PPCAsmPrinter.cpp revision 37efe6764568a3829fee26aba532283131d1a104 
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/Target/MRegisterInfo.h"
37#include "llvm/Target/TargetInstrInfo.h"
38#include "llvm/Target/TargetOptions.h"
39#include "llvm/ADT/Statistic.h"
40#include "llvm/ADT/StringExtras.h"
41#include <iostream>
42#include <set>
43using namespace llvm;
44
45namespace {
46  Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
47
48  class PPCAsmPrinter : public AsmPrinter {
49  public:
50    std::set<std::string> FnStubs, GVStubs;
51
52    PPCAsmPrinter(std::ostream &O, TargetMachine &TM)
53      : AsmPrinter(O, TM) {}
54
55    virtual const char *getPassName() const {
56      return "PowerPC Assembly Printer";
57    }
58
59    PPCTargetMachine &getTM() {
60      return static_cast<PPCTargetMachine&>(TM);
61    }
62
63    unsigned enumRegToMachineReg(unsigned enumReg) {
64      switch (enumReg) {
65      default: assert(0 && "Unhandled register!"); break;
66      case PPC::CR0:  return  0;
67      case PPC::CR1:  return  1;
68      case PPC::CR2:  return  2;
69      case PPC::CR3:  return  3;
70      case PPC::CR4:  return  4;
71      case PPC::CR5:  return  5;
72      case PPC::CR6:  return  6;
73      case PPC::CR7:  return  7;
74      }
75      abort();
76    }
77
78    /// printInstruction - This method is automatically generated by tablegen
79    /// from the instruction set description.  This method returns true if the
80    /// machine instruction was sufficiently described to print it, otherwise it
81    /// returns false.
82    bool printInstruction(const MachineInstr *MI);
83
84    void printMachineInstruction(const MachineInstr *MI);
85    void printOp(const MachineOperand &MO);
86
87    void printOperand(const MachineInstr *MI, unsigned OpNo) {
88      const MachineOperand &MO = MI->getOperand(OpNo);
89      if (MO.getType() == MachineOperand::MO_MachineRegister) {
90        assert(MRegisterInfo::isPhysicalRegister(MO.getReg())&&"Not physreg??");
91        O << TM.getRegisterInfo()->get(MO.getReg()).Name;
92      } else if (MO.isImmediate()) {
93        O << MO.getImmedValue();
94      } else {
95        printOp(MO);
96      }
97    }
98
99    bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
100                         unsigned AsmVariant, const char *ExtraCode);
101    bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
102                               unsigned AsmVariant, const char *ExtraCode);
103
104
105    void printS5ImmOperand(const MachineInstr *MI, unsigned OpNo) {
106      char value = MI->getOperand(OpNo).getImmedValue();
107      value = (value << (32-5)) >> (32-5);
108      O << (int)value;
109    }
110    void printU5ImmOperand(const MachineInstr *MI, unsigned OpNo) {
111      unsigned char value = MI->getOperand(OpNo).getImmedValue();
112      assert(value <= 31 && "Invalid u5imm argument!");
113      O << (unsigned int)value;
114    }
115    void printU6ImmOperand(const MachineInstr *MI, unsigned OpNo) {
116      unsigned char value = MI->getOperand(OpNo).getImmedValue();
117      assert(value <= 63 && "Invalid u6imm argument!");
118      O << (unsigned int)value;
119    }
120    void printS16ImmOperand(const MachineInstr *MI, unsigned OpNo) {
121      O << (short)MI->getOperand(OpNo).getImmedValue();
122    }
123    void printU16ImmOperand(const MachineInstr *MI, unsigned OpNo) {
124      O << (unsigned short)MI->getOperand(OpNo).getImmedValue();
125    }
126    void printS16X4ImmOperand(const MachineInstr *MI, unsigned OpNo) {
127      O << (short)MI->getOperand(OpNo).getImmedValue()*4;
128    }
129    void printBranchOperand(const MachineInstr *MI, unsigned OpNo) {
130      // Branches can take an immediate operand.  This is used by the branch
131      // selection pass to print $+8, an eight byte displacement from the PC.
132      if (MI->getOperand(OpNo).isImmediate()) {
133        O << "$+" << MI->getOperand(OpNo).getImmedValue();
134      } else {
135        printOp(MI->getOperand(OpNo));
136      }
137    }
138    void printCallOperand(const MachineInstr *MI, unsigned OpNo) {
139      const MachineOperand &MO = MI->getOperand(OpNo);
140      if (TM.getRelocationModel() != Reloc::Static) {
141        if (MO.getType() == MachineOperand::MO_GlobalAddress) {
142          GlobalValue *GV = MO.getGlobal();
143          if (((GV->isExternal() || GV->hasWeakLinkage() ||
144                GV->hasLinkOnceLinkage()))) {
145            // Dynamically-resolved functions need a stub for the function.
146            std::string Name = Mang->getValueName(GV);
147            FnStubs.insert(Name);
148            O << "L" << Name << "$stub";
149            return;
150          }
151        }
152        if (MO.getType() == MachineOperand::MO_ExternalSymbol) {
153          std::string Name(GlobalPrefix); Name += MO.getSymbolName();
154          FnStubs.insert(Name);
155          O << "L" << Name << "$stub";
156          return;
157        }
158      }
159
160      printOp(MI->getOperand(OpNo));
161    }
162    void printAbsAddrOperand(const MachineInstr *MI, unsigned OpNo) {
163     O << (int)MI->getOperand(OpNo).getImmedValue()*4;
164    }
165    void printPICLabel(const MachineInstr *MI, unsigned OpNo) {
166      O << "\"L" << getFunctionNumber() << "$pb\"\n";
167      O << "\"L" << getFunctionNumber() << "$pb\":";
168    }
169    void printSymbolHi(const MachineInstr *MI, unsigned OpNo) {
170      if (MI->getOperand(OpNo).isImmediate()) {
171        printS16ImmOperand(MI, OpNo);
172      } else {
173        O << "ha16(";
174        printOp(MI->getOperand(OpNo));
175        if (TM.getRelocationModel() == Reloc::PIC)
176          O << "-\"L" << getFunctionNumber() << "$pb\")";
177        else
178          O << ')';
179      }
180    }
181    void printSymbolLo(const MachineInstr *MI, unsigned OpNo) {
182      if (MI->getOperand(OpNo).isImmediate()) {
183        printS16ImmOperand(MI, OpNo);
184      } else {
185        O << "lo16(";
186        printOp(MI->getOperand(OpNo));
187        if (TM.getRelocationModel() == Reloc::PIC)
188          O << "-\"L" << getFunctionNumber() << "$pb\")";
189        else
190          O << ')';
191      }
192    }
193    void printcrbitm(const MachineInstr *MI, unsigned OpNo) {
194      unsigned CCReg = MI->getOperand(OpNo).getReg();
195      unsigned RegNo = enumRegToMachineReg(CCReg);
196      O << (0x80 >> RegNo);
197    }
198    // The new addressing mode printers.
199    void printMemRegImm(const MachineInstr *MI, unsigned OpNo) {
200      printSymbolLo(MI, OpNo);
201      O << '(';
202      if (MI->getOperand(OpNo+1).isRegister() &&
203          MI->getOperand(OpNo+1).getReg() == PPC::R0)
204        O << "0";
205      else
206        printOperand(MI, OpNo+1);
207      O << ')';
208    }
209    void printMemRegImmShifted(const MachineInstr *MI, unsigned OpNo) {
210      if (MI->getOperand(OpNo).isImmediate())
211        printS16X4ImmOperand(MI, OpNo);
212      else
213        printSymbolLo(MI, OpNo);
214      O << '(';
215      if (MI->getOperand(OpNo+1).isRegister() &&
216          MI->getOperand(OpNo+1).getReg() == PPC::R0)
217        O << "0";
218      else
219        printOperand(MI, OpNo+1);
220      O << ')';
221    }
222
223    void printMemRegReg(const MachineInstr *MI, unsigned OpNo) {
224      // When used as the base register, r0 reads constant zero rather than
225      // the value contained in the register.  For this reason, the darwin
226      // assembler requires that we print r0 as 0 (no r) when used as the base.
227      const MachineOperand &MO = MI->getOperand(OpNo);
228      if (MO.getReg() == PPC::R0)
229        O << '0';
230      else
231        O << TM.getRegisterInfo()->get(MO.getReg()).Name;
232      O << ", ";
233      printOperand(MI, OpNo+1);
234    }
235
236    virtual void printBasicBlockLabel(const MachineBasicBlock *MBB) const;
237
238    virtual bool runOnMachineFunction(MachineFunction &F) = 0;
239    virtual bool doFinalization(Module &M) = 0;
240
241  };
242
243  /// DarwinDwarfWriter - Dwarf debug info writer customized for Darwin/Mac OS X
244  ///
245  struct DarwinDwarfWriter : public DwarfWriter {
246    // Ctor.
247    DarwinDwarfWriter(std::ostream &o, AsmPrinter *ap)
248    : DwarfWriter(o, ap)
249    {
250      needsSet = true;
251      DwarfAbbrevSection = ".section __DWARFA,__debug_abbrev";
252      DwarfInfoSection = ".section __DWARFA,__debug_info";
253      DwarfLineSection = ".section __DWARFA,__debug_line";
254      DwarfFrameSection = ".section __DWARFA,__debug_frame";
255      DwarfPubNamesSection = ".section __DWARFA,__debug_pubnames";
256      DwarfPubTypesSection = ".section __DWARFA,__debug_pubtypes";
257      DwarfStrSection = ".section __DWARFA,__debug_str";
258      DwarfLocSection = ".section __DWARFA,__debug_loc";
259      DwarfARangesSection = ".section __DWARFA,__debug_aranges";
260      DwarfRangesSection = ".section __DWARFA,__debug_ranges";
261      DwarfMacInfoSection = ".section __DWARFA,__debug_macinfo";
262      TextSection = ".text";
263      DataSection = ".data";
264    }
265  };
266
267  /// DarwinAsmPrinter - PowerPC assembly printer, customized for Darwin/Mac OS
268  /// X
269  struct DarwinAsmPrinter : public PPCAsmPrinter {
270
271    DarwinDwarfWriter DW;
272
273    DarwinAsmPrinter(std::ostream &O, TargetMachine &TM)
274      : PPCAsmPrinter(O, TM), DW(O, this) {
275      CommentString = ";";
276      GlobalPrefix = "_";
277      PrivateGlobalPrefix = "L";     // Marker for constant pool idxs
278      ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
279      Data64bitsDirective = 0;       // we can't emit a 64-bit unit
280      AlignmentIsInBytes = false;    // Alignment is by power of 2.
281      ConstantPoolSection = "\t.const\t";
282      // FIXME: Conditionalize jump table section based on PIC
283      JumpTableSection = ".const";
284      LCOMMDirective = "\t.lcomm\t";
285      StaticCtorsSection = ".mod_init_func";
286      StaticDtorsSection = ".mod_term_func";
287      InlineAsmStart = InlineAsmEnd = "";  // Don't use #APP/#NO_APP
288    }
289
290    virtual const char *getPassName() const {
291      return "Darwin PPC Assembly Printer";
292    }
293
294    bool runOnMachineFunction(MachineFunction &F);
295    bool doInitialization(Module &M);
296    bool doFinalization(Module &M);
297
298    void getAnalysisUsage(AnalysisUsage &AU) const {
299      AU.setPreservesAll();
300      AU.addRequired<MachineDebugInfo>();
301      PPCAsmPrinter::getAnalysisUsage(AU);
302    }
303
304  };
305
306  /// AIXAsmPrinter - PowerPC assembly printer, customized for AIX
307  ///
308  struct AIXAsmPrinter : public PPCAsmPrinter {
309    /// Map for labels corresponding to global variables
310    ///
311    std::map<const GlobalVariable*,std::string> GVToLabelMap;
312
313    AIXAsmPrinter(std::ostream &O, TargetMachine &TM)
314      : PPCAsmPrinter(O, TM) {
315      CommentString = "#";
316      GlobalPrefix = ".";
317      ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
318      Data64bitsDirective = 0;       // we can't emit a 64-bit unit
319      AlignmentIsInBytes = false;    // Alignment is by power of 2.
320      ConstantPoolSection = "\t.const\t";
321    }
322
323    virtual const char *getPassName() const {
324      return "AIX PPC Assembly Printer";
325    }
326
327    bool runOnMachineFunction(MachineFunction &F);
328    bool doInitialization(Module &M);
329    bool doFinalization(Module &M);
330  };
331} // end of anonymous namespace
332
333/// createDarwinAsmPrinterPass - Returns a pass that prints the PPC assembly
334/// code for a MachineFunction to the given output stream, in a format that the
335/// Darwin assembler can deal with.
336///
337FunctionPass *llvm::createDarwinAsmPrinter(std::ostream &o,
338                                           PPCTargetMachine &tm) {
339  return new DarwinAsmPrinter(o, tm);
340}
341
342/// createAIXAsmPrinterPass - Returns a pass that prints the PPC assembly code
343/// for a MachineFunction to the given output stream, in a format that the
344/// AIX 5L assembler can deal with.
345///
346FunctionPass *llvm::createAIXAsmPrinter(std::ostream &o, PPCTargetMachine &tm) {
347  return new AIXAsmPrinter(o, tm);
348}
349
350// Include the auto-generated portion of the assembly writer
351#include "PPCGenAsmWriter.inc"
352
353void PPCAsmPrinter::printOp(const MachineOperand &MO) {
354  const MRegisterInfo &RI = *TM.getRegisterInfo();
355  int new_symbol;
356
357  switch (MO.getType()) {
358  case MachineOperand::MO_VirtualRegister:
359    if (Value *V = MO.getVRegValueOrNull()) {
360      O << "<" << V->getName() << ">";
361      return;
362    }
363    // FALLTHROUGH
364  case MachineOperand::MO_MachineRegister:
365  case MachineOperand::MO_CCRegister:
366    O << RI.get(MO.getReg()).Name;
367    return;
368
369  case MachineOperand::MO_SignExtendedImmed:
370  case MachineOperand::MO_UnextendedImmed:
371    std::cerr << "printOp() does not handle immediate values\n";
372    abort();
373    return;
374
375  case MachineOperand::MO_PCRelativeDisp:
376    std::cerr << "Shouldn't use addPCDisp() when building PPC MachineInstrs";
377    abort();
378    return;
379
380  case MachineOperand::MO_MachineBasicBlock:
381    printBasicBlockLabel(MO.getMachineBasicBlock());
382    return;
383  case MachineOperand::MO_JumpTableIndex:
384    O << PrivateGlobalPrefix << "JTI" << getFunctionNumber()
385      << '_' << MO.getJumpTableIndex();
386    // FIXME: PIC relocation model
387    return;
388  case MachineOperand::MO_ConstantPoolIndex:
389    O << PrivateGlobalPrefix << "CPI" << getFunctionNumber()
390      << '_' << MO.getConstantPoolIndex();
391    return;
392  case MachineOperand::MO_ExternalSymbol:
393    // Computing the address of an external symbol, not calling it.
394    if (TM.getRelocationModel() != Reloc::Static) {
395      std::string Name(GlobalPrefix); Name += MO.getSymbolName();
396      GVStubs.insert(Name);
397      O << "L" << Name << "$non_lazy_ptr";
398      return;
399    }
400    O << GlobalPrefix << MO.getSymbolName();
401    return;
402  case MachineOperand::MO_GlobalAddress: {
403    // Computing the address of a global symbol, not calling it.
404    GlobalValue *GV = MO.getGlobal();
405    std::string Name = Mang->getValueName(GV);
406    int offset = MO.getOffset();
407
408    // External or weakly linked global variables need non-lazily-resolved stubs
409    if (TM.getRelocationModel() != Reloc::Static) {
410      if (((GV->isExternal() || GV->hasWeakLinkage() ||
411            GV->hasLinkOnceLinkage()))) {
412        GVStubs.insert(Name);
413        O << "L" << Name << "$non_lazy_ptr";
414        return;
415      }
416    }
417
418    O << Name;
419    return;
420  }
421
422  default:
423    O << "<unknown operand type: " << MO.getType() << ">";
424    return;
425  }
426}
427
428/// PrintAsmOperand - Print out an operand for an inline asm expression.
429///
430bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
431                                    unsigned AsmVariant,
432                                    const char *ExtraCode) {
433  // Does this asm operand have a single letter operand modifier?
434  if (ExtraCode && ExtraCode[0]) {
435    if (ExtraCode[1] != 0) return true; // Unknown modifier.
436
437    switch (ExtraCode[0]) {
438    default: return true;  // Unknown modifier.
439    case 'L': // Write second word of DImode reference.
440      // Verify that this operand has two consecutive registers.
441      if (!MI->getOperand(OpNo).isRegister() ||
442          OpNo+1 == MI->getNumOperands() ||
443          !MI->getOperand(OpNo+1).isRegister())
444        return true;
445      ++OpNo;   // Return the high-part.
446      break;
447    }
448  }
449
450  printOperand(MI, OpNo);
451  return false;
452}
453
454bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
455                                          unsigned AsmVariant,
456                                          const char *ExtraCode) {
457  if (ExtraCode && ExtraCode[0])
458    return true; // Unknown modifier.
459  printMemRegReg(MI, OpNo);
460  return false;
461}
462
463/// printMachineInstruction -- Print out a single PowerPC MI in Darwin syntax to
464/// the current output stream.
465///
466void PPCAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
467  ++EmittedInsts;
468
469  // Check for slwi/srwi mnemonics.
470  if (MI->getOpcode() == PPC::RLWINM) {
471    bool FoundMnemonic = false;
472    unsigned char SH = MI->getOperand(2).getImmedValue();
473    unsigned char MB = MI->getOperand(3).getImmedValue();
474    unsigned char ME = MI->getOperand(4).getImmedValue();
475    if (SH <= 31 && MB == 0 && ME == (31-SH)) {
476      O << "slwi "; FoundMnemonic = true;
477    }
478    if (SH <= 31 && MB == (32-SH) && ME == 31) {
479      O << "srwi "; FoundMnemonic = true;
480      SH = 32-SH;
481    }
482    if (FoundMnemonic) {
483      printOperand(MI, 0);
484      O << ", ";
485      printOperand(MI, 1);
486      O << ", " << (unsigned int)SH << "\n";
487      return;
488    }
489  } else if (MI->getOpcode() == PPC::OR4 || MI->getOpcode() == PPC::OR8) {
490    if (MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
491      O << "mr ";
492      printOperand(MI, 0);
493      O << ", ";
494      printOperand(MI, 1);
495      O << "\n";
496      return;
497    }
498  }
499
500  if (printInstruction(MI))
501    return; // Printer was automatically generated
502
503  assert(0 && "Unhandled instruction in asm writer!");
504  abort();
505  return;
506}
507
508void PPCAsmPrinter::printBasicBlockLabel(const MachineBasicBlock *MBB) const {
509  O << PrivateGlobalPrefix << "BB" << getFunctionNumber() << "_"
510    << MBB->getNumber() << '\t' << CommentString
511    << MBB->getBasicBlock()->getName();
512}
513
514/// runOnMachineFunction - This uses the printMachineInstruction()
515/// method to print assembly for each instruction.
516///
517bool DarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
518  // FIXME - is this the earliest this can be set?
519  DW.SetDebugInfo(&getAnalysis<MachineDebugInfo>());
520
521  SetupMachineFunction(MF);
522  O << "\n\n";
523
524  // Print out constants referenced by the function
525  EmitConstantPool(MF.getConstantPool());
526
527  // Print out jump tables referenced by the function
528  EmitJumpTableInfo(MF.getJumpTableInfo());
529
530  // Print out labels for the function.
531  const Function *F = MF.getFunction();
532  switch (F->getLinkage()) {
533  default: assert(0 && "Unknown linkage type!");
534  case Function::InternalLinkage:  // Symbols default to internal.
535    SwitchSection(".text", F);
536    break;
537  case Function::ExternalLinkage:
538    SwitchSection(".text", F);
539    O << "\t.globl\t" << CurrentFnName << "\n";
540    break;
541  case Function::WeakLinkage:
542  case Function::LinkOnceLinkage:
543    SwitchSection(".section __TEXT,__textcoal_nt,coalesced,pure_instructions",
544                  F);
545    O << "\t.globl\t" << CurrentFnName << "\n";
546    O << "\t.weak_definition\t" << CurrentFnName << "\n";
547    break;
548  }
549  EmitAlignment(4, F);
550  O << CurrentFnName << ":\n";
551
552  // Emit pre-function debug information.
553  DW.BeginFunction(&MF);
554
555  // Print out code for the function.
556  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
557       I != E; ++I) {
558    // Print a label for the basic block.
559    if (I != MF.begin()) {
560      O << PrivateGlobalPrefix << "BB" << getFunctionNumber() << '_'
561        << I->getNumber() << ":\t";
562      if (!I->getBasicBlock()->getName().empty())
563        O << CommentString << " " << I->getBasicBlock()->getName();
564      O << "\n";
565    }
566    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
567         II != E; ++II) {
568      // Print the assembly for the instruction.
569      O << "\t";
570      printMachineInstruction(II);
571    }
572  }
573
574  // Emit post-function debug information.
575  DW.EndFunction();
576
577  // We didn't modify anything.
578  return false;
579}
580
581
582bool DarwinAsmPrinter::doInitialization(Module &M) {
583  if (TM.getSubtarget<PPCSubtarget>().isGigaProcessor())
584    O << "\t.machine ppc970\n";
585  AsmPrinter::doInitialization(M);
586
587  // Darwin wants symbols to be quoted if they have complex names.
588  Mang->setUseQuotes(true);
589
590  // Emit initial debug information.
591  DW.BeginModule(&M);
592  return false;
593}
594
595bool DarwinAsmPrinter::doFinalization(Module &M) {
596  const TargetData &TD = TM.getTargetData();
597
598  // Print out module-level global variables here.
599  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
600       I != E; ++I) {
601    if (!I->hasInitializer()) continue;   // External global require no code
602
603    // Check to see if this is a special global used by LLVM, if so, emit it.
604    if (EmitSpecialLLVMGlobal(I))
605      continue;
606
607    std::string name = Mang->getValueName(I);
608    Constant *C = I->getInitializer();
609    unsigned Size = TD.getTypeSize(C->getType());
610    unsigned Align = getPreferredAlignmentLog(I);
611
612    if (C->isNullValue() && /* FIXME: Verify correct */
613        (I->hasInternalLinkage() || I->hasWeakLinkage() ||
614         I->hasLinkOnceLinkage() ||
615         (I->hasExternalLinkage() && !I->hasSection()))) {
616      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
617      if (I->hasExternalLinkage()) {
618        O << "\t.globl " << name << '\n';
619        O << "\t.zerofill __DATA, __common, " << name << ", "
620          << Size << ", " << Align;
621      } else if (I->hasInternalLinkage()) {
622        SwitchSection(".data", I);
623        O << LCOMMDirective << name << "," << Size << "," << Align;
624      } else {
625        SwitchSection(".data", I);
626        O << ".comm " << name << "," << Size;
627      }
628      O << "\t\t; '" << I->getName() << "'\n";
629    } else {
630      switch (I->getLinkage()) {
631      case GlobalValue::LinkOnceLinkage:
632      case GlobalValue::WeakLinkage:
633        O << "\t.globl " << name << '\n'
634          << "\t.weak_definition " << name << '\n';
635        SwitchSection(".section __DATA,__datacoal_nt,coalesced", I);
636        break;
637      case GlobalValue::AppendingLinkage:
638        // FIXME: appending linkage variables should go into a section of
639        // their name or something.  For now, just emit them as external.
640      case GlobalValue::ExternalLinkage:
641        // If external or appending, declare as a global symbol
642        O << "\t.globl " << name << "\n";
643        // FALL THROUGH
644      case GlobalValue::InternalLinkage:
645        SwitchSection(".data", I);
646        break;
647      default:
648        std::cerr << "Unknown linkage type!";
649        abort();
650      }
651
652      EmitAlignment(Align, I);
653      O << name << ":\t\t\t\t; '" << I->getName() << "'\n";
654      EmitGlobalConstant(C);
655      O << '\n';
656    }
657  }
658
659  // Output stubs for dynamically-linked functions
660  if (TM.getRelocationModel() == Reloc::PIC) {
661    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
662         i != e; ++i) {
663      SwitchSection(".section __TEXT,__picsymbolstub1,symbol_stubs,"
664                    "pure_instructions,32", 0);
665      EmitAlignment(2);
666      O << "L" << *i << "$stub:\n";
667      O << "\t.indirect_symbol " << *i << "\n";
668      O << "\tmflr r0\n";
669      O << "\tbcl 20,31,L0$" << *i << "\n";
670      O << "L0$" << *i << ":\n";
671      O << "\tmflr r11\n";
672      O << "\taddis r11,r11,ha16(L" << *i << "$lazy_ptr-L0$" << *i << ")\n";
673      O << "\tmtlr r0\n";
674      O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
675      O << "\tmtctr r12\n";
676      O << "\tbctr\n";
677      SwitchSection(".lazy_symbol_pointer", 0);
678      O << "L" << *i << "$lazy_ptr:\n";
679      O << "\t.indirect_symbol " << *i << "\n";
680      O << "\t.long dyld_stub_binding_helper\n";
681    }
682  } else {
683    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
684         i != e; ++i) {
685      SwitchSection(".section __TEXT,__symbol_stub1,symbol_stubs,"
686                    "pure_instructions,16", 0);
687      EmitAlignment(4);
688      O << "L" << *i << "$stub:\n";
689      O << "\t.indirect_symbol " << *i << "\n";
690      O << "\tlis r11,ha16(L" << *i << "$lazy_ptr)\n";
691      O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
692      O << "\tmtctr r12\n";
693      O << "\tbctr\n";
694      SwitchSection(".lazy_symbol_pointer", 0);
695      O << "L" << *i << "$lazy_ptr:\n";
696      O << "\t.indirect_symbol " << *i << "\n";
697      O << "\t.long dyld_stub_binding_helper\n";
698    }
699  }
700
701  O << "\n";
702
703  // Output stubs for external and common global variables.
704  if (GVStubs.begin() != GVStubs.end()) {
705    SwitchSection(".non_lazy_symbol_pointer", 0);
706    for (std::set<std::string>::iterator I = GVStubs.begin(),
707         E = GVStubs.end(); I != E; ++I) {
708      O << "L" << *I << "$non_lazy_ptr:\n";
709      O << "\t.indirect_symbol " << *I << "\n";
710      O << "\t.long\t0\n";
711    }
712  }
713
714  // Emit initial debug information.
715  DW.EndModule();
716
717  // Funny Darwin hack: This flag tells the linker that no global symbols
718  // contain code that falls through to other global symbols (e.g. the obvious
719  // implementation of multiple entry points).  If this doesn't occur, the
720  // linker can safely perform dead code stripping.  Since LLVM never generates
721  // code that does this, it is always safe to set.
722  O << "\t.subsections_via_symbols\n";
723
724  AsmPrinter::doFinalization(M);
725  return false; // success
726}
727
728/// runOnMachineFunction - This uses the e()
729/// method to print assembly for each instruction.
730///
731bool AIXAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
732  SetupMachineFunction(MF);
733
734  // Print out constants referenced by the function
735  EmitConstantPool(MF.getConstantPool());
736
737  // Print out header for the function.
738  O << "\t.csect .text[PR]\n"
739    << "\t.align 2\n"
740    << "\t.globl "  << CurrentFnName << '\n'
741    << "\t.globl ." << CurrentFnName << '\n'
742    << "\t.csect "  << CurrentFnName << "[DS],3\n"
743    << CurrentFnName << ":\n"
744    << "\t.llong ." << CurrentFnName << ", TOC[tc0], 0\n"
745    << "\t.csect .text[PR]\n"
746    << '.' << CurrentFnName << ":\n";
747
748  // Print out code for the function.
749  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
750       I != E; ++I) {
751    // Print a label for the basic block.
752    O << PrivateGlobalPrefix << "BB" << getFunctionNumber() << '_'
753      << I->getNumber()
754      << ":\t" << CommentString << I->getBasicBlock()->getName() << '\n';
755    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
756      II != E; ++II) {
757      // Print the assembly for the instruction.
758      O << "\t";
759      printMachineInstruction(II);
760    }
761  }
762
763  O << "LT.." << CurrentFnName << ":\n"
764    << "\t.long 0\n"
765    << "\t.byte 0,0,32,65,128,0,0,0\n"
766    << "\t.long LT.." << CurrentFnName << "-." << CurrentFnName << '\n'
767    << "\t.short 3\n"
768    << "\t.byte \"" << CurrentFnName << "\"\n"
769    << "\t.align 2\n";
770
771  // We didn't modify anything.
772  return false;
773}
774
775bool AIXAsmPrinter::doInitialization(Module &M) {
776  SwitchSection("", 0);
777  const TargetData &TD = TM.getTargetData();
778
779  O << "\t.machine \"ppc64\"\n"
780    << "\t.toc\n"
781    << "\t.csect .text[PR]\n";
782
783  // Print out module-level global variables
784  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
785       I != E; ++I) {
786    if (!I->hasInitializer())
787      continue;
788
789    std::string Name = I->getName();
790    Constant *C = I->getInitializer();
791    // N.B.: We are defaulting to writable strings
792    if (I->hasExternalLinkage()) {
793      O << "\t.globl " << Name << '\n'
794        << "\t.csect .data[RW],3\n";
795    } else {
796      O << "\t.csect _global.rw_c[RW],3\n";
797    }
798    O << Name << ":\n";
799    EmitGlobalConstant(C);
800  }
801
802  // Output labels for globals
803  if (M.global_begin() != M.global_end()) O << "\t.toc\n";
804  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
805       I != E; ++I) {
806    const GlobalVariable *GV = I;
807    // Do not output labels for unused variables
808    if (GV->isExternal() && GV->use_begin() == GV->use_end())
809      continue;
810
811    IncrementFunctionNumber();
812    std::string Name = GV->getName();
813    std::string Label = "LC.." + utostr(getFunctionNumber());
814    GVToLabelMap[GV] = Label;
815    O << Label << ":\n"
816      << "\t.tc " << Name << "[TC]," << Name;
817    if (GV->isExternal()) O << "[RW]";
818    O << '\n';
819   }
820
821  AsmPrinter::doInitialization(M);
822  return false; // success
823}
824
825bool AIXAsmPrinter::doFinalization(Module &M) {
826  const TargetData &TD = TM.getTargetData();
827  // Print out module-level global variables
828  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
829       I != E; ++I) {
830    if (I->hasInitializer() || I->hasExternalLinkage())
831      continue;
832
833    std::string Name = I->getName();
834    if (I->hasInternalLinkage()) {
835      O << "\t.lcomm " << Name << ",16,_global.bss_c";
836    } else {
837      O << "\t.comm " << Name << "," << TD.getTypeSize(I->getType())
838        << "," << Log2_32((unsigned)TD.getTypeAlignment(I->getType()));
839    }
840    O << "\t\t" << CommentString << " ";
841    WriteAsOperand(O, I, false, true, &M);
842    O << "\n";
843  }
844
845  O << "_section_.text:\n"
846    << "\t.csect .data[RW],3\n"
847    << "\t.llong _section_.text\n";
848  AsmPrinter::doFinalization(M);
849  return false; // success
850}
851