PPCAsmPrinter.cpp revision 6b92b8e50d7e5b48407865c3aaf9966c01416c69 
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 bool runOnMachineFunction(MachineFunction &F) = 0;
237    virtual bool doFinalization(Module &M) = 0;
238
239  };
240
241  /// DarwinDwarfWriter - Dwarf debug info writer customized for Darwin/Mac OS X
242  ///
243  struct DarwinDwarfWriter : public DwarfWriter {
244    // Ctor.
245    DarwinDwarfWriter(std::ostream &o, AsmPrinter *ap)
246    : DwarfWriter(o, ap)
247    {
248      needsSet = true;
249      DwarfAbbrevSection = ".section __DWARFA,__debug_abbrev";
250      DwarfInfoSection = ".section __DWARFA,__debug_info";
251      DwarfLineSection = ".section __DWARFA,__debug_line";
252      DwarfFrameSection = ".section __DWARFA,__debug_frame";
253      DwarfPubNamesSection = ".section __DWARFA,__debug_pubnames";
254      DwarfPubTypesSection = ".section __DWARFA,__debug_pubtypes";
255      DwarfStrSection = ".section __DWARFA,__debug_str";
256      DwarfLocSection = ".section __DWARFA,__debug_loc";
257      DwarfARangesSection = ".section __DWARFA,__debug_aranges";
258      DwarfRangesSection = ".section __DWARFA,__debug_ranges";
259      DwarfMacInfoSection = ".section __DWARFA,__debug_macinfo";
260      TextSection = ".text";
261      DataSection = ".data";
262    }
263  };
264
265  /// DarwinAsmPrinter - PowerPC assembly printer, customized for Darwin/Mac OS
266  /// X
267  struct DarwinAsmPrinter : public PPCAsmPrinter {
268
269    DarwinDwarfWriter DW;
270
271    DarwinAsmPrinter(std::ostream &O, TargetMachine &TM)
272      : PPCAsmPrinter(O, TM), DW(O, this) {
273      CommentString = ";";
274      GlobalPrefix = "_";
275      PrivateGlobalPrefix = "L";     // Marker for constant pool idxs
276      ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
277      Data64bitsDirective = 0;       // we can't emit a 64-bit unit
278      AlignmentIsInBytes = false;    // Alignment is by power of 2.
279      ConstantPoolSection = "\t.const\t";
280      LCOMMDirective = "\t.lcomm\t";
281      StaticCtorsSection = ".mod_init_func";
282      StaticDtorsSection = ".mod_term_func";
283      InlineAsmStart = InlineAsmEnd = "";  // Don't use #APP/#NO_APP
284    }
285
286    virtual const char *getPassName() const {
287      return "Darwin PPC Assembly Printer";
288    }
289
290    bool runOnMachineFunction(MachineFunction &F);
291    bool doInitialization(Module &M);
292    bool doFinalization(Module &M);
293
294    void getAnalysisUsage(AnalysisUsage &AU) const {
295      AU.setPreservesAll();
296      AU.addRequired<MachineDebugInfo>();
297      PPCAsmPrinter::getAnalysisUsage(AU);
298    }
299
300  };
301
302  /// AIXAsmPrinter - PowerPC assembly printer, customized for AIX
303  ///
304  struct AIXAsmPrinter : public PPCAsmPrinter {
305    /// Map for labels corresponding to global variables
306    ///
307    std::map<const GlobalVariable*,std::string> GVToLabelMap;
308
309    AIXAsmPrinter(std::ostream &O, TargetMachine &TM)
310      : PPCAsmPrinter(O, TM) {
311      CommentString = "#";
312      GlobalPrefix = ".";
313      ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
314      Data64bitsDirective = 0;       // we can't emit a 64-bit unit
315      AlignmentIsInBytes = false;    // Alignment is by power of 2.
316      ConstantPoolSection = "\t.const\t";
317    }
318
319    virtual const char *getPassName() const {
320      return "AIX PPC Assembly Printer";
321    }
322
323    bool runOnMachineFunction(MachineFunction &F);
324    bool doInitialization(Module &M);
325    bool doFinalization(Module &M);
326  };
327} // end of anonymous namespace
328
329/// createDarwinAsmPrinterPass - Returns a pass that prints the PPC assembly
330/// code for a MachineFunction to the given output stream, in a format that the
331/// Darwin assembler can deal with.
332///
333FunctionPass *llvm::createDarwinAsmPrinter(std::ostream &o,
334                                           PPCTargetMachine &tm) {
335  return new DarwinAsmPrinter(o, tm);
336}
337
338/// createAIXAsmPrinterPass - Returns a pass that prints the PPC assembly code
339/// for a MachineFunction to the given output stream, in a format that the
340/// AIX 5L assembler can deal with.
341///
342FunctionPass *llvm::createAIXAsmPrinter(std::ostream &o, PPCTargetMachine &tm) {
343  return new AIXAsmPrinter(o, tm);
344}
345
346// Include the auto-generated portion of the assembly writer
347#include "PPCGenAsmWriter.inc"
348
349void PPCAsmPrinter::printOp(const MachineOperand &MO) {
350  const MRegisterInfo &RI = *TM.getRegisterInfo();
351  int new_symbol;
352
353  switch (MO.getType()) {
354  case MachineOperand::MO_VirtualRegister:
355    if (Value *V = MO.getVRegValueOrNull()) {
356      O << "<" << V->getName() << ">";
357      return;
358    }
359    // FALLTHROUGH
360  case MachineOperand::MO_MachineRegister:
361  case MachineOperand::MO_CCRegister:
362    O << RI.get(MO.getReg()).Name;
363    return;
364
365  case MachineOperand::MO_SignExtendedImmed:
366  case MachineOperand::MO_UnextendedImmed:
367    std::cerr << "printOp() does not handle immediate values\n";
368    abort();
369    return;
370
371  case MachineOperand::MO_PCRelativeDisp:
372    std::cerr << "Shouldn't use addPCDisp() when building PPC MachineInstrs";
373    abort();
374    return;
375
376  case MachineOperand::MO_MachineBasicBlock: {
377    MachineBasicBlock *MBBOp = MO.getMachineBasicBlock();
378    O << PrivateGlobalPrefix << "BB" << getFunctionNumber() << "_"
379      << MBBOp->getNumber() << "\t; " << MBBOp->getBasicBlock()->getName();
380    return;
381  }
382
383  case MachineOperand::MO_ConstantPoolIndex:
384    O << PrivateGlobalPrefix << "CPI" << getFunctionNumber()
385      << '_' << MO.getConstantPoolIndex();
386    return;
387  case MachineOperand::MO_ExternalSymbol:
388    // Computing the address of an external symbol, not calling it.
389    if (TM.getRelocationModel() != Reloc::Static) {
390      std::string Name(GlobalPrefix); Name += MO.getSymbolName();
391      GVStubs.insert(Name);
392      O << "L" << Name << "$non_lazy_ptr";
393      return;
394    }
395    O << GlobalPrefix << MO.getSymbolName();
396    return;
397  case MachineOperand::MO_GlobalAddress: {
398    // Computing the address of a global symbol, not calling it.
399    GlobalValue *GV = MO.getGlobal();
400    std::string Name = Mang->getValueName(GV);
401    int offset = MO.getOffset();
402
403    // External or weakly linked global variables need non-lazily-resolved stubs
404    if (TM.getRelocationModel() != Reloc::Static) {
405      if (((GV->isExternal() || GV->hasWeakLinkage() ||
406            GV->hasLinkOnceLinkage()))) {
407        GVStubs.insert(Name);
408        O << "L" << Name << "$non_lazy_ptr";
409        return;
410      }
411    }
412
413    O << Name;
414    return;
415  }
416
417  default:
418    O << "<unknown operand type: " << MO.getType() << ">";
419    return;
420  }
421}
422
423/// PrintAsmOperand - Print out an operand for an inline asm expression.
424///
425bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
426                                    unsigned AsmVariant,
427                                    const char *ExtraCode) {
428  // Does this asm operand have a single letter operand modifier?
429  if (ExtraCode && ExtraCode[0]) {
430    if (ExtraCode[1] != 0) return true; // Unknown modifier.
431
432    switch (ExtraCode[0]) {
433    default: return true;  // Unknown modifier.
434    case 'L': // Write second word of DImode reference.
435      // Verify that this operand has two consecutive registers.
436      if (!MI->getOperand(OpNo).isRegister() ||
437          OpNo+1 == MI->getNumOperands() ||
438          !MI->getOperand(OpNo+1).isRegister())
439        return true;
440      ++OpNo;   // Return the high-part.
441      break;
442    }
443  }
444
445  printOperand(MI, OpNo);
446  return false;
447}
448
449bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
450                                          unsigned AsmVariant,
451                                          const char *ExtraCode) {
452  if (ExtraCode && ExtraCode[0])
453    return true; // Unknown modifier.
454  printMemRegReg(MI, OpNo);
455  return false;
456}
457
458/// printMachineInstruction -- Print out a single PowerPC MI in Darwin syntax to
459/// the current output stream.
460///
461void PPCAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
462  ++EmittedInsts;
463
464  // Check for slwi/srwi mnemonics.
465  if (MI->getOpcode() == PPC::RLWINM) {
466    bool FoundMnemonic = false;
467    unsigned char SH = MI->getOperand(2).getImmedValue();
468    unsigned char MB = MI->getOperand(3).getImmedValue();
469    unsigned char ME = MI->getOperand(4).getImmedValue();
470    if (SH <= 31 && MB == 0 && ME == (31-SH)) {
471      O << "slwi "; FoundMnemonic = true;
472    }
473    if (SH <= 31 && MB == (32-SH) && ME == 31) {
474      O << "srwi "; FoundMnemonic = true;
475      SH = 32-SH;
476    }
477    if (FoundMnemonic) {
478      printOperand(MI, 0);
479      O << ", ";
480      printOperand(MI, 1);
481      O << ", " << (unsigned int)SH << "\n";
482      return;
483    }
484  } else if (MI->getOpcode() == PPC::OR4 || MI->getOpcode() == PPC::OR8) {
485    if (MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
486      O << "mr ";
487      printOperand(MI, 0);
488      O << ", ";
489      printOperand(MI, 1);
490      O << "\n";
491      return;
492    }
493  }
494
495  if (printInstruction(MI))
496    return; // Printer was automatically generated
497
498  assert(0 && "Unhandled instruction in asm writer!");
499  abort();
500  return;
501}
502
503
504/// runOnMachineFunction - This uses the printMachineInstruction()
505/// method to print assembly for each instruction.
506///
507bool DarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
508  // FIXME - is this the earliest this can be set?
509  DW.SetDebugInfo(&getAnalysis<MachineDebugInfo>());
510
511  SetupMachineFunction(MF);
512  O << "\n\n";
513
514  // Print out constants referenced by the function
515  EmitConstantPool(MF.getConstantPool());
516
517  // Print out labels for the function.
518  const Function *F = MF.getFunction();
519  switch (F->getLinkage()) {
520  default: assert(0 && "Unknown linkage type!");
521  case Function::InternalLinkage:  // Symbols default to internal.
522    SwitchSection(".text", F);
523    break;
524  case Function::ExternalLinkage:
525    SwitchSection(".text", F);
526    O << "\t.globl\t" << CurrentFnName << "\n";
527    break;
528  case Function::WeakLinkage:
529  case Function::LinkOnceLinkage:
530    SwitchSection(".section __TEXT,__textcoal_nt,coalesced,pure_instructions",
531                  F);
532    O << "\t.globl\t" << CurrentFnName << "\n";
533    O << "\t.weak_definition\t" << CurrentFnName << "\n";
534    break;
535  }
536  EmitAlignment(4, F);
537  O << CurrentFnName << ":\n";
538
539  // Emit pre-function debug information.
540  DW.BeginFunction(&MF);
541
542  // Print out code for the function.
543  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
544       I != E; ++I) {
545    // Print a label for the basic block.
546    if (I != MF.begin()) {
547      O << PrivateGlobalPrefix << "BB" << getFunctionNumber() << '_'
548        << I->getNumber() << ":\t";
549      if (!I->getBasicBlock()->getName().empty())
550        O << CommentString << " " << I->getBasicBlock()->getName();
551      O << "\n";
552    }
553    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
554         II != E; ++II) {
555      // Print the assembly for the instruction.
556      O << "\t";
557      printMachineInstruction(II);
558    }
559  }
560
561  // Emit post-function debug information.
562  DW.EndFunction();
563
564  // We didn't modify anything.
565  return false;
566}
567
568
569bool DarwinAsmPrinter::doInitialization(Module &M) {
570  if (TM.getSubtarget<PPCSubtarget>().isGigaProcessor())
571    O << "\t.machine ppc970\n";
572  AsmPrinter::doInitialization(M);
573
574  // Darwin wants symbols to be quoted if they have complex names.
575  Mang->setUseQuotes(true);
576
577  // Emit initial debug information.
578  DW.BeginModule(&M);
579  return false;
580}
581
582bool DarwinAsmPrinter::doFinalization(Module &M) {
583  const TargetData &TD = TM.getTargetData();
584
585  // Print out module-level global variables here.
586  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
587       I != E; ++I) {
588    if (!I->hasInitializer()) continue;   // External global require no code
589
590    // Check to see if this is a special global used by LLVM, if so, emit it.
591    if (EmitSpecialLLVMGlobal(I))
592      continue;
593
594    std::string name = Mang->getValueName(I);
595    Constant *C = I->getInitializer();
596    unsigned Size = TD.getTypeSize(C->getType());
597    unsigned Align = getPreferredAlignmentLog(I);
598
599    if (C->isNullValue() && /* FIXME: Verify correct */
600        (I->hasInternalLinkage() || I->hasWeakLinkage() ||
601         I->hasLinkOnceLinkage() ||
602         (I->hasExternalLinkage() && !I->hasSection()))) {
603      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
604      if (I->hasExternalLinkage()) {
605        O << "\t.globl " << name << '\n';
606        O << "\t.zerofill __DATA, __common, " << name << ", "
607          << Size << ", " << Align;
608      } else if (I->hasInternalLinkage()) {
609        SwitchSection(".data", I);
610        O << LCOMMDirective << name << "," << Size << "," << Align;
611      } else {
612        SwitchSection(".data", I);
613        O << ".comm " << name << "," << Size;
614      }
615      O << "\t\t; '" << I->getName() << "'\n";
616    } else {
617      switch (I->getLinkage()) {
618      case GlobalValue::LinkOnceLinkage:
619      case GlobalValue::WeakLinkage:
620        O << "\t.globl " << name << '\n'
621          << "\t.weak_definition " << name << '\n';
622        SwitchSection(".section __DATA,__datacoal_nt,coalesced", I);
623        break;
624      case GlobalValue::AppendingLinkage:
625        // FIXME: appending linkage variables should go into a section of
626        // their name or something.  For now, just emit them as external.
627      case GlobalValue::ExternalLinkage:
628        // If external or appending, declare as a global symbol
629        O << "\t.globl " << name << "\n";
630        // FALL THROUGH
631      case GlobalValue::InternalLinkage:
632        SwitchSection(".data", I);
633        break;
634      default:
635        std::cerr << "Unknown linkage type!";
636        abort();
637      }
638
639      EmitAlignment(Align, I);
640      O << name << ":\t\t\t\t; '" << I->getName() << "'\n";
641      EmitGlobalConstant(C);
642      O << '\n';
643    }
644  }
645
646  // Output stubs for dynamically-linked functions
647  if (TM.getRelocationModel() == Reloc::PIC) {
648    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
649         i != e; ++i) {
650      SwitchSection(".section __TEXT,__picsymbolstub1,symbol_stubs,"
651                    "pure_instructions,32", 0);
652      EmitAlignment(2);
653      O << "L" << *i << "$stub:\n";
654      O << "\t.indirect_symbol " << *i << "\n";
655      O << "\tmflr r0\n";
656      O << "\tbcl 20,31,L0$" << *i << "\n";
657      O << "L0$" << *i << ":\n";
658      O << "\tmflr r11\n";
659      O << "\taddis r11,r11,ha16(L" << *i << "$lazy_ptr-L0$" << *i << ")\n";
660      O << "\tmtlr r0\n";
661      O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
662      O << "\tmtctr r12\n";
663      O << "\tbctr\n";
664      SwitchSection(".lazy_symbol_pointer", 0);
665      O << "L" << *i << "$lazy_ptr:\n";
666      O << "\t.indirect_symbol " << *i << "\n";
667      O << "\t.long dyld_stub_binding_helper\n";
668    }
669  } else {
670    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
671         i != e; ++i) {
672      SwitchSection(".section __TEXT,__symbol_stub1,symbol_stubs,"
673                    "pure_instructions,16", 0);
674      EmitAlignment(4);
675      O << "L" << *i << "$stub:\n";
676      O << "\t.indirect_symbol " << *i << "\n";
677      O << "\tlis r11,ha16(L" << *i << "$lazy_ptr)\n";
678      O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
679      O << "\tmtctr r12\n";
680      O << "\tbctr\n";
681      SwitchSection(".lazy_symbol_pointer", 0);
682      O << "L" << *i << "$lazy_ptr:\n";
683      O << "\t.indirect_symbol " << *i << "\n";
684      O << "\t.long dyld_stub_binding_helper\n";
685    }
686  }
687
688  O << "\n";
689
690  // Output stubs for external and common global variables.
691  if (GVStubs.begin() != GVStubs.end()) {
692    SwitchSection(".non_lazy_symbol_pointer", 0);
693    for (std::set<std::string>::iterator I = GVStubs.begin(),
694         E = GVStubs.end(); I != E; ++I) {
695      O << "L" << *I << "$non_lazy_ptr:\n";
696      O << "\t.indirect_symbol " << *I << "\n";
697      O << "\t.long\t0\n";
698    }
699  }
700
701  // Emit initial debug information.
702  DW.EndModule();
703
704  // Funny Darwin hack: This flag tells the linker that no global symbols
705  // contain code that falls through to other global symbols (e.g. the obvious
706  // implementation of multiple entry points).  If this doesn't occur, the
707  // linker can safely perform dead code stripping.  Since LLVM never generates
708  // code that does this, it is always safe to set.
709  O << "\t.subsections_via_symbols\n";
710
711  AsmPrinter::doFinalization(M);
712  return false; // success
713}
714
715/// runOnMachineFunction - This uses the e()
716/// method to print assembly for each instruction.
717///
718bool AIXAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
719  SetupMachineFunction(MF);
720
721  // Print out constants referenced by the function
722  EmitConstantPool(MF.getConstantPool());
723
724  // Print out header for the function.
725  O << "\t.csect .text[PR]\n"
726    << "\t.align 2\n"
727    << "\t.globl "  << CurrentFnName << '\n'
728    << "\t.globl ." << CurrentFnName << '\n'
729    << "\t.csect "  << CurrentFnName << "[DS],3\n"
730    << CurrentFnName << ":\n"
731    << "\t.llong ." << CurrentFnName << ", TOC[tc0], 0\n"
732    << "\t.csect .text[PR]\n"
733    << '.' << CurrentFnName << ":\n";
734
735  // Print out code for the function.
736  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
737       I != E; ++I) {
738    // Print a label for the basic block.
739    O << PrivateGlobalPrefix << "BB" << getFunctionNumber() << '_'
740      << I->getNumber()
741      << ":\t" << CommentString << I->getBasicBlock()->getName() << '\n';
742    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
743      II != E; ++II) {
744      // Print the assembly for the instruction.
745      O << "\t";
746      printMachineInstruction(II);
747    }
748  }
749
750  O << "LT.." << CurrentFnName << ":\n"
751    << "\t.long 0\n"
752    << "\t.byte 0,0,32,65,128,0,0,0\n"
753    << "\t.long LT.." << CurrentFnName << "-." << CurrentFnName << '\n'
754    << "\t.short 3\n"
755    << "\t.byte \"" << CurrentFnName << "\"\n"
756    << "\t.align 2\n";
757
758  // We didn't modify anything.
759  return false;
760}
761
762bool AIXAsmPrinter::doInitialization(Module &M) {
763  SwitchSection("", 0);
764  const TargetData &TD = TM.getTargetData();
765
766  O << "\t.machine \"ppc64\"\n"
767    << "\t.toc\n"
768    << "\t.csect .text[PR]\n";
769
770  // Print out module-level global variables
771  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
772       I != E; ++I) {
773    if (!I->hasInitializer())
774      continue;
775
776    std::string Name = I->getName();
777    Constant *C = I->getInitializer();
778    // N.B.: We are defaulting to writable strings
779    if (I->hasExternalLinkage()) {
780      O << "\t.globl " << Name << '\n'
781        << "\t.csect .data[RW],3\n";
782    } else {
783      O << "\t.csect _global.rw_c[RW],3\n";
784    }
785    O << Name << ":\n";
786    EmitGlobalConstant(C);
787  }
788
789  // Output labels for globals
790  if (M.global_begin() != M.global_end()) O << "\t.toc\n";
791  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
792       I != E; ++I) {
793    const GlobalVariable *GV = I;
794    // Do not output labels for unused variables
795    if (GV->isExternal() && GV->use_begin() == GV->use_end())
796      continue;
797
798    IncrementFunctionNumber();
799    std::string Name = GV->getName();
800    std::string Label = "LC.." + utostr(getFunctionNumber());
801    GVToLabelMap[GV] = Label;
802    O << Label << ":\n"
803      << "\t.tc " << Name << "[TC]," << Name;
804    if (GV->isExternal()) O << "[RW]";
805    O << '\n';
806   }
807
808  AsmPrinter::doInitialization(M);
809  return false; // success
810}
811
812bool AIXAsmPrinter::doFinalization(Module &M) {
813  const TargetData &TD = TM.getTargetData();
814  // Print out module-level global variables
815  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
816       I != E; ++I) {
817    if (I->hasInitializer() || I->hasExternalLinkage())
818      continue;
819
820    std::string Name = I->getName();
821    if (I->hasInternalLinkage()) {
822      O << "\t.lcomm " << Name << ",16,_global.bss_c";
823    } else {
824      O << "\t.comm " << Name << "," << TD.getTypeSize(I->getType())
825        << "," << Log2_32((unsigned)TD.getTypeAlignment(I->getType()));
826    }
827    O << "\t\t" << CommentString << " ";
828    WriteAsOperand(O, I, false, true, &M);
829    O << "\n";
830  }
831
832  O << "_section_.text:\n"
833    << "\t.csect .data[RW],3\n"
834    << "\t.llong _section_.text\n";
835  AsmPrinter::doFinalization(M);
836  return false; // success
837}
838