PPCAsmPrinter.cpp revision ab4022f196059745c0ca0780b71a80fa67e896be 
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/Compiler.h"
37#include "llvm/Target/TargetAsmInfo.h"
38#include "llvm/Target/MRegisterInfo.h"
39#include "llvm/Target/TargetInstrInfo.h"
40#include "llvm/Target/TargetOptions.h"
41#include "llvm/ADT/Statistic.h"
42#include "llvm/ADT/StringExtras.h"
43#include <iostream>
44#include <set>
45using namespace llvm;
46
47namespace {
48  Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
49
50  struct VISIBILITY_HIDDEN PPCAsmPrinter : public AsmPrinter {
51    std::set<std::string> FnStubs, GVStubs;
52    const PPCSubtarget &Subtarget;
53
54    PPCAsmPrinter(std::ostream &O, TargetMachine &TM, const TargetAsmInfo *T)
55      : AsmPrinter(O, TM, T), Subtarget(TM.getSubtarget<PPCSubtarget>()) {
56    }
57
58    virtual const char *getPassName() const {
59      return "PowerPC Assembly Printer";
60    }
61
62    PPCTargetMachine &getTM() {
63      return static_cast<PPCTargetMachine&>(TM);
64    }
65
66    unsigned enumRegToMachineReg(unsigned enumReg) {
67      switch (enumReg) {
68      default: assert(0 && "Unhandled register!"); break;
69      case PPC::CR0:  return  0;
70      case PPC::CR1:  return  1;
71      case PPC::CR2:  return  2;
72      case PPC::CR3:  return  3;
73      case PPC::CR4:  return  4;
74      case PPC::CR5:  return  5;
75      case PPC::CR6:  return  6;
76      case PPC::CR7:  return  7;
77      }
78      abort();
79    }
80
81    /// printInstruction - This method is automatically generated by tablegen
82    /// from the instruction set description.  This method returns true if the
83    /// machine instruction was sufficiently described to print it, otherwise it
84    /// returns false.
85    bool printInstruction(const MachineInstr *MI);
86
87    void printMachineInstruction(const MachineInstr *MI);
88    void printOp(const MachineOperand &MO);
89
90    void printOperand(const MachineInstr *MI, unsigned OpNo) {
91      const MachineOperand &MO = MI->getOperand(OpNo);
92      if (MO.isRegister()) {
93        assert(MRegisterInfo::isPhysicalRegister(MO.getReg())&&"Not physreg??");
94        O << TM.getRegisterInfo()->get(MO.getReg()).Name;
95      } else if (MO.isImmediate()) {
96        O << MO.getImmedValue();
97      } else {
98        printOp(MO);
99      }
100    }
101
102    bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
103                         unsigned AsmVariant, const char *ExtraCode);
104    bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
105                               unsigned AsmVariant, const char *ExtraCode);
106
107
108    void printS5ImmOperand(const MachineInstr *MI, unsigned OpNo) {
109      char value = MI->getOperand(OpNo).getImmedValue();
110      value = (value << (32-5)) >> (32-5);
111      O << (int)value;
112    }
113    void printU5ImmOperand(const MachineInstr *MI, unsigned OpNo) {
114      unsigned char value = MI->getOperand(OpNo).getImmedValue();
115      assert(value <= 31 && "Invalid u5imm argument!");
116      O << (unsigned int)value;
117    }
118    void printU6ImmOperand(const MachineInstr *MI, unsigned OpNo) {
119      unsigned char value = MI->getOperand(OpNo).getImmedValue();
120      assert(value <= 63 && "Invalid u6imm argument!");
121      O << (unsigned int)value;
122    }
123    void printS16ImmOperand(const MachineInstr *MI, unsigned OpNo) {
124      O << (short)MI->getOperand(OpNo).getImmedValue();
125    }
126    void printU16ImmOperand(const MachineInstr *MI, unsigned OpNo) {
127      O << (unsigned short)MI->getOperand(OpNo).getImmedValue();
128    }
129    void printS16X4ImmOperand(const MachineInstr *MI, unsigned OpNo) {
130      O << (short)(MI->getOperand(OpNo).getImmedValue()*4);
131    }
132    void printBranchOperand(const MachineInstr *MI, unsigned OpNo) {
133      // Branches can take an immediate operand.  This is used by the branch
134      // selection pass to print $+8, an eight byte displacement from the PC.
135      if (MI->getOperand(OpNo).isImmediate()) {
136        O << "$+" << MI->getOperand(OpNo).getImmedValue()*4;
137      } else {
138        printOp(MI->getOperand(OpNo));
139      }
140    }
141    void printCallOperand(const MachineInstr *MI, unsigned OpNo) {
142      const MachineOperand &MO = MI->getOperand(OpNo);
143      if (TM.getRelocationModel() != Reloc::Static) {
144        if (MO.getType() == MachineOperand::MO_GlobalAddress) {
145          GlobalValue *GV = MO.getGlobal();
146          if (((GV->isExternal() || GV->hasWeakLinkage() ||
147                GV->hasLinkOnceLinkage()))) {
148            // Dynamically-resolved functions need a stub for the function.
149            std::string Name = Mang->getValueName(GV);
150            FnStubs.insert(Name);
151            O << "L" << Name << "$stub";
152            return;
153          }
154        }
155        if (MO.getType() == MachineOperand::MO_ExternalSymbol) {
156          std::string Name(TAI->getGlobalPrefix()); Name += MO.getSymbolName();
157          FnStubs.insert(Name);
158          O << "L" << Name << "$stub";
159          return;
160        }
161      }
162
163      printOp(MI->getOperand(OpNo));
164    }
165    void printAbsAddrOperand(const MachineInstr *MI, unsigned OpNo) {
166     O << (int)MI->getOperand(OpNo).getImmedValue()*4;
167    }
168    void printPICLabel(const MachineInstr *MI, unsigned OpNo) {
169      O << "\"L" << getFunctionNumber() << "$pb\"\n";
170      O << "\"L" << getFunctionNumber() << "$pb\":";
171    }
172    void printSymbolHi(const MachineInstr *MI, unsigned OpNo) {
173      if (MI->getOperand(OpNo).isImmediate()) {
174        printS16ImmOperand(MI, OpNo);
175      } else {
176        O << "ha16(";
177        printOp(MI->getOperand(OpNo));
178        if (TM.getRelocationModel() == Reloc::PIC_)
179          O << "-\"L" << getFunctionNumber() << "$pb\")";
180        else
181          O << ')';
182      }
183    }
184    void printSymbolLo(const MachineInstr *MI, unsigned OpNo) {
185      if (MI->getOperand(OpNo).isImmediate()) {
186        printS16ImmOperand(MI, OpNo);
187      } else {
188        O << "lo16(";
189        printOp(MI->getOperand(OpNo));
190        if (TM.getRelocationModel() == Reloc::PIC_)
191          O << "-\"L" << getFunctionNumber() << "$pb\")";
192        else
193          O << ')';
194      }
195    }
196    void printcrbitm(const MachineInstr *MI, unsigned OpNo) {
197      unsigned CCReg = MI->getOperand(OpNo).getReg();
198      unsigned RegNo = enumRegToMachineReg(CCReg);
199      O << (0x80 >> RegNo);
200    }
201    // The new addressing mode printers.
202    void printMemRegImm(const MachineInstr *MI, unsigned OpNo) {
203      printSymbolLo(MI, OpNo);
204      O << '(';
205      if (MI->getOperand(OpNo+1).isRegister() &&
206          MI->getOperand(OpNo+1).getReg() == PPC::R0)
207        O << "0";
208      else
209        printOperand(MI, OpNo+1);
210      O << ')';
211    }
212    void printMemRegImmShifted(const MachineInstr *MI, unsigned OpNo) {
213      if (MI->getOperand(OpNo).isImmediate())
214        printS16X4ImmOperand(MI, OpNo);
215      else
216        printSymbolLo(MI, OpNo);
217      O << '(';
218      if (MI->getOperand(OpNo+1).isRegister() &&
219          MI->getOperand(OpNo+1).getReg() == PPC::R0)
220        O << "0";
221      else
222        printOperand(MI, OpNo+1);
223      O << ')';
224    }
225
226    void printMemRegReg(const MachineInstr *MI, unsigned OpNo) {
227      // When used as the base register, r0 reads constant zero rather than
228      // the value contained in the register.  For this reason, the darwin
229      // assembler requires that we print r0 as 0 (no r) when used as the base.
230      const MachineOperand &MO = MI->getOperand(OpNo);
231      if (MO.getReg() == PPC::R0)
232        O << '0';
233      else
234        O << TM.getRegisterInfo()->get(MO.getReg()).Name;
235      O << ", ";
236      printOperand(MI, OpNo+1);
237    }
238
239    virtual bool runOnMachineFunction(MachineFunction &F) = 0;
240    virtual bool doFinalization(Module &M) = 0;
241  };
242
243  /// DarwinAsmPrinter - PowerPC assembly printer, customized for Darwin/Mac OS
244  /// X
245  struct VISIBILITY_HIDDEN DarwinAsmPrinter : public PPCAsmPrinter {
246
247    DwarfWriter DW;
248
249    DarwinAsmPrinter(std::ostream &O, PPCTargetMachine &TM,
250                     const TargetAsmInfo *T)
251      : PPCAsmPrinter(O, TM, T), DW(O, this, T) {
252      bool isPPC64 = Subtarget.isPPC64();
253    }
254
255    virtual const char *getPassName() const {
256      return "Darwin PPC Assembly Printer";
257    }
258
259    bool runOnMachineFunction(MachineFunction &F);
260    bool doInitialization(Module &M);
261    bool doFinalization(Module &M);
262
263    void getAnalysisUsage(AnalysisUsage &AU) const {
264      AU.setPreservesAll();
265      AU.addRequired<MachineDebugInfo>();
266      PPCAsmPrinter::getAnalysisUsage(AU);
267    }
268
269    /// getSectionForFunction - Return the section that we should emit the
270    /// specified function body into.
271    virtual std::string getSectionForFunction(const Function &F) const;
272  };
273} // end of anonymous namespace
274
275// Include the auto-generated portion of the assembly writer
276#include "PPCGenAsmWriter.inc"
277
278void PPCAsmPrinter::printOp(const MachineOperand &MO) {
279  switch (MO.getType()) {
280  case MachineOperand::MO_Immediate:
281    std::cerr << "printOp() does not handle immediate values\n";
282    abort();
283    return;
284
285  case MachineOperand::MO_MachineBasicBlock:
286    printBasicBlockLabel(MO.getMachineBasicBlock());
287    return;
288  case MachineOperand::MO_JumpTableIndex:
289    O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
290      << '_' << MO.getJumpTableIndex();
291    // FIXME: PIC relocation model
292    return;
293  case MachineOperand::MO_ConstantPoolIndex:
294    O << TAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber()
295      << '_' << MO.getConstantPoolIndex();
296    return;
297  case MachineOperand::MO_ExternalSymbol:
298    // Computing the address of an external symbol, not calling it.
299    if (TM.getRelocationModel() != Reloc::Static) {
300      std::string Name(TAI->getGlobalPrefix()); Name += MO.getSymbolName();
301      GVStubs.insert(Name);
302      O << "L" << Name << "$non_lazy_ptr";
303      return;
304    }
305    O << TAI->getGlobalPrefix() << MO.getSymbolName();
306    return;
307  case MachineOperand::MO_GlobalAddress: {
308    // Computing the address of a global symbol, not calling it.
309    GlobalValue *GV = MO.getGlobal();
310    std::string Name = Mang->getValueName(GV);
311    int offset = MO.getOffset();
312
313    // External or weakly linked global variables need non-lazily-resolved stubs
314    if (TM.getRelocationModel() != Reloc::Static) {
315      if (((GV->isExternal() || GV->hasWeakLinkage() ||
316            GV->hasLinkOnceLinkage()))) {
317        GVStubs.insert(Name);
318        O << "L" << Name << "$non_lazy_ptr";
319        return;
320      }
321    }
322
323    O << Name;
324    return;
325  }
326
327  default:
328    O << "<unknown operand type: " << MO.getType() << ">";
329    return;
330  }
331}
332
333/// PrintAsmOperand - Print out an operand for an inline asm expression.
334///
335bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
336                                    unsigned AsmVariant,
337                                    const char *ExtraCode) {
338  // Does this asm operand have a single letter operand modifier?
339  if (ExtraCode && ExtraCode[0]) {
340    if (ExtraCode[1] != 0) return true; // Unknown modifier.
341
342    switch (ExtraCode[0]) {
343    default: return true;  // Unknown modifier.
344    case 'L': // Write second word of DImode reference.
345      // Verify that this operand has two consecutive registers.
346      if (!MI->getOperand(OpNo).isRegister() ||
347          OpNo+1 == MI->getNumOperands() ||
348          !MI->getOperand(OpNo+1).isRegister())
349        return true;
350      ++OpNo;   // Return the high-part.
351      break;
352    }
353  }
354
355  printOperand(MI, OpNo);
356  return false;
357}
358
359bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
360                                          unsigned AsmVariant,
361                                          const char *ExtraCode) {
362  if (ExtraCode && ExtraCode[0])
363    return true; // Unknown modifier.
364  printMemRegReg(MI, OpNo);
365  return false;
366}
367
368/// printMachineInstruction -- Print out a single PowerPC MI in Darwin syntax to
369/// the current output stream.
370///
371void PPCAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
372  ++EmittedInsts;
373
374  // Check for slwi/srwi mnemonics.
375  if (MI->getOpcode() == PPC::RLWINM) {
376    bool FoundMnemonic = false;
377    unsigned char SH = MI->getOperand(2).getImmedValue();
378    unsigned char MB = MI->getOperand(3).getImmedValue();
379    unsigned char ME = MI->getOperand(4).getImmedValue();
380    if (SH <= 31 && MB == 0 && ME == (31-SH)) {
381      O << "slwi "; FoundMnemonic = true;
382    }
383    if (SH <= 31 && MB == (32-SH) && ME == 31) {
384      O << "srwi "; FoundMnemonic = true;
385      SH = 32-SH;
386    }
387    if (FoundMnemonic) {
388      printOperand(MI, 0);
389      O << ", ";
390      printOperand(MI, 1);
391      O << ", " << (unsigned int)SH << "\n";
392      return;
393    }
394  } else if (MI->getOpcode() == PPC::OR || MI->getOpcode() == PPC::OR8) {
395    if (MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
396      O << "mr ";
397      printOperand(MI, 0);
398      O << ", ";
399      printOperand(MI, 1);
400      O << "\n";
401      return;
402    }
403  }
404
405  if (printInstruction(MI))
406    return; // Printer was automatically generated
407
408  assert(0 && "Unhandled instruction in asm writer!");
409  abort();
410  return;
411}
412
413
414
415std::string DarwinAsmPrinter::getSectionForFunction(const Function &F) const {
416  switch (F.getLinkage()) {
417  default: assert(0 && "Unknown linkage type!");
418  case Function::ExternalLinkage:
419  case Function::InternalLinkage: return TAI->getTextSection();
420  case Function::WeakLinkage:
421  case Function::LinkOnceLinkage:
422    return ".section __TEXT,__textcoal_nt,coalesced,pure_instructions";
423  }
424}
425
426/// runOnMachineFunction - This uses the printMachineInstruction()
427/// method to print assembly for each instruction.
428///
429bool DarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
430  DW.SetDebugInfo(&getAnalysis<MachineDebugInfo>());
431
432  SetupMachineFunction(MF);
433  O << "\n\n";
434
435  // Print out constants referenced by the function
436  EmitConstantPool(MF.getConstantPool());
437
438  // Print out labels for the function.
439  const Function *F = MF.getFunction();
440  SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
441
442  switch (F->getLinkage()) {
443  default: assert(0 && "Unknown linkage type!");
444  case Function::InternalLinkage:  // Symbols default to internal.
445    break;
446  case Function::ExternalLinkage:
447    O << "\t.globl\t" << CurrentFnName << "\n";
448    break;
449  case Function::WeakLinkage:
450  case Function::LinkOnceLinkage:
451    O << "\t.globl\t" << CurrentFnName << "\n";
452    O << "\t.weak_definition\t" << CurrentFnName << "\n";
453    break;
454  }
455  EmitAlignment(4, F);
456  O << CurrentFnName << ":\n";
457
458  // Emit pre-function debug information.
459  DW.BeginFunction(&MF);
460
461  // Print out code for the function.
462  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
463       I != E; ++I) {
464    // Print a label for the basic block.
465    if (I != MF.begin()) {
466      printBasicBlockLabel(I, true);
467      O << '\n';
468    }
469    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
470         II != E; ++II) {
471      // Print the assembly for the instruction.
472      O << "\t";
473      printMachineInstruction(II);
474    }
475  }
476
477  // Print out jump tables referenced by the function.
478  EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
479
480  // Emit post-function debug information.
481  DW.EndFunction();
482
483  // We didn't modify anything.
484  return false;
485}
486
487
488bool DarwinAsmPrinter::doInitialization(Module &M) {
489  if (Subtarget.isGigaProcessor())
490    O << "\t.machine ppc970\n";
491  AsmPrinter::doInitialization(M);
492
493  // Darwin wants symbols to be quoted if they have complex names.
494  Mang->setUseQuotes(true);
495
496  // Emit initial debug information.
497  DW.BeginModule(&M);
498  return false;
499}
500
501bool DarwinAsmPrinter::doFinalization(Module &M) {
502  const TargetData *TD = TM.getTargetData();
503
504  // Print out module-level global variables here.
505  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
506       I != E; ++I) {
507    if (!I->hasInitializer()) continue;   // External global require no code
508
509    // Check to see if this is a special global used by LLVM, if so, emit it.
510    if (EmitSpecialLLVMGlobal(I))
511      continue;
512
513    std::string name = Mang->getValueName(I);
514    Constant *C = I->getInitializer();
515    unsigned Size = TD->getTypeSize(C->getType());
516    unsigned Align = TD->getPreferredAlignmentLog(I);
517
518    if (C->isNullValue() && /* FIXME: Verify correct */
519        (I->hasInternalLinkage() || I->hasWeakLinkage() ||
520         I->hasLinkOnceLinkage() ||
521         (I->hasExternalLinkage() && !I->hasSection()))) {
522      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
523      if (I->hasExternalLinkage()) {
524        O << "\t.globl " << name << '\n';
525        O << "\t.zerofill __DATA, __common, " << name << ", "
526          << Size << ", " << Align;
527      } else if (I->hasInternalLinkage()) {
528        SwitchToDataSection("\t.data", I);
529        O << TAI->getLCOMMDirective() << name << "," << Size << "," << Align;
530      } else {
531        SwitchToDataSection("\t.data", I);
532        O << ".comm " << name << "," << Size;
533      }
534      O << "\t\t; '" << I->getName() << "'\n";
535    } else {
536      switch (I->getLinkage()) {
537      case GlobalValue::LinkOnceLinkage:
538      case GlobalValue::WeakLinkage:
539        O << "\t.globl " << name << '\n'
540          << "\t.weak_definition " << name << '\n';
541        SwitchToDataSection(".section __DATA,__datacoal_nt,coalesced", I);
542        break;
543      case GlobalValue::AppendingLinkage:
544        // FIXME: appending linkage variables should go into a section of
545        // their name or something.  For now, just emit them as external.
546      case GlobalValue::ExternalLinkage:
547        // If external or appending, declare as a global symbol
548        O << "\t.globl " << name << "\n";
549        // FALL THROUGH
550      case GlobalValue::InternalLinkage:
551        if (I->isConstant()) {
552          const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
553          if (TAI->getCStringSection() && CVA && CVA->isCString()) {
554            SwitchToDataSection(TAI->getCStringSection(), I);
555            break;
556          }
557        }
558
559        SwitchToDataSection("\t.data", I);
560        break;
561      default:
562        std::cerr << "Unknown linkage type!";
563        abort();
564      }
565
566      EmitAlignment(Align, I);
567      O << name << ":\t\t\t\t; '" << I->getName() << "'\n";
568      EmitGlobalConstant(C);
569      O << '\n';
570    }
571  }
572
573  bool isPPC64 = TD->getPointerSizeInBits() == 64;
574
575  // Output stubs for dynamically-linked functions
576  if (TM.getRelocationModel() == Reloc::PIC_) {
577    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
578         i != e; ++i) {
579      SwitchToTextSection(".section __TEXT,__picsymbolstub1,symbol_stubs,"
580                          "pure_instructions,32");
581      EmitAlignment(4);
582      O << "L" << *i << "$stub:\n";
583      O << "\t.indirect_symbol " << *i << "\n";
584      O << "\tmflr r0\n";
585      O << "\tbcl 20,31,L0$" << *i << "\n";
586      O << "L0$" << *i << ":\n";
587      O << "\tmflr r11\n";
588      O << "\taddis r11,r11,ha16(L" << *i << "$lazy_ptr-L0$" << *i << ")\n";
589      O << "\tmtlr r0\n";
590      if (isPPC64)
591        O << "\tldu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
592      else
593        O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
594      O << "\tmtctr r12\n";
595      O << "\tbctr\n";
596      SwitchToDataSection(".lazy_symbol_pointer");
597      O << "L" << *i << "$lazy_ptr:\n";
598      O << "\t.indirect_symbol " << *i << "\n";
599      if (isPPC64)
600        O << "\t.quad dyld_stub_binding_helper\n";
601      else
602        O << "\t.long dyld_stub_binding_helper\n";
603    }
604  } else {
605    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
606         i != e; ++i) {
607      SwitchToTextSection(".section __TEXT,__symbol_stub1,symbol_stubs,"
608                          "pure_instructions,16");
609      EmitAlignment(4);
610      O << "L" << *i << "$stub:\n";
611      O << "\t.indirect_symbol " << *i << "\n";
612      O << "\tlis r11,ha16(L" << *i << "$lazy_ptr)\n";
613      if (isPPC64)
614        O << "\tldu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
615      else
616        O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
617      O << "\tmtctr r12\n";
618      O << "\tbctr\n";
619      SwitchToDataSection(".lazy_symbol_pointer");
620      O << "L" << *i << "$lazy_ptr:\n";
621      O << "\t.indirect_symbol " << *i << "\n";
622      if (isPPC64)
623        O << "\t.quad dyld_stub_binding_helper\n";
624      else
625        O << "\t.long dyld_stub_binding_helper\n";
626    }
627  }
628
629  O << "\n";
630
631  // Output stubs for external and common global variables.
632  if (GVStubs.begin() != GVStubs.end()) {
633    SwitchToDataSection(".non_lazy_symbol_pointer");
634    for (std::set<std::string>::iterator I = GVStubs.begin(),
635         E = GVStubs.end(); I != E; ++I) {
636      O << "L" << *I << "$non_lazy_ptr:\n";
637      O << "\t.indirect_symbol " << *I << "\n";
638      if (isPPC64)
639        O << "\t.quad\t0\n";
640      else
641        O << "\t.long\t0\n";
642
643    }
644  }
645
646  // Emit initial debug information.
647  DW.EndModule();
648
649  // Funny Darwin hack: This flag tells the linker that no global symbols
650  // contain code that falls through to other global symbols (e.g. the obvious
651  // implementation of multiple entry points).  If this doesn't occur, the
652  // linker can safely perform dead code stripping.  Since LLVM never generates
653  // code that does this, it is always safe to set.
654  O << "\t.subsections_via_symbols\n";
655
656  AsmPrinter::doFinalization(M);
657  return false; // success
658}
659
660
661
662/// createDarwinCodePrinterPass - Returns a pass that prints the PPC assembly
663/// code for a MachineFunction to the given output stream, in a format that the
664/// Darwin assembler can deal with.
665///
666FunctionPass *llvm::createPPCAsmPrinterPass(std::ostream &o,
667                                            PPCTargetMachine &tm) {
668  return new DarwinAsmPrinter(o, tm, tm.getTargetAsmInfo());
669}
670
671