PPCAsmPrinter.cpp revision 7396e595434285d210fdafe51c41385b9fa709e3 
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  if (F->hasHiddenVisibility())
597    if (const char *Directive = TAI->getHiddenDirective())
598      O << Directive << CurrentFnName << "\n";
599
600  EmitAlignment(2, F);
601  O << CurrentFnName << ":\n";
602
603  // Emit pre-function debug information.
604  DW.BeginFunction(&MF);
605
606  // Print out code for the function.
607  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
608       I != E; ++I) {
609    // Print a label for the basic block.
610    if (I != MF.begin()) {
611      printBasicBlockLabel(I, true, true);
612      O << '\n';
613    }
614    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
615         II != E; ++II) {
616      // Print the assembly for the instruction.
617      printMachineInstruction(II);
618    }
619  }
620
621  O << "\t.size\t" << CurrentFnName << ",.-" << CurrentFnName << "\n";
622
623  // Print out jump tables referenced by the function.
624  EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
625
626  // Emit post-function debug information.
627  DW.EndFunction();
628
629  // We didn't modify anything.
630  return false;
631}
632
633bool PPCLinuxAsmPrinter::doInitialization(Module &M) {
634  bool Result = AsmPrinter::doInitialization(M);
635
636  // Emit initial debug information.
637  DW.BeginModule(&M);
638
639  // AsmPrinter::doInitialization should have done this analysis.
640  MMI = getAnalysisToUpdate<MachineModuleInfo>();
641  assert(MMI);
642  DW.SetModuleInfo(MMI);
643
644  // GNU as handles section names wrapped in quotes
645  Mang->setUseQuotes(true);
646
647  SwitchToTextSection(TAI->getTextSection());
648
649  return Result;
650}
651
652/// PrintUnmangledNameSafely - Print out the printable characters in the name.
653/// Don't print things like \n or \0.
654static void PrintUnmangledNameSafely(const Value *V, std::ostream &OS) {
655  for (const char *Name = V->getNameStart(), *E = Name+V->getNameLen();
656       Name != E; ++Name)
657    if (isprint(*Name))
658      OS << *Name;
659}
660
661void PPCLinuxAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
662  const TargetData *TD = TM.getTargetData();
663
664  if (!GVar->hasInitializer())
665    return;   // External global require no code
666
667  // Check to see if this is a special global used by LLVM, if so, emit it.
668  if (EmitSpecialLLVMGlobal(GVar))
669    return;
670
671  std::string name = Mang->getValueName(GVar);
672  std::string SectionName = TAI->SectionForGlobal(GVar);
673
674  if (GVar->hasHiddenVisibility())
675    if (const char *Directive = TAI->getHiddenDirective())
676      O << Directive << name << "\n";
677
678  Constant *C = GVar->getInitializer();
679  const Type *Type = C->getType();
680  unsigned Size = TD->getABITypeSize(Type);
681  unsigned Align = TD->getPreferredAlignmentLog(GVar);
682
683  SwitchToDataSection(SectionName.c_str());
684
685  if (C->isNullValue() && /* FIXME: Verify correct */
686      !GVar->hasSection() &&
687      (GVar->hasInternalLinkage() || GVar->hasExternalLinkage() ||
688       GVar->isWeakForLinker())) {
689      if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
690
691      if (GVar->hasExternalLinkage()) {
692        O << "\t.global " << name << '\n';
693        O << "\t.type " << name << ", @object\n";
694        O << name << ":\n";
695        O << "\t.zero " << Size << "\n";
696      } else if (GVar->hasInternalLinkage()) {
697        O << TAI->getLCOMMDirective() << name << "," << Size;
698      } else {
699        O << ".comm " << name << "," << Size;
700      }
701      O << "\t\t" << TAI->getCommentString() << " '";
702      PrintUnmangledNameSafely(GVar, O);
703      O << "'\n";
704      return;
705  }
706
707  switch (GVar->getLinkage()) {
708   case GlobalValue::LinkOnceLinkage:
709   case GlobalValue::WeakLinkage:
710   case GlobalValue::CommonLinkage:
711    O << "\t.global " << name << '\n'
712      << "\t.type " << name << ", @object\n"
713      << "\t.weak " << name << '\n';
714    break;
715   case GlobalValue::AppendingLinkage:
716    // FIXME: appending linkage variables should go into a section of
717    // their name or something.  For now, just emit them as external.
718   case GlobalValue::ExternalLinkage:
719    // If external or appending, declare as a global symbol
720    O << "\t.global " << name << "\n"
721      << "\t.type " << name << ", @object\n";
722    // FALL THROUGH
723   case GlobalValue::InternalLinkage:
724    break;
725   default:
726    cerr << "Unknown linkage type!";
727    abort();
728  }
729
730  EmitAlignment(Align, GVar);
731  O << name << ":\t\t\t\t" << TAI->getCommentString() << " '";
732  PrintUnmangledNameSafely(GVar, O);
733  O << "'\n";
734
735  // If the initializer is a extern weak symbol, remember to emit the weak
736  // reference!
737  if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
738    if (GV->hasExternalWeakLinkage())
739      ExtWeakSymbols.insert(GV);
740
741  EmitGlobalConstant(C);
742  O << '\n';
743}
744
745bool PPCLinuxAsmPrinter::doFinalization(Module &M) {
746  // Print out module-level global variables here.
747  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
748       I != E; ++I)
749    printModuleLevelGV(I);
750
751  // TODO
752
753  // Emit initial debug information.
754  DW.EndModule();
755
756  return AsmPrinter::doFinalization(M);
757}
758
759std::string PPCLinuxAsmPrinter::getSectionForFunction(const Function &F) const {
760  return TAI->SectionForGlobal(&F);
761}
762
763std::string PPCDarwinAsmPrinter::getSectionForFunction(const Function &F) const {
764  return TAI->SectionForGlobal(&F);
765}
766
767/// runOnMachineFunction - This uses the printMachineInstruction()
768/// method to print assembly for each instruction.
769///
770bool PPCDarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
771  SetupMachineFunction(MF);
772  O << "\n\n";
773
774  // Print out constants referenced by the function
775  EmitConstantPool(MF.getConstantPool());
776
777  // Print out labels for the function.
778  const Function *F = MF.getFunction();
779  SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
780
781  switch (F->getLinkage()) {
782  default: assert(0 && "Unknown linkage type!");
783  case Function::InternalLinkage:  // Symbols default to internal.
784    break;
785  case Function::ExternalLinkage:
786    O << "\t.globl\t" << CurrentFnName << "\n";
787    break;
788  case Function::WeakLinkage:
789  case Function::LinkOnceLinkage:
790    O << "\t.globl\t" << CurrentFnName << "\n";
791    O << "\t.weak_definition\t" << CurrentFnName << "\n";
792    break;
793  }
794
795  if (F->hasHiddenVisibility())
796    if (const char *Directive = TAI->getHiddenDirective())
797      O << Directive << CurrentFnName << "\n";
798
799  EmitAlignment(OptimizeForSize ? 2 : 4, F);
800  O << CurrentFnName << ":\n";
801
802  // Emit pre-function debug information.
803  DW.BeginFunction(&MF);
804
805  // If the function is empty, then we need to emit *something*. Otherwise, the
806  // function's label might be associated with something that it wasn't meant to
807  // be associated with. We emit a noop in this situation.
808  MachineFunction::iterator I = MF.begin();
809
810  if (++I == MF.end() && MF.front().empty())
811    O << "\tnop\n";
812
813  // Print out code for the function.
814  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
815       I != E; ++I) {
816    // Print a label for the basic block.
817    if (I != MF.begin()) {
818      printBasicBlockLabel(I, true, true);
819      O << '\n';
820    }
821    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
822         II != IE; ++II) {
823      // Print the assembly for the instruction.
824      printMachineInstruction(II);
825    }
826  }
827
828  // Print out jump tables referenced by the function.
829  EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
830
831  // Emit post-function debug information.
832  DW.EndFunction();
833
834  // We didn't modify anything.
835  return false;
836}
837
838
839bool PPCDarwinAsmPrinter::doInitialization(Module &M) {
840  static const char *const CPUDirectives[] = {
841    "",
842    "ppc",
843    "ppc601",
844    "ppc602",
845    "ppc603",
846    "ppc7400",
847    "ppc750",
848    "ppc970",
849    "ppc64"
850  };
851
852  unsigned Directive = Subtarget.getDarwinDirective();
853  if (Subtarget.isGigaProcessor() && Directive < PPC::DIR_970)
854    Directive = PPC::DIR_970;
855  if (Subtarget.hasAltivec() && Directive < PPC::DIR_7400)
856    Directive = PPC::DIR_7400;
857  if (Subtarget.isPPC64() && Directive < PPC::DIR_970)
858    Directive = PPC::DIR_64;
859  assert(Directive <= PPC::DIR_64 && "Directive out of range.");
860  O << "\t.machine " << CPUDirectives[Directive] << "\n";
861
862  bool Result = AsmPrinter::doInitialization(M);
863
864  // Emit initial debug information.
865  DW.BeginModule(&M);
866
867  // We need this for Personality functions.
868  // AsmPrinter::doInitialization should have done this analysis.
869  MMI = getAnalysisToUpdate<MachineModuleInfo>();
870  assert(MMI);
871  DW.SetModuleInfo(MMI);
872
873  // Darwin wants symbols to be quoted if they have complex names.
874  Mang->setUseQuotes(true);
875
876  // Prime text sections so they are adjacent.  This reduces the likelihood a
877  // large data or debug section causes a branch to exceed 16M limit.
878  SwitchToTextSection("\t.section __TEXT,__textcoal_nt,coalesced,"
879                      "pure_instructions");
880  if (TM.getRelocationModel() == Reloc::PIC_) {
881    SwitchToTextSection("\t.section __TEXT,__picsymbolstub1,symbol_stubs,"
882                          "pure_instructions,32");
883  } else if (TM.getRelocationModel() == Reloc::DynamicNoPIC) {
884    SwitchToTextSection("\t.section __TEXT,__symbol_stub1,symbol_stubs,"
885                        "pure_instructions,16");
886  }
887  SwitchToTextSection(TAI->getTextSection());
888
889  return Result;
890}
891
892void PPCDarwinAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
893  const TargetData *TD = TM.getTargetData();
894
895  if (!GVar->hasInitializer())
896    return;   // External global require no code
897
898  // Check to see if this is a special global used by LLVM, if so, emit it.
899  if (EmitSpecialLLVMGlobal(GVar)) {
900    if (TM.getRelocationModel() == Reloc::Static) {
901      if (GVar->getName() == "llvm.global_ctors")
902        O << ".reference .constructors_used\n";
903      else if (GVar->getName() == "llvm.global_dtors")
904        O << ".reference .destructors_used\n";
905    }
906    return;
907  }
908
909  std::string name = Mang->getValueName(GVar);
910  std::string SectionName = TAI->SectionForGlobal(GVar);
911
912  if (GVar->hasHiddenVisibility())
913    if (const char *Directive = TAI->getHiddenDirective())
914      O << Directive << name << "\n";
915
916  Constant *C = GVar->getInitializer();
917  const Type *Type = C->getType();
918  unsigned Size = TD->getABITypeSize(Type);
919  unsigned Align = TD->getPreferredAlignmentLog(GVar);
920
921  SwitchToDataSection(SectionName.c_str());
922
923  if (C->isNullValue() && /* FIXME: Verify correct */
924      !GVar->hasSection() &&
925      (GVar->hasInternalLinkage() || GVar->hasExternalLinkage() ||
926       GVar->isWeakForLinker())) {
927    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
928
929    if (GVar->hasExternalLinkage()) {
930      O << "\t.globl " << name << '\n';
931      O << "\t.zerofill __DATA, __common, " << name << ", "
932        << Size << ", " << Align;
933    } else if (GVar->hasInternalLinkage()) {
934      O << TAI->getLCOMMDirective() << name << "," << Size << "," << Align;
935    } else if (!GVar->hasCommonLinkage()) {
936      O << "\t.globl " << name << "\n"
937        << TAI->getWeakDefDirective() << name << "\n";
938      EmitAlignment(Align, GVar);
939      O << name << ":\t\t\t\t" << TAI->getCommentString() << " ";
940      PrintUnmangledNameSafely(GVar, O);
941      O << "\n";
942      EmitGlobalConstant(C);
943      return;
944    } else {
945      O << ".comm " << name << "," << Size;
946      // Darwin 9 and above support aligned common data.
947      if (Subtarget.isDarwin9())
948        O << "," << Align;
949    }
950    O << "\t\t" << TAI->getCommentString() << " '";
951    PrintUnmangledNameSafely(GVar, O);
952    O << "'\n";
953    return;
954  }
955
956  switch (GVar->getLinkage()) {
957   case GlobalValue::LinkOnceLinkage:
958   case GlobalValue::WeakLinkage:
959   case GlobalValue::CommonLinkage:
960    O << "\t.globl " << name << '\n'
961      << "\t.weak_definition " << name << '\n';
962    break;
963   case GlobalValue::AppendingLinkage:
964    // FIXME: appending linkage variables should go into a section of
965    // their name or something.  For now, just emit them as external.
966   case GlobalValue::ExternalLinkage:
967    // If external or appending, declare as a global symbol
968    O << "\t.globl " << name << "\n";
969    // FALL THROUGH
970   case GlobalValue::InternalLinkage:
971    break;
972   default:
973    cerr << "Unknown linkage type!";
974    abort();
975  }
976
977  EmitAlignment(Align, GVar);
978  O << name << ":\t\t\t\t" << TAI->getCommentString() << " '";
979  PrintUnmangledNameSafely(GVar, O);
980  O << "'\n";
981
982  // If the initializer is a extern weak symbol, remember to emit the weak
983  // reference!
984  if (const GlobalValue *GV = dyn_cast<GlobalValue>(C))
985    if (GV->hasExternalWeakLinkage())
986      ExtWeakSymbols.insert(GV);
987
988  EmitGlobalConstant(C);
989  O << '\n';
990}
991
992bool PPCDarwinAsmPrinter::doFinalization(Module &M) {
993  const TargetData *TD = TM.getTargetData();
994
995  // Print out module-level global variables here.
996  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
997       I != E; ++I)
998    printModuleLevelGV(I);
999
1000  bool isPPC64 = TD->getPointerSizeInBits() == 64;
1001
1002  // Output stubs for dynamically-linked functions
1003  if (TM.getRelocationModel() == Reloc::PIC_) {
1004    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
1005         i != e; ++i) {
1006      SwitchToTextSection("\t.section __TEXT,__picsymbolstub1,symbol_stubs,"
1007                          "pure_instructions,32");
1008      EmitAlignment(4);
1009      std::string p = *i;
1010      std::string L0p = (p[0]=='\"') ? "\"L0$" + p.substr(1) : "L0$" + p ;
1011      printSuffixedName(p, "$stub");
1012      O << ":\n";
1013      O << "\t.indirect_symbol " << *i << "\n";
1014      O << "\tmflr r0\n";
1015      O << "\tbcl 20,31," << L0p << "\n";
1016      O << L0p << ":\n";
1017      O << "\tmflr r11\n";
1018      O << "\taddis r11,r11,ha16(";
1019      printSuffixedName(p, "$lazy_ptr");
1020      O << "-" << L0p << ")\n";
1021      O << "\tmtlr r0\n";
1022      if (isPPC64)
1023        O << "\tldu r12,lo16(";
1024      else
1025        O << "\tlwzu r12,lo16(";
1026      printSuffixedName(p, "$lazy_ptr");
1027      O << "-" << L0p << ")(r11)\n";
1028      O << "\tmtctr r12\n";
1029      O << "\tbctr\n";
1030      SwitchToDataSection(".lazy_symbol_pointer");
1031      printSuffixedName(p, "$lazy_ptr");
1032      O << ":\n";
1033      O << "\t.indirect_symbol " << *i << "\n";
1034      if (isPPC64)
1035        O << "\t.quad dyld_stub_binding_helper\n";
1036      else
1037        O << "\t.long dyld_stub_binding_helper\n";
1038    }
1039  } else {
1040    for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
1041         i != e; ++i) {
1042      SwitchToTextSection("\t.section __TEXT,__symbol_stub1,symbol_stubs,"
1043                          "pure_instructions,16");
1044      EmitAlignment(4);
1045      std::string p = *i;
1046      printSuffixedName(p, "$stub");
1047      O << ":\n";
1048      O << "\t.indirect_symbol " << *i << "\n";
1049      O << "\tlis r11,ha16(";
1050      printSuffixedName(p, "$lazy_ptr");
1051      O << ")\n";
1052      if (isPPC64)
1053        O << "\tldu r12,lo16(";
1054      else
1055        O << "\tlwzu r12,lo16(";
1056      printSuffixedName(p, "$lazy_ptr");
1057      O << ")(r11)\n";
1058      O << "\tmtctr r12\n";
1059      O << "\tbctr\n";
1060      SwitchToDataSection(".lazy_symbol_pointer");
1061      printSuffixedName(p, "$lazy_ptr");
1062      O << ":\n";
1063      O << "\t.indirect_symbol " << *i << "\n";
1064      if (isPPC64)
1065        O << "\t.quad dyld_stub_binding_helper\n";
1066      else
1067        O << "\t.long dyld_stub_binding_helper\n";
1068    }
1069  }
1070
1071  O << "\n";
1072
1073  if (TAI->doesSupportExceptionHandling() && MMI) {
1074    // Add the (possibly multiple) personalities to the set of global values.
1075    // Only referenced functions get into the Personalities list.
1076    const std::vector<Function *>& Personalities = MMI->getPersonalities();
1077
1078    for (std::vector<Function *>::const_iterator I = Personalities.begin(),
1079           E = Personalities.end(); I != E; ++I)
1080      if (*I) GVStubs.insert("_" + (*I)->getName());
1081  }
1082
1083  // Output stubs for external and common global variables.
1084  if (!GVStubs.empty()) {
1085    SwitchToDataSection(".non_lazy_symbol_pointer");
1086    for (std::set<std::string>::iterator I = GVStubs.begin(),
1087         E = GVStubs.end(); I != E; ++I) {
1088      std::string p = *I;
1089      printSuffixedName(p, "$non_lazy_ptr");
1090      O << ":\n";
1091      O << "\t.indirect_symbol " << *I << "\n";
1092      if (isPPC64)
1093        O << "\t.quad\t0\n";
1094      else
1095        O << "\t.long\t0\n";
1096    }
1097  }
1098
1099  // Emit initial debug information.
1100  DW.EndModule();
1101
1102  // Funny Darwin hack: This flag tells the linker that no global symbols
1103  // contain code that falls through to other global symbols (e.g. the obvious
1104  // implementation of multiple entry points).  If this doesn't occur, the
1105  // linker can safely perform dead code stripping.  Since LLVM never generates
1106  // code that does this, it is always safe to set.
1107  O << "\t.subsections_via_symbols\n";
1108
1109  return AsmPrinter::doFinalization(M);
1110}
1111
1112
1113
1114/// createPPCAsmPrinterPass - Returns a pass that prints the PPC assembly code
1115/// for a MachineFunction to the given output stream, in a format that the
1116/// Darwin assembler can deal with.
1117///
1118FunctionPass *llvm::createPPCAsmPrinterPass(std::ostream &o,
1119                                            PPCTargetMachine &tm) {
1120  const PPCSubtarget *Subtarget = &tm.getSubtarget<PPCSubtarget>();
1121
1122  if (Subtarget->isDarwin()) {
1123    return new PPCDarwinAsmPrinter(o, tm, tm.getTargetAsmInfo());
1124  } else {
1125    return new PPCLinuxAsmPrinter(o, tm, tm.getTargetAsmInfo());
1126  }
1127}
1128