SparcAsmPrinter.cpp revision d4f2ab5e0059f8398a7882d6c6be50341641b97b 
1//===-- SparcV8AsmPrinter.cpp - SparcV8 LLVM assembly writer --------------===//
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 GAS-format Sparc V8 assembly language.
12//
13//===----------------------------------------------------------------------===//
14
15#include "SparcV8.h"
16#include "SparcV8InstrInfo.h"
17#include "llvm/Constants.h"
18#include "llvm/DerivedTypes.h"
19#include "llvm/Module.h"
20#include "llvm/Assembly/Writer.h"
21#include "llvm/CodeGen/MachineFunctionPass.h"
22#include "llvm/CodeGen/MachineConstantPool.h"
23#include "llvm/CodeGen/MachineInstr.h"
24#include "llvm/Target/TargetMachine.h"
25#include "llvm/Support/Mangler.h"
26#include "llvm/ADT/Statistic.h"
27#include "llvm/ADT/StringExtras.h"
28#include "llvm/Support/CommandLine.h"
29#include "llvm/Support/MathExtras.h"
30#include <cctype>
31using namespace llvm;
32
33namespace {
34  Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
35
36  struct SparcV8AsmPrinter : public MachineFunctionPass {
37    /// Output stream on which we're printing assembly code.
38    ///
39    std::ostream &O;
40
41    /// Target machine description which we query for reg. names, data
42    /// layout, etc.
43    ///
44    TargetMachine &TM;
45
46    /// Name-mangler for global names.
47    ///
48    Mangler *Mang;
49
50    SparcV8AsmPrinter(std::ostream &o, TargetMachine &tm) : O(o), TM(tm) { }
51
52    /// We name each basic block in a Function with a unique number, so
53    /// that we can consistently refer to them later. This is cleared
54    /// at the beginning of each call to runOnMachineFunction().
55    ///
56    typedef std::map<const Value *, unsigned> ValueMapTy;
57    ValueMapTy NumberForBB;
58
59    /// Cache of mangled name for current function. This is
60    /// recalculated at the beginning of each call to
61    /// runOnMachineFunction().
62    ///
63    std::string CurrentFnName;
64
65    virtual const char *getPassName() const {
66      return "SparcV8 Assembly Printer";
67    }
68
69    void emitConstantValueOnly(const Constant *CV);
70    void emitGlobalConstant(const Constant *CV);
71    void printConstantPool(MachineConstantPool *MCP);
72    void printOperand(const MachineInstr *MI, int opNum);
73    void printBaseOffsetPair (const MachineInstr *MI, int i);
74    void printMachineInstruction(const MachineInstr *MI);
75    bool printInstruction(const MachineInstr *MI);  // autogenerated.
76    bool runOnMachineFunction(MachineFunction &F);
77    bool doInitialization(Module &M);
78    bool doFinalization(Module &M);
79  };
80} // end of anonymous namespace
81
82#include "SparcV8GenAsmWriter.inc"
83
84/// createSparcV8CodePrinterPass - Returns a pass that prints the SparcV8
85/// assembly code for a MachineFunction to the given output stream,
86/// using the given target machine description.  This should work
87/// regardless of whether the function is in SSA form.
88///
89FunctionPass *llvm::createSparcV8CodePrinterPass (std::ostream &o,
90                                                  TargetMachine &tm) {
91  return new SparcV8AsmPrinter(o, tm);
92}
93
94/// toOctal - Convert the low order bits of X into an octal digit.
95///
96static inline char toOctal(int X) {
97  return (X&7)+'0';
98}
99
100/// getAsCString - Return the specified array as a C compatible
101/// string, only if the predicate isStringCompatible is true.
102///
103static void printAsCString(std::ostream &O, const ConstantArray *CVA) {
104  assert(CVA->isString() && "Array is not string compatible!");
105
106  O << "\"";
107  for (unsigned i = 0; i != CVA->getNumOperands(); ++i) {
108    unsigned char C = cast<ConstantInt>(CVA->getOperand(i))->getRawValue();
109
110    if (C == '"') {
111      O << "\\\"";
112    } else if (C == '\\') {
113      O << "\\\\";
114    } else if (isprint(C)) {
115      O << C;
116    } else {
117      switch(C) {
118      case '\b': O << "\\b"; break;
119      case '\f': O << "\\f"; break;
120      case '\n': O << "\\n"; break;
121      case '\r': O << "\\r"; break;
122      case '\t': O << "\\t"; break;
123      default:
124        O << '\\';
125        O << toOctal(C >> 6);
126        O << toOctal(C >> 3);
127        O << toOctal(C >> 0);
128        break;
129      }
130    }
131  }
132  O << "\"";
133}
134
135// Print out the specified constant, without a storage class.  Only the
136// constants valid in constant expressions can occur here.
137void SparcV8AsmPrinter::emitConstantValueOnly(const Constant *CV) {
138  if (CV->isNullValue() || isa<UndefValue> (CV))
139    O << "0";
140  else if (const ConstantBool *CB = dyn_cast<ConstantBool>(CV)) {
141    assert(CB == ConstantBool::True);
142    O << "1";
143  } else if (const ConstantSInt *CI = dyn_cast<ConstantSInt>(CV))
144    if (((CI->getValue() << 32) >> 32) == CI->getValue())
145      O << CI->getValue();
146    else
147      O << (unsigned long long)CI->getValue();
148  else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV))
149    O << CI->getValue();
150  else if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
151    // This is a constant address for a global variable or function.  Use the
152    // name of the variable or function as the address value.
153    O << Mang->getValueName(GV);
154  else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
155    const TargetData &TD = TM.getTargetData();
156    switch(CE->getOpcode()) {
157    case Instruction::GetElementPtr: {
158      // generate a symbolic expression for the byte address
159      const Constant *ptrVal = CE->getOperand(0);
160      std::vector<Value*> idxVec(CE->op_begin()+1, CE->op_end());
161      if (unsigned Offset = TD.getIndexedOffset(ptrVal->getType(), idxVec)) {
162        O << "(";
163        emitConstantValueOnly(ptrVal);
164        O << ") + " << Offset;
165      } else {
166        emitConstantValueOnly(ptrVal);
167      }
168      break;
169    }
170    case Instruction::Cast: {
171      // Support only non-converting or widening casts for now, that is, ones
172      // that do not involve a change in value.  This assertion is really gross,
173      // and may not even be a complete check.
174      Constant *Op = CE->getOperand(0);
175      const Type *OpTy = Op->getType(), *Ty = CE->getType();
176
177      // Pointers on ILP32 machines can be losslessly converted back and
178      // forth into 32-bit or wider integers, regardless of signedness.
179      assert(((isa<PointerType>(OpTy)
180               && (Ty == Type::LongTy || Ty == Type::ULongTy
181                   || Ty == Type::IntTy || Ty == Type::UIntTy))
182              || (isa<PointerType>(Ty)
183                  && (OpTy == Type::LongTy || OpTy == Type::ULongTy
184                      || OpTy == Type::IntTy || OpTy == Type::UIntTy))
185              || (((TD.getTypeSize(Ty) >= TD.getTypeSize(OpTy))
186                   && OpTy->isLosslesslyConvertibleTo(Ty))))
187             && "FIXME: Don't yet support this kind of constant cast expr");
188      O << "(";
189      emitConstantValueOnly(Op);
190      O << ")";
191      break;
192    }
193    case Instruction::Add:
194      O << "(";
195      emitConstantValueOnly(CE->getOperand(0));
196      O << ") + (";
197      emitConstantValueOnly(CE->getOperand(1));
198      O << ")";
199      break;
200    default:
201      assert(0 && "Unsupported operator!");
202    }
203  } else {
204    assert(0 && "Unknown constant value!");
205  }
206}
207
208// Print a constant value or values, with the appropriate storage class as a
209// prefix.
210void SparcV8AsmPrinter::emitGlobalConstant(const Constant *CV) {
211  const TargetData &TD = TM.getTargetData();
212
213  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
214    if (CVA->isString()) {
215      O << "\t.ascii\t";
216      printAsCString(O, CVA);
217      O << "\n";
218    } else { // Not a string.  Print the values in successive locations
219      for (unsigned i = 0, e = CVA->getNumOperands(); i != e; i++)
220        emitGlobalConstant(CVA->getOperand(i));
221    }
222    return;
223  } else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
224    // Print the fields in successive locations. Pad to align if needed!
225    const StructLayout *cvsLayout = TD.getStructLayout(CVS->getType());
226    unsigned sizeSoFar = 0;
227    for (unsigned i = 0, e = CVS->getNumOperands(); i != e; i++) {
228      const Constant* field = CVS->getOperand(i);
229
230      // Check if padding is needed and insert one or more 0s.
231      unsigned fieldSize = TD.getTypeSize(field->getType());
232      unsigned padSize = ((i == e-1? cvsLayout->StructSize
233                           : cvsLayout->MemberOffsets[i+1])
234                          - cvsLayout->MemberOffsets[i]) - fieldSize;
235      sizeSoFar += fieldSize + padSize;
236
237      // Now print the actual field value
238      emitGlobalConstant(field);
239
240      // Insert the field padding unless it's zero bytes...
241      if (padSize)
242        O << "\t.skip\t " << padSize << "\n";
243    }
244    assert(sizeSoFar == cvsLayout->StructSize &&
245           "Layout of constant struct may be incorrect!");
246    return;
247  } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
248    // FP Constants are printed as integer constants to avoid losing
249    // precision...
250    double Val = CFP->getValue();
251    switch (CFP->getType()->getTypeID()) {
252    default: assert(0 && "Unknown floating point type!");
253    case Type::FloatTyID: {
254      O << ".long\t" << FloatToBits(Val) << "\t! float " << Val << "\n";
255      return;
256    }
257    case Type::DoubleTyID: {
258      O << ".word\t0x" << std::hex << (DoubleToBits(Val) >> 32) << std::dec << "\t! double " << Val << "\n";
259      O << ".word\t0x" << std::hex << (DoubleToBits(Val) & 0xffffffffUL) << std::dec << "\t! double " << Val << "\n";
260      return;
261    }
262    }
263  } else if (isa<UndefValue> (CV)) {
264    unsigned size = TD.getTypeSize (CV->getType ());
265    O << "\t.skip\t " << size << "\n";
266    return;
267  } else if (isa<ConstantAggregateZero> (CV)) {
268    unsigned size = TD.getTypeSize (CV->getType ());
269    for (unsigned i = 0; i < size; ++i)
270      O << "\t.byte 0\n";
271    return;
272  }
273
274  const Type *type = CV->getType();
275  O << "\t";
276  switch (type->getTypeID()) {
277  case Type::BoolTyID: case Type::UByteTyID: case Type::SByteTyID:
278    O << ".byte";
279    break;
280  case Type::UShortTyID: case Type::ShortTyID:
281    O << ".half";
282    break;
283  case Type::FloatTyID: case Type::PointerTyID:
284  case Type::UIntTyID: case Type::IntTyID:
285    O << ".word";
286    break;
287  case Type::DoubleTyID:
288  case Type::ULongTyID: case Type::LongTyID:
289    O << ".xword";
290    break;
291  default:
292    assert (0 && "Can't handle printing this type of thing");
293    break;
294  }
295  O << "\t";
296  emitConstantValueOnly(CV);
297  O << "\n";
298}
299
300/// printConstantPool - Print to the current output stream assembly
301/// representations of the constants in the constant pool MCP. This is
302/// used to print out constants which have been "spilled to memory" by
303/// the code generator.
304///
305void SparcV8AsmPrinter::printConstantPool(MachineConstantPool *MCP) {
306  const std::vector<Constant*> &CP = MCP->getConstants();
307  const TargetData &TD = TM.getTargetData();
308
309  if (CP.empty()) return;
310
311  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
312    O << "\t.section \".rodata\"\n";
313    O << "\t.align " << (unsigned)TD.getTypeAlignment(CP[i]->getType())
314      << "\n";
315    O << ".CPI" << CurrentFnName << "_" << i << ":\t\t\t\t\t!"
316      << *CP[i] << "\n";
317    emitGlobalConstant(CP[i]);
318  }
319}
320
321/// runOnMachineFunction - This uses the printMachineInstruction()
322/// method to print assembly for each instruction.
323///
324bool SparcV8AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
325  // BBNumber is used here so that a given Printer will never give two
326  // BBs the same name. (If you have a better way, please let me know!)
327  static unsigned BBNumber = 0;
328
329  O << "\n\n";
330  // What's my mangled name?
331  CurrentFnName = Mang->getValueName(MF.getFunction());
332
333  // Print out constants referenced by the function
334  printConstantPool(MF.getConstantPool());
335
336  // Print out labels for the function.
337  O << "\t.text\n";
338  O << "\t.align 16\n";
339  O << "\t.globl\t" << CurrentFnName << "\n";
340  O << "\t.type\t" << CurrentFnName << ", #function\n";
341  O << CurrentFnName << ":\n";
342
343  // Number each basic block so that we can consistently refer to them
344  // in PC-relative references.
345  NumberForBB.clear();
346  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
347       I != E; ++I) {
348    NumberForBB[I->getBasicBlock()] = BBNumber++;
349  }
350
351  // Print out code for the function.
352  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
353       I != E; ++I) {
354    // Print a label for the basic block.
355    O << ".LBB" << Mang->getValueName(MF.getFunction ())
356      << "_" << I->getNumber () << ":\t! "
357      << I->getBasicBlock ()->getName () << "\n";
358    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
359         II != E; ++II) {
360      // Print the assembly for the instruction.
361      printMachineInstruction(II);
362    }
363  }
364
365  // We didn't modify anything.
366  return false;
367}
368
369void SparcV8AsmPrinter::printOperand(const MachineInstr *MI, int opNum) {
370  const MachineOperand &MO = MI->getOperand (opNum);
371  const MRegisterInfo &RI = *TM.getRegisterInfo();
372  bool CloseParen = false;
373  if (MI->getOpcode() == V8::SETHIi && !MO.isRegister() && !MO.isImmediate()) {
374    O << "%hi(";
375    CloseParen = true;
376  } else if (MI->getOpcode() ==V8::ORri &&!MO.isRegister() &&!MO.isImmediate())
377  {
378    O << "%lo(";
379    CloseParen = true;
380  }
381  switch (MO.getType()) {
382  case MachineOperand::MO_VirtualRegister:
383    if (Value *V = MO.getVRegValueOrNull()) {
384      O << "<" << V->getName() << ">";
385      break;
386    }
387    // FALLTHROUGH
388  case MachineOperand::MO_MachineRegister:
389    if (MRegisterInfo::isPhysicalRegister(MO.getReg()))
390      O << "%" << LowercaseString (RI.get(MO.getReg()).Name);
391    else
392      O << "%reg" << MO.getReg();
393    break;
394
395  case MachineOperand::MO_SignExtendedImmed:
396  case MachineOperand::MO_UnextendedImmed:
397    O << (int)MO.getImmedValue();
398    break;
399  case MachineOperand::MO_MachineBasicBlock: {
400    MachineBasicBlock *MBBOp = MO.getMachineBasicBlock();
401    O << ".LBB" << Mang->getValueName(MBBOp->getParent()->getFunction())
402      << "_" << MBBOp->getNumber () << "\t! "
403      << MBBOp->getBasicBlock ()->getName ();
404    return;
405  }
406  case MachineOperand::MO_PCRelativeDisp:
407    std::cerr << "Shouldn't use addPCDisp() when building SparcV8 MachineInstrs";
408    abort ();
409    return;
410  case MachineOperand::MO_GlobalAddress:
411    O << Mang->getValueName(MO.getGlobal());
412    break;
413  case MachineOperand::MO_ExternalSymbol:
414    O << MO.getSymbolName();
415    break;
416  case MachineOperand::MO_ConstantPoolIndex:
417    O << ".CPI" << CurrentFnName << "_" << MO.getConstantPoolIndex();
418    break;
419  default:
420    O << "<unknown operand type>"; abort (); break;
421  }
422  if (CloseParen) O << ")";
423}
424
425static bool isPseudoInstruction (const MachineInstr *MI) {
426  switch (MI->getOpcode ()) {
427  case V8::PHI:
428  case V8::ADJCALLSTACKUP:
429  case V8::ADJCALLSTACKDOWN:
430  case V8::IMPLICIT_USE:
431  case V8::IMPLICIT_DEF:
432    return true;
433  default:
434    return false;
435  }
436}
437
438/// printBaseOffsetPair - Print two consecutive operands of MI, starting at #i,
439/// which form a base + offset pair (which may have brackets around it, if
440/// brackets is true, or may be in the form base - constant, if offset is a
441/// negative constant).
442///
443void SparcV8AsmPrinter::printBaseOffsetPair (const MachineInstr *MI, int i) {
444  O << "[";
445  printOperand (MI, i);
446  if (MI->getOperand (i + 1).isImmediate()) {
447    int Val = (int) MI->getOperand (i + 1).getImmedValue ();
448    if (Val != 0) {
449      O << ((Val >= 0) ? " + " : " - ");
450      O << ((Val >= 0) ? Val : -Val);
451    }
452  } else {
453    O << " + ";
454    printOperand (MI, i + 1);
455  }
456  O << "]";
457}
458
459/// printMachineInstruction -- Print out a single SparcV8 LLVM instruction
460/// MI in GAS syntax to the current output stream.
461///
462void SparcV8AsmPrinter::printMachineInstruction(const MachineInstr *MI) {
463  O << "\t";
464  if (printInstruction(MI)) return;
465
466  unsigned Opcode = MI->getOpcode();
467  const TargetInstrInfo &TII = *TM.getInstrInfo();
468  const TargetInstrDescriptor &Desc = TII.get(Opcode);
469
470  // If it's a pseudo-instruction, comment it out.
471  if (isPseudoInstruction (MI))
472    O << "! ";
473
474  O << Desc.Name << " ";
475
476  // print non-immediate, non-register-def operands
477  // then print immediate operands
478  // then print register-def operands.
479  std::vector<int> print_order;
480  for (unsigned i = 0; i < MI->getNumOperands (); ++i)
481    if (!(MI->getOperand (i).isImmediate ()
482          || (MI->getOperand (i).isRegister ()
483              && MI->getOperand (i).isDef ())))
484      print_order.push_back (i);
485  for (unsigned i = 0; i < MI->getNumOperands (); ++i)
486    if (MI->getOperand (i).isImmediate ())
487      print_order.push_back (i);
488  for (unsigned i = 0; i < MI->getNumOperands (); ++i)
489    if (MI->getOperand (i).isRegister () && MI->getOperand (i).isDef ())
490      print_order.push_back (i);
491  for (unsigned i = 0, e = print_order.size (); i != e; ++i) {
492    printOperand (MI, print_order[i]);
493    if (i != (print_order.size () - 1))
494      O << ", ";
495  }
496  O << "\n";
497}
498
499bool SparcV8AsmPrinter::doInitialization(Module &M) {
500  Mang = new Mangler(M);
501  return false; // success
502}
503
504// SwitchSection - Switch to the specified section of the executable if we are
505// not already in it!
506//
507static void SwitchSection(std::ostream &OS, std::string &CurSection,
508                          const char *NewSection) {
509  if (CurSection != NewSection) {
510    CurSection = NewSection;
511    if (!CurSection.empty())
512      OS << "\t.section \"" << NewSection << "\"\n";
513  }
514}
515
516bool SparcV8AsmPrinter::doFinalization(Module &M) {
517  const TargetData &TD = TM.getTargetData();
518  std::string CurSection;
519
520  // Print out module-level global variables here.
521  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I)
522    if (I->hasInitializer()) {   // External global require no code
523      O << "\n\n";
524      std::string name = Mang->getValueName(I);
525      Constant *C = I->getInitializer();
526      unsigned Size = TD.getTypeSize(C->getType());
527      unsigned Align = TD.getTypeAlignment(C->getType());
528
529      if (C->isNullValue() &&
530          (I->hasLinkOnceLinkage() || I->hasInternalLinkage() ||
531           I->hasWeakLinkage() /* FIXME: Verify correct */)) {
532        SwitchSection(O, CurSection, ".data");
533        if (I->hasInternalLinkage())
534          O << "\t.local " << name << "\n";
535
536        O << "\t.comm " << name << "," << TD.getTypeSize(C->getType())
537          << "," << (unsigned)TD.getTypeAlignment(C->getType());
538        O << "\t\t! ";
539        WriteAsOperand(O, I, true, true, &M);
540        O << "\n";
541      } else {
542        switch (I->getLinkage()) {
543        case GlobalValue::LinkOnceLinkage:
544        case GlobalValue::WeakLinkage:   // FIXME: Verify correct for weak.
545          // Nonnull linkonce -> weak
546          O << "\t.weak " << name << "\n";
547          SwitchSection(O, CurSection, "");
548          O << "\t.section\t\".llvm.linkonce.d." << name << "\",\"aw\",@progbits\n";
549          break;
550
551        case GlobalValue::AppendingLinkage:
552          // FIXME: appending linkage variables should go into a section of
553          // their name or something.  For now, just emit them as external.
554        case GlobalValue::ExternalLinkage:
555          // If external or appending, declare as a global symbol
556          O << "\t.globl " << name << "\n";
557          // FALL THROUGH
558        case GlobalValue::InternalLinkage:
559          if (C->isNullValue())
560            SwitchSection(O, CurSection, ".bss");
561          else
562            SwitchSection(O, CurSection, ".data");
563          break;
564        case GlobalValue::GhostLinkage:
565          std::cerr << "Should not have any unmaterialized functions!\n";
566          abort();
567        }
568
569        O << "\t.align " << Align << "\n";
570        O << "\t.type " << name << ",#object\n";
571        O << "\t.size " << name << "," << Size << "\n";
572        O << name << ":\t\t\t\t! ";
573        WriteAsOperand(O, I, true, true, &M);
574        O << " = ";
575        WriteAsOperand(O, C, false, false, &M);
576        O << "\n";
577        emitGlobalConstant(C);
578      }
579    }
580
581  delete Mang;
582  return false; // success
583}
584