SparcAsmPrinter.cpp revision 7330248482817762c810c0b20165f8f1b59af283 
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 "Support/Statistic.h"
27#include "Support/StringExtras.h"
28#include "Support/CommandLine.h"
29#include <cctype>
30using namespace llvm;
31
32namespace {
33  Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
34
35  struct V8Printer : public MachineFunctionPass {
36    /// Output stream on which we're printing assembly code.
37    ///
38    std::ostream &O;
39
40    /// Target machine description which we query for reg. names, data
41    /// layout, etc.
42    ///
43    TargetMachine &TM;
44
45    /// Name-mangler for global names.
46    ///
47    Mangler *Mang;
48
49    V8Printer(std::ostream &o, TargetMachine &tm) : O(o), TM(tm) { }
50
51    /// We name each basic block in a Function with a unique number, so
52    /// that we can consistently refer to them later. This is cleared
53    /// at the beginning of each call to runOnMachineFunction().
54    ///
55    typedef std::map<const Value *, unsigned> ValueMapTy;
56    ValueMapTy NumberForBB;
57
58    /// Cache of mangled name for current function. This is
59    /// recalculated at the beginning of each call to
60    /// runOnMachineFunction().
61    ///
62    std::string CurrentFnName;
63
64    virtual const char *getPassName() const {
65      return "SparcV8 Assembly Printer";
66    }
67
68    void emitConstantValueOnly(const Constant *CV);
69    void emitGlobalConstant(const Constant *CV);
70    void printConstantPool(MachineConstantPool *MCP);
71    void printOperand(const MachineInstr *MI, int opNum);
72    void printBaseOffsetPair (const MachineInstr *MI, int i, bool brackets=true);
73    void printMachineInstruction(const MachineInstr *MI);
74    bool runOnMachineFunction(MachineFunction &F);
75    bool doInitialization(Module &M);
76    bool doFinalization(Module &M);
77  };
78} // end of anonymous namespace
79
80/// createSparcV8CodePrinterPass - Returns a pass that prints the SparcV8
81/// assembly code for a MachineFunction to the given output stream,
82/// using the given target machine description.  This should work
83/// regardless of whether the function is in SSA form.
84///
85FunctionPass *llvm::createSparcV8CodePrinterPass (std::ostream &o,
86                                                  TargetMachine &tm) {
87  return new V8Printer(o, tm);
88}
89
90/// toOctal - Convert the low order bits of X into an octal digit.
91///
92static inline char toOctal(int X) {
93  return (X&7)+'0';
94}
95
96/// getAsCString - Return the specified array as a C compatible
97/// string, only if the predicate isStringCompatible is true.
98///
99static void printAsCString(std::ostream &O, const ConstantArray *CVA) {
100  assert(CVA->isString() && "Array is not string compatible!");
101
102  O << "\"";
103  for (unsigned i = 0; i != CVA->getNumOperands(); ++i) {
104    unsigned char C = cast<ConstantInt>(CVA->getOperand(i))->getRawValue();
105
106    if (C == '"') {
107      O << "\\\"";
108    } else if (C == '\\') {
109      O << "\\\\";
110    } else if (isprint(C)) {
111      O << C;
112    } else {
113      switch(C) {
114      case '\b': O << "\\b"; break;
115      case '\f': O << "\\f"; break;
116      case '\n': O << "\\n"; break;
117      case '\r': O << "\\r"; break;
118      case '\t': O << "\\t"; break;
119      default:
120        O << '\\';
121        O << toOctal(C >> 6);
122        O << toOctal(C >> 3);
123        O << toOctal(C >> 0);
124        break;
125      }
126    }
127  }
128  O << "\"";
129}
130
131// Print out the specified constant, without a storage class.  Only the
132// constants valid in constant expressions can occur here.
133void V8Printer::emitConstantValueOnly(const Constant *CV) {
134  if (CV->isNullValue())
135    O << "0";
136  else if (const ConstantBool *CB = dyn_cast<ConstantBool>(CV)) {
137    assert(CB == ConstantBool::True);
138    O << "1";
139  } else if (const ConstantSInt *CI = dyn_cast<ConstantSInt>(CV))
140    if (((CI->getValue() << 32) >> 32) == CI->getValue())
141      O << CI->getValue();
142    else
143      O << (unsigned long long)CI->getValue();
144  else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV))
145    O << CI->getValue();
146  else if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
147    // This is a constant address for a global variable or function.  Use the
148    // name of the variable or function as the address value.
149    O << Mang->getValueName(GV);
150  else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
151    const TargetData &TD = TM.getTargetData();
152    switch(CE->getOpcode()) {
153    case Instruction::GetElementPtr: {
154      // generate a symbolic expression for the byte address
155      const Constant *ptrVal = CE->getOperand(0);
156      std::vector<Value*> idxVec(CE->op_begin()+1, CE->op_end());
157      if (unsigned Offset = TD.getIndexedOffset(ptrVal->getType(), idxVec)) {
158        O << "(";
159        emitConstantValueOnly(ptrVal);
160        O << ") + " << Offset;
161      } else {
162        emitConstantValueOnly(ptrVal);
163      }
164      break;
165    }
166    case Instruction::Cast: {
167      // Support only non-converting or widening casts for now, that is, ones
168      // that do not involve a change in value.  This assertion is really gross,
169      // and may not even be a complete check.
170      Constant *Op = CE->getOperand(0);
171      const Type *OpTy = Op->getType(), *Ty = CE->getType();
172
173      // Pointers on ILP32 machines can be losslessly converted back and
174      // forth into 32-bit or wider integers, regardless of signedness.
175      assert(((isa<PointerType>(OpTy)
176               && (Ty == Type::LongTy || Ty == Type::ULongTy
177                   || Ty == Type::IntTy || Ty == Type::UIntTy))
178              || (isa<PointerType>(Ty)
179                  && (OpTy == Type::LongTy || OpTy == Type::ULongTy
180                      || OpTy == Type::IntTy || OpTy == Type::UIntTy))
181              || (((TD.getTypeSize(Ty) >= TD.getTypeSize(OpTy))
182                   && OpTy->isLosslesslyConvertibleTo(Ty))))
183             && "FIXME: Don't yet support this kind of constant cast expr");
184      O << "(";
185      emitConstantValueOnly(Op);
186      O << ")";
187      break;
188    }
189    case Instruction::Add:
190      O << "(";
191      emitConstantValueOnly(CE->getOperand(0));
192      O << ") + (";
193      emitConstantValueOnly(CE->getOperand(1));
194      O << ")";
195      break;
196    default:
197      assert(0 && "Unsupported operator!");
198    }
199  } else {
200    assert(0 && "Unknown constant value!");
201  }
202}
203
204// Print a constant value or values, with the appropriate storage class as a
205// prefix.
206void V8Printer::emitGlobalConstant(const Constant *CV) {
207  const TargetData &TD = TM.getTargetData();
208
209  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
210    if (CVA->isString()) {
211      O << "\t.ascii\t";
212      printAsCString(O, CVA);
213      O << "\n";
214    } else { // Not a string.  Print the values in successive locations
215      const std::vector<Use> &constValues = CVA->getValues();
216      for (unsigned i=0; i < constValues.size(); i++)
217        emitGlobalConstant(cast<Constant>(constValues[i].get()));
218    }
219    return;
220  } else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
221    // Print the fields in successive locations. Pad to align if needed!
222    const StructLayout *cvsLayout = TD.getStructLayout(CVS->getType());
223    const std::vector<Use>& constValues = CVS->getValues();
224    unsigned sizeSoFar = 0;
225    for (unsigned i=0, N = constValues.size(); i < N; i++) {
226      const Constant* field = cast<Constant>(constValues[i].get());
227
228      // Check if padding is needed and insert one or more 0s.
229      unsigned fieldSize = TD.getTypeSize(field->getType());
230      unsigned padSize = ((i == N-1? cvsLayout->StructSize
231                           : cvsLayout->MemberOffsets[i+1])
232                          - cvsLayout->MemberOffsets[i]) - fieldSize;
233      sizeSoFar += fieldSize + padSize;
234
235      // Now print the actual field value
236      emitGlobalConstant(field);
237
238      // Insert the field padding unless it's zero bytes...
239      if (padSize)
240        O << "\t.skip\t " << padSize << "\n";
241    }
242    assert(sizeSoFar == cvsLayout->StructSize &&
243           "Layout of constant struct may be incorrect!");
244    return;
245  } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
246    // FP Constants are printed as integer constants to avoid losing
247    // precision...
248    double Val = CFP->getValue();
249    switch (CFP->getType()->getTypeID()) {
250    default: assert(0 && "Unknown floating point type!");
251    case Type::FloatTyID: {
252      union FU {                            // Abide by C TBAA rules
253        float FVal;
254        unsigned UVal;
255      } U;
256      U.FVal = Val;
257      O << ".long\t" << U.UVal << "\t! float " << Val << "\n";
258      return;
259    }
260    case Type::DoubleTyID: {
261      union DU {                            // Abide by C TBAA rules
262        double FVal;
263        uint64_t UVal;
264      } U;
265      U.FVal = Val;
266      O << ".quad\t" << U.UVal << "\t! double " << Val << "\n";
267      return;
268    }
269    }
270  }
271
272  const Type *type = CV->getType();
273  O << "\t";
274  switch (type->getTypeID()) {
275  case Type::BoolTyID: case Type::UByteTyID: case Type::SByteTyID:
276    O << ".byte";
277    break;
278  case Type::UShortTyID: case Type::ShortTyID:
279    O << ".word";
280    break;
281  case Type::FloatTyID: case Type::PointerTyID:
282  case Type::UIntTyID: case Type::IntTyID:
283    O << ".long";
284    break;
285  case Type::DoubleTyID:
286  case Type::ULongTyID: case Type::LongTyID:
287    O << ".quad";
288    break;
289  default:
290    assert (0 && "Can't handle printing this type of thing");
291    break;
292  }
293  O << "\t";
294  emitConstantValueOnly(CV);
295  O << "\n";
296}
297
298/// printConstantPool - Print to the current output stream assembly
299/// representations of the constants in the constant pool MCP. This is
300/// used to print out constants which have been "spilled to memory" by
301/// the code generator.
302///
303void V8Printer::printConstantPool(MachineConstantPool *MCP) {
304  const std::vector<Constant*> &CP = MCP->getConstants();
305  const TargetData &TD = TM.getTargetData();
306
307  if (CP.empty()) return;
308
309  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
310    O << "\t.section .rodata\n";
311    O << "\t.align " << (unsigned)TD.getTypeAlignment(CP[i]->getType())
312      << "\n";
313    O << ".CPI" << CurrentFnName << "_" << i << ":\t\t\t\t\t!"
314      << *CP[i] << "\n";
315    emitGlobalConstant(CP[i]);
316  }
317}
318
319/// runOnMachineFunction - This uses the printMachineInstruction()
320/// method to print assembly for each instruction.
321///
322bool V8Printer::runOnMachineFunction(MachineFunction &MF) {
323  // BBNumber is used here so that a given Printer will never give two
324  // BBs the same name. (If you have a better way, please let me know!)
325  static unsigned BBNumber = 0;
326
327  O << "\n\n";
328  // What's my mangled name?
329  CurrentFnName = Mang->getValueName(MF.getFunction());
330
331  // Print out constants referenced by the function
332  printConstantPool(MF.getConstantPool());
333
334  // Print out labels for the function.
335  O << "\t.text\n";
336  O << "\t.align 16\n";
337  O << "\t.globl\t" << CurrentFnName << "\n";
338  O << "\t.type\t" << CurrentFnName << ", #function\n";
339  O << CurrentFnName << ":\n";
340
341  // Number each basic block so that we can consistently refer to them
342  // in PC-relative references.
343  NumberForBB.clear();
344  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
345       I != E; ++I) {
346    NumberForBB[I->getBasicBlock()] = BBNumber++;
347  }
348
349  // Print out code for the function.
350  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
351       I != E; ++I) {
352    // Print a label for the basic block.
353    O << ".LBB" << Mang->getValueName(MF.getFunction ())
354      << "_" << I->getNumber () << ":\t! "
355      << I->getBasicBlock ()->getName () << "\n";
356    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
357	 II != E; ++II) {
358      // Print the assembly for the instruction.
359      O << "\t";
360      printMachineInstruction(II);
361    }
362  }
363
364  // We didn't modify anything.
365  return false;
366}
367
368void V8Printer::printOperand(const MachineInstr *MI, int opNum) {
369  const MachineOperand &MO = MI->getOperand (opNum);
370  const MRegisterInfo &RI = *TM.getRegisterInfo();
371  bool CloseParen = false;
372  if (MI->getOpcode() == V8::SETHIi && !MO.isRegister() && !MO.isImmediate()) {
373    O << "%hi(";
374    CloseParen = true;
375  } else if (MI->getOpcode() ==V8::ORri &&!MO.isRegister() &&!MO.isImmediate())
376  {
377    O << "%lo(";
378    CloseParen = true;
379  }
380  switch (MO.getType()) {
381  case MachineOperand::MO_VirtualRegister:
382    if (Value *V = MO.getVRegValueOrNull()) {
383      O << "<" << V->getName() << ">";
384      break;
385    }
386    // FALLTHROUGH
387  case MachineOperand::MO_MachineRegister:
388    if (MRegisterInfo::isPhysicalRegister(MO.getReg()))
389      O << "%" << LowercaseString (RI.get(MO.getReg()).Name);
390    else
391      O << "%reg" << MO.getReg();
392    break;
393
394  case MachineOperand::MO_SignExtendedImmed:
395  case MachineOperand::MO_UnextendedImmed:
396    O << (int)MO.getImmedValue();
397    break;
398  case MachineOperand::MO_MachineBasicBlock: {
399    MachineBasicBlock *MBBOp = MO.getMachineBasicBlock();
400    O << ".LBB" << Mang->getValueName(MBBOp->getParent()->getFunction())
401      << "_" << MBBOp->getNumber () << "\t! "
402      << MBBOp->getBasicBlock ()->getName ();
403    return;
404  }
405  case MachineOperand::MO_PCRelativeDisp:
406    std::cerr << "Shouldn't use addPCDisp() when building SparcV8 MachineInstrs";
407    abort ();
408    return;
409  case MachineOperand::MO_GlobalAddress:
410    O << Mang->getValueName(MO.getGlobal());
411    break;
412  case MachineOperand::MO_ExternalSymbol:
413    O << MO.getSymbolName();
414    break;
415  case MachineOperand::MO_ConstantPoolIndex:
416    O << ".CPI" << CurrentFnName << "_" << MO.getConstantPoolIndex();
417    break;
418  default:
419    O << "<unknown operand type>"; abort (); break;
420  }
421  if (CloseParen) O << ")";
422}
423
424static bool isLoadInstruction (const MachineInstr *MI) {
425  switch (MI->getOpcode ()) {
426  case V8::LDSB:
427  case V8::LDSH:
428  case V8::LDUB:
429  case V8::LDUH:
430  case V8::LD:
431  case V8::LDD:
432  case V8::LDFrr:
433  case V8::LDFri:
434  case V8::LDDFrr:
435  case V8::LDDFri:
436    return true;
437  default:
438    return false;
439  }
440}
441
442static bool isStoreInstruction (const MachineInstr *MI) {
443  switch (MI->getOpcode ()) {
444  case V8::STB:
445  case V8::STH:
446  case V8::ST:
447  case V8::STD:
448  case V8::STFrr:
449  case V8::STFri:
450  case V8::STDFrr:
451  case V8::STDFri:
452    return true;
453  default:
454    return false;
455  }
456}
457
458static bool isPseudoInstruction (const MachineInstr *MI) {
459  switch (MI->getOpcode ()) {
460  case V8::PHI:
461  case V8::ADJCALLSTACKUP:
462  case V8::ADJCALLSTACKDOWN:
463  case V8::IMPLICIT_USE:
464  case V8::IMPLICIT_DEF:
465    return true;
466  default:
467    return false;
468  }
469}
470
471/// printBaseOffsetPair - Print two consecutive operands of MI, starting at #i,
472/// which form a base + offset pair (which may have brackets around it, if
473/// brackets is true, or may be in the form base - constant, if offset is a
474/// negative constant).
475///
476void V8Printer::printBaseOffsetPair (const MachineInstr *MI, int i,
477                                     bool brackets) {
478  if (brackets) O << "[";
479  printOperand (MI, i);
480  if (MI->getOperand (i + 1).isImmediate()) {
481    int Val = (int) MI->getOperand (i + 1).getImmedValue ();
482    if (Val != 0) {
483      O << ((Val >= 0) ? " + " : " - ");
484      O << ((Val >= 0) ? Val : -Val);
485    }
486  } else {
487    O << " + ";
488    printOperand (MI, i + 1);
489  }
490  if (brackets) O << "]";
491}
492
493/// printMachineInstruction -- Print out a single SparcV8 LLVM instruction
494/// MI in GAS syntax to the current output stream.
495///
496void V8Printer::printMachineInstruction(const MachineInstr *MI) {
497  unsigned Opcode = MI->getOpcode();
498  const TargetInstrInfo &TII = *TM.getInstrInfo();
499  const TargetInstrDescriptor &Desc = TII.get(Opcode);
500
501  // If it's a pseudo-instruction, comment it out.
502  if (isPseudoInstruction (MI))
503    O << "! ";
504
505  O << Desc.Name << " ";
506
507  // Printing memory instructions is a special case.
508  // for loads:  %dest = op %base, offset --> op [%base + offset], %dest
509  // for stores: op %base, offset, %src   --> op %src, [%base + offset]
510  if (isLoadInstruction (MI)) {
511    printBaseOffsetPair (MI, 1);
512    O << ", ";
513    printOperand (MI, 0);
514    O << "\n";
515    return;
516  } else if (isStoreInstruction (MI)) {
517    printOperand (MI, 2);
518    O << ", ";
519    printBaseOffsetPair (MI, 0);
520    O << "\n";
521    return;
522  } else if (Opcode == V8::JMPLrr) {
523    printBaseOffsetPair (MI, 1, false);
524    O << ", ";
525    printOperand (MI, 0);
526    O << "\n";
527    return;
528  }
529
530  // print non-immediate, non-register-def operands
531  // then print immediate operands
532  // then print register-def operands.
533  std::vector<int> print_order;
534  for (unsigned i = 0; i < MI->getNumOperands (); ++i)
535    if (!(MI->getOperand (i).isImmediate ()
536          || (MI->getOperand (i).isRegister ()
537              && MI->getOperand (i).isDef ())))
538      print_order.push_back (i);
539  for (unsigned i = 0; i < MI->getNumOperands (); ++i)
540    if (MI->getOperand (i).isImmediate ())
541      print_order.push_back (i);
542  for (unsigned i = 0; i < MI->getNumOperands (); ++i)
543    if (MI->getOperand (i).isRegister () && MI->getOperand (i).isDef ())
544      print_order.push_back (i);
545  for (unsigned i = 0, e = print_order.size (); i != e; ++i) {
546    printOperand (MI, print_order[i]);
547    if (i != (print_order.size () - 1))
548      O << ", ";
549  }
550  O << "\n";
551}
552
553bool V8Printer::doInitialization(Module &M) {
554  Mang = new Mangler(M);
555  return false; // success
556}
557
558// SwitchSection - Switch to the specified section of the executable if we are
559// not already in it!
560//
561static void SwitchSection(std::ostream &OS, std::string &CurSection,
562                          const char *NewSection) {
563  if (CurSection != NewSection) {
564    CurSection = NewSection;
565    if (!CurSection.empty())
566      OS << "\t.section " << NewSection << "\n";
567  }
568}
569
570bool V8Printer::doFinalization(Module &M) {
571  const TargetData &TD = TM.getTargetData();
572  std::string CurSection;
573
574  // Print out module-level global variables here.
575  for (Module::const_giterator I = M.gbegin(), E = M.gend(); I != E; ++I)
576    if (I->hasInitializer()) {   // External global require no code
577      O << "\n\n";
578      std::string name = Mang->getValueName(I);
579      Constant *C = I->getInitializer();
580      unsigned Size = TD.getTypeSize(C->getType());
581      unsigned Align = TD.getTypeAlignment(C->getType());
582
583      if (C->isNullValue() &&
584          (I->hasLinkOnceLinkage() || I->hasInternalLinkage() ||
585           I->hasWeakLinkage() /* FIXME: Verify correct */)) {
586        SwitchSection(O, CurSection, ".data");
587        if (I->hasInternalLinkage())
588          O << "\t.local " << name << "\n";
589
590        O << "\t.comm " << name << "," << TD.getTypeSize(C->getType())
591          << "," << (unsigned)TD.getTypeAlignment(C->getType());
592        O << "\t\t! ";
593        WriteAsOperand(O, I, true, true, &M);
594        O << "\n";
595      } else {
596        switch (I->getLinkage()) {
597        case GlobalValue::LinkOnceLinkage:
598        case GlobalValue::WeakLinkage:   // FIXME: Verify correct for weak.
599          // Nonnull linkonce -> weak
600          O << "\t.weak " << name << "\n";
601          SwitchSection(O, CurSection, "");
602          O << "\t.section\t.llvm.linkonce.d." << name << ",\"aw\",@progbits\n";
603          break;
604
605        case GlobalValue::AppendingLinkage:
606          // FIXME: appending linkage variables should go into a section of
607          // their name or something.  For now, just emit them as external.
608        case GlobalValue::ExternalLinkage:
609          // If external or appending, declare as a global symbol
610          O << "\t.globl " << name << "\n";
611          // FALL THROUGH
612        case GlobalValue::InternalLinkage:
613          if (C->isNullValue())
614            SwitchSection(O, CurSection, ".bss");
615          else
616            SwitchSection(O, CurSection, ".data");
617          break;
618        }
619
620        O << "\t.align " << Align << "\n";
621        O << "\t.type " << name << ",#object\n";
622        O << "\t.size " << name << "," << Size << "\n";
623        O << name << ":\t\t\t\t! ";
624        WriteAsOperand(O, I, true, true, &M);
625        O << " = ";
626        WriteAsOperand(O, C, false, false, &M);
627        O << "\n";
628        emitGlobalConstant(C);
629      }
630    }
631
632  delete Mang;
633  return false; // success
634}
635