PPCAsmPrinter.cpp revision ec321b4d64ee02a1b90021c09d9513618787c6e8 
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).Name;
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()))) {
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 << "$non_lazy_ptr";
381      return;
382    }
383    O << TAI->getGlobalPrefix() << MO.getSymbolName();
384    return;
385  case MachineOperand::MO_GlobalAddress: {
386    // Computing the address of a global symbol, not calling it.
387    GlobalValue *GV = MO.getGlobal();
388    std::string Name = Mang->getValueName(GV);
389
390    // External or weakly linked global variables need non-lazily-resolved stubs
391    if (TM.getRelocationModel() != Reloc::Static) {
392      if (((GV->isDeclaration() || GV->hasWeakLinkage() ||
393            GV->hasLinkOnceLinkage()))) {
394        GVStubs.insert(Name);
395        O << "L" << Name << "$non_lazy_ptr";
396        return;
397      }
398    }
399    O << Name;
400
401    if (MO.getOffset() > 0)
402      O << "+" << MO.getOffset();
403    else if (MO.getOffset() < 0)
404      O << MO.getOffset();
405
406    if (GV->hasExternalWeakLinkage())
407      ExtWeakSymbols.insert(GV);
408    return;
409  }
410
411  default:
412    O << "<unknown operand type: " << MO.getType() << ">";
413    return;
414  }
415}
416
417/// EmitExternalGlobal - In this case we need to use the indirect symbol.
418///
419void PPCAsmPrinter::EmitExternalGlobal(const GlobalVariable *GV) {
420  std::string Name = getGlobalLinkName(GV);
421  if (TM.getRelocationModel() != Reloc::Static) {
422    GVStubs.insert(Name);
423    O << "L" << Name << "$non_lazy_ptr";
424    return;
425  }
426  O << Name;
427}
428
429/// PrintAsmOperand - Print out an operand for an inline asm expression.
430///
431bool PPCAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
432                                    unsigned AsmVariant,
433                                    const char *ExtraCode) {
434  // Does this asm operand have a single letter operand modifier?
435  if (ExtraCode && ExtraCode[0]) {
436    if (ExtraCode[1] != 0) return true; // Unknown modifier.
437
438    switch (ExtraCode[0]) {
439    default: return true;  // Unknown modifier.
440    case 'c': // Don't print "$" before a global var name or constant.
441      // PPC never has a prefix.
442      printOperand(MI, OpNo);
443      return false;
444    case 'L': // Write second word of DImode reference.
445      // Verify that this operand has two consecutive registers.
446      if (!MI->getOperand(OpNo).isRegister() ||
447          OpNo+1 == MI->getNumOperands() ||
448          !MI->getOperand(OpNo+1).isRegister())
449        return true;
450      ++OpNo;   // Return the high-part.
451      break;
452    case 'I':
453      // Write 'i' if an integer constant, otherwise nothing.  Used to print
454      // addi vs add, etc.
455      if (MI->getOperand(OpNo).isImmediate())
456        O << "i";
457      return false;
458    }
459  }
460
461  printOperand(MI, OpNo);
462  return false;
463}
464
465bool PPCAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
466                                          unsigned AsmVariant,
467                                          const char *ExtraCode) {
468  if (ExtraCode && ExtraCode[0])
469    return true; // Unknown modifier.
470  if (MI->getOperand(OpNo).isRegister())
471    printMemRegReg(MI, OpNo);
472  else
473    printMemRegImm(MI, OpNo);
474  return false;
475}
476
477void PPCAsmPrinter::printPredicateOperand(const MachineInstr *MI, unsigned OpNo,
478                                          const char *Modifier) {
479  assert(Modifier && "Must specify 'cc' or 'reg' as predicate op modifier!");
480  unsigned Code = MI->getOperand(OpNo).getImm();
481  if (!strcmp(Modifier, "cc")) {
482    switch ((PPC::Predicate)Code) {
483    case PPC::PRED_ALWAYS: return; // Don't print anything for always.
484    case PPC::PRED_LT: O << "lt"; return;
485    case PPC::PRED_LE: O << "le"; return;
486    case PPC::PRED_EQ: O << "eq"; return;
487    case PPC::PRED_GE: O << "ge"; return;
488    case PPC::PRED_GT: O << "gt"; return;
489    case PPC::PRED_NE: O << "ne"; return;
490    case PPC::PRED_UN: O << "un"; return;
491    case PPC::PRED_NU: O << "nu"; return;
492    }
493
494  } else {
495    assert(!strcmp(Modifier, "reg") &&
496           "Need to specify 'cc' or 'reg' as predicate op modifier!");
497    // Don't print the register for 'always'.
498    if (Code == PPC::PRED_ALWAYS) return;
499    printOperand(MI, OpNo+1);
500  }
501}
502
503
504/// printMachineInstruction -- Print out a single PowerPC MI in Darwin syntax to
505/// the current output stream.
506///
507void PPCAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
508  ++EmittedInsts;
509
510  // Check for slwi/srwi mnemonics.
511  if (MI->getOpcode() == PPC::RLWINM) {
512    bool FoundMnemonic = false;
513    unsigned char SH = MI->getOperand(2).getImm();
514    unsigned char MB = MI->getOperand(3).getImm();
515    unsigned char ME = MI->getOperand(4).getImm();
516    if (SH <= 31 && MB == 0 && ME == (31-SH)) {
517      O << "\tslwi "; FoundMnemonic = true;
518    }
519    if (SH <= 31 && MB == (32-SH) && ME == 31) {
520      O << "\tsrwi "; FoundMnemonic = true;
521      SH = 32-SH;
522    }
523    if (FoundMnemonic) {
524      printOperand(MI, 0);
525      O << ", ";
526      printOperand(MI, 1);
527      O << ", " << (unsigned int)SH << "\n";
528      return;
529    }
530  } else if (MI->getOpcode() == PPC::OR || MI->getOpcode() == PPC::OR8) {
531    if (MI->getOperand(1).getReg() == MI->getOperand(2).getReg()) {
532      O << "\tmr ";
533      printOperand(MI, 0);
534      O << ", ";
535      printOperand(MI, 1);
536      O << "\n";
537      return;
538    }
539  } else if (MI->getOpcode() == PPC::RLDICR) {
540    unsigned char SH = MI->getOperand(2).getImm();
541    unsigned char ME = MI->getOperand(3).getImm();
542    // rldicr RA, RS, SH, 63-SH == sldi RA, RS, SH
543    if (63-SH == ME) {
544      O << "\tsldi ";
545      printOperand(MI, 0);
546      O << ", ";
547      printOperand(MI, 1);
548      O << ", " << (unsigned int)SH << "\n";
549      return;
550    }
551  }
552
553  if (printInstruction(MI))
554    return; // Printer was automatically generated
555
556  assert(0 && "Unhandled instruction in asm writer!");
557  abort();
558  return;
559}
560
561/// runOnMachineFunction - This uses the printMachineInstruction()
562/// method to print assembly for each instruction.
563///
564bool LinuxAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
565  DW.SetModuleInfo(&getAnalysis<MachineModuleInfo>());
566
567  SetupMachineFunction(MF);
568  O << "\n\n";
569
570  // Print out constants referenced by the function
571  EmitConstantPool(MF.getConstantPool());
572
573  // Print out labels for the function.
574  const Function *F = MF.getFunction();
575  SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
576
577  switch (F->getLinkage()) {
578  default: assert(0 && "Unknown linkage type!");
579  case Function::InternalLinkage:  // Symbols default to internal.
580    break;
581  case Function::ExternalLinkage:
582    O << "\t.global\t" << CurrentFnName << '\n'
583      << "\t.type\t" << CurrentFnName << ", @function\n";
584    break;
585  case Function::WeakLinkage:
586  case Function::LinkOnceLinkage:
587    O << "\t.global\t" << CurrentFnName << '\n';
588    O << "\t.weak\t" << CurrentFnName << '\n';
589    break;
590  }
591
592  if (F->hasHiddenVisibility())
593    if (const char *Directive = TAI->getHiddenDirective())
594      O << Directive << CurrentFnName << "\n";
595
596  EmitAlignment(2, F);
597  O << CurrentFnName << ":\n";
598
599  // Emit pre-function debug information.
600  DW.BeginFunction(&MF);
601
602  // Print out code for the function.
603  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
604       I != E; ++I) {
605    // Print a label for the basic block.
606    if (I != MF.begin()) {
607      printBasicBlockLabel(I, true);
608      O << '\n';
609    }
610    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
611         II != E; ++II) {
612      // Print the assembly for the instruction.
613      printMachineInstruction(II);
614    }
615  }
616
617  O << "\t.size\t" << CurrentFnName << ",.-" << CurrentFnName << "\n";
618
619  // Print out jump tables referenced by the function.
620  EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
621
622  // Emit post-function debug information.
623  DW.EndFunction();
624
625  // We didn't modify anything.
626  return false;
627}
628
629bool LinuxAsmPrinter::doInitialization(Module &M) {
630  bool Result = AsmPrinter::doInitialization(M);
631
632  // GNU as handles section names wrapped in quotes
633  Mang->setUseQuotes(true);
634
635  SwitchToTextSection(TAI->getTextSection());
636
637  // Emit initial debug information.
638  DW.BeginModule(&M);
639  return Result;
640}
641
642/// PrintUnmangledNameSafely - Print out the printable characters in the name.
643/// Don't print things like \n or \0.
644static void PrintUnmangledNameSafely(const Value *V, std::ostream &OS) {
645  for (const char *Name = V->getNameStart(), *E = Name+V->getNameLen();
646       Name != E; ++Name)
647    if (isprint(*Name))
648      OS << *Name;
649}
650
651bool LinuxAsmPrinter::doFinalization(Module &M) {
652  const TargetData *TD = TM.getTargetData();
653
654  // Print out module-level global variables here.
655  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
656       I != E; ++I) {
657    if (!I->hasInitializer()) continue;   // External global require no code
658
659    // Check to see if this is a special global used by LLVM, if so, emit it.
660    if (EmitSpecialLLVMGlobal(I))
661      continue;
662
663    std::string name = Mang->getValueName(I);
664
665    if (I->hasHiddenVisibility())
666      if (const char *Directive = TAI->getHiddenDirective())
667        O << Directive << name << "\n";
668
669    Constant *C = I->getInitializer();
670    unsigned Size = TD->getABITypeSize(C->getType());
671    unsigned Align = TD->getPreferredAlignmentLog(I);
672
673    if (C->isNullValue() && /* FIXME: Verify correct */
674        !I->hasSection() &&
675        (I->hasInternalLinkage() || I->hasWeakLinkage() ||
676         I->hasLinkOnceLinkage() || I->hasExternalLinkage())) {
677      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
678      if (I->hasExternalLinkage()) {
679        O << "\t.global " << name << '\n';
680        O << "\t.type " << name << ", @object\n";
681        if (TAI->getBSSSection())
682          SwitchToDataSection(TAI->getBSSSection(), I);
683        O << name << ":\n";
684        O << "\t.zero " << Size << "\n";
685      } else if (I->hasInternalLinkage()) {
686        SwitchToDataSection("\t.data", I);
687        O << TAI->getLCOMMDirective() << name << "," << Size;
688      } else {
689        SwitchToDataSection("\t.data", I);
690        O << ".comm " << name << "," << Size;
691      }
692      O << "\t\t" << TAI->getCommentString() << " '";
693      PrintUnmangledNameSafely(I, O);
694      O << "'\n";
695    } else {
696      switch (I->getLinkage()) {
697      case GlobalValue::LinkOnceLinkage:
698      case GlobalValue::WeakLinkage:
699        O << "\t.global " << name << '\n'
700          << "\t.type " << name << ", @object\n"
701          << "\t.weak " << name << '\n';
702        SwitchToDataSection("\t.data", I);
703        break;
704      case GlobalValue::AppendingLinkage:
705        // FIXME: appending linkage variables should go into a section of
706        // their name or something.  For now, just emit them as external.
707      case GlobalValue::ExternalLinkage:
708        // If external or appending, declare as a global symbol
709        O << "\t.global " << name << "\n"
710          << "\t.type " << name << ", @object\n";
711        // FALL THROUGH
712      case GlobalValue::InternalLinkage:
713        if (I->isConstant()) {
714          const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
715          if (TAI->getCStringSection() && CVA && CVA->isCString()) {
716            SwitchToDataSection(TAI->getCStringSection(), I);
717            break;
718          }
719        }
720
721        // FIXME: special handling for ".ctors" & ".dtors" sections
722        if (I->hasSection() &&
723            (I->getSection() == ".ctors" ||
724             I->getSection() == ".dtors")) {
725          std::string SectionName = ".section " + I->getSection()
726                                                + ",\"aw\",@progbits";
727          SwitchToDataSection(SectionName.c_str());
728        } else {
729          if (I->isConstant() && TAI->getReadOnlySection())
730            SwitchToDataSection(TAI->getReadOnlySection(), I);
731          else
732            SwitchToDataSection(TAI->getDataSection(), I);
733        }
734        break;
735      default:
736        cerr << "Unknown linkage type!";
737        abort();
738      }
739
740      EmitAlignment(Align, I);
741      O << name << ":\t\t\t\t" << TAI->getCommentString() << " '";
742      PrintUnmangledNameSafely(I, O);
743      O << "'\n";
744
745      // If the initializer is a extern weak symbol, remember to emit the weak
746      // reference!
747      if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
748        if (GV->hasExternalWeakLinkage())
749          ExtWeakSymbols.insert(GV);
750
751      EmitGlobalConstant(C);
752      O << '\n';
753    }
754  }
755
756  // TODO
757
758  // Emit initial debug information.
759  DW.EndModule();
760
761  return AsmPrinter::doFinalization(M);
762}
763
764std::string LinuxAsmPrinter::getSectionForFunction(const Function &F) const {
765  switch (F.getLinkage()) {
766  default: assert(0 && "Unknown linkage type!");
767  case Function::ExternalLinkage:
768  case Function::InternalLinkage: return TAI->getTextSection();
769  case Function::WeakLinkage:
770  case Function::LinkOnceLinkage:
771    return ".text";
772  }
773}
774
775std::string DarwinAsmPrinter::getSectionForFunction(const Function &F) const {
776  switch (F.getLinkage()) {
777  default: assert(0 && "Unknown linkage type!");
778  case Function::ExternalLinkage:
779  case Function::InternalLinkage: return TAI->getTextSection();
780  case Function::WeakLinkage:
781  case Function::LinkOnceLinkage:
782    return "\t.section __TEXT,__textcoal_nt,coalesced,pure_instructions";
783  }
784}
785
786/// runOnMachineFunction - This uses the printMachineInstruction()
787/// method to print assembly for each instruction.
788///
789bool DarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
790  // We need this for Personality functions.
791  MMI = &getAnalysis<MachineModuleInfo>();
792  DW.SetModuleInfo(MMI);
793
794  SetupMachineFunction(MF);
795  O << "\n\n";
796
797  // Print out constants referenced by the function
798  EmitConstantPool(MF.getConstantPool());
799
800  // Print out labels for the function.
801  const Function *F = MF.getFunction();
802  SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
803
804  switch (F->getLinkage()) {
805  default: assert(0 && "Unknown linkage type!");
806  case Function::InternalLinkage:  // Symbols default to internal.
807    break;
808  case Function::ExternalLinkage:
809    O << "\t.globl\t" << CurrentFnName << "\n";
810    break;
811  case Function::WeakLinkage:
812  case Function::LinkOnceLinkage:
813    O << "\t.globl\t" << CurrentFnName << "\n";
814    O << "\t.weak_definition\t" << CurrentFnName << "\n";
815    break;
816  }
817
818  if (F->hasHiddenVisibility())
819    if (const char *Directive = TAI->getHiddenDirective())
820      O << Directive << CurrentFnName << "\n";
821
822  EmitAlignment(4, F);
823  O << CurrentFnName << ":\n";
824
825  // Emit pre-function debug information.
826  DW.BeginFunction(&MF);
827
828  // If the function is empty, then we need to emit *something*. Otherwise, the
829  // function's label might be associated with something that it wasn't meant to
830  // be associated with. We emit a noop in this situation.
831  MachineFunction::iterator I = MF.begin();
832
833  if (++I == MF.end() && MF.front().empty())
834    O << "\tnop\n";
835
836  // Print out code for the function.
837  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
838       I != E; ++I) {
839    // Print a label for the basic block.
840    if (I != MF.begin()) {
841      printBasicBlockLabel(I, true);
842      O << '\n';
843    }
844    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
845         II != IE; ++II) {
846      // Print the assembly for the instruction.
847      printMachineInstruction(II);
848    }
849  }
850
851  // Print out jump tables referenced by the function.
852  EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
853
854  // Emit post-function debug information.
855  DW.EndFunction();
856
857  // We didn't modify anything.
858  return false;
859}
860
861
862bool DarwinAsmPrinter::doInitialization(Module &M) {
863  static const char *CPUDirectives[] = {
864    "",
865    "ppc",
866    "ppc601",
867    "ppc602",
868    "ppc603",
869    "ppc7400",
870    "ppc750",
871    "ppc970",
872    "ppc64"
873  };
874
875  unsigned Directive = Subtarget.getDarwinDirective();
876  if (Subtarget.isGigaProcessor() && Directive < PPC::DIR_970)
877    Directive = PPC::DIR_970;
878  if (Subtarget.hasAltivec() && Directive < PPC::DIR_7400)
879    Directive = PPC::DIR_7400;
880  if (Subtarget.isPPC64() && Directive < PPC::DIR_970)
881    Directive = PPC::DIR_64;
882  assert(Directive <= PPC::DIR_64 && "Directive out of range.");
883  O << "\t.machine " << CPUDirectives[Directive] << "\n";
884
885  bool Result = AsmPrinter::doInitialization(M);
886
887  // Darwin wants symbols to be quoted if they have complex names.
888  Mang->setUseQuotes(true);
889
890  // Prime text sections so they are adjacent.  This reduces the likelihood a
891  // large data or debug section causes a branch to exceed 16M limit.
892  SwitchToTextSection("\t.section __TEXT,__textcoal_nt,coalesced,"
893                      "pure_instructions");
894  if (TM.getRelocationModel() == Reloc::PIC_) {
895    SwitchToTextSection("\t.section __TEXT,__picsymbolstub1,symbol_stubs,"
896                          "pure_instructions,32");
897  } else if (TM.getRelocationModel() == Reloc::DynamicNoPIC) {
898    SwitchToTextSection("\t.section __TEXT,__symbol_stub1,symbol_stubs,"
899                        "pure_instructions,16");
900  }
901  SwitchToTextSection(TAI->getTextSection());
902
903  // Emit initial debug information.
904  DW.BeginModule(&M);
905  return Result;
906}
907
908bool DarwinAsmPrinter::doFinalization(Module &M) {
909  const TargetData *TD = TM.getTargetData();
910
911  // Print out module-level global variables here.
912  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
913       I != E; ++I) {
914    if (!I->hasInitializer()) continue;   // External global require no code
915
916    // Check to see if this is a special global used by LLVM, if so, emit it.
917    if (EmitSpecialLLVMGlobal(I)) {
918      if (TM.getRelocationModel() == Reloc::Static) {
919        if (I->getName() == "llvm.global_ctors")
920          O << ".reference .constructors_used\n";
921        else if (I->getName() == "llvm.global_dtors")
922          O << ".reference .destructors_used\n";
923      }
924      continue;
925    }
926
927    std::string name = Mang->getValueName(I);
928
929    if (I->hasHiddenVisibility())
930      if (const char *Directive = TAI->getHiddenDirective())
931        O << Directive << name << "\n";
932
933    Constant *C = I->getInitializer();
934    const Type *Type = C->getType();
935    unsigned Size = TD->getABITypeSize(Type);
936    unsigned Align = TD->getPreferredAlignmentLog(I);
937
938    if (C->isNullValue() && /* FIXME: Verify correct */
939        !I->hasSection() &&
940        (I->hasInternalLinkage() || I->hasWeakLinkage() ||
941         I->hasLinkOnceLinkage() || I->hasExternalLinkage())) {
942      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
943      if (I->hasExternalLinkage()) {
944        O << "\t.globl " << name << '\n';
945        O << "\t.zerofill __DATA, __common, " << name << ", "
946          << Size << ", " << Align;
947      } else if (I->hasInternalLinkage()) {
948        SwitchToDataSection("\t.data", I);
949        O << TAI->getLCOMMDirective() << name << "," << Size << "," << Align;
950      } else {
951        SwitchToDataSection("\t.data", I);
952        O << ".comm " << name << "," << Size;
953        // Darwin 9 and above support aligned common data.
954        if (Subtarget.isDarwin9())
955          O << "," << Align;
956      }
957      O << "\t\t" << TAI->getCommentString() << " '";
958      PrintUnmangledNameSafely(I, O);
959      O << "'\n";
960    } else {
961      switch (I->getLinkage()) {
962      case GlobalValue::LinkOnceLinkage:
963      case GlobalValue::WeakLinkage:
964        O << "\t.globl " << name << '\n'
965          << "\t.weak_definition " << name << '\n';
966        SwitchToDataSection("\t.section __DATA,__datacoal_nt,coalesced", I);
967        break;
968      case GlobalValue::AppendingLinkage:
969        // FIXME: appending linkage variables should go into a section of
970        // their name or something.  For now, just emit them as external.
971      case GlobalValue::ExternalLinkage:
972        // If external or appending, declare as a global symbol
973        O << "\t.globl " << name << "\n";
974        // FALL THROUGH
975      case GlobalValue::InternalLinkage:
976        if (I->isConstant()) {
977          const ConstantArray *CVA = dyn_cast<ConstantArray>(C);
978          if (TAI->getCStringSection() && CVA && CVA->isCString()) {
979            SwitchToDataSection(TAI->getCStringSection(), I);
980            break;
981          }
982        }
983        if (I->hasSection()) {
984          // Honor all section names on Darwin; ObjC uses this
985          std::string SectionName = ".section " + I->getSection();
986          SwitchToDataSection(SectionName.c_str());
987        } else if (!I->isConstant())
988          SwitchToDataSection(TAI->getDataSection(), I);
989        else {
990          // Read-only data.
991          bool HasReloc = C->ContainsRelocations();
992          if (HasReloc &&
993              TM.getRelocationModel() != Reloc::Static)
994            SwitchToDataSection("\t.const_data\n");
995          else if (!HasReloc && Size == 4 &&
996                   TAI->getFourByteConstantSection())
997            SwitchToDataSection(TAI->getFourByteConstantSection(), I);
998          else if (!HasReloc && Size == 8 &&
999                   TAI->getEightByteConstantSection())
1000            SwitchToDataSection(TAI->getEightByteConstantSection(), I);
1001          else if (!HasReloc && Size == 16 &&
1002                   TAI->getSixteenByteConstantSection())
1003            SwitchToDataSection(TAI->getSixteenByteConstantSection(), I);
1004          else if (TAI->getReadOnlySection())
1005            SwitchToDataSection(TAI->getReadOnlySection(), I);
1006          else
1007            SwitchToDataSection(TAI->getDataSection(), I);
1008        }
1009        break;
1010      default:
1011        cerr << "Unknown linkage type!";
1012        abort();
1013      }
1014
1015      EmitAlignment(Align, I);
1016      O << name << ":\t\t\t\t" << TAI->getCommentString() << " '";
1017      PrintUnmangledNameSafely(I, O);
1018      O << "'\n";
1019
1020      // If the initializer is a extern weak symbol, remember to emit the weak
1021      // reference!
1022      if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
1023        if (GV->hasExternalWeakLinkage())
1024          ExtWeakSymbols.insert(GV);
1025
1026      EmitGlobalConstant(C);
1027      O << '\n';
1028    }
1029  }
1030
1031  bool isPPC64 = TD->getPointerSizeInBits() == 64;
1032
1033  // Output stubs for dynamically-linked functions
1034  if (TM.getRelocationModel() == Reloc::PIC_) {
1035    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
1036         i != e; ++i) {
1037      SwitchToTextSection("\t.section __TEXT,__picsymbolstub1,symbol_stubs,"
1038                          "pure_instructions,32");
1039      EmitAlignment(4);
1040      O << "L" << *i << "$stub:\n";
1041      O << "\t.indirect_symbol " << *i << "\n";
1042      O << "\tmflr r0\n";
1043      O << "\tbcl 20,31,L0$" << *i << "\n";
1044      O << "L0$" << *i << ":\n";
1045      O << "\tmflr r11\n";
1046      O << "\taddis r11,r11,ha16(L" << *i << "$lazy_ptr-L0$" << *i << ")\n";
1047      O << "\tmtlr r0\n";
1048      if (isPPC64)
1049        O << "\tldu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
1050      else
1051        O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
1052      O << "\tmtctr r12\n";
1053      O << "\tbctr\n";
1054      SwitchToDataSection(".lazy_symbol_pointer");
1055      O << "L" << *i << "$lazy_ptr:\n";
1056      O << "\t.indirect_symbol " << *i << "\n";
1057      if (isPPC64)
1058        O << "\t.quad dyld_stub_binding_helper\n";
1059      else
1060        O << "\t.long dyld_stub_binding_helper\n";
1061    }
1062  } else {
1063    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
1064         i != e; ++i) {
1065      SwitchToTextSection("\t.section __TEXT,__symbol_stub1,symbol_stubs,"
1066                          "pure_instructions,16");
1067      EmitAlignment(4);
1068      O << "L" << *i << "$stub:\n";
1069      O << "\t.indirect_symbol " << *i << "\n";
1070      O << "\tlis r11,ha16(L" << *i << "$lazy_ptr)\n";
1071      if (isPPC64)
1072        O << "\tldu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
1073      else
1074        O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr)(r11)\n";
1075      O << "\tmtctr r12\n";
1076      O << "\tbctr\n";
1077      SwitchToDataSection(".lazy_symbol_pointer");
1078      O << "L" << *i << "$lazy_ptr:\n";
1079      O << "\t.indirect_symbol " << *i << "\n";
1080      if (isPPC64)
1081        O << "\t.quad dyld_stub_binding_helper\n";
1082      else
1083        O << "\t.long dyld_stub_binding_helper\n";
1084    }
1085  }
1086
1087  O << "\n";
1088
1089  if (ExceptionHandling && TAI->doesSupportExceptionHandling() && MMI) {
1090    // Add the (possibly multiple) personalities to the set of global values.
1091    const std::vector<Function *>& Personalities = MMI->getPersonalities();
1092
1093    for (std::vector<Function *>::const_iterator I = Personalities.begin(),
1094           E = Personalities.end(); I != E; ++I)
1095      if (*I) GVStubs.insert("_" + (*I)->getName());
1096  }
1097
1098  // Output stubs for external and common global variables.
1099  if (!GVStubs.empty()) {
1100    SwitchToDataSection(".non_lazy_symbol_pointer");
1101    for (std::set<std::string>::iterator I = GVStubs.begin(),
1102         E = GVStubs.end(); I != E; ++I) {
1103      O << "L" << *I << "$non_lazy_ptr:\n";
1104      O << "\t.indirect_symbol " << *I << "\n";
1105      if (isPPC64)
1106        O << "\t.quad\t0\n";
1107      else
1108        O << "\t.long\t0\n";
1109
1110    }
1111  }
1112
1113  // Emit initial debug information.
1114  DW.EndModule();
1115
1116  // Funny Darwin hack: This flag tells the linker that no global symbols
1117  // contain code that falls through to other global symbols (e.g. the obvious
1118  // implementation of multiple entry points).  If this doesn't occur, the
1119  // linker can safely perform dead code stripping.  Since LLVM never generates
1120  // code that does this, it is always safe to set.
1121  O << "\t.subsections_via_symbols\n";
1122
1123  return AsmPrinter::doFinalization(M);
1124}
1125
1126
1127
1128/// createPPCAsmPrinterPass - Returns a pass that prints the PPC assembly code
1129/// for a MachineFunction to the given output stream, in a format that the
1130/// Darwin assembler can deal with.
1131///
1132FunctionPass *llvm::createPPCAsmPrinterPass(std::ostream &o,
1133                                            PPCTargetMachine &tm) {
1134  const PPCSubtarget *Subtarget = &tm.getSubtarget<PPCSubtarget>();
1135
1136  if (Subtarget->isDarwin()) {
1137    return new DarwinAsmPrinter(o, tm, tm.getTargetAsmInfo());
1138  } else {
1139    return new LinuxAsmPrinter(o, tm, tm.getTargetAsmInfo());
1140  }
1141}
1142
1143