PPCAsmPrinter.cpp revision 869f45937b843cf342865ba5b03196df0601d10b 
1//===-- PowerPCAsmPrinter.cpp - Print machine instrs to PowerPC assembly --===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file contains a printer that converts from our internal representation
11// of machine-dependent LLVM code to PowerPC assembly language. This printer is
12// the output mechanism used by `llc'.
13//
14// Documentation at http://developer.apple.com/documentation/DeveloperTools/
15// Reference/Assembler/ASMIntroduction/chapter_1_section_1.html
16//
17//===----------------------------------------------------------------------===//
18
19#define DEBUG_TYPE "asmprinter"
20#include "PowerPC.h"
21#include "PowerPCTargetMachine.h"
22#include "llvm/Constants.h"
23#include "llvm/DerivedTypes.h"
24#include "llvm/Module.h"
25#include "llvm/Assembly/Writer.h"
26#include "llvm/CodeGen/AsmPrinter.h"
27#include "llvm/CodeGen/MachineConstantPool.h"
28#include "llvm/CodeGen/MachineFunctionPass.h"
29#include "llvm/CodeGen/MachineInstr.h"
30#include "llvm/CodeGen/ValueTypes.h"
31#include "llvm/Support/Mangler.h"
32#include "llvm/Support/MathExtras.h"
33#include "llvm/Support/CommandLine.h"
34#include "llvm/Support/Debug.h"
35#include "llvm/Target/MRegisterInfo.h"
36#include "llvm/Target/TargetInstrInfo.h"
37#include "llvm/ADT/Statistic.h"
38#include "llvm/ADT/StringExtras.h"
39#include <set>
40using namespace llvm;
41
42namespace {
43  Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
44
45  struct PowerPCAsmPrinter : public AsmPrinter {
46    std::set<std::string> FnStubs, GVStubs, LinkOnceStubs;
47    std::set<std::string> Strings;
48
49    PowerPCAsmPrinter(std::ostream &O, TargetMachine &TM)
50      : AsmPrinter(O, TM), LabelNumber(0) {}
51
52    /// Unique incrementer for label values for referencing Global values.
53    ///
54    unsigned LabelNumber;
55
56    virtual const char *getPassName() const {
57      return "PowerPC Assembly Printer";
58    }
59
60    PowerPCTargetMachine &getTM() {
61      return static_cast<PowerPCTargetMachine&>(TM);
62    }
63
64    /// printInstruction - This method is automatically generated by tablegen
65    /// from the instruction set description.  This method returns true if the
66    /// machine instruction was sufficiently described to print it, otherwise it
67    /// returns false.
68    bool printInstruction(const MachineInstr *MI);
69
70    void printMachineInstruction(const MachineInstr *MI);
71    void printOp(const MachineOperand &MO, bool IsCallOp = false);
72
73    void printOperand(const MachineInstr *MI, unsigned OpNo, MVT::ValueType VT){
74      const MachineOperand &MO = MI->getOperand(OpNo);
75      if (MO.getType() == MachineOperand::MO_MachineRegister) {
76        assert(MRegisterInfo::isPhysicalRegister(MO.getReg())&&"Not physreg??");
77        O << LowercaseString(TM.getRegisterInfo()->get(MO.getReg()).Name);
78      } else if (MO.isImmediate()) {
79        O << MO.getImmedValue();
80      } else {
81        printOp(MO);
82      }
83    }
84
85    void printU5ImmOperand(const MachineInstr *MI, unsigned OpNo,
86                            MVT::ValueType VT) {
87      unsigned char value = MI->getOperand(OpNo).getImmedValue();
88      assert(value <= 31 && "Invalid u5imm argument!");
89      O << (unsigned int)value;
90    }
91    void printU6ImmOperand(const MachineInstr *MI, unsigned OpNo,
92                            MVT::ValueType VT) {
93      unsigned char value = MI->getOperand(OpNo).getImmedValue();
94      assert(value <= 63 && "Invalid u6imm argument!");
95      O << (unsigned int)value;
96    }
97    void printS16ImmOperand(const MachineInstr *MI, unsigned OpNo,
98                            MVT::ValueType VT) {
99      O << (short)MI->getOperand(OpNo).getImmedValue();
100    }
101    void printU16ImmOperand(const MachineInstr *MI, unsigned OpNo,
102                            MVT::ValueType VT) {
103      O << (unsigned short)MI->getOperand(OpNo).getImmedValue();
104    }
105    void printBranchOperand(const MachineInstr *MI, unsigned OpNo,
106                            MVT::ValueType VT) {
107      // Branches can take an immediate operand.  This is used by the branch
108      // selection pass to print $+8, an eight byte displacement from the PC.
109      if (MI->getOperand(OpNo).isImmediate()) {
110        O << "$+" << MI->getOperand(OpNo).getImmedValue() << '\n';
111      } else {
112        printOp(MI->getOperand(OpNo),
113                TM.getInstrInfo()->isCall(MI->getOpcode()));
114      }
115    }
116    void printPICLabel(const MachineInstr *MI, unsigned OpNo,
117                       MVT::ValueType VT) {
118      // FIXME: should probably be converted to cout.width and cout.fill
119      O << "\"L0000" << LabelNumber << "$pb\"\n";
120      O << "\"L0000" << LabelNumber << "$pb\":";
121    }
122    void printSymbolHi(const MachineInstr *MI, unsigned OpNo,
123                       MVT::ValueType VT) {
124      O << "ha16(";
125      printOp(MI->getOperand(OpNo));
126      O << "-\"L0000" << LabelNumber << "$pb\")";
127    }
128    void printSymbolLo(const MachineInstr *MI, unsigned OpNo,
129                       MVT::ValueType VT) {
130      // FIXME: Because LFS, LFD, and LWZ can be used either with a s16imm or
131      // a lo16 of a global or constant pool operand, we must handle both here.
132      // this isn't a great design, but it works for now.
133      if (MI->getOperand(OpNo).isImmediate()) {
134        O << (short)MI->getOperand(OpNo).getImmedValue();
135      } else {
136        O << "lo16(";
137        printOp(MI->getOperand(OpNo));
138        O << "-\"L0000" << LabelNumber << "$pb\")";
139      }
140    }
141
142    virtual void printConstantPool(MachineConstantPool *MCP) = 0;
143    virtual bool runOnMachineFunction(MachineFunction &F) = 0;
144    virtual bool doFinalization(Module &M) = 0;
145  };
146
147  /// DarwinAsmPrinter - PowerPC assembly printer, customized for Darwin/Mac OS
148  /// X
149  ///
150  struct DarwinAsmPrinter : public PowerPCAsmPrinter {
151
152    DarwinAsmPrinter(std::ostream &O, TargetMachine &TM)
153      : PowerPCAsmPrinter(O, TM) {
154      CommentString = ";";
155      GlobalPrefix = "_";
156      ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
157      Data64bitsDirective = 0;       // we can't emit a 64-bit unit
158      AlignmentIsInBytes = false;    // Alignment is by power of 2.
159    }
160
161    virtual const char *getPassName() const {
162      return "Darwin PPC Assembly Printer";
163    }
164
165    void printConstantPool(MachineConstantPool *MCP);
166    bool runOnMachineFunction(MachineFunction &F);
167    bool doFinalization(Module &M);
168  };
169
170  /// AIXAsmPrinter - PowerPC assembly printer, customized for AIX
171  ///
172  struct AIXAsmPrinter : public PowerPCAsmPrinter {
173    /// Map for labels corresponding to global variables
174    ///
175    std::map<const GlobalVariable*,std::string> GVToLabelMap;
176
177    AIXAsmPrinter(std::ostream &O, TargetMachine &TM)
178      : PowerPCAsmPrinter(O, TM) {
179      CommentString = "#";
180      GlobalPrefix = "_";
181      ZeroDirective = "\t.space\t";  // ".space N" emits N zeros.
182      Data64bitsDirective = 0;       // we can't emit a 64-bit unit
183      AlignmentIsInBytes = false;    // Alignment is by power of 2.
184    }
185
186    virtual const char *getPassName() const {
187      return "AIX PPC Assembly Printer";
188    }
189
190    void printConstantPool(MachineConstantPool *MCP);
191    bool runOnMachineFunction(MachineFunction &F);
192    bool doInitialization(Module &M);
193    bool doFinalization(Module &M);
194  };
195} // end of anonymous namespace
196
197// SwitchSection - Switch to the specified section of the executable if we are
198// not already in it!
199//
200static void SwitchSection(std::ostream &OS, std::string &CurSection,
201                          const char *NewSection) {
202  if (CurSection != NewSection) {
203    CurSection = NewSection;
204    if (!CurSection.empty())
205      OS << "\t" << NewSection << "\n";
206  }
207}
208
209/// isStringCompatible - Can we treat the specified array as a string?
210/// Only if it is an array of ubytes or non-negative sbytes.
211///
212static bool isStringCompatible(const ConstantArray *CVA) {
213  const Type *ETy = cast<ArrayType>(CVA->getType())->getElementType();
214  if (ETy == Type::UByteTy) return true;
215  if (ETy != Type::SByteTy) return false;
216
217  for (unsigned i = 0; i < CVA->getNumOperands(); ++i)
218    if (cast<ConstantSInt>(CVA->getOperand(i))->getValue() < 0)
219      return false;
220
221  return true;
222}
223
224/// toOctal - Convert the low order bits of X into an octal digit.
225///
226static inline char toOctal(int X) {
227  return (X&7)+'0';
228}
229
230// Possible states while outputting ASCII strings
231namespace {
232  enum StringSection {
233    None,
234    Alpha,
235    Numeric
236  };
237}
238
239/// SwitchStringSection - manage the changes required to output bytes as
240/// characters in a string vs. numeric decimal values
241///
242static inline void SwitchStringSection(std::ostream &O, StringSection NewSect,
243                                       StringSection &Current) {
244  if (Current == None) {
245    if (NewSect == Alpha)
246      O << "\t.byte \"";
247    else if (NewSect == Numeric)
248      O << "\t.byte ";
249  } else if (Current == Alpha) {
250    if (NewSect == None)
251      O << "\"";
252    else if (NewSect == Numeric)
253      O << "\"\n"
254        << "\t.byte ";
255  } else if (Current == Numeric) {
256    if (NewSect == Alpha)
257      O << '\n'
258        << "\t.byte \"";
259    else if (NewSect == Numeric)
260      O << ", ";
261  }
262
263  Current = NewSect;
264}
265
266/// getAsCString - Return the specified array as a C compatible
267/// string, only if the predicate isStringCompatible is true.
268///
269static void printAsCString(std::ostream &O, const ConstantArray *CVA) {
270  assert(isStringCompatible(CVA) && "Array is not string compatible!");
271
272  if (CVA->getNumOperands() == 0)
273    return;
274
275  StringSection Current = None;
276  for (unsigned i = 0, e = CVA->getNumOperands(); i != e; ++i) {
277    unsigned char C = cast<ConstantInt>(CVA->getOperand(i))->getRawValue();
278    if (C == '"') {
279      SwitchStringSection(O, Alpha, Current);
280      O << "\"\"";
281    } else if (isprint(C)) {
282      SwitchStringSection(O, Alpha, Current);
283      O << C;
284    } else {
285      SwitchStringSection(O, Numeric, Current);
286      O << utostr((unsigned)C);
287    }
288  }
289  SwitchStringSection(O, None, Current);
290  O << '\n';
291}
292
293/// createDarwinAsmPrinterPass - Returns a pass that prints the PPC assembly
294/// code for a MachineFunction to the given output stream, in a format that the
295/// Darwin assembler can deal with.
296///
297FunctionPass *llvm::createDarwinAsmPrinter(std::ostream &o, TargetMachine &tm) {
298  return new DarwinAsmPrinter(o, tm);
299}
300
301/// createAIXAsmPrinterPass - Returns a pass that prints the PPC assembly code
302/// for a MachineFunction to the given output stream, in a format that the
303/// AIX 5L assembler can deal with.
304///
305FunctionPass *llvm::createAIXAsmPrinter(std::ostream &o, TargetMachine &tm) {
306  return new AIXAsmPrinter(o, tm);
307}
308
309// Include the auto-generated portion of the assembly writer
310#include "PowerPCGenAsmWriter.inc"
311
312void PowerPCAsmPrinter::printOp(const MachineOperand &MO, bool IsCallOp) {
313  const MRegisterInfo &RI = *TM.getRegisterInfo();
314  int new_symbol;
315
316  switch (MO.getType()) {
317  case MachineOperand::MO_VirtualRegister:
318    if (Value *V = MO.getVRegValueOrNull()) {
319      O << "<" << V->getName() << ">";
320      return;
321    }
322    // FALLTHROUGH
323  case MachineOperand::MO_MachineRegister:
324  case MachineOperand::MO_CCRegister:
325    O << LowercaseString(RI.get(MO.getReg()).Name);
326    return;
327
328  case MachineOperand::MO_SignExtendedImmed:
329  case MachineOperand::MO_UnextendedImmed:
330    std::cerr << "printOp() does not handle immediate values\n";
331    abort();
332    return;
333
334  case MachineOperand::MO_PCRelativeDisp:
335    std::cerr << "Shouldn't use addPCDisp() when building PPC MachineInstrs";
336    abort();
337    return;
338
339  case MachineOperand::MO_MachineBasicBlock: {
340    MachineBasicBlock *MBBOp = MO.getMachineBasicBlock();
341    O << ".LBB" << Mang->getValueName(MBBOp->getParent()->getFunction())
342      << "_" << MBBOp->getNumber() << "\t; "
343      << MBBOp->getBasicBlock()->getName();
344    return;
345  }
346
347  case MachineOperand::MO_ConstantPoolIndex:
348    O << ".CPI" << CurrentFnName << "_" << MO.getConstantPoolIndex();
349    return;
350
351  case MachineOperand::MO_ExternalSymbol:
352    O << MO.getSymbolName();
353    return;
354
355  case MachineOperand::MO_GlobalAddress: {
356    GlobalValue *GV = MO.getGlobal();
357    std::string Name = Mang->getValueName(GV);
358
359    // Dynamically-resolved functions need a stub for the function.  Be
360    // wary however not to output $stub for external functions whose addresses
361    // are taken.  Those should be emitted as $non_lazy_ptr below.
362    Function *F = dyn_cast<Function>(GV);
363    if (F && IsCallOp && F->isExternal()) {
364      FnStubs.insert(Name);
365      O << "L" << Name << "$stub";
366      return;
367    }
368
369    // External or weakly linked global variables need non-lazily-resolved stubs
370    if ((GV->isExternal() || GV->hasWeakLinkage() || GV->hasLinkOnceLinkage())){
371      if (GV->hasLinkOnceLinkage())
372        LinkOnceStubs.insert(Name);
373      else
374        GVStubs.insert(Name);
375      O << "L" << Name << "$non_lazy_ptr";
376      return;
377    }
378
379    O << Mang->getValueName(GV);
380    return;
381  }
382
383  default:
384    O << "<unknown operand type: " << MO.getType() << ">";
385    return;
386  }
387}
388
389/// printMachineInstruction -- Print out a single PowerPC MI in Darwin syntax to
390/// the current output stream.
391///
392void PowerPCAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
393  ++EmittedInsts;
394  if (printInstruction(MI))
395    return; // Printer was automatically generated
396
397  assert(0 && "Unhandled instruction in asm writer!");
398  abort();
399  return;
400}
401
402/// runOnMachineFunction - This uses the printMachineInstruction()
403/// method to print assembly for each instruction.
404///
405bool DarwinAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
406  setupMachineFunction(MF);
407  O << "\n\n";
408
409  // Print out constants referenced by the function
410  printConstantPool(MF.getConstantPool());
411
412  // Print out labels for the function.
413  O << "\t.text\n";
414  emitAlignment(2);
415  O << "\t.globl\t" << CurrentFnName << "\n";
416  O << CurrentFnName << ":\n";
417
418  // Print out code for the function.
419  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
420       I != E; ++I) {
421    // Print a label for the basic block.
422    O << ".LBB" << CurrentFnName << "_" << I->getNumber() << ":\t"
423      << CommentString << " " << I->getBasicBlock()->getName() << "\n";
424    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
425         II != E; ++II) {
426      // Print the assembly for the instruction.
427      O << "\t";
428      printMachineInstruction(II);
429    }
430  }
431  ++LabelNumber;
432
433  // We didn't modify anything.
434  return false;
435}
436
437/// printConstantPool - Print to the current output stream assembly
438/// representations of the constants in the constant pool MCP. This is
439/// used to print out constants which have been "spilled to memory" by
440/// the code generator.
441///
442void DarwinAsmPrinter::printConstantPool(MachineConstantPool *MCP) {
443  const std::vector<Constant*> &CP = MCP->getConstants();
444  const TargetData &TD = TM.getTargetData();
445
446  if (CP.empty()) return;
447
448  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
449    O << "\t.const\n";
450    emitAlignment(TD.getTypeAlignmentShift(CP[i]->getType()));
451    O << ".CPI" << CurrentFnName << "_" << i << ":\t\t\t\t\t" << CommentString
452      << *CP[i] << "\n";
453    emitGlobalConstant(CP[i]);
454  }
455}
456
457bool DarwinAsmPrinter::doFinalization(Module &M) {
458  const TargetData &TD = TM.getTargetData();
459  std::string CurSection;
460
461  // Print out module-level global variables here.
462  for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
463    if (I->hasInitializer()) {   // External global require no code
464      O << '\n';
465      std::string name = Mang->getValueName(I);
466      Constant *C = I->getInitializer();
467      unsigned Size = TD.getTypeSize(C->getType());
468      unsigned Align = TD.getTypeAlignmentShift(C->getType());
469
470      if (C->isNullValue() && /* FIXME: Verify correct */
471          (I->hasInternalLinkage() || I->hasWeakLinkage() ||
472           I->hasLinkOnceLinkage())) {
473        SwitchSection(O, CurSection, ".data");
474        if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
475        if (I->hasInternalLinkage())
476          O << ".lcomm " << name << "," << Size << "," << Align;
477        else
478          O << ".comm " << name << "," << Size;
479        O << "\t\t; ";
480        WriteAsOperand(O, I, true, true, &M);
481        O << '\n';
482      } else {
483        switch (I->getLinkage()) {
484        case GlobalValue::LinkOnceLinkage:
485          O << ".section __TEXT,__textcoal_nt,coalesced,no_toc\n"
486            << ".weak_definition " << name << '\n'
487            << ".private_extern " << name << '\n'
488            << ".section __DATA,__datacoal_nt,coalesced,no_toc\n";
489          LinkOnceStubs.insert(name);
490          break;
491        case GlobalValue::WeakLinkage:   // FIXME: Verify correct for weak.
492          // Nonnull linkonce -> weak
493          O << "\t.weak " << name << "\n";
494          SwitchSection(O, CurSection, "");
495          O << "\t.section\t.llvm.linkonce.d." << name << ",\"aw\",@progbits\n";
496          break;
497        case GlobalValue::AppendingLinkage:
498          // FIXME: appending linkage variables should go into a section of
499          // their name or something.  For now, just emit them as external.
500        case GlobalValue::ExternalLinkage:
501          // If external or appending, declare as a global symbol
502          O << "\t.globl " << name << "\n";
503          // FALL THROUGH
504        case GlobalValue::InternalLinkage:
505          SwitchSection(O, CurSection, ".data");
506          break;
507        case GlobalValue::GhostLinkage:
508          std::cerr << "Error: unmaterialized (GhostLinkage) function in asm!";
509          abort();
510        }
511
512        emitAlignment(Align);
513        O << name << ":\t\t\t\t; ";
514        WriteAsOperand(O, I, true, true, &M);
515        O << " = ";
516        WriteAsOperand(O, C, false, false, &M);
517        O << "\n";
518        emitGlobalConstant(C);
519      }
520    }
521
522  // Output stubs for dynamically-linked functions
523  for (std::set<std::string>::iterator i = FnStubs.begin(), e = FnStubs.end();
524       i != e; ++i)
525  {
526    O << ".data\n";
527    O << ".section __TEXT,__picsymbolstub1,symbol_stubs,pure_instructions,32\n";
528    emitAlignment(2);
529    O << "L" << *i << "$stub:\n";
530    O << "\t.indirect_symbol " << *i << "\n";
531    O << "\tmflr r0\n";
532    O << "\tbcl 20,31,L0$" << *i << "\n";
533    O << "L0$" << *i << ":\n";
534    O << "\tmflr r11\n";
535    O << "\taddis r11,r11,ha16(L" << *i << "$lazy_ptr-L0$" << *i << ")\n";
536    O << "\tmtlr r0\n";
537    O << "\tlwzu r12,lo16(L" << *i << "$lazy_ptr-L0$" << *i << ")(r11)\n";
538    O << "\tmtctr r12\n";
539    O << "\tbctr\n";
540    O << ".data\n";
541    O << ".lazy_symbol_pointer\n";
542    O << "L" << *i << "$lazy_ptr:\n";
543    O << "\t.indirect_symbol " << *i << "\n";
544    O << "\t.long dyld_stub_binding_helper\n";
545  }
546
547  O << "\n";
548
549  // Output stubs for external global variables
550  if (GVStubs.begin() != GVStubs.end())
551    O << ".data\n.non_lazy_symbol_pointer\n";
552  for (std::set<std::string>::iterator i = GVStubs.begin(), e = GVStubs.end();
553       i != e; ++i) {
554    O << "L" << *i << "$non_lazy_ptr:\n";
555    O << "\t.indirect_symbol " << *i << "\n";
556    O << "\t.long\t0\n";
557  }
558
559  // Output stubs for link-once variables
560  if (LinkOnceStubs.begin() != LinkOnceStubs.end())
561    O << ".data\n.align 2\n";
562  for (std::set<std::string>::iterator i = LinkOnceStubs.begin(),
563         e = LinkOnceStubs.end(); i != e; ++i) {
564    O << "L" << *i << "$non_lazy_ptr:\n"
565      << "\t.long\t" << *i << '\n';
566  }
567
568  AsmPrinter::doFinalization(M);
569  return false; // success
570}
571
572/// runOnMachineFunction - This uses the printMachineInstruction()
573/// method to print assembly for each instruction.
574///
575bool AIXAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
576  CurrentFnName = MF.getFunction()->getName();
577
578  // Print out constants referenced by the function
579  printConstantPool(MF.getConstantPool());
580
581  // Print out header for the function.
582  O << "\t.csect .text[PR]\n"
583    << "\t.align 2\n"
584    << "\t.globl "  << CurrentFnName << '\n'
585    << "\t.globl ." << CurrentFnName << '\n'
586    << "\t.csect "  << CurrentFnName << "[DS],3\n"
587    << CurrentFnName << ":\n"
588    << "\t.llong ." << CurrentFnName << ", TOC[tc0], 0\n"
589    << "\t.csect .text[PR]\n"
590    << '.' << CurrentFnName << ":\n";
591
592  // Print out code for the function.
593  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
594       I != E; ++I) {
595    // Print a label for the basic block.
596    O << "LBB" << CurrentFnName << "_" << I->getNumber() << ":\t# "
597      << I->getBasicBlock()->getName() << "\n";
598    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
599      II != E; ++II) {
600      // Print the assembly for the instruction.
601      O << "\t";
602      printMachineInstruction(II);
603    }
604  }
605  ++LabelNumber;
606
607  O << "LT.." << CurrentFnName << ":\n"
608    << "\t.long 0\n"
609    << "\t.byte 0,0,32,65,128,0,0,0\n"
610    << "\t.long LT.." << CurrentFnName << "-." << CurrentFnName << '\n'
611    << "\t.short 3\n"
612    << "\t.byte \"" << CurrentFnName << "\"\n"
613    << "\t.align 2\n";
614
615  // We didn't modify anything.
616  return false;
617}
618
619/// printConstantPool - Print to the current output stream assembly
620/// representations of the constants in the constant pool MCP. This is
621/// used to print out constants which have been "spilled to memory" by
622/// the code generator.
623///
624void AIXAsmPrinter::printConstantPool(MachineConstantPool *MCP) {
625  const std::vector<Constant*> &CP = MCP->getConstants();
626  const TargetData &TD = TM.getTargetData();
627
628  if (CP.empty()) return;
629
630  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
631    O << "\t.const\n";
632    O << "\t.align " << (unsigned)TD.getTypeAlignment(CP[i]->getType())
633      << "\n";
634    O << ".CPI" << CurrentFnName << "_" << i << ":\t\t\t\t\t;"
635      << *CP[i] << "\n";
636    emitGlobalConstant(CP[i]);
637  }
638}
639
640bool AIXAsmPrinter::doInitialization(Module &M) {
641  const TargetData &TD = TM.getTargetData();
642  std::string CurSection;
643
644  O << "\t.machine \"ppc64\"\n"
645    << "\t.toc\n"
646    << "\t.csect .text[PR]\n";
647
648  // Print out module-level global variables
649  for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I) {
650    if (!I->hasInitializer())
651      continue;
652
653    std::string Name = I->getName();
654    Constant *C = I->getInitializer();
655    // N.B.: We are defaulting to writable strings
656    if (I->hasExternalLinkage()) {
657      O << "\t.globl " << Name << '\n'
658        << "\t.csect .data[RW],3\n";
659    } else {
660      O << "\t.csect _global.rw_c[RW],3\n";
661    }
662    O << Name << ":\n";
663    emitGlobalConstant(C);
664  }
665
666  // Output labels for globals
667  if (M.gbegin() != M.gend()) O << "\t.toc\n";
668  for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I) {
669    const GlobalVariable *GV = I;
670    // Do not output labels for unused variables
671    if (GV->isExternal() && GV->use_begin() == GV->use_end())
672      continue;
673
674    std::string Name = GV->getName();
675    std::string Label = "LC.." + utostr(LabelNumber++);
676    GVToLabelMap[GV] = Label;
677    O << Label << ":\n"
678      << "\t.tc " << Name << "[TC]," << Name;
679    if (GV->isExternal()) O << "[RW]";
680    O << '\n';
681  }
682
683  Mang = new Mangler(M, ".");
684  return false; // success
685}
686
687bool AIXAsmPrinter::doFinalization(Module &M) {
688  const TargetData &TD = TM.getTargetData();
689  // Print out module-level global variables
690  for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I) {
691    if (I->hasInitializer() || I->hasExternalLinkage())
692      continue;
693
694    std::string Name = I->getName();
695    if (I->hasInternalLinkage()) {
696      O << "\t.lcomm " << Name << ",16,_global.bss_c";
697    } else {
698      O << "\t.comm " << Name << "," << TD.getTypeSize(I->getType())
699        << "," << log2((unsigned)TD.getTypeAlignment(I->getType()));
700    }
701    O << "\t\t# ";
702    WriteAsOperand(O, I, true, true, &M);
703    O << "\n";
704  }
705
706  O << "_section_.text:\n"
707    << "\t.csect .data[RW],3\n"
708    << "\t.llong _section_.text\n";
709
710  delete Mang;
711  return false; // success
712}
713