PPCAsmPrinter.cpp revision f5b6a47bb57fb5ffc734416d4d5d993e1a06273b 
1//===-- PPCAsmPrinter.cpp - Print machine instrs to PowerPC assembly --------=//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// 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 "PPCPredicates.h"
22#include "PPCTargetMachine.h"
23#include "PPCSubtarget.h"
24#include "llvm/Constants.h"
25#include "llvm/DerivedTypes.h"
26#include "llvm/Module.h"
27#include "llvm/Assembly/Writer.h"
28#include "llvm/CodeGen/AsmPrinter.h"
29#include "llvm/CodeGen/DwarfWriter.h"
30#include "llvm/CodeGen/MachineModuleInfo.h"
31#include "llvm/CodeGen/MachineFunctionPass.h"
32#include "llvm/CodeGen/MachineInstr.h"
33#include "llvm/CodeGen/MachineInstrBuilder.h"
34#include "llvm/Support/Mangler.h"
35#include "llvm/Support/MathExtras.h"
36#include "llvm/Support/CommandLine.h"
37#include "llvm/Support/Debug.h"
38#include "llvm/Support/Compiler.h"
39#include "llvm/Target/TargetAsmInfo.h"
40#include "llvm/Target/TargetRegisterInfo.h"
41#include "llvm/Target/TargetInstrInfo.h"
42#include "llvm/Target/TargetOptions.h"
43#include "llvm/ADT/Statistic.h"
44#include "llvm/ADT/StringExtras.h"
45#include <set>
46using namespace llvm;
47
48STATISTIC(EmittedInsts, "Number of machine instrs printed");
49
50namespace {
51  struct VISIBILITY_HIDDEN PPCAsmPrinter : public AsmPrinter {
52    std::set<std::string> FnStubs, GVStubs;
53    const PPCSubtarget &Subtarget;
54
55    PPCAsmPrinter(std::ostream &O, TargetMachine &TM, const TargetAsmInfo *T)
56      : AsmPrinter(O, TM, T), Subtarget(TM.getSubtarget<PPCSubtarget>()) {
57    }
58
59    virtual const char *getPassName() const {
60      return "PowerPC Assembly Printer";
61    }
62
63    PPCTargetMachine &getTM() {
64      return static_cast<PPCTargetMachine&>(TM);
65    }
66
67    unsigned enumRegToMachineReg(unsigned enumReg) {
68      switch (enumReg) {
69      default: assert(0 && "Unhandled register!"); break;
70      case PPC::CR0:  return  0;
71      case PPC::CR1:  return  1;
72      case PPC::CR2:  return  2;
73      case PPC::CR3:  return  3;
74      case PPC::CR4:  return  4;
75      case PPC::CR5:  return  5;
76      case PPC::CR6:  return  6;
77      case PPC::CR7:  return  7;
78      }
79      abort();
80    }
81
82    /// printInstruction - This method is automatically generated by tablegen
83    /// from the instruction set description.  This method returns true if the
84    /// machine instruction was sufficiently described to print it, otherwise it
85    /// returns false.
86    bool printInstruction(const MachineInstr *MI);
87
88    void printMachineInstruction(const MachineInstr *MI);
89    void printOp(const MachineOperand &MO);
90
91    /// stripRegisterPrefix - This method strips the character prefix from a
92    /// register name so that only the number is left.  Used by for linux asm.
93    const char *stripRegisterPrefix(const char *RegName) {
94      switch (RegName[0]) {
95      case 'r':
96      case 'f':
97      case 'v': return RegName + 1;
98      case 'c': if (RegName[1] == 'r') return RegName + 2;
99      }
100
101      return RegName;
102    }
103
104    /// printRegister - Print register according to target requirements.
105    ///
106    void printRegister(const MachineOperand &MO, bool R0AsZero) {
107      unsigned RegNo = MO.getReg();
108      assert(TargetRegisterInfo::isPhysicalRegister(RegNo) && "Not physreg??");
109
110      // If we should use 0 for R0.
111      if (R0AsZero && RegNo == PPC::R0) {
112        O << "0";
113        return;
114      }
115
116      const char *RegName = TM.getRegisterInfo()->get(RegNo).AsmName;
117      // Linux assembler (Others?) does not take register mnemonics.
118      // FIXME - What about special registers used in mfspr/mtspr?
119      if (!Subtarget.isDarwin()) RegName = stripRegisterPrefix(RegName);
120      O << RegName;
121    }
122
123    void printOperand(const MachineInstr *MI, unsigned OpNo) {
124      const MachineOperand &MO = MI->getOperand(OpNo);
125      if (MO.isRegister()) {
126        printRegister(MO, false);
127      } else if (MO.isImmediate()) {
128        O << MO.getImm();
129      } else {
130        printOp(MO);
131      }
132    }
133
134    bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
135                         unsigned AsmVariant, const char *ExtraCode);
136    bool PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
137                               unsigned AsmVariant, const char *ExtraCode);
138
139
140    void printS5ImmOperand(const MachineInstr *MI, unsigned OpNo) {
141      char value = MI->getOperand(OpNo).getImm();
142      value = (value << (32-5)) >> (32-5);
143      O << (int)value;
144    }
145    void printU5ImmOperand(const MachineInstr *MI, unsigned OpNo) {
146      unsigned char value = MI->getOperand(OpNo).getImm();
147      assert(value <= 31 && "Invalid u5imm argument!");
148      O << (unsigned int)value;
149    }
150    void printU6ImmOperand(const MachineInstr *MI, unsigned OpNo) {
151      unsigned char value = MI->getOperand(OpNo).getImm();
152      assert(value <= 63 && "Invalid u6imm argument!");
153      O << (unsigned int)value;
154    }
155    void printS16ImmOperand(const MachineInstr *MI, unsigned OpNo) {
156      O << (short)MI->getOperand(OpNo).getImm();
157    }
158    void printU16ImmOperand(const MachineInstr *MI, unsigned OpNo) {
159      O << (unsigned short)MI->getOperand(OpNo).getImm();
160    }
161    void printS16X4ImmOperand(const MachineInstr *MI, unsigned OpNo) {
162      if (MI->getOperand(OpNo).isImmediate()) {
163        O << (short)(MI->getOperand(OpNo).getImm()*4);
164      } else {
165        O << "lo16(";
166        printOp(MI->getOperand(OpNo));
167        if (TM.getRelocationModel() == Reloc::PIC_)
168          O << "-\"L" << getFunctionNumber() << "$pb\")";
169        else
170          O << ')';
171      }
172    }
173    void printBranchOperand(const MachineInstr *MI, unsigned OpNo) {
174      // Branches can take an immediate operand.  This is used by the branch
175      // selection pass to print $+8, an eight byte displacement from the PC.
176      if (MI->getOperand(OpNo).isImmediate()) {
177        O << "$+" << MI->getOperand(OpNo).getImm()*4;
178      } else {
179        printOp(MI->getOperand(OpNo));
180      }
181    }
182    void printCallOperand(const MachineInstr *MI, unsigned OpNo) {
183      const MachineOperand &MO = MI->getOperand(OpNo);
184      if (TM.getRelocationModel() != Reloc::Static) {
185        if (MO.getType() == MachineOperand::MO_GlobalAddress) {
186          GlobalValue *GV = MO.getGlobal();
187          if (((GV->isDeclaration() || GV->hasWeakLinkage() ||
188                GV->hasLinkOnceLinkage() || GV->hasCommonLinkage()))) {
189            // Dynamically-resolved functions need a stub for the function.
190            std::string Name = Mang->getValueName(GV);
191            FnStubs.insert(Name);
192            printSuffixedName(Name, "$stub");
193            if (GV->hasExternalWeakLinkage())
194              ExtWeakSymbols.insert(GV);
195            return;
196          }
197        }
198        if (MO.getType() == MachineOperand::MO_ExternalSymbol) {
199          std::string Name(TAI->getGlobalPrefix()); Name += MO.getSymbolName();
200          FnStubs.insert(Name);
201          printSuffixedName(Name, "$stub");
202          return;
203        }
204      }
205
206      printOp(MI->getOperand(OpNo));
207    }
208    void printAbsAddrOperand(const MachineInstr *MI, unsigned OpNo) {
209     O << (int)MI->getOperand(OpNo).getImm()*4;
210    }
211    void printPICLabel(const MachineInstr *MI, unsigned OpNo) {
212      O << "\"L" << getFunctionNumber() << "$pb\"\n";
213      O << "\"L" << getFunctionNumber() << "$pb\":";
214    }
215    void printSymbolHi(const MachineInstr *MI, unsigned OpNo) {
216      if (MI->getOperand(OpNo).isImmediate()) {
217        printS16ImmOperand(MI, OpNo);
218      } else {
219        if (Subtarget.isDarwin()) O << "ha16(";
220        printOp(MI->getOperand(OpNo));
221        if (TM.getRelocationModel() == Reloc::PIC_)
222          O << "-\"L" << getFunctionNumber() << "$pb\"";
223        if (Subtarget.isDarwin())
224          O << ')';
225        else
226          O << "@ha";
227      }
228    }
229    void printSymbolLo(const MachineInstr *MI, unsigned OpNo) {
230      if (MI->getOperand(OpNo).isImmediate()) {
231        printS16ImmOperand(MI, OpNo);
232      } else {
233        if (Subtarget.isDarwin()) O << "lo16(";
234        printOp(MI->getOperand(OpNo));
235        if (TM.getRelocationModel() == Reloc::PIC_)
236          O << "-\"L" << getFunctionNumber() << "$pb\"";
237        if (Subtarget.isDarwin())
238          O << ')';
239        else
240          O << "@l";
241      }
242    }
243    void printcrbitm(const MachineInstr *MI, unsigned OpNo) {
244      unsigned CCReg = MI->getOperand(OpNo).getReg();
245      unsigned RegNo = enumRegToMachineReg(CCReg);
246      O << (0x80 >> RegNo);
247    }
248    // The new addressing mode printers.
249    void printMemRegImm(const MachineInstr *MI, unsigned OpNo) {
250      printSymbolLo(MI, OpNo);
251      O << '(';
252      if (MI->getOperand(OpNo+1).isRegister() &&
253          MI->getOperand(OpNo+1).getReg() == PPC::R0)
254        O << "0";
255      else
256        printOperand(MI, OpNo+1);
257      O << ')';
258    }
259    void printMemRegImmShifted(const MachineInstr *MI, unsigned OpNo) {
260      if (MI->getOperand(OpNo).isImmediate())
261        printS16X4ImmOperand(MI, OpNo);
262      else
263        printSymbolLo(MI, OpNo);
264      O << '(';
265      if (MI->getOperand(OpNo+1).isRegister() &&
266          MI->getOperand(OpNo+1).getReg() == PPC::R0)
267        O << "0";
268      else
269        printOperand(MI, OpNo+1);
270      O << ')';
271    }
272
273    void printMemRegReg(const MachineInstr *MI, unsigned OpNo) {
274      // When used as the base register, r0 reads constant zero rather than
275      // the value contained in the register.  For this reason, the darwin
276      // assembler requires that we print r0 as 0 (no r) when used as the base.
277      const MachineOperand &MO = MI->getOperand(OpNo);
278      printRegister(MO, true);
279      O << ", ";
280      printOperand(MI, OpNo+1);
281    }
282
283    void printPredicateOperand(const MachineInstr *MI, unsigned OpNo,
284                               const char *Modifier);
285
286    virtual bool runOnMachineFunction(MachineFunction &F) = 0;
287    virtual bool doFinalization(Module &M) = 0;
288
289    virtual void EmitExternalGlobal(const GlobalVariable *GV);
290  };
291
292  /// PPCLinuxAsmPrinter - PowerPC assembly printer, customized for Linux
293  struct VISIBILITY_HIDDEN PPCLinuxAsmPrinter : public PPCAsmPrinter {
294
295    DwarfWriter DW;
296    MachineModuleInfo *MMI;
297
298    PPCLinuxAsmPrinter(std::ostream &O, PPCTargetMachine &TM,
299                    const TargetAsmInfo *T)
300      : PPCAsmPrinter(O, TM, T), DW(O, this, T), MMI(0) {
301    }
302
303    virtual const char *getPassName() const {
304      return "Linux PPC Assembly Printer";
305    }
306
307    bool runOnMachineFunction(MachineFunction &F);
308    bool doInitialization(Module &M);
309    bool doFinalization(Module &M);
310
311    void getAnalysisUsage(AnalysisUsage &AU) const {
312      AU.setPreservesAll();
313      AU.addRequired<MachineModuleInfo>();
314      PPCAsmPrinter::getAnalysisUsage(AU);
315    }
316
317    /// getSectionForFunction - Return the section that we should emit the
318    /// specified function body into.
319    virtual std::string getSectionForFunction(const Function &F) const;
320    void printModuleLevelGV(const GlobalVariable* GVar);
321  };
322
323  /// PPCDarwinAsmPrinter - PowerPC assembly printer, customized for Darwin/Mac
324  /// OS X
325  struct VISIBILITY_HIDDEN PPCDarwinAsmPrinter : public PPCAsmPrinter {
326
327    DwarfWriter DW;
328    MachineModuleInfo *MMI;
329
330    PPCDarwinAsmPrinter(std::ostream &O, PPCTargetMachine &TM,
331                        const TargetAsmInfo *T)
332      : PPCAsmPrinter(O, TM, T), DW(O, this, T), MMI(0) {
333    }
334
335    virtual const char *getPassName() const {
336      return "Darwin PPC Assembly Printer";
337    }
338
339    bool runOnMachineFunction(MachineFunction &F);
340    bool doInitialization(Module &M);
341    bool doFinalization(Module &M);
342
343    void getAnalysisUsage(AnalysisUsage &AU) const {
344      AU.setPreservesAll();
345      AU.addRequired<MachineModuleInfo>();
346      PPCAsmPrinter::getAnalysisUsage(AU);
347    }
348
349    /// getSectionForFunction - Return the section that we should emit the
350    /// specified function body into.
351    virtual std::string getSectionForFunction(const Function &F) const;
352    void printModuleLevelGV(const GlobalVariable* GVar);
353  };
354} // end of anonymous namespace
355
356// Include the auto-generated portion of the assembly writer
357#include "PPCGenAsmWriter.inc"
358
359void PPCAsmPrinter::printOp(const MachineOperand &MO) {
360  switch (MO.getType()) {
361  case MachineOperand::MO_Immediate:
362    cerr << "printOp() does not handle immediate values\n";
363    abort();
364    return;
365
366  case MachineOperand::MO_MachineBasicBlock:
367    printBasicBlockLabel(MO.getMBB());
368    return;
369  case MachineOperand::MO_JumpTableIndex:
370    O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
371      << '_' << MO.getIndex();
372    // FIXME: PIC relocation model
373    return;
374  case MachineOperand::MO_ConstantPoolIndex:
375    O << TAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber()
376      << '_' << MO.getIndex();
377    return;
378  case MachineOperand::MO_ExternalSymbol:
379    // Computing the address of an external symbol, not calling it.
380    if (TM.getRelocationModel() != Reloc::Static) {
381      std::string Name(TAI->getGlobalPrefix()); Name += MO.getSymbolName();
382      GVStubs.insert(Name);
383      printSuffixedName(Name, "$non_lazy_ptr");
384      return;
385    }
386    O << TAI->getGlobalPrefix() << MO.getSymbolName();
387    return;
388  case MachineOperand::MO_GlobalAddress: {
389    // Computing the address of a global symbol, not calling it.
390    GlobalValue *GV = MO.getGlobal();
391    std::string Name = Mang->getValueName(GV);
392
393    // External or weakly linked global variables need non-lazily-resolved stubs
394    if (TM.getRelocationModel() != Reloc::Static) {
395      if (((GV->isDeclaration() || GV->hasWeakLinkage() ||
396            GV->hasLinkOnceLinkage() || GV->hasCommonLinkage()))) {
397        GVStubs.insert(Name);
398        printSuffixedName(Name, "$non_lazy_ptr");
399        if (GV->hasExternalWeakLinkage())
400          ExtWeakSymbols.insert(GV);
401        return;
402      }
403    }
404    O << Name;
405
406    if (MO.getOffset() > 0)
407      O << "+" << MO.getOffset();
408    else if (MO.getOffset() < 0)
409      O << MO.getOffset();
410
411    if (GV->hasExternalWeakLinkage())
412      ExtWeakSymbols.insert(GV);
413    return;
414  }
415
416  default:
417    O << "<unknown operand type: " << MO.getType() << ">";
418    return;
419  }
420}
421
422/// EmitExternalGlobal - In this case we need to use the indirect symbol.
423///
424void PPCAsmPrinter::EmitExternalGlobal(const GlobalVariable *GV) {
425  std::string Name = getGlobalLinkName(GV);
426  if (TM.getRelocationModel() != Reloc::Static) {
427    GVStubs.insert(Name);
428    printSuffixedName(Name, "$non_lazy_ptr");
429    return;
430  }
431  O << Name;
432}
433
434/// PrintAsmOperand - Print out an operand for an inline asm expression.
435///
436bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
437                                    unsigned AsmVariant,
438                                    const char *ExtraCode) {
439  // Does this asm operand have a single letter operand modifier?
440  if (ExtraCode && ExtraCode[0]) {
441    if (ExtraCode[1] != 0) return true; // Unknown modifier.
442
443    switch (ExtraCode[0]) {
444    default: return true;  // Unknown modifier.
445    case 'c': // Don't print "$" before a global var name or constant.
446      // PPC never has a prefix.
447      printOperand(MI, OpNo);
448      return false;
449    case 'L': // Write second word of DImode reference.
450      // Verify that this operand has two consecutive registers.
451      if (!MI->getOperand(OpNo).isRegister() ||
452          OpNo+1 == MI->getNumOperands() ||
453          !MI->getOperand(OpNo+1).isRegister())
454        return true;
455      ++OpNo;   // Return the high-part.
456      break;
457    case 'I':
458      // Write 'i' if an integer constant, otherwise nothing.  Used to print
459      // addi vs add, etc.
460      if (MI->getOperand(OpNo).isImmediate())
461        O << "i";
462      return false;
463    }
464  }
465
466  printOperand(MI, OpNo);
467  return false;
468}
469
470bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
471                                          unsigned AsmVariant,
472                                          const char *ExtraCode) {
473  if (ExtraCode && ExtraCode[0])
474    return true; // Unknown modifier.
475  if (MI->getOperand(OpNo).isRegister())
476    printMemRegReg(MI, OpNo);
477  else
478    printMemRegImm(MI, OpNo);
479  return false;
480}
481
482void PPCAsmPrinter::printPredicateOperand(const MachineInstr *MI, unsigned OpNo,
483                                          const char *Modifier) {
484  assert(Modifier && "Must specify 'cc' or 'reg' as predicate op modifier!");
485  unsigned Code = MI->getOperand(OpNo).getImm();
486  if (!strcmp(Modifier, "cc")) {
487    switch ((PPC::Predicate)Code) {
488    case PPC::PRED_ALWAYS: return; // Don't print anything for always.
489    case PPC::PRED_LT: O << "lt"; return;
490    case PPC::PRED_LE: O << "le"; return;
491    case PPC::PRED_EQ: O << "eq"; return;
492    case PPC::PRED_GE: O << "ge"; return;
493    case PPC::PRED_GT: O << "gt"; return;
494    case PPC::PRED_NE: O << "ne"; return;
495    case PPC::PRED_UN: O << "un"; return;
496    case PPC::PRED_NU: O << "nu"; return;
497    }
498
499  } else {
500    assert(!strcmp(Modifier, "reg") &&
501           "Need to specify 'cc' or 'reg' as predicate op modifier!");
502    // Don't print the register for 'always'.
503    if (Code == PPC::PRED_ALWAYS) return;
504    printOperand(MI, OpNo+1);
505  }
506}
507
508
509/// printMachineInstruction -- Print out a single PowerPC MI in Darwin syntax to
510/// the current output stream.
511///
512void PPCAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
513  ++EmittedInsts;
514
515  // Check for slwi/srwi mnemonics.
516  if (MI->getOpcode() == PPC::RLWINM) {
517    bool FoundMnemonic = false;
518    unsigned char SH = MI->getOperand(2).getImm();
519    unsigned char MB = MI->getOperand(3).getImm();
520    unsigned char ME = MI->getOperand(4).getImm();
521    if (SH <= 31 && MB == 0 && ME == (31-SH)) {
522      O << "\tslwi "; FoundMnemonic = true;
523    }
524    if (SH <= 31 && MB == (32-SH) && ME == 31) {
525      O << "\tsrwi "; FoundMnemonic = true;
526      SH = 32-SH;
527    }
528    if (FoundMnemonic) {
529      printOperand(MI, 0);
530      O << ", ";
531      printOperand(MI, 1);
532      O << ", " << (unsigned int)SH << '\n';
533      return;
534    }
535  } else if (MI->getOpcode() == PPC::OR || MI->getOpcode() == PPC::OR8) {
536    if (MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
537      O << "\tmr ";
538      printOperand(MI, 0);
539      O << ", ";
540      printOperand(MI, 1);
541      O << '\n';
542      return;
543    }
544  } else if (MI->getOpcode() == PPC::RLDICR) {
545    unsigned char SH = MI->getOperand(2).getImm();
546    unsigned char ME = MI->getOperand(3).getImm();
547    // rldicr RA, RS, SH, 63-SH == sldi RA, RS, SH
548    if (63-SH == ME) {
549      O << "\tsldi ";
550      printOperand(MI, 0);
551      O << ", ";
552      printOperand(MI, 1);
553      O << ", " << (unsigned int)SH << '\n';
554      return;
555    }
556  }
557
558  if (printInstruction(MI))
559    return; // Printer was automatically generated
560
561  assert(0 && "Unhandled instruction in asm writer!");
562  abort();
563  return;
564}
565
566/// runOnMachineFunction - This uses the printMachineInstruction()
567/// method to print assembly for each instruction.
568///
569bool PPCLinuxAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
570
571  SetupMachineFunction(MF);
572  O << "\n\n";
573
574  // Print out constants referenced by the function
575  EmitConstantPool(MF.getConstantPool());
576
577  // Print out labels for the function.
578  const Function *F = MF.getFunction();
579  SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
580
581  switch (F->getLinkage()) {
582  default: assert(0 && "Unknown linkage type!");
583  case Function::InternalLinkage:  // Symbols default to internal.
584    break;
585  case Function::ExternalLinkage:
586    O << "\t.global\t" << CurrentFnName << '\n'
587      << "\t.type\t" << CurrentFnName << ", @function\n";
588    break;
589  case Function::WeakLinkage:
590  case Function::LinkOnceLinkage:
591    O << "\t.global\t" << CurrentFnName << '\n';
592    O << "\t.weak\t" << CurrentFnName << '\n';
593    break;
594  }
595
596  printVisibility(CurrentFnName, F->getVisibility());
597
598  EmitAlignment(2, F);
599  O << CurrentFnName << ":\n";
600
601  // Emit pre-function debug information.
602  DW.BeginFunction(&MF);
603
604  // Print out code for the function.
605  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
606       I != E; ++I) {
607    // Print a label for the basic block.
608    if (I != MF.begin()) {
609      printBasicBlockLabel(I, true, true);
610      O << '\n';
611    }
612    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
613         II != E; ++II) {
614      // Print the assembly for the instruction.
615      printMachineInstruction(II);
616    }
617  }
618
619  O << "\t.size\t" << CurrentFnName << ",.-" << CurrentFnName << '\n';
620
621  // Print out jump tables referenced by the function.
622  EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
623
624  // Emit post-function debug information.
625  DW.EndFunction();
626
627  // We didn't modify anything.
628  return false;
629}
630
631bool PPCLinuxAsmPrinter::doInitialization(Module &M) {
632  bool Result = AsmPrinter::doInitialization(M);
633
634  // Emit initial debug information.
635  DW.BeginModule(&M);
636
637  // AsmPrinter::doInitialization should have done this analysis.
638  MMI = getAnalysisToUpdate<MachineModuleInfo>();
639  assert(MMI);
640  DW.SetModuleInfo(MMI);
641
642  // GNU as handles section names wrapped in quotes
643  Mang->setUseQuotes(true);
644
645  SwitchToTextSection(TAI->getTextSection());
646
647  return Result;
648}
649
650/// PrintUnmangledNameSafely - Print out the printable characters in the name.
651/// Don't print things like \n or \0.
652static void PrintUnmangledNameSafely(const Value *V, std::ostream &OS) {
653  for (const char *Name = V->getNameStart(), *E = Name+V->getNameLen();
654       Name != E; ++Name)
655    if (isprint(*Name))
656      OS << *Name;
657}
658
659void PPCLinuxAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
660  const TargetData *TD = TM.getTargetData();
661
662  if (!GVar->hasInitializer())
663    return;   // External global require no code
664
665  // Check to see if this is a special global used by LLVM, if so, emit it.
666  if (EmitSpecialLLVMGlobal(GVar))
667    return;
668
669  std::string name = Mang->getValueName(GVar);
670  std::string SectionName = TAI->SectionForGlobal(GVar);
671
672  printVisibility(name, GVar->getVisibility());
673
674  Constant *C = GVar->getInitializer();
675  const Type *Type = C->getType();
676  unsigned Size = TD->getABITypeSize(Type);
677  unsigned Align = TD->getPreferredAlignmentLog(GVar);
678
679  SwitchToDataSection(SectionName.c_str());
680
681  if (C->isNullValue() && /* FIXME: Verify correct */
682      !GVar->hasSection() &&
683      (GVar->hasInternalLinkage() || GVar->hasExternalLinkage() ||
684       GVar->isWeakForLinker())) {
685      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
686
687      if (GVar->hasExternalLinkage()) {
688        O << "\t.global " << name << '\n';
689        O << "\t.type " << name << ", @object\n";
690        O << name << ":\n";
691        O << "\t.zero " << Size << '\n';
692      } else if (GVar->hasInternalLinkage()) {
693        O << TAI->getLCOMMDirective() << name << ',' << Size;
694      } else {
695        O << ".comm " << name << ',' << Size;
696      }
697      O << "\t\t" << TAI->getCommentString() << " '";
698      PrintUnmangledNameSafely(GVar, O);
699      O << "'\n";
700      return;
701  }
702
703  switch (GVar->getLinkage()) {
704   case GlobalValue::LinkOnceLinkage:
705   case GlobalValue::WeakLinkage:
706   case GlobalValue::CommonLinkage:
707    O << "\t.global " << name << '\n'
708      << "\t.type " << name << ", @object\n"
709      << "\t.weak " << name << '\n';
710    break;
711   case GlobalValue::AppendingLinkage:
712    // FIXME: appending linkage variables should go into a section of
713    // their name or something.  For now, just emit them as external.
714   case GlobalValue::ExternalLinkage:
715    // If external or appending, declare as a global symbol
716    O << "\t.global " << name << '\n'
717      << "\t.type " << name << ", @object\n";
718    // FALL THROUGH
719   case GlobalValue::InternalLinkage:
720    break;
721   default:
722    cerr << "Unknown linkage type!";
723    abort();
724  }
725
726  EmitAlignment(Align, GVar);
727  O << name << ":\t\t\t\t" << TAI->getCommentString() << " '";
728  PrintUnmangledNameSafely(GVar, O);
729  O << "'\n";
730
731  // If the initializer is a extern weak symbol, remember to emit the weak
732  // reference!
733  if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
734    if (GV->hasExternalWeakLinkage())
735      ExtWeakSymbols.insert(GV);
736
737  EmitGlobalConstant(C);
738  O << '\n';
739}
740
741bool PPCLinuxAsmPrinter::doFinalization(Module &M) {
742  // Print out module-level global variables here.
743  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
744       I != E; ++I)
745    printModuleLevelGV(I);
746
747  // TODO
748
749  // Emit initial debug information.
750  DW.EndModule();
751
752  return AsmPrinter::doFinalization(M);
753}
754
755std::string PPCLinuxAsmPrinter::getSectionForFunction(const Function &F) const {
756  return TAI->SectionForGlobal(&F);
757}
758
759std::string PPCDarwinAsmPrinter::getSectionForFunction(const Function &F) const {
760  return TAI->SectionForGlobal(&F);
761}
762
763/// runOnMachineFunction - This uses the printMachineInstruction()
764/// method to print assembly for each instruction.
765///
766bool PPCDarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
767  SetupMachineFunction(MF);
768  O << "\n\n";
769
770  // Print out constants referenced by the function
771  EmitConstantPool(MF.getConstantPool());
772
773  // Print out labels for the function.
774  const Function *F = MF.getFunction();
775  SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
776
777  switch (F->getLinkage()) {
778  default: assert(0 && "Unknown linkage type!");
779  case Function::InternalLinkage:  // Symbols default to internal.
780    break;
781  case Function::ExternalLinkage:
782    O << "\t.globl\t" << CurrentFnName << '\n';
783    break;
784  case Function::WeakLinkage:
785  case Function::LinkOnceLinkage:
786    O << "\t.globl\t" << CurrentFnName << '\n';
787    O << "\t.weak_definition\t" << CurrentFnName << '\n';
788    break;
789  }
790
791  printVisibility(CurrentFnName, F->getVisibility());
792
793  EmitAlignment(OptimizeForSize ? 2 : 4, F);
794  O << CurrentFnName << ":\n";
795
796  // Emit pre-function debug information.
797  DW.BeginFunction(&MF);
798
799  // If the function is empty, then we need to emit *something*. Otherwise, the
800  // function's label might be associated with something that it wasn't meant to
801  // be associated with. We emit a noop in this situation.
802  MachineFunction::iterator I = MF.begin();
803
804  if (++I == MF.end() && MF.front().empty())
805    O << "\tnop\n";
806
807  // Print out code for the function.
808  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
809       I != E; ++I) {
810    // Print a label for the basic block.
811    if (I != MF.begin()) {
812      printBasicBlockLabel(I, true, true);
813      O << '\n';
814    }
815    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
816         II != IE; ++II) {
817      // Print the assembly for the instruction.
818      printMachineInstruction(II);
819    }
820  }
821
822  // Print out jump tables referenced by the function.
823  EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
824
825  // Emit post-function debug information.
826  DW.EndFunction();
827
828  // We didn't modify anything.
829  return false;
830}
831
832
833bool PPCDarwinAsmPrinter::doInitialization(Module &M) {
834  static const char *const CPUDirectives[] = {
835    "",
836    "ppc",
837    "ppc601",
838    "ppc602",
839    "ppc603",
840    "ppc7400",
841    "ppc750",
842    "ppc970",
843    "ppc64"
844  };
845
846  unsigned Directive = Subtarget.getDarwinDirective();
847  if (Subtarget.isGigaProcessor() && Directive < PPC::DIR_970)
848    Directive = PPC::DIR_970;
849  if (Subtarget.hasAltivec() && Directive < PPC::DIR_7400)
850    Directive = PPC::DIR_7400;
851  if (Subtarget.isPPC64() && Directive < PPC::DIR_970)
852    Directive = PPC::DIR_64;
853  assert(Directive <= PPC::DIR_64 && "Directive out of range.");
854  O << "\t.machine " << CPUDirectives[Directive] << '\n';
855
856  bool Result = AsmPrinter::doInitialization(M);
857
858  // Emit initial debug information.
859  DW.BeginModule(&M);
860
861  // We need this for Personality functions.
862  // AsmPrinter::doInitialization should have done this analysis.
863  MMI = getAnalysisToUpdate<MachineModuleInfo>();
864  assert(MMI);
865  DW.SetModuleInfo(MMI);
866
867  // Darwin wants symbols to be quoted if they have complex names.
868  Mang->setUseQuotes(true);
869
870  // Prime text sections so they are adjacent.  This reduces the likelihood a
871  // large data or debug section causes a branch to exceed 16M limit.
872  SwitchToTextSection("\t.section __TEXT,__textcoal_nt,coalesced,"
873                      "pure_instructions");
874  if (TM.getRelocationModel() == Reloc::PIC_) {
875    SwitchToTextSection("\t.section __TEXT,__picsymbolstub1,symbol_stubs,"
876                          "pure_instructions,32");
877  } else if (TM.getRelocationModel() == Reloc::DynamicNoPIC) {
878    SwitchToTextSection("\t.section __TEXT,__symbol_stub1,symbol_stubs,"
879                        "pure_instructions,16");
880  }
881  SwitchToTextSection(TAI->getTextSection());
882
883  return Result;
884}
885
886void PPCDarwinAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
887  const TargetData *TD = TM.getTargetData();
888
889  if (!GVar->hasInitializer())
890    return;   // External global require no code
891
892  // Check to see if this is a special global used by LLVM, if so, emit it.
893  if (EmitSpecialLLVMGlobal(GVar)) {
894    if (TM.getRelocationModel() == Reloc::Static) {
895      if (GVar->getName() == "llvm.global_ctors")
896        O << ".reference .constructors_used\n";
897      else if (GVar->getName() == "llvm.global_dtors")
898        O << ".reference .destructors_used\n";
899    }
900    return;
901  }
902
903  std::string name = Mang->getValueName(GVar);
904  std::string SectionName = TAI->SectionForGlobal(GVar);
905
906  printVisibility(name, GVar->getVisibility());
907
908  Constant *C = GVar->getInitializer();
909  const Type *Type = C->getType();
910  unsigned Size = TD->getABITypeSize(Type);
911  unsigned Align = TD->getPreferredAlignmentLog(GVar);
912
913  SwitchToDataSection(SectionName.c_str());
914
915  if (C->isNullValue() && /* FIXME: Verify correct */
916      !GVar->hasSection() &&
917      (GVar->hasInternalLinkage() || GVar->hasExternalLinkage() ||
918       GVar->isWeakForLinker())) {
919    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
920
921    if (GVar->hasExternalLinkage()) {
922      O << "\t.globl " << name << '\n';
923      O << "\t.zerofill __DATA, __common, " << name << ", "
924        << Size << ", " << Align;
925    } else if (GVar->hasInternalLinkage()) {
926      O << TAI->getLCOMMDirective() << name << ',' << Size << ',' << Align;
927    } else if (!GVar->hasCommonLinkage()) {
928      O << "\t.globl " << name << '\n'
929        << TAI->getWeakDefDirective() << name << '\n';
930      EmitAlignment(Align, GVar);
931      O << name << ":\t\t\t\t" << TAI->getCommentString() << " ";
932      PrintUnmangledNameSafely(GVar, O);
933      O << '\n';
934      EmitGlobalConstant(C);
935      return;
936    } else {
937      O << ".comm " << name << ',' << Size;
938      // Darwin 9 and above support aligned common data.
939      if (Subtarget.isDarwin9())
940        O << ',' << Align;
941    }
942    O << "\t\t" << TAI->getCommentString() << " '";
943    PrintUnmangledNameSafely(GVar, O);
944    O << "'\n";
945    return;
946  }
947
948  switch (GVar->getLinkage()) {
949   case GlobalValue::LinkOnceLinkage:
950   case GlobalValue::WeakLinkage:
951   case GlobalValue::CommonLinkage:
952    O << "\t.globl " << name << '\n'
953      << "\t.weak_definition " << name << '\n';
954    break;
955   case GlobalValue::AppendingLinkage:
956    // FIXME: appending linkage variables should go into a section of
957    // their name or something.  For now, just emit them as external.
958   case GlobalValue::ExternalLinkage:
959    // If external or appending, declare as a global symbol
960    O << "\t.globl " << name << '\n';
961    // FALL THROUGH
962   case GlobalValue::InternalLinkage:
963    break;
964   default:
965    cerr << "Unknown linkage type!";
966    abort();
967  }
968
969  EmitAlignment(Align, GVar);
970  O << name << ":\t\t\t\t" << TAI->getCommentString() << " '";
971  PrintUnmangledNameSafely(GVar, O);
972  O << "'\n";
973
974  // If the initializer is a extern weak symbol, remember to emit the weak
975  // reference!
976  if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
977    if (GV->hasExternalWeakLinkage())
978      ExtWeakSymbols.insert(GV);
979
980  EmitGlobalConstant(C);
981  O << '\n';
982}
983
984bool PPCDarwinAsmPrinter::doFinalization(Module &M) {
985  const TargetData *TD = TM.getTargetData();
986
987  // Print out module-level global variables here.
988  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
989       I != E; ++I)
990    printModuleLevelGV(I);
991
992  bool isPPC64 = TD->getPointerSizeInBits() == 64;
993
994  // Output stubs for dynamically-linked functions
995  if (TM.getRelocationModel() == Reloc::PIC_) {
996    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
997         i != e; ++i) {
998      SwitchToTextSection("\t.section __TEXT,__picsymbolstub1,symbol_stubs,"
999                          "pure_instructions,32");
1000      EmitAlignment(4);
1001      std::string p = *i;
1002      std::string L0p = (p[0]=='\"') ? "\"L0$" + p.substr(1) : "L0$" + p ;
1003      printSuffixedName(p, "$stub");
1004      O << ":\n";
1005      O << "\t.indirect_symbol " << *i << '\n';
1006      O << "\tmflr r0\n";
1007      O << "\tbcl 20,31," << L0p << '\n';
1008      O << L0p << ":\n";
1009      O << "\tmflr r11\n";
1010      O << "\taddis r11,r11,ha16(";
1011      printSuffixedName(p, "$lazy_ptr");
1012      O << "-" << L0p << ")\n";
1013      O << "\tmtlr r0\n";
1014      if (isPPC64)
1015        O << "\tldu r12,lo16(";
1016      else
1017        O << "\tlwzu r12,lo16(";
1018      printSuffixedName(p, "$lazy_ptr");
1019      O << "-" << L0p << ")(r11)\n";
1020      O << "\tmtctr r12\n";
1021      O << "\tbctr\n";
1022      SwitchToDataSection(".lazy_symbol_pointer");
1023      printSuffixedName(p, "$lazy_ptr");
1024      O << ":\n";
1025      O << "\t.indirect_symbol " << *i << '\n';
1026      if (isPPC64)
1027        O << "\t.quad dyld_stub_binding_helper\n";
1028      else
1029        O << "\t.long dyld_stub_binding_helper\n";
1030    }
1031  } else {
1032    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
1033         i != e; ++i) {
1034      SwitchToTextSection("\t.section __TEXT,__symbol_stub1,symbol_stubs,"
1035                          "pure_instructions,16");
1036      EmitAlignment(4);
1037      std::string p = *i;
1038      printSuffixedName(p, "$stub");
1039      O << ":\n";
1040      O << "\t.indirect_symbol " << *i << '\n';
1041      O << "\tlis r11,ha16(";
1042      printSuffixedName(p, "$lazy_ptr");
1043      O << ")\n";
1044      if (isPPC64)
1045        O << "\tldu r12,lo16(";
1046      else
1047        O << "\tlwzu r12,lo16(";
1048      printSuffixedName(p, "$lazy_ptr");
1049      O << ")(r11)\n";
1050      O << "\tmtctr r12\n";
1051      O << "\tbctr\n";
1052      SwitchToDataSection(".lazy_symbol_pointer");
1053      printSuffixedName(p, "$lazy_ptr");
1054      O << ":\n";
1055      O << "\t.indirect_symbol " << *i << '\n';
1056      if (isPPC64)
1057        O << "\t.quad dyld_stub_binding_helper\n";
1058      else
1059        O << "\t.long dyld_stub_binding_helper\n";
1060    }
1061  }
1062
1063  O << '\n';
1064
1065  if (TAI->doesSupportExceptionHandling() && MMI) {
1066    // Add the (possibly multiple) personalities to the set of global values.
1067    // Only referenced functions get into the Personalities list.
1068    const std::vector<Function *>& Personalities = MMI->getPersonalities();
1069
1070    for (std::vector<Function *>::const_iterator I = Personalities.begin(),
1071           E = Personalities.end(); I != E; ++I)
1072      if (*I) GVStubs.insert("_" + (*I)->getName());
1073  }
1074
1075  // Output stubs for external and common global variables.
1076  if (!GVStubs.empty()) {
1077    SwitchToDataSection(".non_lazy_symbol_pointer");
1078    for (std::set<std::string>::iterator I = GVStubs.begin(),
1079         E = GVStubs.end(); I != E; ++I) {
1080      std::string p = *I;
1081      printSuffixedName(p, "$non_lazy_ptr");
1082      O << ":\n";
1083      O << "\t.indirect_symbol " << *I << '\n';
1084      if (isPPC64)
1085        O << "\t.quad\t0\n";
1086      else
1087        O << "\t.long\t0\n";
1088    }
1089  }
1090
1091  // Emit initial debug information.
1092  DW.EndModule();
1093
1094  // Funny Darwin hack: This flag tells the linker that no global symbols
1095  // contain code that falls through to other global symbols (e.g. the obvious
1096  // implementation of multiple entry points).  If this doesn't occur, the
1097  // linker can safely perform dead code stripping.  Since LLVM never generates
1098  // code that does this, it is always safe to set.
1099  O << "\t.subsections_via_symbols\n";
1100
1101  return AsmPrinter::doFinalization(M);
1102}
1103
1104
1105
1106/// createPPCAsmPrinterPass - Returns a pass that prints the PPC assembly code
1107/// for a MachineFunction to the given output stream, in a format that the
1108/// Darwin assembler can deal with.
1109///
1110FunctionPass *llvm::createPPCAsmPrinterPass(std::ostream &o,
1111                                            PPCTargetMachine &tm) {
1112  const PPCSubtarget *Subtarget = &tm.getSubtarget<PPCSubtarget>();
1113
1114  if (Subtarget->isDarwin()) {
1115    return new PPCDarwinAsmPrinter(o, tm, tm.getTargetAsmInfo());
1116  } else {
1117    return new PPCLinuxAsmPrinter(o, tm, tm.getTargetAsmInfo());
1118  }
1119}
1120