PPCAsmPrinter.cpp revision ea7dd407149332e5ab1ffc42c8344ecd1751008f 
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            O << "L" << Name << "$stub";
193            if (GV->hasExternalWeakLinkage())
194              ExtWeakSymbols.insert(GV);
195            return;
196          }
197        }
198        if (MO.getType() == MachineOperand::MO_ExternalSymbol) {
199          std::string Name(TAI->getGlobalPrefix()); Name += MO.getSymbolName();
200          FnStubs.insert(Name);
201          O << "L" << Name << "$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  /// LinuxAsmPrinter - PowerPC assembly printer, customized for Linux
293  struct VISIBILITY_HIDDEN LinuxAsmPrinter : public PPCAsmPrinter {
294
295    DwarfWriter DW;
296
297    LinuxAsmPrinter(std::ostream &O, PPCTargetMachine &TM,
298                    const TargetAsmInfo *T)
299      : PPCAsmPrinter(O, TM, T), DW(O, this, T) {
300    }
301
302    virtual const char *getPassName() const {
303      return "Linux PPC Assembly Printer";
304    }
305
306    bool runOnMachineFunction(MachineFunction &F);
307    bool doInitialization(Module &M);
308    bool doFinalization(Module &M);
309
310    void getAnalysisUsage(AnalysisUsage &AU) const {
311      AU.setPreservesAll();
312      AU.addRequired<MachineModuleInfo>();
313      PPCAsmPrinter::getAnalysisUsage(AU);
314    }
315
316    /// getSectionForFunction - Return the section that we should emit the
317    /// specified function body into.
318    virtual std::string getSectionForFunction(const Function &F) const;
319  };
320
321  /// DarwinAsmPrinter - PowerPC assembly printer, customized for Darwin/Mac OS
322  /// X
323  struct VISIBILITY_HIDDEN DarwinAsmPrinter : public PPCAsmPrinter {
324
325    DwarfWriter DW;
326    MachineModuleInfo *MMI;
327
328    DarwinAsmPrinter(std::ostream &O, PPCTargetMachine &TM,
329                     const TargetAsmInfo *T)
330      : PPCAsmPrinter(O, TM, T), DW(O, this, T), MMI(0) {
331    }
332
333    virtual const char *getPassName() const {
334      return "Darwin PPC Assembly Printer";
335    }
336
337    bool runOnMachineFunction(MachineFunction &F);
338    bool doInitialization(Module &M);
339    bool doFinalization(Module &M);
340
341    void getAnalysisUsage(AnalysisUsage &AU) const {
342      AU.setPreservesAll();
343      AU.addRequired<MachineModuleInfo>();
344      PPCAsmPrinter::getAnalysisUsage(AU);
345    }
346
347    /// getSectionForFunction - Return the section that we should emit the
348    /// specified function body into.
349    virtual std::string getSectionForFunction(const Function &F) const;
350  };
351} // end of anonymous namespace
352
353// Include the auto-generated portion of the assembly writer
354#include "PPCGenAsmWriter.inc"
355
356void PPCAsmPrinter::printOp(const MachineOperand &MO) {
357  switch (MO.getType()) {
358  case MachineOperand::MO_Immediate:
359    cerr << "printOp() does not handle immediate values\n";
360    abort();
361    return;
362
363  case MachineOperand::MO_MachineBasicBlock:
364    printBasicBlockLabel(MO.getMBB());
365    return;
366  case MachineOperand::MO_JumpTableIndex:
367    O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
368      << '_' << MO.getIndex();
369    // FIXME: PIC relocation model
370    return;
371  case MachineOperand::MO_ConstantPoolIndex:
372    O << TAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber()
373      << '_' << MO.getIndex();
374    return;
375  case MachineOperand::MO_ExternalSymbol:
376    // Computing the address of an external symbol, not calling it.
377    if (TM.getRelocationModel() != Reloc::Static) {
378      std::string Name(TAI->getGlobalPrefix()); Name += MO.getSymbolName();
379      GVStubs.insert(Name);
380      O << "L" << Name << "$non_lazy_ptr";
381      return;
382    }
383    O << TAI->getGlobalPrefix() << MO.getSymbolName();
384    return;
385  case MachineOperand::MO_GlobalAddress: {
386    // Computing the address of a global symbol, not calling it.
387    GlobalValue *GV = MO.getGlobal();
388    std::string Name = Mang->getValueName(GV);
389
390    // External or weakly linked global variables need non-lazily-resolved stubs
391    if (TM.getRelocationModel() != Reloc::Static) {
392      if (((GV->isDeclaration() || GV->hasWeakLinkage() ||
393            GV->hasLinkOnceLinkage() || GV->hasCommonLinkage()))) {
394        GVStubs.insert(Name);
395        O << "L" << Name << "$non_lazy_ptr";
396        if (GV->hasExternalWeakLinkage())
397          ExtWeakSymbols.insert(GV);
398        return;
399      }
400    }
401    O << Name;
402
403    if (MO.getOffset() > 0)
404      O << "+" << MO.getOffset();
405    else if (MO.getOffset() < 0)
406      O << MO.getOffset();
407
408    if (GV->hasExternalWeakLinkage())
409      ExtWeakSymbols.insert(GV);
410    return;
411  }
412
413  default:
414    O << "<unknown operand type: " << MO.getType() << ">";
415    return;
416  }
417}
418
419/// EmitExternalGlobal - In this case we need to use the indirect symbol.
420///
421void PPCAsmPrinter::EmitExternalGlobal(const GlobalVariable *GV) {
422  std::string Name = getGlobalLinkName(GV);
423  if (TM.getRelocationModel() != Reloc::Static) {
424    GVStubs.insert(Name);
425    O << "L" << Name << "$non_lazy_ptr";
426    return;
427  }
428  O << Name;
429}
430
431/// PrintAsmOperand - Print out an operand for an inline asm expression.
432///
433bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
434                                    unsigned AsmVariant,
435                                    const char *ExtraCode) {
436  // Does this asm operand have a single letter operand modifier?
437  if (ExtraCode && ExtraCode[0]) {
438    if (ExtraCode[1] != 0) return true; // Unknown modifier.
439
440    switch (ExtraCode[0]) {
441    default: return true;  // Unknown modifier.
442    case 'c': // Don't print "$" before a global var name or constant.
443      // PPC never has a prefix.
444      printOperand(MI, OpNo);
445      return false;
446    case 'L': // Write second word of DImode reference.
447      // Verify that this operand has two consecutive registers.
448      if (!MI->getOperand(OpNo).isRegister() ||
449          OpNo+1 == MI->getNumOperands() ||
450          !MI->getOperand(OpNo+1).isRegister())
451        return true;
452      ++OpNo;   // Return the high-part.
453      break;
454    case 'I':
455      // Write 'i' if an integer constant, otherwise nothing.  Used to print
456      // addi vs add, etc.
457      if (MI->getOperand(OpNo).isImmediate())
458        O << "i";
459      return false;
460    }
461  }
462
463  printOperand(MI, OpNo);
464  return false;
465}
466
467bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
468                                          unsigned AsmVariant,
469                                          const char *ExtraCode) {
470  if (ExtraCode && ExtraCode[0])
471    return true; // Unknown modifier.
472  if (MI->getOperand(OpNo).isRegister())
473    printMemRegReg(MI, OpNo);
474  else
475    printMemRegImm(MI, OpNo);
476  return false;
477}
478
479void PPCAsmPrinter::printPredicateOperand(const MachineInstr *MI, unsigned OpNo,
480                                          const char *Modifier) {
481  assert(Modifier && "Must specify 'cc' or 'reg' as predicate op modifier!");
482  unsigned Code = MI->getOperand(OpNo).getImm();
483  if (!strcmp(Modifier, "cc")) {
484    switch ((PPC::Predicate)Code) {
485    case PPC::PRED_ALWAYS: return; // Don't print anything for always.
486    case PPC::PRED_LT: O << "lt"; return;
487    case PPC::PRED_LE: O << "le"; return;
488    case PPC::PRED_EQ: O << "eq"; return;
489    case PPC::PRED_GE: O << "ge"; return;
490    case PPC::PRED_GT: O << "gt"; return;
491    case PPC::PRED_NE: O << "ne"; return;
492    case PPC::PRED_UN: O << "un"; return;
493    case PPC::PRED_NU: O << "nu"; return;
494    }
495
496  } else {
497    assert(!strcmp(Modifier, "reg") &&
498           "Need to specify 'cc' or 'reg' as predicate op modifier!");
499    // Don't print the register for 'always'.
500    if (Code == PPC::PRED_ALWAYS) return;
501    printOperand(MI, OpNo+1);
502  }
503}
504
505
506/// printMachineInstruction -- Print out a single PowerPC MI in Darwin syntax to
507/// the current output stream.
508///
509void PPCAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
510  ++EmittedInsts;
511
512  // Check for slwi/srwi mnemonics.
513  if (MI->getOpcode() == PPC::RLWINM) {
514    bool FoundMnemonic = false;
515    unsigned char SH = MI->getOperand(2).getImm();
516    unsigned char MB = MI->getOperand(3).getImm();
517    unsigned char ME = MI->getOperand(4).getImm();
518    if (SH <= 31 && MB == 0 && ME == (31-SH)) {
519      O << "\tslwi "; FoundMnemonic = true;
520    }
521    if (SH <= 31 && MB == (32-SH) && ME == 31) {
522      O << "\tsrwi "; FoundMnemonic = true;
523      SH = 32-SH;
524    }
525    if (FoundMnemonic) {
526      printOperand(MI, 0);
527      O << ", ";
528      printOperand(MI, 1);
529      O << ", " << (unsigned int)SH << "\n";
530      return;
531    }
532  } else if (MI->getOpcode() == PPC::OR || MI->getOpcode() == PPC::OR8) {
533    if (MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
534      O << "\tmr ";
535      printOperand(MI, 0);
536      O << ", ";
537      printOperand(MI, 1);
538      O << "\n";
539      return;
540    }
541  } else if (MI->getOpcode() == PPC::RLDICR) {
542    unsigned char SH = MI->getOperand(2).getImm();
543    unsigned char ME = MI->getOperand(3).getImm();
544    // rldicr RA, RS, SH, 63-SH == sldi RA, RS, SH
545    if (63-SH == ME) {
546      O << "\tsldi ";
547      printOperand(MI, 0);
548      O << ", ";
549      printOperand(MI, 1);
550      O << ", " << (unsigned int)SH << "\n";
551      return;
552    }
553  }
554
555  if (printInstruction(MI))
556    return; // Printer was automatically generated
557
558  assert(0 && "Unhandled instruction in asm writer!");
559  abort();
560  return;
561}
562
563/// runOnMachineFunction - This uses the printMachineInstruction()
564/// method to print assembly for each instruction.
565///
566bool LinuxAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
567  DW.SetModuleInfo(&getAnalysis<MachineModuleInfo>());
568
569  SetupMachineFunction(MF);
570  O << "\n\n";
571
572  // Print out constants referenced by the function
573  EmitConstantPool(MF.getConstantPool());
574
575  // Print out labels for the function.
576  const Function *F = MF.getFunction();
577  SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
578
579  switch (F->getLinkage()) {
580  default: assert(0 && "Unknown linkage type!");
581  case Function::InternalLinkage:  // Symbols default to internal.
582    break;
583  case Function::ExternalLinkage:
584    O << "\t.global\t" << CurrentFnName << '\n'
585      << "\t.type\t" << CurrentFnName << ", @function\n";
586    break;
587  case Function::WeakLinkage:
588  case Function::LinkOnceLinkage:
589    O << "\t.global\t" << CurrentFnName << '\n';
590    O << "\t.weak\t" << CurrentFnName << '\n';
591    break;
592  }
593
594  if (F->hasHiddenVisibility())
595    if (const char *Directive = TAI->getHiddenDirective())
596      O << Directive << CurrentFnName << "\n";
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 LinuxAsmPrinter::doInitialization(Module &M) {
632  bool Result = AsmPrinter::doInitialization(M);
633
634  // GNU as handles section names wrapped in quotes
635  Mang->setUseQuotes(true);
636
637  SwitchToTextSection(TAI->getTextSection());
638
639  // Emit initial debug information.
640  DW.BeginModule(&M);
641  return Result;
642}
643
644/// PrintUnmangledNameSafely - Print out the printable characters in the name.
645/// Don't print things like \n or \0.
646static void PrintUnmangledNameSafely(const Value *V, std::ostream &OS) {
647  for (const char *Name = V->getNameStart(), *E = Name+V->getNameLen();
648       Name != E; ++Name)
649    if (isprint(*Name))
650      OS << *Name;
651}
652
653bool LinuxAsmPrinter::doFinalization(Module &M) {
654  const TargetData *TD = TM.getTargetData();
655
656  // Print out module-level global variables here.
657  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
658       I != E; ++I) {
659    if (!I->hasInitializer()) continue;   // External global require no code
660
661    // Check to see if this is a special global used by LLVM, if so, emit it.
662    if (EmitSpecialLLVMGlobal(I))
663      continue;
664
665    std::string name = Mang->getValueName(I);
666
667    if (I->hasHiddenVisibility())
668      if (const char *Directive = TAI->getHiddenDirective())
669        O << Directive << name << "\n";
670
671    Constant *C = I->getInitializer();
672    unsigned Size = TD->getABITypeSize(C->getType());
673    unsigned Align = TD->getPreferredAlignmentLog(I);
674
675    if (C->isNullValue() && /* FIXME: Verify correct */
676        !I->hasSection() && (I->hasCommonLinkage() ||
677         I->hasInternalLinkage() || I->hasWeakLinkage() ||
678         I->hasLinkOnceLinkage() || I->hasExternalLinkage())) {
679      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
680      if (I->hasExternalLinkage()) {
681        O << "\t.global " << name << '\n';
682        O << "\t.type " << name << ", @object\n";
683        if (TAI->getBSSSection())
684          SwitchToDataSection(TAI->getBSSSection(), I);
685        O << name << ":\n";
686        O << "\t.zero " << Size << "\n";
687      } else if (I->hasInternalLinkage()) {
688        SwitchToDataSection("\t.data", I);
689        O << TAI->getLCOMMDirective() << name << "," << Size;
690      } else {
691        SwitchToDataSection("\t.data", I);
692        O << ".comm " << name << "," << Size;
693      }
694      O << "\t\t" << TAI->getCommentString() << " '";
695      PrintUnmangledNameSafely(I, O);
696      O << "'\n";
697    } else {
698      switch (I->getLinkage()) {
699      case GlobalValue::LinkOnceLinkage:
700      case GlobalValue::WeakLinkage:
701      case GlobalValue::CommonLinkage:
702        O << "\t.global " << name << '\n'
703          << "\t.type " << name << ", @object\n"
704          << "\t.weak " << name << '\n';
705        SwitchToDataSection("\t.data", I);
706        break;
707      case GlobalValue::AppendingLinkage:
708        // FIXME: appending linkage variables should go into a section of
709        // their name or something.  For now, just emit them as external.
710      case GlobalValue::ExternalLinkage:
711        // If external or appending, declare as a global symbol
712        O << "\t.global " << name << "\n"
713          << "\t.type " << name << ", @object\n";
714        // FALL THROUGH
715      case GlobalValue::InternalLinkage:
716        if (I->isConstant()) {
717          const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
718          if (TAI->getCStringSection() && CVA && CVA->isCString()) {
719            SwitchToDataSection(TAI->getCStringSection(), I);
720            break;
721          }
722        }
723
724        // FIXME: special handling for ".ctors" & ".dtors" sections
725        if (I->hasSection() &&
726            (I->getSection() == ".ctors" ||
727             I->getSection() == ".dtors")) {
728          std::string SectionName = ".section " + I->getSection()
729                                                + ",\"aw\",@progbits";
730          SwitchToDataSection(SectionName.c_str());
731        } else {
732          if (I->isConstant() && TAI->getReadOnlySection())
733            SwitchToDataSection(TAI->getReadOnlySection(), I);
734          else
735            SwitchToDataSection(TAI->getDataSection(), I);
736        }
737        break;
738      default:
739        cerr << "Unknown linkage type!";
740        abort();
741      }
742
743      EmitAlignment(Align, I);
744      O << name << ":\t\t\t\t" << TAI->getCommentString() << " '";
745      PrintUnmangledNameSafely(I, O);
746      O << "'\n";
747
748      // If the initializer is a extern weak symbol, remember to emit the weak
749      // reference!
750      if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
751        if (GV->hasExternalWeakLinkage())
752          ExtWeakSymbols.insert(GV);
753
754      EmitGlobalConstant(C);
755      O << '\n';
756    }
757  }
758
759  // TODO
760
761  // Emit initial debug information.
762  DW.EndModule();
763
764  return AsmPrinter::doFinalization(M);
765}
766
767std::string LinuxAsmPrinter::getSectionForFunction(const Function &F) const {
768  switch (F.getLinkage()) {
769  default: assert(0 && "Unknown linkage type!");
770  case Function::ExternalLinkage:
771  case Function::InternalLinkage: return TAI->getTextSection();
772  case Function::WeakLinkage:
773  case Function::LinkOnceLinkage:
774    return ".text";
775  }
776}
777
778std::string DarwinAsmPrinter::getSectionForFunction(const Function &F) const {
779  switch (F.getLinkage()) {
780  default: assert(0 && "Unknown linkage type!");
781  case Function::ExternalLinkage:
782  case Function::InternalLinkage: return TAI->getTextSection();
783  case Function::WeakLinkage:
784  case Function::LinkOnceLinkage:
785    return "\t.section __TEXT,__textcoal_nt,coalesced,pure_instructions";
786  }
787}
788
789/// runOnMachineFunction - This uses the printMachineInstruction()
790/// method to print assembly for each instruction.
791///
792bool DarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
793  // We need this for Personality functions.
794  MMI = &getAnalysis<MachineModuleInfo>();
795  DW.SetModuleInfo(MMI);
796
797  SetupMachineFunction(MF);
798  O << "\n\n";
799
800  // Print out constants referenced by the function
801  EmitConstantPool(MF.getConstantPool());
802
803  // Print out labels for the function.
804  const Function *F = MF.getFunction();
805  SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
806
807  switch (F->getLinkage()) {
808  default: assert(0 && "Unknown linkage type!");
809  case Function::InternalLinkage:  // Symbols default to internal.
810    break;
811  case Function::ExternalLinkage:
812    O << "\t.globl\t" << CurrentFnName << "\n";
813    break;
814  case Function::WeakLinkage:
815  case Function::LinkOnceLinkage:
816    O << "\t.globl\t" << CurrentFnName << "\n";
817    O << "\t.weak_definition\t" << CurrentFnName << "\n";
818    break;
819  }
820
821  if (F->hasHiddenVisibility())
822    if (const char *Directive = TAI->getHiddenDirective())
823      O << Directive << CurrentFnName << "\n";
824
825  EmitAlignment(OptimizeForSize ? 2 : 4, F);
826  O << CurrentFnName << ":\n";
827
828  // Emit pre-function debug information.
829  DW.BeginFunction(&MF);
830
831  // If the function is empty, then we need to emit *something*. Otherwise, the
832  // function's label might be associated with something that it wasn't meant to
833  // be associated with. We emit a noop in this situation.
834  MachineFunction::iterator I = MF.begin();
835
836  if (++I == MF.end() && MF.front().empty())
837    O << "\tnop\n";
838
839  // Print out code for the function.
840  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
841       I != E; ++I) {
842    // Print a label for the basic block.
843    if (I != MF.begin()) {
844      printBasicBlockLabel(I, true, true);
845      O << '\n';
846    }
847    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
848         II != IE; ++II) {
849      // Print the assembly for the instruction.
850      printMachineInstruction(II);
851    }
852  }
853
854  // Print out jump tables referenced by the function.
855  EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
856
857  // Emit post-function debug information.
858  DW.EndFunction();
859
860  // We didn't modify anything.
861  return false;
862}
863
864
865bool DarwinAsmPrinter::doInitialization(Module &M) {
866  static const char *const CPUDirectives[] = {
867    "",
868    "ppc",
869    "ppc601",
870    "ppc602",
871    "ppc603",
872    "ppc7400",
873    "ppc750",
874    "ppc970",
875    "ppc64"
876  };
877
878  unsigned Directive = Subtarget.getDarwinDirective();
879  if (Subtarget.isGigaProcessor() && Directive < PPC::DIR_970)
880    Directive = PPC::DIR_970;
881  if (Subtarget.hasAltivec() && Directive < PPC::DIR_7400)
882    Directive = PPC::DIR_7400;
883  if (Subtarget.isPPC64() && Directive < PPC::DIR_970)
884    Directive = PPC::DIR_64;
885  assert(Directive <= PPC::DIR_64 && "Directive out of range.");
886  O << "\t.machine " << CPUDirectives[Directive] << "\n";
887
888  bool Result = AsmPrinter::doInitialization(M);
889
890  // Darwin wants symbols to be quoted if they have complex names.
891  Mang->setUseQuotes(true);
892
893  // Prime text sections so they are adjacent.  This reduces the likelihood a
894  // large data or debug section causes a branch to exceed 16M limit.
895  SwitchToTextSection("\t.section __TEXT,__textcoal_nt,coalesced,"
896                      "pure_instructions");
897  if (TM.getRelocationModel() == Reloc::PIC_) {
898    SwitchToTextSection("\t.section __TEXT,__picsymbolstub1,symbol_stubs,"
899                          "pure_instructions,32");
900  } else if (TM.getRelocationModel() == Reloc::DynamicNoPIC) {
901    SwitchToTextSection("\t.section __TEXT,__symbol_stub1,symbol_stubs,"
902                        "pure_instructions,16");
903  }
904  SwitchToTextSection(TAI->getTextSection());
905
906  // Emit initial debug information.
907  DW.BeginModule(&M);
908  return Result;
909}
910
911bool DarwinAsmPrinter::doFinalization(Module &M) {
912  const TargetData *TD = TM.getTargetData();
913
914  // Print out module-level global variables here.
915  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
916       I != E; ++I) {
917    if (!I->hasInitializer()) continue;   // External global require no code
918
919    // Check to see if this is a special global used by LLVM, if so, emit it.
920    if (EmitSpecialLLVMGlobal(I)) {
921      if (TM.getRelocationModel() == Reloc::Static) {
922        if (I->getName() == "llvm.global_ctors")
923          O << ".reference .constructors_used\n";
924        else if (I->getName() == "llvm.global_dtors")
925          O << ".reference .destructors_used\n";
926      }
927      continue;
928    }
929
930    std::string name = Mang->getValueName(I);
931
932    if (I->hasHiddenVisibility())
933      if (const char *Directive = TAI->getHiddenDirective())
934        O << Directive << name << "\n";
935
936    Constant *C = I->getInitializer();
937    const Type *Type = C->getType();
938    unsigned Size = TD->getABITypeSize(Type);
939    unsigned Align = TD->getPreferredAlignmentLog(I);
940
941    if (C->isNullValue() && /* FIXME: Verify correct */
942        !I->hasSection() && (I->hasCommonLinkage() ||
943         I->hasInternalLinkage() || I->hasWeakLinkage() ||
944         I->hasLinkOnceLinkage() || I->hasExternalLinkage())) {
945      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
946      if (I->hasExternalLinkage()) {
947        O << "\t.globl " << name << '\n';
948        O << "\t.zerofill __DATA, __common, " << name << ", "
949          << Size << ", " << Align;
950      } else if (I->hasInternalLinkage()) {
951        SwitchToDataSection("\t.data", I);
952        O << TAI->getLCOMMDirective() << name << "," << Size << "," << Align;
953      } else if (!I->hasCommonLinkage()) {
954        O << "\t.globl " << name << "\n"
955          << TAI->getWeakDefDirective() << name << "\n";
956        SwitchToDataSection("\t.section __DATA,__datacoal_nt,coalesced", I);
957        EmitAlignment(Align, I);
958        O << name << ":\t\t\t\t" << TAI->getCommentString() << " ";
959        PrintUnmangledNameSafely(I, O);
960        O << "\n";
961        EmitGlobalConstant(C);
962        continue;
963      } else {
964        SwitchToDataSection("\t.data", I);
965        O << ".comm " << name << "," << Size;
966        // Darwin 9 and above support aligned common data.
967        if (Subtarget.isDarwin9())
968          O << "," << Align;
969      }
970      O << "\t\t" << TAI->getCommentString() << " '";
971      PrintUnmangledNameSafely(I, O);
972      O << "'\n";
973    } else {
974      switch (I->getLinkage()) {
975      case GlobalValue::LinkOnceLinkage:
976      case GlobalValue::WeakLinkage:
977      case GlobalValue::CommonLinkage:
978        O << "\t.globl " << name << '\n'
979          << "\t.weak_definition " << name << '\n';
980        SwitchToDataSection("\t.section __DATA,__datacoal_nt,coalesced", I);
981        break;
982      case GlobalValue::AppendingLinkage:
983        // FIXME: appending linkage variables should go into a section of
984        // their name or something.  For now, just emit them as external.
985      case GlobalValue::ExternalLinkage:
986        // If external or appending, declare as a global symbol
987        O << "\t.globl " << name << "\n";
988        // FALL THROUGH
989      case GlobalValue::InternalLinkage:
990        if (I->isConstant()) {
991          const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
992          if (TAI->getCStringSection() && CVA && CVA->isCString()) {
993            SwitchToDataSection(TAI->getCStringSection(), I);
994            break;
995          }
996        }
997        if (I->hasSection()) {
998          // Honor all section names on Darwin; ObjC uses this
999          std::string SectionName = ".section " + I->getSection();
1000          SwitchToDataSection(SectionName.c_str());
1001        } else if (!I->isConstant())
1002          SwitchToDataSection(TAI->getDataSection(), I);
1003        else {
1004          // Read-only data.
1005          bool HasReloc = C->ContainsRelocations();
1006          if (HasReloc &&
1007              TM.getRelocationModel() != Reloc::Static)
1008            SwitchToDataSection("\t.const_data\n");
1009          else if (!HasReloc && Size == 4 &&
1010                   TAI->getFourByteConstantSection())
1011            SwitchToDataSection(TAI->getFourByteConstantSection(), I);
1012          else if (!HasReloc && Size == 8 &&
1013                   TAI->getEightByteConstantSection())
1014            SwitchToDataSection(TAI->getEightByteConstantSection(), I);
1015          else if (!HasReloc && Size == 16 &&
1016                   TAI->getSixteenByteConstantSection())
1017            SwitchToDataSection(TAI->getSixteenByteConstantSection(), I);
1018          else if (TAI->getReadOnlySection())
1019            SwitchToDataSection(TAI->getReadOnlySection(), I);
1020          else
1021            SwitchToDataSection(TAI->getDataSection(), I);
1022        }
1023        break;
1024      default:
1025        cerr << "Unknown linkage type!";
1026        abort();
1027      }
1028
1029      EmitAlignment(Align, I);
1030      O << name << ":\t\t\t\t" << TAI->getCommentString() << " '";
1031      PrintUnmangledNameSafely(I, O);
1032      O << "'\n";
1033
1034      // If the initializer is a extern weak symbol, remember to emit the weak
1035      // reference!
1036      if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
1037        if (GV->hasExternalWeakLinkage())
1038          ExtWeakSymbols.insert(GV);
1039
1040      EmitGlobalConstant(C);
1041      O << '\n';
1042    }
1043  }
1044
1045  bool isPPC64 = TD->getPointerSizeInBits() == 64;
1046
1047  // Output stubs for dynamically-linked functions
1048  if (TM.getRelocationModel() == Reloc::PIC_) {
1049    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
1050         i != e; ++i) {
1051      SwitchToTextSection("\t.section __TEXT,__picsymbolstub1,symbol_stubs,"
1052                          "pure_instructions,32");
1053      EmitAlignment(4);
1054      O << "L" << *i << "$stub:\n";
1055      O << "\t.indirect_symbol " << *i << "\n";
1056      O << "\tmflr r0\n";
1057      O << "\tbcl 20,31,L0$" << *i << "\n";
1058      O << "L0$" << *i << ":\n";
1059      O << "\tmflr r11\n";
1060      O << "\taddis r11,r11,ha16(L" << *i << "$lazy_ptr-L0$" << *i << ")\n";
1061      O << "\tmtlr r0\n";
1062      if (isPPC64)
1063        O << "\tldu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
1064      else
1065        O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
1066      O << "\tmtctr r12\n";
1067      O << "\tbctr\n";
1068      SwitchToDataSection(".lazy_symbol_pointer");
1069      O << "L" << *i << "$lazy_ptr:\n";
1070      O << "\t.indirect_symbol " << *i << "\n";
1071      if (isPPC64)
1072        O << "\t.quad dyld_stub_binding_helper\n";
1073      else
1074        O << "\t.long dyld_stub_binding_helper\n";
1075    }
1076  } else {
1077    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
1078         i != e; ++i) {
1079      SwitchToTextSection("\t.section __TEXT,__symbol_stub1,symbol_stubs,"
1080                          "pure_instructions,16");
1081      EmitAlignment(4);
1082      O << "L" << *i << "$stub:\n";
1083      O << "\t.indirect_symbol " << *i << "\n";
1084      O << "\tlis r11,ha16(L" << *i << "$lazy_ptr)\n";
1085      if (isPPC64)
1086        O << "\tldu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
1087      else
1088        O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
1089      O << "\tmtctr r12\n";
1090      O << "\tbctr\n";
1091      SwitchToDataSection(".lazy_symbol_pointer");
1092      O << "L" << *i << "$lazy_ptr:\n";
1093      O << "\t.indirect_symbol " << *i << "\n";
1094      if (isPPC64)
1095        O << "\t.quad dyld_stub_binding_helper\n";
1096      else
1097        O << "\t.long dyld_stub_binding_helper\n";
1098    }
1099  }
1100
1101  O << "\n";
1102
1103  if (TAI->doesSupportExceptionHandling() && MMI) {
1104    // Add the (possibly multiple) personalities to the set of global values.
1105    // Only referenced functions get into the Personalities list.
1106    const std::vector<Function *>& Personalities = MMI->getPersonalities();
1107
1108    for (std::vector<Function *>::const_iterator I = Personalities.begin(),
1109           E = Personalities.end(); I != E; ++I)
1110      if (*I) GVStubs.insert("_" + (*I)->getName());
1111  }
1112
1113  // Output stubs for external and common global variables.
1114  if (!GVStubs.empty()) {
1115    SwitchToDataSection(".non_lazy_symbol_pointer");
1116    for (std::set<std::string>::iterator I = GVStubs.begin(),
1117         E = GVStubs.end(); I != E; ++I) {
1118      O << "L" << *I << "$non_lazy_ptr:\n";
1119      O << "\t.indirect_symbol " << *I << "\n";
1120      if (isPPC64)
1121        O << "\t.quad\t0\n";
1122      else
1123        O << "\t.long\t0\n";
1124
1125    }
1126  }
1127
1128  // Emit initial debug information.
1129  DW.EndModule();
1130
1131  // Funny Darwin hack: This flag tells the linker that no global symbols
1132  // contain code that falls through to other global symbols (e.g. the obvious
1133  // implementation of multiple entry points).  If this doesn't occur, the
1134  // linker can safely perform dead code stripping.  Since LLVM never generates
1135  // code that does this, it is always safe to set.
1136  O << "\t.subsections_via_symbols\n";
1137
1138  return AsmPrinter::doFinalization(M);
1139}
1140
1141
1142
1143/// createPPCAsmPrinterPass - Returns a pass that prints the PPC assembly code
1144/// for a MachineFunction to the given output stream, in a format that the
1145/// Darwin assembler can deal with.
1146///
1147FunctionPass *llvm::createPPCAsmPrinterPass(std::ostream &o,
1148                                            PPCTargetMachine &tm) {
1149  const PPCSubtarget *Subtarget = &tm.getSubtarget<PPCSubtarget>();
1150
1151  if (Subtarget->isDarwin()) {
1152    return new DarwinAsmPrinter(o, tm, tm.getTargetAsmInfo());
1153  } else {
1154    return new LinuxAsmPrinter(o, tm, tm.getTargetAsmInfo());
1155  }
1156}
1157
1158