PPCAsmPrinter.cpp revision ea50fabfd4e5fad25a25b312f64a9b2a53363586 
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_VirtualRegister) {
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      // FIXME: Conditionalize jump table section based on PIC
281      JumpTableSection = ".const";
282      LCOMMDirective = "\t.lcomm\t";
283      StaticCtorsSection = ".mod_init_func";
284      StaticDtorsSection = ".mod_term_func";
285      InlineAsmStart = InlineAsmEnd = "";  // Don't use #APP/#NO_APP
286    }
287
288    virtual const char *getPassName() const {
289      return "Darwin PPC Assembly Printer";
290    }
291
292    bool runOnMachineFunction(MachineFunction &F);
293    bool doInitialization(Module &M);
294    bool doFinalization(Module &M);
295
296    void getAnalysisUsage(AnalysisUsage &AU) const {
297      AU.setPreservesAll();
298      AU.addRequired<MachineDebugInfo>();
299      PPCAsmPrinter::getAnalysisUsage(AU);
300    }
301
302  };
303
304  /// AIXAsmPrinter - PowerPC assembly printer, customized for AIX
305  ///
306  struct AIXAsmPrinter : public PPCAsmPrinter {
307    /// Map for labels corresponding to global variables
308    ///
309    std::map<const GlobalVariable*,std::string> GVToLabelMap;
310
311    AIXAsmPrinter(std::ostream &O, TargetMachine &TM)
312      : PPCAsmPrinter(O, TM) {
313      CommentString = "#";
314      GlobalPrefix = ".";
315      ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
316      Data64bitsDirective = 0;       // we can't emit a 64-bit unit
317      AlignmentIsInBytes = false;    // Alignment is by power of 2.
318      ConstantPoolSection = "\t.const\t";
319    }
320
321    virtual const char *getPassName() const {
322      return "AIX PPC Assembly Printer";
323    }
324
325    bool runOnMachineFunction(MachineFunction &F);
326    bool doInitialization(Module &M);
327    bool doFinalization(Module &M);
328  };
329} // end of anonymous namespace
330
331/// createDarwinAsmPrinterPass - Returns a pass that prints the PPC assembly
332/// code for a MachineFunction to the given output stream, in a format that the
333/// Darwin assembler can deal with.
334///
335FunctionPass *llvm::createDarwinAsmPrinter(std::ostream &o,
336                                           PPCTargetMachine &tm) {
337  return new DarwinAsmPrinter(o, tm);
338}
339
340/// createAIXAsmPrinterPass - Returns a pass that prints the PPC assembly code
341/// for a MachineFunction to the given output stream, in a format that the
342/// AIX 5L assembler can deal with.
343///
344FunctionPass *llvm::createAIXAsmPrinter(std::ostream &o, PPCTargetMachine &tm) {
345  return new AIXAsmPrinter(o, tm);
346}
347
348// Include the auto-generated portion of the assembly writer
349#include "PPCGenAsmWriter.inc"
350
351void PPCAsmPrinter::printOp(const MachineOperand &MO) {
352  const MRegisterInfo &RI = *TM.getRegisterInfo();
353  int new_symbol;
354
355  switch (MO.getType()) {
356    O << RI.get(MO.getReg()).Name;
357    return;
358
359  case MachineOperand::MO_SignExtendedImmed:
360  case MachineOperand::MO_UnextendedImmed:
361    std::cerr << "printOp() does not handle immediate values\n";
362    abort();
363    return;
364
365  case MachineOperand::MO_MachineBasicBlock:
366    printBasicBlockLabel(MO.getMachineBasicBlock());
367    return;
368  case MachineOperand::MO_JumpTableIndex:
369    O << PrivateGlobalPrefix << "JTI" << getFunctionNumber()
370      << '_' << MO.getJumpTableIndex();
371    // FIXME: PIC relocation model
372    return;
373  case MachineOperand::MO_ConstantPoolIndex:
374    O << PrivateGlobalPrefix << "CPI" << getFunctionNumber()
375      << '_' << MO.getConstantPoolIndex();
376    return;
377  case MachineOperand::MO_ExternalSymbol:
378    // Computing the address of an external symbol, not calling it.
379    if (TM.getRelocationModel() != Reloc::Static) {
380      std::string Name(GlobalPrefix); Name += MO.getSymbolName();
381      GVStubs.insert(Name);
382      O << "L" << Name << "$non_lazy_ptr";
383      return;
384    }
385    O << GlobalPrefix << MO.getSymbolName();
386    return;
387  case MachineOperand::MO_GlobalAddress: {
388    // Computing the address of a global symbol, not calling it.
389    GlobalValue *GV = MO.getGlobal();
390    std::string Name = Mang->getValueName(GV);
391    int offset = MO.getOffset();
392
393    // External or weakly linked global variables need non-lazily-resolved stubs
394    if (TM.getRelocationModel() != Reloc::Static) {
395      if (((GV->isExternal() || GV->hasWeakLinkage() ||
396            GV->hasLinkOnceLinkage()))) {
397        GVStubs.insert(Name);
398        O << "L" << Name << "$non_lazy_ptr";
399        return;
400      }
401    }
402
403    O << Name;
404    return;
405  }
406
407  default:
408    O << "<unknown operand type: " << MO.getType() << ">";
409    return;
410  }
411}
412
413/// PrintAsmOperand - Print out an operand for an inline asm expression.
414///
415bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
416                                    unsigned AsmVariant,
417                                    const char *ExtraCode) {
418  // Does this asm operand have a single letter operand modifier?
419  if (ExtraCode && ExtraCode[0]) {
420    if (ExtraCode[1] != 0) return true; // Unknown modifier.
421
422    switch (ExtraCode[0]) {
423    default: return true;  // Unknown modifier.
424    case 'L': // Write second word of DImode reference.
425      // Verify that this operand has two consecutive registers.
426      if (!MI->getOperand(OpNo).isRegister() ||
427          OpNo+1 == MI->getNumOperands() ||
428          !MI->getOperand(OpNo+1).isRegister())
429        return true;
430      ++OpNo;   // Return the high-part.
431      break;
432    }
433  }
434
435  printOperand(MI, OpNo);
436  return false;
437}
438
439bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
440                                          unsigned AsmVariant,
441                                          const char *ExtraCode) {
442  if (ExtraCode && ExtraCode[0])
443    return true; // Unknown modifier.
444  printMemRegReg(MI, OpNo);
445  return false;
446}
447
448/// printMachineInstruction -- Print out a single PowerPC MI in Darwin syntax to
449/// the current output stream.
450///
451void PPCAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
452  ++EmittedInsts;
453
454  // Check for slwi/srwi mnemonics.
455  if (MI->getOpcode() == PPC::RLWINM) {
456    bool FoundMnemonic = false;
457    unsigned char SH = MI->getOperand(2).getImmedValue();
458    unsigned char MB = MI->getOperand(3).getImmedValue();
459    unsigned char ME = MI->getOperand(4).getImmedValue();
460    if (SH <= 31 && MB == 0 && ME == (31-SH)) {
461      O << "slwi "; FoundMnemonic = true;
462    }
463    if (SH <= 31 && MB == (32-SH) && ME == 31) {
464      O << "srwi "; FoundMnemonic = true;
465      SH = 32-SH;
466    }
467    if (FoundMnemonic) {
468      printOperand(MI, 0);
469      O << ", ";
470      printOperand(MI, 1);
471      O << ", " << (unsigned int)SH << "\n";
472      return;
473    }
474  } else if (MI->getOpcode() == PPC::OR4 || MI->getOpcode() == PPC::OR8) {
475    if (MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
476      O << "mr ";
477      printOperand(MI, 0);
478      O << ", ";
479      printOperand(MI, 1);
480      O << "\n";
481      return;
482    }
483  }
484
485  if (printInstruction(MI))
486    return; // Printer was automatically generated
487
488  assert(0 && "Unhandled instruction in asm writer!");
489  abort();
490  return;
491}
492
493/// runOnMachineFunction - This uses the printMachineInstruction()
494/// method to print assembly for each instruction.
495///
496bool DarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
497  // FIXME - is this the earliest this can be set?
498  DW.SetDebugInfo(&getAnalysis<MachineDebugInfo>());
499
500  SetupMachineFunction(MF);
501  O << "\n\n";
502
503  // Print out constants referenced by the function
504  EmitConstantPool(MF.getConstantPool());
505
506  // Print out jump tables referenced by the function
507  EmitJumpTableInfo(MF.getJumpTableInfo());
508
509  // Print out labels for the function.
510  const Function *F = MF.getFunction();
511  switch (F->getLinkage()) {
512  default: assert(0 && "Unknown linkage type!");
513  case Function::InternalLinkage:  // Symbols default to internal.
514    SwitchSection(".text", F);
515    break;
516  case Function::ExternalLinkage:
517    SwitchSection(".text", F);
518    O << "\t.globl\t" << CurrentFnName << "\n";
519    break;
520  case Function::WeakLinkage:
521  case Function::LinkOnceLinkage:
522    SwitchSection(".section __TEXT,__textcoal_nt,coalesced,pure_instructions",
523                  F);
524    O << "\t.globl\t" << CurrentFnName << "\n";
525    O << "\t.weak_definition\t" << CurrentFnName << "\n";
526    break;
527  }
528  EmitAlignment(4, F);
529  O << CurrentFnName << ":\n";
530
531  // Emit pre-function debug information.
532  DW.BeginFunction(&MF);
533
534  // Print out code for the function.
535  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
536       I != E; ++I) {
537    // Print a label for the basic block.
538    if (I != MF.begin()) {
539      printBasicBlockLabel(I, true);
540      O << '\n';
541    }
542    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
543         II != E; ++II) {
544      // Print the assembly for the instruction.
545      O << "\t";
546      printMachineInstruction(II);
547    }
548  }
549
550  // Emit post-function debug information.
551  DW.EndFunction();
552
553  // We didn't modify anything.
554  return false;
555}
556
557
558bool DarwinAsmPrinter::doInitialization(Module &M) {
559  if (TM.getSubtarget<PPCSubtarget>().isGigaProcessor())
560    O << "\t.machine ppc970\n";
561  AsmPrinter::doInitialization(M);
562
563  // Darwin wants symbols to be quoted if they have complex names.
564  Mang->setUseQuotes(true);
565
566  // Emit initial debug information.
567  DW.BeginModule(&M);
568  return false;
569}
570
571bool DarwinAsmPrinter::doFinalization(Module &M) {
572  const TargetData *TD = TM.getTargetData();
573
574  // Print out module-level global variables here.
575  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
576       I != E; ++I) {
577    if (!I->hasInitializer()) continue;   // External global require no code
578
579    // Check to see if this is a special global used by LLVM, if so, emit it.
580    if (EmitSpecialLLVMGlobal(I))
581      continue;
582
583    std::string name = Mang->getValueName(I);
584    Constant *C = I->getInitializer();
585    unsigned Size = TD->getTypeSize(C->getType());
586    unsigned Align = getPreferredAlignmentLog(I);
587
588    if (C->isNullValue() && /* FIXME: Verify correct */
589        (I->hasInternalLinkage() || I->hasWeakLinkage() ||
590         I->hasLinkOnceLinkage() ||
591         (I->hasExternalLinkage() && !I->hasSection()))) {
592      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
593      if (I->hasExternalLinkage()) {
594        O << "\t.globl " << name << '\n';
595        O << "\t.zerofill __DATA, __common, " << name << ", "
596          << Size << ", " << Align;
597      } else if (I->hasInternalLinkage()) {
598        SwitchSection(".data", I);
599        O << LCOMMDirective << name << "," << Size << "," << Align;
600      } else {
601        SwitchSection(".data", I);
602        O << ".comm " << name << "," << Size;
603      }
604      O << "\t\t; '" << I->getName() << "'\n";
605    } else {
606      switch (I->getLinkage()) {
607      case GlobalValue::LinkOnceLinkage:
608      case GlobalValue::WeakLinkage:
609        O << "\t.globl " << name << '\n'
610          << "\t.weak_definition " << name << '\n';
611        SwitchSection(".section __DATA,__datacoal_nt,coalesced", I);
612        break;
613      case GlobalValue::AppendingLinkage:
614        // FIXME: appending linkage variables should go into a section of
615        // their name or something.  For now, just emit them as external.
616      case GlobalValue::ExternalLinkage:
617        // If external or appending, declare as a global symbol
618        O << "\t.globl " << name << "\n";
619        // FALL THROUGH
620      case GlobalValue::InternalLinkage:
621        SwitchSection(".data", I);
622        break;
623      default:
624        std::cerr << "Unknown linkage type!";
625        abort();
626      }
627
628      EmitAlignment(Align, I);
629      O << name << ":\t\t\t\t; '" << I->getName() << "'\n";
630      EmitGlobalConstant(C);
631      O << '\n';
632    }
633  }
634
635  // Output stubs for dynamically-linked functions
636  if (TM.getRelocationModel() == Reloc::PIC) {
637    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
638         i != e; ++i) {
639      SwitchSection(".section __TEXT,__picsymbolstub1,symbol_stubs,"
640                    "pure_instructions,32", 0);
641      EmitAlignment(2);
642      O << "L" << *i << "$stub:\n";
643      O << "\t.indirect_symbol " << *i << "\n";
644      O << "\tmflr r0\n";
645      O << "\tbcl 20,31,L0$" << *i << "\n";
646      O << "L0$" << *i << ":\n";
647      O << "\tmflr r11\n";
648      O << "\taddis r11,r11,ha16(L" << *i << "$lazy_ptr-L0$" << *i << ")\n";
649      O << "\tmtlr r0\n";
650      O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
651      O << "\tmtctr r12\n";
652      O << "\tbctr\n";
653      SwitchSection(".lazy_symbol_pointer", 0);
654      O << "L" << *i << "$lazy_ptr:\n";
655      O << "\t.indirect_symbol " << *i << "\n";
656      O << "\t.long dyld_stub_binding_helper\n";
657    }
658  } else {
659    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
660         i != e; ++i) {
661      SwitchSection(".section __TEXT,__symbol_stub1,symbol_stubs,"
662                    "pure_instructions,16", 0);
663      EmitAlignment(4);
664      O << "L" << *i << "$stub:\n";
665      O << "\t.indirect_symbol " << *i << "\n";
666      O << "\tlis r11,ha16(L" << *i << "$lazy_ptr)\n";
667      O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
668      O << "\tmtctr r12\n";
669      O << "\tbctr\n";
670      SwitchSection(".lazy_symbol_pointer", 0);
671      O << "L" << *i << "$lazy_ptr:\n";
672      O << "\t.indirect_symbol " << *i << "\n";
673      O << "\t.long dyld_stub_binding_helper\n";
674    }
675  }
676
677  O << "\n";
678
679  // Output stubs for external and common global variables.
680  if (GVStubs.begin() != GVStubs.end()) {
681    SwitchSection(".non_lazy_symbol_pointer", 0);
682    for (std::set<std::string>::iterator I = GVStubs.begin(),
683         E = GVStubs.end(); I != E; ++I) {
684      O << "L" << *I << "$non_lazy_ptr:\n";
685      O << "\t.indirect_symbol " << *I << "\n";
686      O << "\t.long\t0\n";
687    }
688  }
689
690  // Emit initial debug information.
691  DW.EndModule();
692
693  // Funny Darwin hack: This flag tells the linker that no global symbols
694  // contain code that falls through to other global symbols (e.g. the obvious
695  // implementation of multiple entry points).  If this doesn't occur, the
696  // linker can safely perform dead code stripping.  Since LLVM never generates
697  // code that does this, it is always safe to set.
698  O << "\t.subsections_via_symbols\n";
699
700  AsmPrinter::doFinalization(M);
701  return false; // success
702}
703
704/// runOnMachineFunction - This uses the printMachineInstruction()
705/// method to print assembly for each instruction.
706///
707bool AIXAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
708  SetupMachineFunction(MF);
709
710  // Print out constants referenced by the function
711  EmitConstantPool(MF.getConstantPool());
712
713  // Print out header for the function.
714  O << "\t.csect .text[PR]\n"
715    << "\t.align 2\n"
716    << "\t.globl "  << CurrentFnName << '\n'
717    << "\t.globl ." << CurrentFnName << '\n'
718    << "\t.csect "  << CurrentFnName << "[DS],3\n"
719    << CurrentFnName << ":\n"
720    << "\t.llong ." << CurrentFnName << ", TOC[tc0], 0\n"
721    << "\t.csect .text[PR]\n"
722    << '.' << CurrentFnName << ":\n";
723
724  // Print out code for the function.
725  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
726       I != E; ++I) {
727    printBasicBlockLabel(I);
728    O << '\n';
729    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
730      II != E; ++II) {
731      // Print the assembly for the instruction.
732      O << "\t";
733      printMachineInstruction(II);
734    }
735  }
736
737  O << "LT.." << CurrentFnName << ":\n"
738    << "\t.long 0\n"
739    << "\t.byte 0,0,32,65,128,0,0,0\n"
740    << "\t.long LT.." << CurrentFnName << "-." << CurrentFnName << '\n'
741    << "\t.short 3\n"
742    << "\t.byte \"" << CurrentFnName << "\"\n"
743    << "\t.align 2\n";
744
745  // We didn't modify anything.
746  return false;
747}
748
749bool AIXAsmPrinter::doInitialization(Module &M) {
750  SwitchSection("", 0);
751  const TargetData *TD = TM.getTargetData();
752
753  O << "\t.machine \"ppc64\"\n"
754    << "\t.toc\n"
755    << "\t.csect .text[PR]\n";
756
757  // Print out module-level global variables
758  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
759       I != E; ++I) {
760    if (!I->hasInitializer())
761      continue;
762
763    std::string Name = I->getName();
764    Constant *C = I->getInitializer();
765    // N.B.: We are defaulting to writable strings
766    if (I->hasExternalLinkage()) {
767      O << "\t.globl " << Name << '\n'
768        << "\t.csect .data[RW],3\n";
769    } else {
770      O << "\t.csect _global.rw_c[RW],3\n";
771    }
772    O << Name << ":\n";
773    EmitGlobalConstant(C);
774  }
775
776  // Output labels for globals
777  if (M.global_begin() != M.global_end()) O << "\t.toc\n";
778  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
779       I != E; ++I) {
780    const GlobalVariable *GV = I;
781    // Do not output labels for unused variables
782    if (GV->isExternal() && GV->use_begin() == GV->use_end())
783      continue;
784
785    IncrementFunctionNumber();
786    std::string Name = GV->getName();
787    std::string Label = "LC.." + utostr(getFunctionNumber());
788    GVToLabelMap[GV] = Label;
789    O << Label << ":\n"
790      << "\t.tc " << Name << "[TC]," << Name;
791    if (GV->isExternal()) O << "[RW]";
792    O << '\n';
793   }
794
795  AsmPrinter::doInitialization(M);
796  return false; // success
797}
798
799bool AIXAsmPrinter::doFinalization(Module &M) {
800  const TargetData *TD = TM.getTargetData();
801  // Print out module-level global variables
802  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
803       I != E; ++I) {
804    if (I->hasInitializer() || I->hasExternalLinkage())
805      continue;
806
807    std::string Name = I->getName();
808    if (I->hasInternalLinkage()) {
809      O << "\t.lcomm " << Name << ",16,_global.bss_c";
810    } else {
811      O << "\t.comm " << Name << "," << TD->getTypeSize(I->getType())
812        << "," << Log2_32((unsigned)TD->getTypeAlignment(I->getType()));
813    }
814    O << "\t\t" << CommentString << " ";
815    WriteAsOperand(O, I, false, true, &M);
816    O << "\n";
817  }
818
819  O << "_section_.text:\n"
820    << "\t.csect .data[RW],3\n"
821    << "\t.llong _section_.text\n";
822  AsmPrinter::doFinalization(M);
823  return false; // success
824}
825