PPCAsmPrinter.cpp revision f8a01a966120a041fe96300271573a8bf5a3e668 
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.isRegister()) {
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 __DWARF,__debug_abbrev";
250      DwarfInfoSection = ".section __DWARF,__debug_info";
251      DwarfLineSection = ".section __DWARF,__debug_line";
252      DwarfFrameSection = ".section __DWARF,__debug_frame";
253      DwarfPubNamesSection = ".section __DWARF,__debug_pubnames";
254      DwarfPubTypesSection = ".section __DWARF,__debug_pubtypes";
255      DwarfStrSection = ".section __DWARF,__debug_str";
256      DwarfLocSection = ".section __DWARF,__debug_loc";
257      DwarfARangesSection = ".section __DWARF,__debug_aranges";
258      DwarfRangesSection = ".section __DWARF,__debug_ranges";
259      DwarfMacInfoSection = ".section __DWARF,__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 = "# InlineAsm Start";
286      InlineAsmEnd = "# InlineAsm End";
287    }
288
289    virtual const char *getPassName() const {
290      return "Darwin PPC Assembly Printer";
291    }
292
293    bool runOnMachineFunction(MachineFunction &F);
294    bool doInitialization(Module &M);
295    bool doFinalization(Module &M);
296
297    void getAnalysisUsage(AnalysisUsage &AU) const {
298      AU.setPreservesAll();
299      AU.addRequired<MachineDebugInfo>();
300      PPCAsmPrinter::getAnalysisUsage(AU);
301    }
302
303  };
304
305  /// AIXAsmPrinter - PowerPC assembly printer, customized for AIX
306  ///
307  struct AIXAsmPrinter : public PPCAsmPrinter {
308    /// Map for labels corresponding to global variables
309    ///
310    std::map<const GlobalVariable*,std::string> GVToLabelMap;
311
312    AIXAsmPrinter(std::ostream &O, TargetMachine &TM)
313      : PPCAsmPrinter(O, TM) {
314      CommentString = "#";
315      GlobalPrefix = ".";
316      ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
317      Data64bitsDirective = 0;       // we can't emit a 64-bit unit
318      AlignmentIsInBytes = false;    // Alignment is by power of 2.
319      ConstantPoolSection = "\t.const\t";
320    }
321
322    virtual const char *getPassName() const {
323      return "AIX PPC Assembly Printer";
324    }
325
326    bool runOnMachineFunction(MachineFunction &F);
327    bool doInitialization(Module &M);
328    bool doFinalization(Module &M);
329  };
330} // end of anonymous namespace
331
332/// createDarwinAsmPrinterPass - Returns a pass that prints the PPC assembly
333/// code for a MachineFunction to the given output stream, in a format that the
334/// Darwin assembler can deal with.
335///
336FunctionPass *llvm::createDarwinAsmPrinter(std::ostream &o,
337                                           PPCTargetMachine &tm) {
338  return new DarwinAsmPrinter(o, tm);
339}
340
341/// createAIXAsmPrinterPass - Returns a pass that prints the PPC assembly code
342/// for a MachineFunction to the given output stream, in a format that the
343/// AIX 5L assembler can deal with.
344///
345FunctionPass *llvm::createAIXAsmPrinter(std::ostream &o, PPCTargetMachine &tm) {
346  return new AIXAsmPrinter(o, tm);
347}
348
349// Include the auto-generated portion of the assembly writer
350#include "PPCGenAsmWriter.inc"
351
352void PPCAsmPrinter::printOp(const MachineOperand &MO) {
353  switch (MO.getType()) {
354  case MachineOperand::MO_Immediate:
355    std::cerr << "printOp() does not handle immediate values\n";
356    abort();
357    return;
358
359  case MachineOperand::MO_MachineBasicBlock:
360    printBasicBlockLabel(MO.getMachineBasicBlock());
361    return;
362  case MachineOperand::MO_JumpTableIndex:
363    O << PrivateGlobalPrefix << "JTI" << getFunctionNumber()
364      << '_' << MO.getJumpTableIndex();
365    // FIXME: PIC relocation model
366    return;
367  case MachineOperand::MO_ConstantPoolIndex:
368    O << PrivateGlobalPrefix << "CPI" << getFunctionNumber()
369      << '_' << MO.getConstantPoolIndex();
370    return;
371  case MachineOperand::MO_ExternalSymbol:
372    // Computing the address of an external symbol, not calling it.
373    if (TM.getRelocationModel() != Reloc::Static) {
374      std::string Name(GlobalPrefix); Name += MO.getSymbolName();
375      GVStubs.insert(Name);
376      O << "L" << Name << "$non_lazy_ptr";
377      return;
378    }
379    O << GlobalPrefix << MO.getSymbolName();
380    return;
381  case MachineOperand::MO_GlobalAddress: {
382    // Computing the address of a global symbol, not calling it.
383    GlobalValue *GV = MO.getGlobal();
384    std::string Name = Mang->getValueName(GV);
385    int offset = MO.getOffset();
386
387    // External or weakly linked global variables need non-lazily-resolved stubs
388    if (TM.getRelocationModel() != Reloc::Static) {
389      if (((GV->isExternal() || GV->hasWeakLinkage() ||
390            GV->hasLinkOnceLinkage()))) {
391        GVStubs.insert(Name);
392        O << "L" << Name << "$non_lazy_ptr";
393        return;
394      }
395    }
396
397    O << Name;
398    return;
399  }
400
401  default:
402    O << "<unknown operand type: " << MO.getType() << ">";
403    return;
404  }
405}
406
407/// PrintAsmOperand - Print out an operand for an inline asm expression.
408///
409bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
410                                    unsigned AsmVariant,
411                                    const char *ExtraCode) {
412  // Does this asm operand have a single letter operand modifier?
413  if (ExtraCode && ExtraCode[0]) {
414    if (ExtraCode[1] != 0) return true; // Unknown modifier.
415
416    switch (ExtraCode[0]) {
417    default: return true;  // Unknown modifier.
418    case 'L': // Write second word of DImode reference.
419      // Verify that this operand has two consecutive registers.
420      if (!MI->getOperand(OpNo).isRegister() ||
421          OpNo+1 == MI->getNumOperands() ||
422          !MI->getOperand(OpNo+1).isRegister())
423        return true;
424      ++OpNo;   // Return the high-part.
425      break;
426    }
427  }
428
429  printOperand(MI, OpNo);
430  return false;
431}
432
433bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
434                                          unsigned AsmVariant,
435                                          const char *ExtraCode) {
436  if (ExtraCode && ExtraCode[0])
437    return true; // Unknown modifier.
438  printMemRegReg(MI, OpNo);
439  return false;
440}
441
442/// printMachineInstruction -- Print out a single PowerPC MI in Darwin syntax to
443/// the current output stream.
444///
445void PPCAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
446  ++EmittedInsts;
447
448  // Check for slwi/srwi mnemonics.
449  if (MI->getOpcode() == PPC::RLWINM) {
450    bool FoundMnemonic = false;
451    unsigned char SH = MI->getOperand(2).getImmedValue();
452    unsigned char MB = MI->getOperand(3).getImmedValue();
453    unsigned char ME = MI->getOperand(4).getImmedValue();
454    if (SH <= 31 && MB == 0 && ME == (31-SH)) {
455      O << "slwi "; FoundMnemonic = true;
456    }
457    if (SH <= 31 && MB == (32-SH) && ME == 31) {
458      O << "srwi "; FoundMnemonic = true;
459      SH = 32-SH;
460    }
461    if (FoundMnemonic) {
462      printOperand(MI, 0);
463      O << ", ";
464      printOperand(MI, 1);
465      O << ", " << (unsigned int)SH << "\n";
466      return;
467    }
468  } else if (MI->getOpcode() == PPC::OR4 || MI->getOpcode() == PPC::OR8) {
469    if (MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
470      O << "mr ";
471      printOperand(MI, 0);
472      O << ", ";
473      printOperand(MI, 1);
474      O << "\n";
475      return;
476    }
477  }
478
479  if (printInstruction(MI))
480    return; // Printer was automatically generated
481
482  assert(0 && "Unhandled instruction in asm writer!");
483  abort();
484  return;
485}
486
487/// runOnMachineFunction - This uses the printMachineInstruction()
488/// method to print assembly for each instruction.
489///
490bool DarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
491  DW.SetDebugInfo(&getAnalysis<MachineDebugInfo>());
492  // FIXME - should be able to debug coalesced functions.
493  bool IsNormalText = true;
494
495  SetupMachineFunction(MF);
496  O << "\n\n";
497
498  // Print out constants referenced by the function
499  EmitConstantPool(MF.getConstantPool());
500
501  // Print out jump tables referenced by the function
502  EmitJumpTableInfo(MF.getJumpTableInfo());
503
504  // Print out labels for the function.
505  const Function *F = MF.getFunction();
506  switch (F->getLinkage()) {
507  default: assert(0 && "Unknown linkage type!");
508  case Function::InternalLinkage:  // Symbols default to internal.
509    SwitchToTextSection("\t.text", F);
510    break;
511  case Function::ExternalLinkage:
512    SwitchToTextSection("\t.text", F);
513    O << "\t.globl\t" << CurrentFnName << "\n";
514    break;
515  case Function::WeakLinkage:
516  case Function::LinkOnceLinkage:
517    SwitchToTextSection(
518                ".section __TEXT,__textcoal_nt,coalesced,pure_instructions", F);
519    O << "\t.globl\t" << CurrentFnName << "\n";
520    O << "\t.weak_definition\t" << CurrentFnName << "\n";
521    IsNormalText = false;
522    break;
523  }
524  EmitAlignment(4, F);
525  O << CurrentFnName << ":\n";
526
527  // Emit pre-function debug information.
528  DW.BeginFunction(&MF, IsNormalText);
529
530  // Print out code for the function.
531  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
532       I != E; ++I) {
533    // Print a label for the basic block.
534    if (I != MF.begin()) {
535      printBasicBlockLabel(I, true);
536      O << '\n';
537    }
538    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
539         II != E; ++II) {
540      // Print the assembly for the instruction.
541      O << "\t";
542      printMachineInstruction(II);
543    }
544  }
545
546  // Emit post-function debug information.
547  DW.EndFunction();
548
549  // We didn't modify anything.
550  return false;
551}
552
553
554bool DarwinAsmPrinter::doInitialization(Module &M) {
555  if (TM.getSubtarget<PPCSubtarget>().isGigaProcessor())
556    O << "\t.machine ppc970\n";
557  AsmPrinter::doInitialization(M);
558
559  // Darwin wants symbols to be quoted if they have complex names.
560  Mang->setUseQuotes(true);
561
562  // Emit initial debug information.
563  DW.BeginModule(&M);
564  return false;
565}
566
567bool DarwinAsmPrinter::doFinalization(Module &M) {
568  const TargetData *TD = TM.getTargetData();
569
570  // Print out module-level global variables here.
571  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
572       I != E; ++I) {
573    if (!I->hasInitializer()) continue;   // External global require no code
574
575    // Check to see if this is a special global used by LLVM, if so, emit it.
576    if (EmitSpecialLLVMGlobal(I))
577      continue;
578
579    std::string name = Mang->getValueName(I);
580    Constant *C = I->getInitializer();
581    unsigned Size = TD->getTypeSize(C->getType());
582    unsigned Align = getPreferredAlignmentLog(I);
583
584    if (C->isNullValue() && /* FIXME: Verify correct */
585        (I->hasInternalLinkage() || I->hasWeakLinkage() ||
586         I->hasLinkOnceLinkage() ||
587         (I->hasExternalLinkage() && !I->hasSection()))) {
588      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
589      if (I->hasExternalLinkage()) {
590        O << "\t.globl " << name << '\n';
591        O << "\t.zerofill __DATA, __common, " << name << ", "
592          << Size << ", " << Align;
593      } else if (I->hasInternalLinkage()) {
594        SwitchToDataSection("\t.data", I);
595        O << LCOMMDirective << name << "," << Size << "," << Align;
596      } else {
597        SwitchToDataSection("\t.data", I);
598        O << ".comm " << name << "," << Size;
599      }
600      O << "\t\t; '" << I->getName() << "'\n";
601    } else {
602      switch (I->getLinkage()) {
603      case GlobalValue::LinkOnceLinkage:
604      case GlobalValue::WeakLinkage:
605        O << "\t.globl " << name << '\n'
606          << "\t.weak_definition " << name << '\n';
607        SwitchToDataSection(".section __DATA,__datacoal_nt,coalesced", I);
608        break;
609      case GlobalValue::AppendingLinkage:
610        // FIXME: appending linkage variables should go into a section of
611        // their name or something.  For now, just emit them as external.
612      case GlobalValue::ExternalLinkage:
613        // If external or appending, declare as a global symbol
614        O << "\t.globl " << name << "\n";
615        // FALL THROUGH
616      case GlobalValue::InternalLinkage:
617        SwitchToDataSection("\t.data", I);
618        break;
619      default:
620        std::cerr << "Unknown linkage type!";
621        abort();
622      }
623
624      EmitAlignment(Align, I);
625      O << name << ":\t\t\t\t; '" << I->getName() << "'\n";
626      EmitGlobalConstant(C);
627      O << '\n';
628    }
629  }
630
631  // Output stubs for dynamically-linked functions
632  if (TM.getRelocationModel() == Reloc::PIC) {
633    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
634         i != e; ++i) {
635      SwitchToTextSection(".section __TEXT,__picsymbolstub1,symbol_stubs,"
636                          "pure_instructions,32", 0);
637      EmitAlignment(2);
638      O << "L" << *i << "$stub:\n";
639      O << "\t.indirect_symbol " << *i << "\n";
640      O << "\tmflr r0\n";
641      O << "\tbcl 20,31,L0$" << *i << "\n";
642      O << "L0$" << *i << ":\n";
643      O << "\tmflr r11\n";
644      O << "\taddis r11,r11,ha16(L" << *i << "$lazy_ptr-L0$" << *i << ")\n";
645      O << "\tmtlr r0\n";
646      O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
647      O << "\tmtctr r12\n";
648      O << "\tbctr\n";
649      SwitchToDataSection(".lazy_symbol_pointer", 0);
650      O << "L" << *i << "$lazy_ptr:\n";
651      O << "\t.indirect_symbol " << *i << "\n";
652      O << "\t.long dyld_stub_binding_helper\n";
653    }
654  } else {
655    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
656         i != e; ++i) {
657      SwitchToTextSection(".section __TEXT,__symbol_stub1,symbol_stubs,"
658                          "pure_instructions,16", 0);
659      EmitAlignment(4);
660      O << "L" << *i << "$stub:\n";
661      O << "\t.indirect_symbol " << *i << "\n";
662      O << "\tlis r11,ha16(L" << *i << "$lazy_ptr)\n";
663      O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
664      O << "\tmtctr r12\n";
665      O << "\tbctr\n";
666      SwitchToDataSection(".lazy_symbol_pointer", 0);
667      O << "L" << *i << "$lazy_ptr:\n";
668      O << "\t.indirect_symbol " << *i << "\n";
669      O << "\t.long dyld_stub_binding_helper\n";
670    }
671  }
672
673  O << "\n";
674
675  // Output stubs for external and common global variables.
676  if (GVStubs.begin() != GVStubs.end()) {
677    SwitchToDataSection(".non_lazy_symbol_pointer", 0);
678    for (std::set<std::string>::iterator I = GVStubs.begin(),
679         E = GVStubs.end(); I != E; ++I) {
680      O << "L" << *I << "$non_lazy_ptr:\n";
681      O << "\t.indirect_symbol " << *I << "\n";
682      O << "\t.long\t0\n";
683    }
684  }
685
686  // Emit initial debug information.
687  DW.EndModule();
688
689  // Funny Darwin hack: This flag tells the linker that no global symbols
690  // contain code that falls through to other global symbols (e.g. the obvious
691  // implementation of multiple entry points).  If this doesn't occur, the
692  // linker can safely perform dead code stripping.  Since LLVM never generates
693  // code that does this, it is always safe to set.
694  O << "\t.subsections_via_symbols\n";
695
696  AsmPrinter::doFinalization(M);
697  return false; // success
698}
699
700/// runOnMachineFunction - This uses the printMachineInstruction()
701/// method to print assembly for each instruction.
702///
703bool AIXAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
704  SetupMachineFunction(MF);
705
706  // Print out constants referenced by the function
707  EmitConstantPool(MF.getConstantPool());
708
709  // Print out header for the function.
710  O << "\t.csect .text[PR]\n"
711    << "\t.align 2\n"
712    << "\t.globl "  << CurrentFnName << '\n'
713    << "\t.globl ." << CurrentFnName << '\n'
714    << "\t.csect "  << CurrentFnName << "[DS],3\n"
715    << CurrentFnName << ":\n"
716    << "\t.llong ." << CurrentFnName << ", TOC[tc0], 0\n"
717    << "\t.csect .text[PR]\n"
718    << '.' << CurrentFnName << ":\n";
719
720  // Print out code for the function.
721  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
722       I != E; ++I) {
723    printBasicBlockLabel(I);
724    O << '\n';
725    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
726      II != E; ++II) {
727      // Print the assembly for the instruction.
728      O << "\t";
729      printMachineInstruction(II);
730    }
731  }
732
733  O << "LT.." << CurrentFnName << ":\n"
734    << "\t.long 0\n"
735    << "\t.byte 0,0,32,65,128,0,0,0\n"
736    << "\t.long LT.." << CurrentFnName << "-." << CurrentFnName << '\n'
737    << "\t.short 3\n"
738    << "\t.byte \"" << CurrentFnName << "\"\n"
739    << "\t.align 2\n";
740
741  // We didn't modify anything.
742  return false;
743}
744
745bool AIXAsmPrinter::doInitialization(Module &M) {
746  SwitchToDataSection("", 0);
747
748  O << "\t.machine \"ppc64\"\n"
749    << "\t.toc\n"
750    << "\t.csect .text[PR]\n";
751
752  // Print out module-level global variables
753  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
754       I != E; ++I) {
755    if (!I->hasInitializer())
756      continue;
757
758    std::string Name = I->getName();
759    Constant *C = I->getInitializer();
760    // N.B.: We are defaulting to writable strings
761    if (I->hasExternalLinkage()) {
762      O << "\t.globl " << Name << '\n'
763        << "\t.csect .data[RW],3\n";
764    } else {
765      O << "\t.csect _global.rw_c[RW],3\n";
766    }
767    O << Name << ":\n";
768    EmitGlobalConstant(C);
769  }
770
771  // Output labels for globals
772  if (M.global_begin() != M.global_end()) O << "\t.toc\n";
773  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
774       I != E; ++I) {
775    const GlobalVariable *GV = I;
776    // Do not output labels for unused variables
777    if (GV->isExternal() && GV->use_begin() == GV->use_end())
778      continue;
779
780    IncrementFunctionNumber();
781    std::string Name = GV->getName();
782    std::string Label = "LC.." + utostr(getFunctionNumber());
783    GVToLabelMap[GV] = Label;
784    O << Label << ":\n"
785      << "\t.tc " << Name << "[TC]," << Name;
786    if (GV->isExternal()) O << "[RW]";
787    O << '\n';
788   }
789
790  AsmPrinter::doInitialization(M);
791  return false; // success
792}
793
794bool AIXAsmPrinter::doFinalization(Module &M) {
795  const TargetData *TD = TM.getTargetData();
796  // Print out module-level global variables
797  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
798       I != E; ++I) {
799    if (I->hasInitializer() || I->hasExternalLinkage())
800      continue;
801
802    std::string Name = I->getName();
803    if (I->hasInternalLinkage()) {
804      O << "\t.lcomm " << Name << ",16,_global.bss_c";
805    } else {
806      O << "\t.comm " << Name << "," << TD->getTypeSize(I->getType())
807        << "," << Log2_32((unsigned)TD->getTypeAlignment(I->getType()));
808    }
809    O << "\t\t" << CommentString << " ";
810    WriteAsOperand(O, I, false, true, &M);
811    O << "\n";
812  }
813
814  O << "_section_.text:\n"
815    << "\t.csect .data[RW],3\n"
816    << "\t.llong _section_.text\n";
817  AsmPrinter::doFinalization(M);
818  return false; // success
819}
820