcoal_nt,coalesced,pure_instructions", F);
488    O << "\t.globl\t" << CurrentFnName << "\n";
489    O << "\t.weak_definition\t" << CurrentFnName << "\n";
490    break;
491  }
492  EmitAlignment(4, F);
493  O << CurrentFnName << ":\n";
494
495  // Emit pre-function debug information.
496  DW.BeginFunction(&MF);
497
498  // Print out code for the function.
499  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
500       I != E; ++I) {
501    // Print a label for the basic block.
502    if (I != MF.begin()) {
503      printBasicBlockLabel(I, true);
504      O << '\n';
505    }
506    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
507         II != E; ++II) {
508      // Print the assembly for the instruction.
509      O << "\t";
510      printMachineInstruction(II);
511    }
512  }
513
514  // Emit post-function debug information.
515  DW.EndFunction();
516
517  // We didn't modify anything.
518  return false;
519}
520
521
522bool DarwinAsmPrinter::doInitialization(Module &M) {
523  if (TM.getSubtarget<PPCSubtarget>().isGigaProcessor())
524    O << "\t.machine ppc970\n";
525  AsmPrinter::doInitialization(M);
526
527  // Darwin wants symbols to be quoted if they have complex names.
528  Mang->setUseQuotes(true);
529
530  // Emit initial debug information.
531  DW.BeginModule(&M);
532  return false;
533}
534
535bool DarwinAsmPrinter::doFinalization(Module &M) {
536  const TargetData *TD = TM.getTargetData();
537
538  // Print out module-level global variables here.
539  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
540       I != E; ++I) {
541    if (!I->hasInitializer()) continue;   // External global require no code
542
543    // Check to see if this is a special global used by LLVM, if so, emit it.
544    if (EmitSpecialLLVMGlobal(I))
545      continue;
546
547    std::string name = Mang->getValueName(I);
548    Constant *C = I->getInitializer();
549    unsigned Size = TD->getTypeSize(C->getType());
550    unsigned Align = getPreferredAlignmentLog(I);
551
552    if (C->isNullValue() && /* FIXME: Verify correct */
553        (I->hasInternalLinkage() || I->hasWeakLinkage() ||
554         I->hasLinkOnceLinkage() ||
555         (I->hasExternalLinkage() && !I->hasSection()))) {
556      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
557      if (I->hasExternalLinkage()) {
558        O << "\t.globl " << name << '\n';
559        O << "\t.zerofill __DATA, __common, " << name << ", "
560          << Size << ", " << Align;
561      } else if (I->hasInternalLinkage()) {
562        SwitchToDataSection("\t.data", I);
563        O << LCOMMDirective << name << "," << Size << "," << Align;
564      } else {
565        SwitchToDataSection("\t.data", I);
566        O << ".comm " << name << "," << Size;
567      }
568      O << "\t\t; '" << I->getName() << "'\n";
569    } else {
570      switch (I->getLinkage()) {
571      case GlobalValue::LinkOnceLinkage:
572      case GlobalValue::WeakLinkage:
573        O << "\t.globl " << name << '\n'
574          << "\t.weak_definition " << name << '\n';
575        SwitchToDataSection(".section __DATA,__datacoal_nt,coalesced", I);
576        break;
577      case GlobalValue::AppendingLinkage:
578        // FIXME: appending linkage variables should go into a section of
579        // their name or something.  For now, just emit them as external.
580      case GlobalValue::ExternalLinkage:
581        // If external or appending, declare as a global symbol
582        O << "\t.globl " << name << "\n";
583        // FALL THROUGH
584      case GlobalValue::InternalLinkage:
585        SwitchToDataSection("\t.data", I);
586        break;
587      default:
588        std::cerr << "Unknown linkage type!";
589        abort();
590      }
591
592      EmitAlignment(Align, I);
593      O << name << ":\t\t\t\t; '" << I->getName() << "'\n";
594      EmitGlobalConstant(C);
595      O << '\n';
596    }
597  }
598
599  bool isPPC64 = TD->getPointerSizeInBits() == 64;
600
601  // Output stubs for dynamically-linked functions
602  if (TM.getRelocationModel() == Reloc::PIC) {
603    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
604         i != e; ++i) {
605      SwitchToTextSection(".section __TEXT,__picsymbolstub1,symbol_stubs,"
606                          "pure_instructions,32", 0);
607      EmitAlignment(4);
608      O << "L" << *i << "$stub:\n";
609      O << "\t.indirect_symbol " << *i << "\n";
610      O << "\tmflr r0\n";
611      O << "\tbcl 20,31,L0$" << *i << "\n";
612      O << "L0$" << *i << ":\n";
613      O << "\tmflr r11\n";
614      O << "\taddis r11,r11,ha16(L" << *i << "$lazy_ptr-L0$" << *i << ")\n";
615      O << "\tmtlr r0\n";
616      if (isPPC64)
617        O << "\tldu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
618      else
619        O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
620      O << "\tmtctr r12\n";
621      O << "\tbctr\n";
622      SwitchToDataSection(".lazy_symbol_pointer", 0);
623      O << "L" << *i << "$lazy_ptr:\n";
624      O << "\t.indirect_symbol " << *i << "\n";
625      if (isPPC64)
626        O << "\t.quad dyld_stub_binding_helper\n";
627      else
628        O << "\t.long dyld_stub_binding_helper\n";
629    }
630  } else {
631    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
632         i != e; ++i) {
633      SwitchToTextSection(".section __TEXT,__symbol_stub1,symbol_stubs,"
634                          "pure_instructions,16", 0);
635      EmitAlignment(4);
636      O << "L" << *i << "$stub:\n";
637      O << "\t.indirect_symbol " << *i << "\n";
638      O << "\tlis r11,ha16(L" << *i << "$lazy_ptr)\n";
639      if (isPPC64)
640        O << "\tldu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
641      else
642        O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
643      O << "\tmtctr r12\n";
644      O << "\tbctr\n";
645      SwitchToDataSection(".lazy_symbol_pointer", 0);
646      O << "L" << *i << "$lazy_ptr:\n";
647      O << "\t.indirect_symbol " << *i << "\n";
648      if (isPPC64)
649        O << "\t.quad dyld_stub_binding_helper\n";
650      else
651        O << "\t.long dyld_stub_binding_helper\n";
652    }
653  }
654
655  O << "\n";
656
657  // Output stubs for external and common global variables.
658  if (GVStubs.begin() != GVStubs.end()) {
659    SwitchToDataSection(".non_lazy_symbol_pointer", 0);
660    for (std::set<std::string>::iterator I = GVStubs.begin(),
661         E = GVStubs.end(); I != E; ++I) {
662      O << "L" << *I << "$non_lazy_ptr:\n";
663      O << "\t.indirect_symbol " << *I << "\n";
664      if (isPPC64)
665        O << "\t.quad\t0\n";
666      else
667        O << "\t.long\t0\n";
668
669    }
670  }
671
672  // Emit initial debug information.
673  DW.EndModule();
674
675  // Funny Darwin hack: This flag tells the linker that no global symbols
676  // contain code that falls through to other global symbols (e.g. the obvious
677  // implementation of multiple entry points).  If this doesn't occur, the
678  // linker can safely perform dead code stripping.  Since LLVM never generates
679  // code that does this, it is always safe to set.
680  O << "\t.subsections_via_symbols\n";
681
682  AsmPrinter::doFinalization(M);
683  return false; // success
684}
685
686