PPCAsmPrinter.cpp revision 13feb58aa1042ed01962ade548459b8f01ba1a48 
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 printU5ImmOperand(const MachineInstr *MI, unsigned OpNo) {
106      unsigned char value = MI->getOperand(OpNo).getImmedValue();
107      assert(value <= 31 && "Invalid u5imm argument!");
108      O << (unsigned int)value;
109    }
110    void printU6ImmOperand(const MachineInstr *MI, unsigned OpNo) {
111      unsigned char value = MI->getOperand(OpNo).getImmedValue();
112      assert(value <= 63 && "Invalid u6imm argument!");
113      O << (unsigned int)value;
114    }
115    void printS16ImmOperand(const MachineInstr *MI, unsigned OpNo) {
116      O << (short)MI->getOperand(OpNo).getImmedValue();
117    }
118    void printU16ImmOperand(const MachineInstr *MI, unsigned OpNo) {
119      O << (unsigned short)MI->getOperand(OpNo).getImmedValue();
120    }
121    void printS16X4ImmOperand(const MachineInstr *MI, unsigned OpNo) {
122      O << (short)MI->getOperand(OpNo).getImmedValue()*4;
123    }
124    void printBranchOperand(const MachineInstr *MI, unsigned OpNo) {
125      // Branches can take an immediate operand.  This is used by the branch
126      // selection pass to print $+8, an eight byte displacement from the PC.
127      if (MI->getOperand(OpNo).isImmediate()) {
128        O << "$+" << MI->getOperand(OpNo).getImmedValue();
129      } else {
130        printOp(MI->getOperand(OpNo));
131      }
132    }
133    void printCallOperand(const MachineInstr *MI, unsigned OpNo) {
134      const MachineOperand &MO = MI->getOperand(OpNo);
135      if (TM.getRelocationModel() != Reloc::Static) {
136        if (MO.getType() == MachineOperand::MO_GlobalAddress) {
137          GlobalValue *GV = MO.getGlobal();
138          if (((GV->isExternal() || GV->hasWeakLinkage() ||
139                GV->hasLinkOnceLinkage()))) {
140            // Dynamically-resolved functions need a stub for the function.
141            std::string Name = Mang->getValueName(GV);
142            FnStubs.insert(Name);
143            O << "L" << Name << "$stub";
144            return;
145          }
146        }
147        if (MO.getType() == MachineOperand::MO_ExternalSymbol) {
148          std::string Name(GlobalPrefix); Name += MO.getSymbolName();
149          FnStubs.insert(Name);
150          O << "L" << Name << "$stub";
151          return;
152        }
153      }
154
155      printOp(MI->getOperand(OpNo));
156    }
157    void printAbsAddrOperand(const MachineInstr *MI, unsigned OpNo) {
158     O << (int)MI->getOperand(OpNo).getImmedValue()*4;
159    }
160    void printPICLabel(const MachineInstr *MI, unsigned OpNo) {
161      O << "\"L" << getFunctionNumber() << "$pb\"\n";
162      O << "\"L" << getFunctionNumber() << "$pb\":";
163    }
164    void printSymbolHi(const MachineInstr *MI, unsigned OpNo) {
165      if (MI->getOperand(OpNo).isImmediate()) {
166        printS16ImmOperand(MI, OpNo);
167      } else {
168        O << "ha16(";
169        printOp(MI->getOperand(OpNo));
170        if (TM.getRelocationModel() == Reloc::PIC)
171          O << "-\"L" << getFunctionNumber() << "$pb\")";
172        else
173          O << ')';
174      }
175    }
176    void printSymbolLo(const MachineInstr *MI, unsigned OpNo) {
177      if (MI->getOperand(OpNo).isImmediate()) {
178        printS16ImmOperand(MI, OpNo);
179      } else {
180        O << "lo16(";
181        printOp(MI->getOperand(OpNo));
182        if (TM.getRelocationModel() == Reloc::PIC)
183          O << "-\"L" << getFunctionNumber() << "$pb\")";
184        else
185          O << ')';
186      }
187    }
188    void printcrbitm(const MachineInstr *MI, unsigned OpNo) {
189      unsigned CCReg = MI->getOperand(OpNo).getReg();
190      unsigned RegNo = enumRegToMachineReg(CCReg);
191      O << (0x80 >> RegNo);
192    }
193    // The new addressing mode printers.
194    void printMemRegImm(const MachineInstr *MI, unsigned OpNo) {
195      printSymbolLo(MI, OpNo);
196      O << '(';
197      if (MI->getOperand(OpNo+1).isRegister() &&
198          MI->getOperand(OpNo+1).getReg() == PPC::R0)
199        O << "0";
200      else
201        printOperand(MI, OpNo+1);
202      O << ')';
203    }
204    void printMemRegReg(const MachineInstr *MI, unsigned OpNo) {
205      // When used as the base register, r0 reads constant zero rather than
206      // the value contained in the register.  For this reason, the darwin
207      // assembler requires that we print r0 as 0 (no r) when used as the base.
208      const MachineOperand &MO = MI->getOperand(OpNo);
209      if (MO.getReg() == PPC::R0)
210        O << '0';
211      else
212        O << TM.getRegisterInfo()->get(MO.getReg()).Name;
213      O << ", ";
214      printOperand(MI, OpNo+1);
215    }
216
217    virtual bool runOnMachineFunction(MachineFunction &F) = 0;
218    virtual bool doFinalization(Module &M) = 0;
219
220  };
221
222  /// DarwinDwarfWriter - Dwarf debug info writer customized for Darwin/Mac OS X
223  ///
224  struct DarwinDwarfWriter : public DwarfWriter {
225    // Ctor.
226    DarwinDwarfWriter(std::ostream &o, AsmPrinter *ap)
227    : DwarfWriter(o, ap)
228    {
229      needsSet = true;
230      DwarfAbbrevSection = ".section __DWARFA,__debug_abbrev";
231      DwarfInfoSection = ".section __DWARFA,__debug_info";
232      DwarfLineSection = ".section __DWARFA,__debug_line";
233      DwarfFrameSection = ".section __DWARFA,__debug_frame";
234      DwarfPubNamesSection = ".section __DWARFA,__debug_pubnames";
235      DwarfPubTypesSection = ".section __DWARFA,__debug_pubtypes";
236      DwarfStrSection = ".section __DWARFA,__debug_str";
237      DwarfLocSection = ".section __DWARFA,__debug_loc";
238      DwarfARangesSection = ".section __DWARFA,__debug_aranges";
239      DwarfRangesSection = ".section __DWARFA,__debug_ranges";
240      DwarfMacInfoSection = ".section __DWARFA,__debug_macinfo";
241      TextSection = ".text";
242      DataSection = ".data";
243    }
244  };
245
246  /// DarwinAsmPrinter - PowerPC assembly printer, customized for Darwin/Mac OS
247  /// X
248  struct DarwinAsmPrinter : public PPCAsmPrinter {
249
250    DarwinDwarfWriter DW;
251
252    DarwinAsmPrinter(std::ostream &O, TargetMachine &TM)
253      : PPCAsmPrinter(O, TM), DW(O, this) {
254      CommentString = ";";
255      GlobalPrefix = "_";
256      PrivateGlobalPrefix = "L";     // Marker for constant pool idxs
257      ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
258      Data64bitsDirective = 0;       // we can't emit a 64-bit unit
259      AlignmentIsInBytes = false;    // Alignment is by power of 2.
260      ConstantPoolSection = "\t.const\t";
261      LCOMMDirective = "\t.lcomm\t";
262      StaticCtorsSection = ".mod_init_func";
263      StaticDtorsSection = ".mod_term_func";
264      InlineAsmStart = InlineAsmEnd = "";  // Don't use #APP/#NO_APP
265    }
266
267    virtual const char *getPassName() const {
268      return "Darwin PPC Assembly Printer";
269    }
270
271    bool runOnMachineFunction(MachineFunction &F);
272    bool doInitialization(Module &M);
273    bool doFinalization(Module &M);
274
275    void getAnalysisUsage(AnalysisUsage &AU) const {
276      AU.setPreservesAll();
277      AU.addRequired<MachineDebugInfo>();
278      PPCAsmPrinter::getAnalysisUsage(AU);
279    }
280
281  };
282
283  /// AIXAsmPrinter - PowerPC assembly printer, customized for AIX
284  ///
285  struct AIXAsmPrinter : public PPCAsmPrinter {
286    /// Map for labels corresponding to global variables
287    ///
288    std::map<const GlobalVariable*,std::string> GVToLabelMap;
289
290    AIXAsmPrinter(std::ostream &O, TargetMachine &TM)
291      : PPCAsmPrinter(O, TM) {
292      CommentString = "#";
293      GlobalPrefix = ".";
294      ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
295      Data64bitsDirective = 0;       // we can't emit a 64-bit unit
296      AlignmentIsInBytes = false;    // Alignment is by power of 2.
297      ConstantPoolSection = "\t.const\t";
298    }
299
300    virtual const char *getPassName() const {
301      return "AIX PPC Assembly Printer";
302    }
303
304    bool runOnMachineFunction(MachineFunction &F);
305    bool doInitialization(Module &M);
306    bool doFinalization(Module &M);
307  };
308} // end of anonymous namespace
309
310/// createDarwinAsmPrinterPass - Returns a pass that prints the PPC assembly
311/// code for a MachineFunction to the given output stream, in a format that the
312/// Darwin assembler can deal with.
313///
314FunctionPass *llvm::createDarwinAsmPrinter(std::ostream &o,
315                                           PPCTargetMachine &tm) {
316  return new DarwinAsmPrinter(o, tm);
317}
318
319/// createAIXAsmPrinterPass - Returns a pass that prints the PPC assembly code
320/// for a MachineFunction to the given output stream, in a format that the
321/// AIX 5L assembler can deal with.
322///
323FunctionPass *llvm::createAIXAsmPrinter(std::ostream &o, PPCTargetMachine &tm) {
324  return new AIXAsmPrinter(o, tm);
325}
326
327// Include the auto-generated portion of the assembly writer
328#include "PPCGenAsmWriter.inc"
329
330void PPCAsmPrinter::printOp(const MachineOperand &MO) {
331  const MRegisterInfo &RI = *TM.getRegisterInfo();
332  int new_symbol;
333
334  switch (MO.getType()) {
335  case MachineOperand::MO_VirtualRegister:
336    if (Value *V = MO.getVRegValueOrNull()) {
337      O << "<" << V->getName() << ">";
338      return;
339    }
340    // FALLTHROUGH
341  case MachineOperand::MO_MachineRegister:
342  case MachineOperand::MO_CCRegister:
343    O << RI.get(MO.getReg()).Name;
344    return;
345
346  case MachineOperand::MO_SignExtendedImmed:
347  case MachineOperand::MO_UnextendedImmed:
348    std::cerr << "printOp() does not handle immediate values\n";
349    abort();
350    return;
351
352  case MachineOperand::MO_PCRelativeDisp:
353    std::cerr << "Shouldn't use addPCDisp() when building PPC MachineInstrs";
354    abort();
355    return;
356
357  case MachineOperand::MO_MachineBasicBlock: {
358    MachineBasicBlock *MBBOp = MO.getMachineBasicBlock();
359    O << PrivateGlobalPrefix << "BB" << getFunctionNumber() << "_"
360      << MBBOp->getNumber() << "\t; " << MBBOp->getBasicBlock()->getName();
361    return;
362  }
363
364  case MachineOperand::MO_ConstantPoolIndex:
365    O << PrivateGlobalPrefix << "CPI" << getFunctionNumber()
366      << '_' << MO.getConstantPoolIndex();
367    return;
368  case MachineOperand::MO_ExternalSymbol:
369    // Computing the address of an external symbol, not calling it.
370    if (TM.getRelocationModel() != Reloc::Static) {
371      std::string Name(GlobalPrefix); Name += MO.getSymbolName();
372      GVStubs.insert(Name);
373      O << "L" << Name << "$non_lazy_ptr";
374      return;
375    }
376    O << GlobalPrefix << MO.getSymbolName();
377    return;
378  case MachineOperand::MO_GlobalAddress: {
379    // Computing the address of a global symbol, not calling it.
380    GlobalValue *GV = MO.getGlobal();
381    std::string Name = Mang->getValueName(GV);
382    int offset = MO.getOffset();
383
384    // External or weakly linked global variables need non-lazily-resolved stubs
385    if (TM.getRelocationModel() != Reloc::Static) {
386      if (((GV->isExternal() || GV->hasWeakLinkage() ||
387            GV->hasLinkOnceLinkage()))) {
388        GVStubs.insert(Name);
389        O << "L" << Name << "$non_lazy_ptr";
390        return;
391      }
392    }
393
394    O << Name;
395    return;
396  }
397
398  default:
399    O << "<unknown operand type: " << MO.getType() << ">";
400    return;
401  }
402}
403
404/// PrintAsmOperand - Print out an operand for an inline asm expression.
405///
406bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
407                                    unsigned AsmVariant,
408                                    const char *ExtraCode) {
409  // Does this asm operand have a single letter operand modifier?
410  if (ExtraCode && ExtraCode[0]) {
411    if (ExtraCode[1] != 0) return true; // Unknown modifier.
412
413    switch (ExtraCode[0]) {
414    default: return true;  // Unknown modifier.
415    case 'L': // Write second word of DImode reference.
416      // Verify that this operand has two consecutive registers.
417      if (!MI->getOperand(OpNo).isRegister() ||
418          OpNo+1 == MI->getNumOperands() ||
419          !MI->getOperand(OpNo+1).isRegister())
420        return true;
421      ++OpNo;   // Return the high-part.
422      break;
423    }
424  }
425
426  printOperand(MI, OpNo);
427  return false;
428}
429
430bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
431                                          unsigned AsmVariant,
432                                          const char *ExtraCode) {
433  if (ExtraCode && ExtraCode[0])
434    return true; // Unknown modifier.
435  printMemRegReg(MI, OpNo);
436  return false;
437}
438
439/// printMachineInstruction -- Print out a single PowerPC MI in Darwin syntax to
440/// the current output stream.
441///
442void PPCAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
443  ++EmittedInsts;
444
445  // Check for slwi/srwi mnemonics.
446  if (MI->getOpcode() == PPC::RLWINM) {
447    bool FoundMnemonic = false;
448    unsigned char SH = MI->getOperand(2).getImmedValue();
449    unsigned char MB = MI->getOperand(3).getImmedValue();
450    unsigned char ME = MI->getOperand(4).getImmedValue();
451    if (SH <= 31 && MB == 0 && ME == (31-SH)) {
452      O << "slwi "; FoundMnemonic = true;
453    }
454    if (SH <= 31 && MB == (32-SH) && ME == 31) {
455      O << "srwi "; FoundMnemonic = true;
456      SH = 32-SH;
457    }
458    if (FoundMnemonic) {
459      printOperand(MI, 0);
460      O << ", ";
461      printOperand(MI, 1);
462      O << ", " << (unsigned int)SH << "\n";
463      return;
464    }
465  } else if (MI->getOpcode() == PPC::OR4 || MI->getOpcode() == PPC::OR8) {
466    if (MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
467      O << "mr ";
468      printOperand(MI, 0);
469      O << ", ";
470      printOperand(MI, 1);
471      O << "\n";
472      return;
473    }
474  }
475
476  if (printInstruction(MI))
477    return; // Printer was automatically generated
478
479  assert(0 && "Unhandled instruction in asm writer!");
480  abort();
481  return;
482}
483
484
485/// runOnMachineFunction - This uses the printMachineInstruction()
486/// method to print assembly for each instruction.
487///
488bool DarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
489  // FIXME - is this the earliest this can be set?
490  DW.SetDebugInfo(&getAnalysis<MachineDebugInfo>());
491
492  SetupMachineFunction(MF);
493  O << "\n\n";
494
495  // Emit pre-function debug information.
496  DW.BeginFunction(MF);
497
498  // Print out constants referenced by the function
499  EmitConstantPool(MF.getConstantPool());
500
501  // Print out labels for the function.
502  const Function *F = MF.getFunction();
503  switch (F->getLinkage()) {
504  default: assert(0 && "Unknown linkage type!");
505  case Function::InternalLinkage:  // Symbols default to internal.
506    SwitchSection(".text", F);
507    break;
508  case Function::ExternalLinkage:
509    SwitchSection(".text", F);
510    O << "\t.globl\t" << CurrentFnName << "\n";
511    break;
512  case Function::WeakLinkage:
513  case Function::LinkOnceLinkage:
514    SwitchSection(".section __TEXT,__textcoal_nt,coalesced,pure_instructions",
515                  F);
516    O << "\t.globl\t" << CurrentFnName << "\n";
517    O << "\t.weak_definition\t" << CurrentFnName << "\n";
518    break;
519  }
520  EmitAlignment(4, F);
521  O << CurrentFnName << ":\n";
522
523  // Print out code for the function.
524  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
525       I != E; ++I) {
526    // Print a label for the basic block.
527    if (I != MF.begin()) {
528      O << PrivateGlobalPrefix << "BB" << getFunctionNumber() << '_'
529        << I->getNumber() << ":\t";
530      if (!I->getBasicBlock()->getName().empty())
531        O << CommentString << " " << I->getBasicBlock()->getName();
532      O << "\n";
533    }
534    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
535         II != E; ++II) {
536      // Print the assembly for the instruction.
537      O << "\t";
538      printMachineInstruction(II);
539    }
540  }
541
542  // Emit post-function debug information.
543  DW.EndFunction(MF);
544
545  // We didn't modify anything.
546  return false;
547}
548
549
550bool DarwinAsmPrinter::doInitialization(Module &M) {
551  if (TM.getSubtarget<PPCSubtarget>().isGigaProcessor())
552    O << "\t.machine ppc970\n";
553  AsmPrinter::doInitialization(M);
554
555  // Darwin wants symbols to be quoted if they have complex names.
556  Mang->setUseQuotes(true);
557
558  // Emit initial debug information.
559  DW.BeginModule(M);
560  return false;
561}
562
563bool DarwinAsmPrinter::doFinalization(Module &M) {
564  const TargetData &TD = TM.getTargetData();
565
566  // Print out module-level global variables here.
567  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
568       I != E; ++I) {
569    if (!I->hasInitializer()) continue;   // External global require no code
570
571    // Check to see if this is a special global used by LLVM, if so, emit it.
572    if (EmitSpecialLLVMGlobal(I))
573      continue;
574
575    std::string name = Mang->getValueName(I);
576    Constant *C = I->getInitializer();
577    unsigned Size = TD.getTypeSize(C->getType());
578    unsigned Align = getPreferredAlignmentLog(I);
579
580    if (C->isNullValue() && /* FIXME: Verify correct */
581        (I->hasInternalLinkage() || I->hasWeakLinkage() ||
582         I->hasLinkOnceLinkage() ||
583         (I->hasExternalLinkage() && !I->hasSection()))) {
584      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
585      if (I->hasExternalLinkage()) {
586        O << "\t.globl " << name << '\n';
587        O << "\t.zerofill __DATA, __common, " << name << ", "
588          << Size << ", " << Align;
589      } else if (I->hasInternalLinkage()) {
590        SwitchSection(".data", I);
591        O << LCOMMDirective << name << "," << Size << "," << Align;
592      } else {
593        SwitchSection(".data", I);
594        O << ".comm " << name << "," << Size;
595      }
596      O << "\t\t; '" << I->getName() << "'\n";
597    } else {
598      switch (I->getLinkage()) {
599      case GlobalValue::LinkOnceLinkage:
600      case GlobalValue::WeakLinkage:
601        O << "\t.globl " << name << '\n'
602          << "\t.weak_definition " << name << '\n';
603        SwitchSection(".section __DATA,__datacoal_nt,coalesced", I);
604        break;
605      case GlobalValue::AppendingLinkage:
606        // FIXME: appending linkage variables should go into a section of
607        // their name or something.  For now, just emit them as external.
608      case GlobalValue::ExternalLinkage:
609        // If external or appending, declare as a global symbol
610        O << "\t.globl " << name << "\n";
611        // FALL THROUGH
612      case GlobalValue::InternalLinkage:
613        SwitchSection(".data", I);
614        break;
615      default:
616        std::cerr << "Unknown linkage type!";
617        abort();
618      }
619
620      EmitAlignment(Align, I);
621      O << name << ":\t\t\t\t; '" << I->getName() << "'\n";
622      EmitGlobalConstant(C);
623      O << '\n';
624    }
625  }
626
627  // Output stubs for dynamically-linked functions
628  if (TM.getRelocationModel() == Reloc::PIC) {
629    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
630         i != e; ++i) {
631      SwitchSection(".section __TEXT,__picsymbolstub1,symbol_stubs,"
632                    "pure_instructions,32", 0);
633      EmitAlignment(2);
634      O << "L" << *i << "$stub:\n";
635      O << "\t.indirect_symbol " << *i << "\n";
636      O << "\tmflr r0\n";
637      O << "\tbcl 20,31,L0$" << *i << "\n";
638      O << "L0$" << *i << ":\n";
639      O << "\tmflr r11\n";
640      O << "\taddis r11,r11,ha16(L" << *i << "$lazy_ptr-L0$" << *i << ")\n";
641      O << "\tmtlr r0\n";
642      O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
643      O << "\tmtctr r12\n";
644      O << "\tbctr\n";
645      SwitchSection(".lazy_symbol_pointer", 0);
646      O << "L" << *i << "$lazy_ptr:\n";
647      O << "\t.indirect_symbol " << *i << "\n";
648      O << "\t.long dyld_stub_binding_helper\n";
649    }
650  } else {
651    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
652         i != e; ++i) {
653      SwitchSection(".section __TEXT,__symbol_stub1,symbol_stubs,"
654                    "pure_instructions,16", 0);
655      EmitAlignment(4);
656      O << "L" << *i << "$stub:\n";
657      O << "\t.indirect_symbol " << *i << "\n";
658      O << "\tlis r11,ha16(L" << *i << "$lazy_ptr)\n";
659      O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
660      O << "\tmtctr r12\n";
661      O << "\tbctr\n";
662      SwitchSection(".lazy_symbol_pointer", 0);
663      O << "L" << *i << "$lazy_ptr:\n";
664      O << "\t.indirect_symbol " << *i << "\n";
665      O << "\t.long dyld_stub_binding_helper\n";
666    }
667  }
668
669  O << "\n";
670
671  // Output stubs for external and common global variables.
672  if (GVStubs.begin() != GVStubs.end()) {
673    SwitchSection(".non_lazy_symbol_pointer", 0);
674    for (std::set<std::string>::iterator I = GVStubs.begin(),
675         E = GVStubs.end(); I != E; ++I) {
676      O << "L" << *I << "$non_lazy_ptr:\n";
677      O << "\t.indirect_symbol " << *I << "\n";
678      O << "\t.long\t0\n";
679    }
680  }
681
682  // Emit initial debug information.
683  DW.EndModule(M);
684
685  // Funny Darwin hack: This flag tells the linker that no global symbols
686  // contain code that falls through to other global symbols (e.g. the obvious
687  // implementation of multiple entry points).  If this doesn't occur, the
688  // linker can safely perform dead code stripping.  Since LLVM never generates
689  // code that does this, it is always safe to set.
690  O << "\t.subsections_via_symbols\n";
691
692  AsmPrinter::doFinalization(M);
693  return false; // success
694}
695
696/// runOnMachineFunction - This uses the e()
697/// method to print assembly for each instruction.
698///
699bool AIXAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
700  SetupMachineFunction(MF);
701
702  // Print out constants referenced by the function
703  EmitConstantPool(MF.getConstantPool());
704
705  // Print out header for the function.
706  O << "\t.csect .text[PR]\n"
707    << "\t.align 2\n"
708    << "\t.globl "  << CurrentFnName << '\n'
709    << "\t.globl ." << CurrentFnName << '\n'
710    << "\t.csect "  << CurrentFnName << "[DS],3\n"
711    << CurrentFnName << ":\n"
712    << "\t.llong ." << CurrentFnName << ", TOC[tc0], 0\n"
713    << "\t.csect .text[PR]\n"
714    << '.' << CurrentFnName << ":\n";
715
716  // Print out code for the function.
717  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
718       I != E; ++I) {
719    // Print a label for the basic block.
720    O << PrivateGlobalPrefix << "BB" << getFunctionNumber() << '_'
721      << I->getNumber()
722      << ":\t" << CommentString << I->getBasicBlock()->getName() << '\n';
723    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
724      II != E; ++II) {
725      // Print the assembly for the instruction.
726      O << "\t";
727      printMachineInstruction(II);
728    }
729  }
730
731  O << "LT.." << CurrentFnName << ":\n"
732    << "\t.long 0\n"
733    << "\t.byte 0,0,32,65,128,0,0,0\n"
734    << "\t.long LT.." << CurrentFnName << "-." << CurrentFnName << '\n'
735    << "\t.short 3\n"
736    << "\t.byte \"" << CurrentFnName << "\"\n"
737    << "\t.align 2\n";
738
739  // We didn't modify anything.
740  return false;
741}
742
743bool AIXAsmPrinter::doInitialization(Module &M) {
744  SwitchSection("", 0);
745  const TargetData &TD = TM.getTargetData();
746
747  O << "\t.machine \"ppc64\"\n"
748    << "\t.toc\n"
749    << "\t.csect .text[PR]\n";
750
751  // Print out module-level global variables
752  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
753       I != E; ++I) {
754    if (!I->hasInitializer())
755      continue;
756
757    std::string Name = I->getName();
758    Constant *C = I->getInitializer();
759    // N.B.: We are defaulting to writable strings
760    if (I->hasExternalLinkage()) {
761      O << "\t.globl " << Name << '\n'
762        << "\t.csect .data[RW],3\n";
763    } else {
764      O << "\t.csect _global.rw_c[RW],3\n";
765    }
766    O << Name << ":\n";
767    EmitGlobalConstant(C);
768  }
769
770  // Output labels for globals
771  if (M.global_begin() != M.global_end()) O << "\t.toc\n";
772  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
773       I != E; ++I) {
774    const GlobalVariable *GV = I;
775    // Do not output labels for unused variables
776    if (GV->isExternal() && GV->use_begin() == GV->use_end())
777      continue;
778
779    IncrementFunctionNumber();
780    std::string Name = GV->getName();
781    std::string Label = "LC.." + utostr(getFunctionNumber());
782    GVToLabelMap[GV] = Label;
783    O << Label << ":\n"
784      << "\t.tc " << Name << "[TC]," << Name;
785    if (GV->isExternal()) O << "[RW]";
786    O << '\n';
787   }
788
789  AsmPrinter::doInitialization(M);
790  return false; // success
791}
792
793bool AIXAsmPrinter::doFinalization(Module &M) {
794  const TargetData &TD = TM.getTargetData();
795  // Print out module-level global variables
796  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
797       I != E; ++I) {
798    if (I->hasInitializer() || I->hasExternalLinkage())
799      continue;
800
801    std::string Name = I->getName();
802    if (I->hasInternalLinkage()) {
803      O << "\t.lcomm " << Name << ",16,_global.bss_c";
804    } else {
805      O << "\t.comm " << Name << "," << TD.getTypeSize(I->getType())
806        << "," << Log2_32((unsigned)TD.getTypeAlignment(I->getType()));
807    }
808    O << "\t\t" << CommentString << " ";
809    WriteAsOperand(O, I, false, true, &M);
810    O << "\n";
811  }
812
813  O << "_section_.text:\n"
814    << "\t.csect .data[RW],3\n"
815    << "\t.llong _section_.text\n";
816  AsmPrinter::doFinalization(M);
817  return false; // success
818}
819