SparcAsmPrinter.cpp revision b5e9eb6089676ba807da70348079fb6e8df3e40e 
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/AsmPrinter.h"
22#include "llvm/CodeGen/MachineFunctionPass.h"
23#include "llvm/CodeGen/MachineConstantPool.h"
24#include "llvm/CodeGen/MachineInstr.h"
25#include "llvm/Target/TargetMachine.h"
26#include "llvm/Support/Mangler.h"
27#include "llvm/ADT/Statistic.h"
28#include "llvm/ADT/StringExtras.h"
29#include "llvm/Support/CommandLine.h"
30#include "llvm/Support/MathExtras.h"
31#include <cctype>
32using namespace llvm;
33
34namespace {
35  Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
36
37  struct SparcV8AsmPrinter : public AsmPrinter {
38    SparcV8AsmPrinter(std::ostream &O, TargetMachine &TM) : AsmPrinter(O, TM) {
39      Data16bitsDirective = "\t.half\t";
40      Data32bitsDirective = "\t.word\t";
41      Data64bitsDirective = "\t.xword\t";
42    }
43
44    /// We name each basic block in a Function with a unique number, so
45    /// that we can consistently refer to them later. This is cleared
46    /// at the beginning of each call to runOnMachineFunction().
47    ///
48    typedef std::map<const Value *, unsigned> ValueMapTy;
49    ValueMapTy NumberForBB;
50
51    virtual const char *getPassName() const {
52      return "SparcV8 Assembly Printer";
53    }
54
55    void emitConstantValueOnly(const Constant *CV);
56    void emitGlobalConstant(const Constant *CV);
57    void printOperand(const MachineInstr *MI, int opNum);
58    bool printInstruction(const MachineInstr *MI);  // autogenerated.
59    bool runOnMachineFunction(MachineFunction &F);
60    bool doInitialization(Module &M);
61    bool doFinalization(Module &M);
62  };
63} // end of anonymous namespace
64
65#include "SparcV8GenAsmWriter.inc"
66
67/// createSparcV8CodePrinterPass - Returns a pass that prints the SparcV8
68/// assembly code for a MachineFunction to the given output stream,
69/// using the given target machine description.  This should work
70/// regardless of whether the function is in SSA form.
71///
72FunctionPass *llvm::createSparcV8CodePrinterPass (std::ostream &o,
73                                                  TargetMachine &tm) {
74  return new SparcV8AsmPrinter(o, tm);
75}
76
77/// toOctal - Convert the low order bits of X into an octal digit.
78///
79static inline char toOctal(int X) {
80  return (X&7)+'0';
81}
82
83/// getAsCString - Return the specified array as a C compatible
84/// string, only if the predicate isStringCompatible is true.
85///
86static void printAsCString(std::ostream &O, const ConstantArray *CVA) {
87  assert(CVA->isString() && "Array is not string compatible!");
88
89  O << "\"";
90  for (unsigned i = 0; i != CVA->getNumOperands(); ++i) {
91    unsigned char C = cast<ConstantInt>(CVA->getOperand(i))->getRawValue();
92
93    if (C == '"') {
94      O << "\\\"";
95    } else if (C == '\\') {
96      O << "\\\\";
97    } else if (isprint(C)) {
98      O << C;
99    } else {
100      switch(C) {
101      case '\b': O << "\\b"; break;
102      case '\f': O << "\\f"; break;
103      case '\n': O << "\\n"; break;
104      case '\r': O << "\\r"; break;
105      case '\t': O << "\\t"; break;
106      default:
107        O << '\\';
108        O << toOctal(C >> 6);
109        O << toOctal(C >> 3);
110        O << toOctal(C >> 0);
111        break;
112      }
113    }
114  }
115  O << "\"";
116}
117
118// Print out the specified constant, without a storage class.  Only the
119// constants valid in constant expressions can occur here.
120void SparcV8AsmPrinter::emitConstantValueOnly(const Constant *CV) {
121  if (CV->isNullValue() || isa<UndefValue> (CV))
122    O << "0";
123  else if (const ConstantBool *CB = dyn_cast<ConstantBool>(CV)) {
124    assert(CB == ConstantBool::True);
125    O << "1";
126  } else if (const ConstantSInt *CI = dyn_cast<ConstantSInt>(CV))
127    if (((CI->getValue() << 32) >> 32) == CI->getValue())
128      O << CI->getValue();
129    else
130      O << (unsigned long long)CI->getValue();
131  else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV))
132    O << CI->getValue();
133  else if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
134    // This is a constant address for a global variable or function.  Use the
135    // name of the variable or function as the address value.
136    O << Mang->getValueName(GV);
137  else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
138    const TargetData &TD = TM.getTargetData();
139    switch(CE->getOpcode()) {
140    case Instruction::GetElementPtr: {
141      // generate a symbolic expression for the byte address
142      const Constant *ptrVal = CE->getOperand(0);
143      std::vector<Value*> idxVec(CE->op_begin()+1, CE->op_end());
144      if (unsigned Offset = TD.getIndexedOffset(ptrVal->getType(), idxVec)) {
145        O << "(";
146        emitConstantValueOnly(ptrVal);
147        O << ") + " << Offset;
148      } else {
149        emitConstantValueOnly(ptrVal);
150      }
151      break;
152    }
153    case Instruction::Cast: {
154      // Support only non-converting or widening casts for now, that is, ones
155      // that do not involve a change in value.  This assertion is really gross,
156      // and may not even be a complete check.
157      Constant *Op = CE->getOperand(0);
158      const Type *OpTy = Op->getType(), *Ty = CE->getType();
159
160      // Pointers on ILP32 machines can be losslessly converted back and
161      // forth into 32-bit or wider integers, regardless of signedness.
162      assert(((isa<PointerType>(OpTy)
163               && (Ty == Type::LongTy || Ty == Type::ULongTy
164                   || Ty == Type::IntTy || Ty == Type::UIntTy))
165              || (isa<PointerType>(Ty)
166                  && (OpTy == Type::LongTy || OpTy == Type::ULongTy
167                      || OpTy == Type::IntTy || OpTy == Type::UIntTy))
168              || (((TD.getTypeSize(Ty) >= TD.getTypeSize(OpTy))
169                   && OpTy->isLosslesslyConvertibleTo(Ty))))
170             && "FIXME: Don't yet support this kind of constant cast expr");
171      O << "(";
172      emitConstantValueOnly(Op);
173      O << ")";
174      break;
175    }
176    case Instruction::Add:
177      O << "(";
178      emitConstantValueOnly(CE->getOperand(0));
179      O << ") + (";
180      emitConstantValueOnly(CE->getOperand(1));
181      O << ")";
182      break;
183    default:
184      assert(0 && "Unsupported operator!");
185    }
186  } else {
187    assert(0 && "Unknown constant value!");
188  }
189}
190
191// Print a constant value or values, with the appropriate storage class as a
192// prefix.
193void SparcV8AsmPrinter::emitGlobalConstant(const Constant *CV) {
194  const TargetData &TD = TM.getTargetData();
195
196  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
197    if (CVA->isString()) {
198      O << "\t.ascii\t";
199      printAsCString(O, CVA);
200      O << "\n";
201    } else { // Not a string.  Print the values in successive locations
202      for (unsigned i = 0, e = CVA->getNumOperands(); i != e; i++)
203        emitGlobalConstant(CVA->getOperand(i));
204    }
205    return;
206  } else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
207    // Print the fields in successive locations. Pad to align if needed!
208    const StructLayout *cvsLayout = TD.getStructLayout(CVS->getType());
209    unsigned sizeSoFar = 0;
210    for (unsigned i = 0, e = CVS->getNumOperands(); i != e; i++) {
211      const Constant* field = CVS->getOperand(i);
212
213      // Check if padding is needed and insert one or more 0s.
214      unsigned fieldSize = TD.getTypeSize(field->getType());
215      unsigned padSize = ((i == e-1? cvsLayout->StructSize
216                           : cvsLayout->MemberOffsets[i+1])
217                          - cvsLayout->MemberOffsets[i]) - fieldSize;
218      sizeSoFar += fieldSize + padSize;
219
220      // Now print the actual field value
221      emitGlobalConstant(field);
222
223      // Insert the field padding unless it's zero bytes...
224      if (padSize)
225        O << "\t.skip\t " << padSize << "\n";
226    }
227    assert(sizeSoFar == cvsLayout->StructSize &&
228           "Layout of constant struct may be incorrect!");
229    return;
230  } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
231    // FP Constants are printed as integer constants to avoid losing
232    // precision...
233    double Val = CFP->getValue();
234    switch (CFP->getType()->getTypeID()) {
235    default: assert(0 && "Unknown floating point type!");
236    case Type::FloatTyID: {
237      O << ".long\t" << FloatToBits(Val) << "\t! float " << Val << "\n";
238      return;
239    }
240    case Type::DoubleTyID: {
241      O << ".word\t0x" << std::hex << (DoubleToBits(Val) >> 32) << std::dec << "\t! double " << Val << "\n";
242      O << ".word\t0x" << std::hex << (DoubleToBits(Val) & 0xffffffffUL) << std::dec << "\t! double " << Val << "\n";
243      return;
244    }
245    }
246  } else if (isa<UndefValue> (CV)) {
247    unsigned size = TD.getTypeSize (CV->getType ());
248    O << "\t.skip\t " << size << "\n";
249    return;
250  } else if (isa<ConstantAggregateZero> (CV)) {
251    unsigned size = TD.getTypeSize (CV->getType ());
252    for (unsigned i = 0; i < size; ++i)
253      O << "\t.byte 0\n";
254    return;
255  }
256
257  const Type *type = CV->getType();
258  O << "\t";
259  switch (type->getTypeID()) {
260  case Type::BoolTyID: case Type::UByteTyID: case Type::SByteTyID:
261    O << ".byte";
262    break;
263  case Type::UShortTyID: case Type::ShortTyID:
264    O << ".half";
265    break;
266  case Type::FloatTyID: case Type::PointerTyID:
267  case Type::UIntTyID: case Type::IntTyID:
268    O << ".word";
269    break;
270  case Type::DoubleTyID:
271  case Type::ULongTyID: case Type::LongTyID:
272    O << ".xword";
273    break;
274  default:
275    assert (0 && "Can't handle printing this type of thing");
276    break;
277  }
278  O << "\t";
279  emitConstantValueOnly(CV);
280  O << "\n";
281}
282
283/// runOnMachineFunction - This uses the printMachineInstruction()
284/// method to print assembly for each instruction.
285///
286bool SparcV8AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
287  SetupMachineFunction(MF);
288
289  // Print out constants referenced by the function
290  EmitConstantPool(MF.getConstantPool());
291
292  // BBNumber is used here so that a given Printer will never give two
293  // BBs the same name. (If you have a better way, please let me know!)
294  static unsigned BBNumber = 0;
295
296  O << "\n\n";
297  // What's my mangled name?
298  CurrentFnName = Mang->getValueName(MF.getFunction());
299
300  // Print out labels for the function.
301  O << "\t.text\n";
302  O << "\t.align 16\n";
303  O << "\t.globl\t" << CurrentFnName << "\n";
304  O << "\t.type\t" << CurrentFnName << ", #function\n";
305  O << CurrentFnName << ":\n";
306
307  // Number each basic block so that we can consistently refer to them
308  // in PC-relative references.
309  NumberForBB.clear();
310  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
311       I != E; ++I) {
312    NumberForBB[I->getBasicBlock()] = BBNumber++;
313  }
314
315  // Print out code for the function.
316  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
317       I != E; ++I) {
318    // Print a label for the basic block.
319    O << ".LBB" << Mang->getValueName(MF.getFunction ())
320      << "_" << I->getNumber () << ":\t! "
321      << I->getBasicBlock ()->getName () << "\n";
322    for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
323         II != E; ++II) {
324      // Print the assembly for the instruction.
325      O << "\t";
326      printInstruction(II);
327      ++EmittedInsts;
328    }
329  }
330
331  // We didn't modify anything.
332  return false;
333}
334
335void SparcV8AsmPrinter::printOperand(const MachineInstr *MI, int opNum) {
336  const MachineOperand &MO = MI->getOperand (opNum);
337  const MRegisterInfo &RI = *TM.getRegisterInfo();
338  bool CloseParen = false;
339  if (MI->getOpcode() == V8::SETHIi && !MO.isRegister() && !MO.isImmediate()) {
340    O << "%hi(";
341    CloseParen = true;
342  } else if (MI->getOpcode() ==V8::ORri &&!MO.isRegister() &&!MO.isImmediate())
343  {
344    O << "%lo(";
345    CloseParen = true;
346  }
347  switch (MO.getType()) {
348  case MachineOperand::MO_VirtualRegister:
349    if (Value *V = MO.getVRegValueOrNull()) {
350      O << "<" << V->getName() << ">";
351      break;
352    }
353    // FALLTHROUGH
354  case MachineOperand::MO_MachineRegister:
355    if (MRegisterInfo::isPhysicalRegister(MO.getReg()))
356      O << "%" << LowercaseString (RI.get(MO.getReg()).Name);
357    else
358      O << "%reg" << MO.getReg();
359    break;
360
361  case MachineOperand::MO_SignExtendedImmed:
362  case MachineOperand::MO_UnextendedImmed:
363    O << (int)MO.getImmedValue();
364    break;
365  case MachineOperand::MO_MachineBasicBlock: {
366    MachineBasicBlock *MBBOp = MO.getMachineBasicBlock();
367    O << ".LBB" << Mang->getValueName(MBBOp->getParent()->getFunction())
368      << "_" << MBBOp->getNumber () << "\t! "
369      << MBBOp->getBasicBlock ()->getName ();
370    return;
371  }
372  case MachineOperand::MO_PCRelativeDisp:
373    std::cerr << "Shouldn't use addPCDisp() when building SparcV8 MachineInstrs";
374    abort ();
375    return;
376  case MachineOperand::MO_GlobalAddress:
377    O << Mang->getValueName(MO.getGlobal());
378    break;
379  case MachineOperand::MO_ExternalSymbol:
380    O << MO.getSymbolName();
381    break;
382  case MachineOperand::MO_ConstantPoolIndex:
383    O << PrivateGlobalPrefix << "CPI" << getFunctionNumber() << "_"
384      << MO.getConstantPoolIndex();
385    break;
386  default:
387    O << "<unknown operand type>"; abort (); break;
388  }
389  if (CloseParen) O << ")";
390}
391
392bool SparcV8AsmPrinter::doInitialization(Module &M) {
393  Mang = new Mangler(M);
394  return false; // success
395}
396
397bool SparcV8AsmPrinter::doFinalization(Module &M) {
398  const TargetData &TD = TM.getTargetData();
399
400  // Print out module-level global variables here.
401  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I)
402    if (I->hasInitializer()) {   // External global require no code
403      O << "\n\n";
404      std::string name = Mang->getValueName(I);
405      Constant *C = I->getInitializer();
406      unsigned Size = TD.getTypeSize(C->getType());
407      unsigned Align = TD.getTypeAlignment(C->getType());
408
409      if (C->isNullValue() &&
410          (I->hasLinkOnceLinkage() || I->hasInternalLinkage() ||
411           I->hasWeakLinkage() /* FIXME: Verify correct */)) {
412        SwitchSection(".data", I);
413        if (I->hasInternalLinkage())
414          O << "\t.local " << name << "\n";
415
416        O << "\t.comm " << name << "," << TD.getTypeSize(C->getType())
417          << "," << (unsigned)TD.getTypeAlignment(C->getType());
418        O << "\t\t! ";
419        WriteAsOperand(O, I, true, true, &M);
420        O << "\n";
421      } else {
422        switch (I->getLinkage()) {
423        case GlobalValue::LinkOnceLinkage:
424        case GlobalValue::WeakLinkage:   // FIXME: Verify correct for weak.
425          // Nonnull linkonce -> weak
426          O << "\t.weak " << name << "\n";
427          SwitchSection("", I);
428          O << "\t.section\t\".llvm.linkonce.d." << name
429            << "\",\"aw\",@progbits\n";
430          break;
431
432        case GlobalValue::AppendingLinkage:
433          // FIXME: appending linkage variables should go into a section of
434          // their name or something.  For now, just emit them as external.
435        case GlobalValue::ExternalLinkage:
436          // If external or appending, declare as a global symbol
437          O << "\t.globl " << name << "\n";
438          // FALL THROUGH
439        case GlobalValue::InternalLinkage:
440          if (C->isNullValue())
441            SwitchSection(".bss", I);
442          else
443            SwitchSection(".data", I);
444          break;
445        case GlobalValue::GhostLinkage:
446          std::cerr << "Should not have any unmaterialized functions!\n";
447          abort();
448        }
449
450        O << "\t.align " << Align << "\n";
451        O << "\t.type " << name << ",#object\n";
452        O << "\t.size " << name << "," << Size << "\n";
453        O << name << ":\t\t\t\t! ";
454        WriteAsOperand(O, I, true, true, &M);
455        O << " = ";
456        WriteAsOperand(O, C, false, false, &M);
457        O << "\n";
458        emitGlobalConstant(C);
459      }
460    }
461
462  AsmPrinter::doFinalization(M);
463  return false; // success
464}
465