lib/CodeGen/AsmPrinter.cpp

   1 //===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
   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 implements the AsmPrinter class.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/CodeGen/AsmPrinter.h"
  15 #include "llvm/Assembly/Writer.h"
  16 #include "llvm/DerivedTypes.h"
  17 #include "llvm/Constants.h"
  18 #include "llvm/Module.h"
  19 #include "llvm/CodeGen/MachineConstantPool.h"
  20 #include "llvm/CodeGen/MachineJumpTableInfo.h"
  21 #include "llvm/Support/Mangler.h"
  22 #include "llvm/Support/MathExtras.h"
  23 #include "llvm/Target/TargetData.h"
  24 #include "llvm/Target/TargetMachine.h"
  25 #include <iostream>
  26 #include <cerrno>
  27 using namespace llvm;
  28
  29 AsmPrinter::AsmPrinter(std::ostream &o, TargetMachine &tm)
  30 : FunctionNumber(0), O(o), TM(tm),
  31   CommentString("#"),
  32   GlobalPrefix(""),
  33   PrivateGlobalPrefix("."),
  34   GlobalVarAddrPrefix(""),
  35   GlobalVarAddrSuffix(""),
  36   FunctionAddrPrefix(""),
  37   FunctionAddrSuffix(""),
  38   InlineAsmStart("#APP"),
  39   InlineAsmEnd("#NO_APP"),
  40   ZeroDirective("\t.zero\t"),
  41   ZeroDirectiveSuffix(0),
  42   AsciiDirective("\t.ascii\t"),
  43   AscizDirective("\t.asciz\t"),
  44   Data8bitsDirective("\t.byte\t"),
  45   Data16bitsDirective("\t.short\t"),
  46   Data32bitsDirective("\t.long\t"),
  47   Data64bitsDirective("\t.quad\t"),
  48   AlignDirective("\t.align\t"),
  49   AlignmentIsInBytes(true),
  50   SwitchToSectionDirective("\t.section\t"),
  51   TextSectionStartSuffix(""),
  52   DataSectionStartSuffix(""),
  53   SectionEndDirectiveSuffix(0),
  54   ConstantPoolSection("\t.section .rodata\n"),
  55   JumpTableDataSection("\t.section .rodata\n"),
  56   JumpTableTextSection("\t.text\n"),
  57   StaticCtorsSection("\t.section .ctors,\"aw\",@progbits"),
  58   StaticDtorsSection("\t.section .dtors,\"aw\",@progbits"),
  59   FourByteConstantSection(0),
  60   EightByteConstantSection(0),
  61   SixteenByteConstantSection(0),
  62   LCOMMDirective(0),
  63   COMMDirective("\t.comm\t"),
  64   COMMDirectiveTakesAlignment(true),
  65   HasDotTypeDotSizeDirective(true) {
  66 }
  67
  68
  69 /// SwitchToTextSection - Switch to the specified text section of the executable
  70 /// if we are not already in it!
  71 ///
  72 void AsmPrinter::SwitchToTextSection(const char *NewSection,
  73                                      const GlobalValue *GV) {
  74   std::string NS;
  75   if (GV && GV->hasSection())
  76     NS = SwitchToSectionDirective + GV->getSection();
  77   else
  78     NS = NewSection;
  79
  80   // If we're already in this section, we're done.
  81   if (CurrentSection == NS) return;
  82
  83   // Close the current section, if applicable.
  84   if (SectionEndDirectiveSuffix && !CurrentSection.empty())
  85     O << CurrentSection << SectionEndDirectiveSuffix << "\n";
  86
  87   CurrentSection = NS;
  88
  89   if (!CurrentSection.empty())
  90     O << CurrentSection << TextSectionStartSuffix << '\n';
  91 }
  92
  93 /// SwitchToDataSection - Switch to the specified data section of the executable
  94 /// if we are not already in it!
  95 ///
  96 void AsmPrinter::SwitchToDataSection(const char *NewSection,
  97                                      const GlobalValue *GV) {
  98   std::string NS;
  99   if (GV && GV->hasSection())
 100     NS = SwitchToSectionDirective + GV->getSection();
 101   else
 102     NS = NewSection;
 103
 104   // If we're already in this section, we're done.
 105   if (CurrentSection == NS) return;
 106
 107   // Close the current section, if applicable.
 108   if (SectionEndDirectiveSuffix && !CurrentSection.empty())
 109     O << CurrentSection << SectionEndDirectiveSuffix << "\n";
 110
 111   CurrentSection = NS;
 112
 113   if (!CurrentSection.empty())
 114     O << CurrentSection << DataSectionStartSuffix << '\n';
 115 }
 116
 117
 118 bool AsmPrinter::doInitialization(Module &M) {
 119   Mang = new Mangler(M, GlobalPrefix);
 120
 121   if (!M.getModuleInlineAsm().empty())
 122     O << CommentString << " Start of file scope inline assembly\n"
 123       << M.getModuleInlineAsm()
 124       << "\n" << CommentString << " End of file scope inline assembly\n";
 125
 126   SwitchToDataSection("", 0);   // Reset back to no section.
 127
 128   if (MachineDebugInfo *DebugInfo = getAnalysisToUpdate<MachineDebugInfo>()) {
 129     DebugInfo->AnalyzeModule(M);
 130   }
 131
 132   return false;
 133 }
 134
 135 bool AsmPrinter::doFinalization(Module &M) {
 136   delete Mang; Mang = 0;
 137   return false;
 138 }
 139
 140 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
 141   // What's my mangled name?
 142   CurrentFnName = Mang->getValueName(MF.getFunction());
 143   IncrementFunctionNumber();
 144 }
 145
 146 /// EmitConstantPool - Print to the current output stream assembly
 147 /// representations of the constants in the constant pool MCP. This is
 148 /// used to print out constants which have been "spilled to memory" by
 149 /// the code generator.
 150 ///
 151 void AsmPrinter::EmitConstantPool(MachineConstantPool *MCP) {
 152   const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
 153   if (CP.empty()) return;
 154
 155   // Some targets require 4-, 8-, and 16- byte constant literals to be placed
 156   // in special sections.
 157   std::vector<std::pair<MachineConstantPoolEntry,unsigned> > FourByteCPs;
 158   std::vector<std::pair<MachineConstantPoolEntry,unsigned> > EightByteCPs;
 159   std::vector<std::pair<MachineConstantPoolEntry,unsigned> > SixteenByteCPs;
 160   std::vector<std::pair<MachineConstantPoolEntry,unsigned> > OtherCPs;
 161   for (unsigned i = 0, e = CP.size(); i != e; ++i) {
 162     MachineConstantPoolEntry CPE = CP[i];
 163     const Constant *CV = CPE.Val;
 164     const Type *Ty = CV->getType();
 165     if (FourByteConstantSection &&
 166         TM.getTargetData()->getTypeSize(Ty) == 4)
 167       FourByteCPs.push_back(std::make_pair(CPE, i));
 168     else if (EightByteConstantSection &&
 169              TM.getTargetData()->getTypeSize(Ty) == 8)
 170       EightByteCPs.push_back(std::make_pair(CPE, i));
 171     else if (SixteenByteConstantSection &&
 172              TM.getTargetData()->getTypeSize(Ty) == 16)
 173       SixteenByteCPs.push_back(std::make_pair(CPE, i));
 174     else
 175       OtherCPs.push_back(std::make_pair(CPE, i));
 176   }
 177
 178   unsigned Alignment = MCP->getConstantPoolAlignment();
 179   EmitConstantPool(Alignment, FourByteConstantSection,    FourByteCPs);
 180   EmitConstantPool(Alignment, EightByteConstantSection,   EightByteCPs);
 181   EmitConstantPool(Alignment, SixteenByteConstantSection, SixteenByteCPs);
 182   EmitConstantPool(Alignment, ConstantPoolSection,        OtherCPs);
 183 }
 184
 185 void AsmPrinter::EmitConstantPool(unsigned Alignment, const char *Section,
 186                std::vector<std::pair<MachineConstantPoolEntry,unsigned> > &CP) {
 187   if (CP.empty()) return;
 188
 189   SwitchToDataSection(Section, 0);
 190   EmitAlignment(Alignment);
 191   for (unsigned i = 0, e = CP.size(); i != e; ++i) {
 192     O << PrivateGlobalPrefix << "CPI" << getFunctionNumber() << '_'
 193       << CP[i].second << ":\t\t\t\t\t" << CommentString << " ";
 194     WriteTypeSymbolic(O, CP[i].first.Val->getType(), 0) << '\n';
 195     EmitGlobalConstant(CP[i].first.Val);
 196     if (i != e-1) {
 197       unsigned EntSize =
 198         TM.getTargetData()->getTypeSize(CP[i].first.Val->getType());
 199       unsigned ValEnd = CP[i].first.Offset + EntSize;
 200       // Emit inter-object padding for alignment.
 201       EmitZeros(CP[i+1].first.Offset-ValEnd);
 202     }
 203   }
 204 }
 205
 206 /// EmitJumpTableInfo - Print assembly representations of the jump tables used
 207 /// by the current function to the current output stream.
 208 ///
 209 void AsmPrinter::EmitJumpTableInfo(MachineJumpTableInfo *MJTI) {
 210   const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
 211   if (JT.empty()) return;
 212   const TargetData *TD = TM.getTargetData();
 213
 214   // JTEntryDirective is a string to print sizeof(ptr) for non-PIC jump tables,
 215   // and 32 bits for PIC since PIC jump table entries are differences, not
 216   // pointers to blocks.
 217   const char *JTEntryDirective = Data32bitsDirective;
 218
 219   // Pick the directive to use to print the jump table entries, and switch to
 220   // the appropriate section.
 221   if (TM.getRelocationModel() == Reloc::PIC_) {
 222     SwitchToTextSection(JumpTableTextSection, 0);
 223   } else {
 224     SwitchToDataSection(JumpTableDataSection, 0);
 225     if (TD->getPointerSize() == 8)
 226       JTEntryDirective = Data64bitsDirective;
 227   }
 228   EmitAlignment(Log2_32(TD->getPointerAlignment()));
 229
 230   for (unsigned i = 0, e = JT.size(); i != e; ++i) {
 231     O << PrivateGlobalPrefix << "JTI" << getFunctionNumber() << '_' << i
 232       << ":\n";
 233     const std::vector<MachineBasicBlock*> &JTBBs = JT[i].MBBs;
 234     for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
 235       O << JTEntryDirective << ' ';
 236       printBasicBlockLabel(JTBBs[ii], false, false);
 237       if (TM.getRelocationModel() == Reloc::PIC_) {
 238         O << '-' << PrivateGlobalPrefix << "JTI" << getFunctionNumber()
 239           << '_' << i;
 240       }
 241       O << '\n';
 242     }
 243   }
 244 }
 245
 246 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a
 247 /// special global used by LLVM.  If so, emit it and return true, otherwise
 248 /// do nothing and return false.
 249 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
 250   // Ignore debug and non-emitted data.
 251   if (GV->getSection() == "llvm.metadata") return true;
 252
 253   if (!GV->hasAppendingLinkage()) return false;
 254
 255   assert(GV->hasInitializer() && "Not a special LLVM global!");
 256
 257   if (GV->getName() == "llvm.used")
 258     return true;  // No need to emit this at all.
 259
 260   if (GV->getName() == "llvm.global_ctors" && GV->use_empty()) {
 261     SwitchToDataSection(StaticCtorsSection, 0);
 262     EmitAlignment(2, 0);
 263     EmitXXStructorList(GV->getInitializer());
 264     return true;
 265   }
 266
 267   if (GV->getName() == "llvm.global_dtors" && GV->use_empty()) {
 268     SwitchToDataSection(StaticDtorsSection, 0);
 269     EmitAlignment(2, 0);
 270     EmitXXStructorList(GV->getInitializer());
 271     return true;
 272   }
 273
 274   return false;
 275 }
 276
 277 /// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
 278 /// function pointers, ignoring the init priority.
 279 void AsmPrinter::EmitXXStructorList(Constant *List) {
 280   // Should be an array of '{ int, void ()* }' structs.  The first value is the
 281   // init priority, which we ignore.
 282   if (!isa<ConstantArray>(List)) return;
 283   ConstantArray *InitList = cast<ConstantArray>(List);
 284   for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
 285     if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
 286       if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
 287
 288       if (CS->getOperand(1)->isNullValue())
 289         return;  // Found a null terminator, exit printing.
 290       // Emit the function pointer.
 291       EmitGlobalConstant(CS->getOperand(1));
 292     }
 293 }
 294
 295 /// getPreferredAlignmentLog - Return the preferred alignment of the
 296 /// specified global, returned in log form.  This includes an explicitly
 297 /// requested alignment (if the global has one).
 298 unsigned AsmPrinter::getPreferredAlignmentLog(const GlobalVariable *GV) const {
 299   const Type *ElemType = GV->getType()->getElementType();
 300   unsigned Alignment = TM.getTargetData()->getTypeAlignmentShift(ElemType);
 301   if (GV->getAlignment() > (1U << Alignment))
 302     Alignment = Log2_32(GV->getAlignment());
 303
 304   if (GV->hasInitializer()) {
 305     // Always round up alignment of global doubles to 8 bytes.
 306     if (GV->getType()->getElementType() == Type::DoubleTy && Alignment < 3)
 307       Alignment = 3;
 308     if (Alignment < 4) {
 309       // If the global is not external, see if it is large.  If so, give it a
 310       // larger alignment.
 311       if (TM.getTargetData()->getTypeSize(ElemType) > 128)
 312         Alignment = 4;    // 16-byte alignment.
 313     }
 314   }
 315   return Alignment;
 316 }
 317
 318 // EmitAlignment - Emit an alignment directive to the specified power of two.
 319 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
 320   if (GV && GV->getAlignment())
 321     NumBits = Log2_32(GV->getAlignment());
 322   if (NumBits == 0) return;   // No need to emit alignment.
 323   if (AlignmentIsInBytes) NumBits = 1 << NumBits;
 324   O << AlignDirective << NumBits << "\n";
 325 }
 326
 327 /// EmitZeros - Emit a block of zeros.
 328 ///
 329 void AsmPrinter::EmitZeros(uint64_t NumZeros) const {
 330   if (NumZeros) {
 331     if (ZeroDirective) {
 332       O << ZeroDirective << NumZeros;
 333       if (ZeroDirectiveSuffix)
 334         O << ZeroDirectiveSuffix;
 335       O << "\n";
 336     } else {
 337       for (; NumZeros; --NumZeros)
 338         O << Data8bitsDirective << "0\n";
 339     }
 340   }
 341 }
 342
 343 // Print out the specified constant, without a storage class.  Only the
 344 // constants valid in constant expressions can occur here.
 345 void AsmPrinter::EmitConstantValueOnly(const Constant *CV) {
 346   if (CV->isNullValue() || isa<UndefValue>(CV))
 347     O << "0";
 348   else if (const ConstantBool *CB = dyn_cast<ConstantBool>(CV)) {
 349     assert(CB == ConstantBool::True);
 350     O << "1";
 351   } else if (const ConstantSInt *CI = dyn_cast<ConstantSInt>(CV))
 352     if (((CI->getValue() << 32) >> 32) == CI->getValue())
 353       O << CI->getValue();
 354     else
 355       O << (uint64_t)CI->getValue();
 356   else if (const ConstantUInt *CI = dyn_cast<ConstantUInt>(CV))
 357     O << CI->getValue();
 358   else if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) {
 359     // This is a constant address for a global variable or function. Use the
 360     // name of the variable or function as the address value, possibly
 361     // decorating it with GlobalVarAddrPrefix/Suffix or
 362     // FunctionAddrPrefix/Suffix (these all default to "" )
 363     if (isa<Function>(GV))
 364       O << FunctionAddrPrefix << Mang->getValueName(GV) << FunctionAddrSuffix;
 365     else
 366       O << GlobalVarAddrPrefix << Mang->getValueName(GV) << GlobalVarAddrSuffix;
 367   } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
 368     const TargetData *TD = TM.getTargetData();
 369     switch(CE->getOpcode()) {
 370     case Instruction::GetElementPtr: {
 371       // generate a symbolic expression for the byte address
 372       const Constant *ptrVal = CE->getOperand(0);
 373       std::vector<Value*> idxVec(CE->op_begin()+1, CE->op_end());
 374       if (int64_t Offset = TD->getIndexedOffset(ptrVal->getType(), idxVec)) {
 375         if (Offset)
 376           O << "(";
 377         EmitConstantValueOnly(ptrVal);
 378         if (Offset > 0)
 379           O << ") + " << Offset;
 380         else if (Offset < 0)
 381           O << ") - " << -Offset;
 382       } else {
 383         EmitConstantValueOnly(ptrVal);
 384       }
 385       break;
 386     }
 387     case Instruction::Cast: {
 388       // Support only foldable casts to/from pointers that can be eliminated by
 389       // changing the pointer to the appropriately sized integer type.
 390       Constant *Op = CE->getOperand(0);
 391       const Type *OpTy = Op->getType(), *Ty = CE->getType();
 392
 393       // Handle casts to pointers by changing them into casts to the appropriate
 394       // integer type.  This promotes constant folding and simplifies this code.
 395       if (isa<PointerType>(Ty)) {
 396         const Type *IntPtrTy = TD->getIntPtrType();
 397         Op = ConstantExpr::getCast(Op, IntPtrTy);
 398         return EmitConstantValueOnly(Op);
 399       }
 400
 401       // We know the dest type is not a pointer.  Is the src value a pointer or
 402       // integral?
 403       if (isa<PointerType>(OpTy) || OpTy->isIntegral()) {
 404         // We can emit the pointer value into this slot if the slot is an
 405         // integer slot greater or equal to the size of the pointer.
 406         if (Ty->isIntegral() && TD->getTypeSize(Ty) >= TD->getTypeSize(OpTy))
 407           return EmitConstantValueOnly(Op);
 408       }
 409
 410       assert(0 && "FIXME: Don't yet support this kind of constant cast expr");
 411       EmitConstantValueOnly(Op);
 412       break;
 413     }
 414     case Instruction::Add:
 415       O << "(";
 416       EmitConstantValueOnly(CE->getOperand(0));
 417       O << ") + (";
 418       EmitConstantValueOnly(CE->getOperand(1));
 419       O << ")";
 420       break;
 421     default:
 422       assert(0 && "Unsupported operator!");
 423     }
 424   } else {
 425     assert(0 && "Unknown constant value!");
 426   }
 427 }
 428
 429 /// toOctal - Convert the low order bits of X into an octal digit.
 430 ///
 431 static inline char toOctal(int X) {
 432   return (X&7)+'0';
 433 }
 434
 435 /// printAsCString - Print the specified array as a C compatible string, only if
 436 /// the predicate isString is true.
 437 ///
 438 static void printAsCString(std::ostream &O, const ConstantArray *CVA,
 439                            unsigned LastElt) {
 440   assert(CVA->isString() && "Array is not string compatible!");
 441
 442   O << "\"";
 443   for (unsigned i = 0; i != LastElt; ++i) {
 444     unsigned char C =
 445         (unsigned char)cast<ConstantInt>(CVA->getOperand(i))->getRawValue();
 446
 447     if (C == '"') {
 448       O << "\\\"";
 449     } else if (C == '\\') {
 450       O << "\\\\";
 451     } else if (isprint(C)) {
 452       O << C;
 453     } else {
 454       switch(C) {
 455       case '\b': O << "\\b"; break;
 456       case '\f': O << "\\f"; break;
 457       case '\n': O << "\\n"; break;
 458       case '\r': O << "\\r"; break;
 459       case '\t': O << "\\t"; break;
 460       default:
 461         O << '\\';
 462         O << toOctal(C >> 6);
 463         O << toOctal(C >> 3);
 464         O << toOctal(C >> 0);
 465         break;
 466       }
 467     }
 468   }
 469   O << "\"";
 470 }
 471
 472 /// EmitString - Emit a zero-byte-terminated string constant.
 473 ///
 474 void AsmPrinter::EmitString(const ConstantArray *CVA) const {
 475   unsigned NumElts = CVA->getNumOperands();
 476   if (AscizDirective && NumElts &&
 477       cast<ConstantInt>(CVA->getOperand(NumElts-1))->getRawValue() == 0) {
 478     O << AscizDirective;
 479     printAsCString(O, CVA, NumElts-1);
 480   } else {
 481     O << AsciiDirective;
 482     printAsCString(O, CVA, NumElts);
 483   }
 484   O << "\n";
 485 }
 486
 487 /// EmitGlobalConstant - Print a general LLVM constant to the .s file.
 488 ///
 489 void AsmPrinter::EmitGlobalConstant(const Constant *CV) {
 490   const TargetData *TD = TM.getTargetData();
 491
 492   if (CV->isNullValue() || isa<UndefValue>(CV)) {
 493     EmitZeros(TD->getTypeSize(CV->getType()));
 494     return;
 495   } else if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) {
 496     if (CVA->isString()) {
 497       EmitString(CVA);
 498     } else { // Not a string.  Print the values in successive locations
 499       for (unsigned i = 0, e = CVA->getNumOperands(); i != e; ++i)
 500         EmitGlobalConstant(CVA->getOperand(i));
 501     }
 502     return;
 503   } else if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) {
 504     // Print the fields in successive locations. Pad to align if needed!
 505     const StructLayout *cvsLayout = TD->getStructLayout(CVS->getType());
 506     uint64_t sizeSoFar = 0;
 507     for (unsigned i = 0, e = CVS->getNumOperands(); i != e; ++i) {
 508       const Constant* field = CVS->getOperand(i);
 509
 510       // Check if padding is needed and insert one or more 0s.
 511       uint64_t fieldSize = TD->getTypeSize(field->getType());
 512       uint64_t padSize = ((i == e-1? cvsLayout->StructSize
 513                            : cvsLayout->MemberOffsets[i+1])
 514                           - cvsLayout->MemberOffsets[i]) - fieldSize;
 515       sizeSoFar += fieldSize + padSize;
 516
 517       // Now print the actual field value
 518       EmitGlobalConstant(field);
 519
 520       // Insert the field padding unless it's zero bytes...
 521       EmitZeros(padSize);
 522     }
 523     assert(sizeSoFar == cvsLayout->StructSize &&
 524            "Layout of constant struct may be incorrect!");
 525     return;
 526   } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) {
 527     // FP Constants are printed as integer constants to avoid losing
 528     // precision...
 529     double Val = CFP->getValue();
 530     if (CFP->getType() == Type::DoubleTy) {
 531       if (Data64bitsDirective)
 532         O << Data64bitsDirective << DoubleToBits(Val) << "\t" << CommentString
 533           << " double value: " << Val << "\n";
 534       else if (TD->isBigEndian()) {
 535         O << Data32bitsDirective << unsigned(DoubleToBits(Val) >> 32)
 536           << "\t" << CommentString << " double most significant word "
 537           << Val << "\n";
 538         O << Data32bitsDirective << unsigned(DoubleToBits(Val))
 539           << "\t" << CommentString << " double least significant word "
 540           << Val << "\n";
 541       } else {
 542         O << Data32bitsDirective << unsigned(DoubleToBits(Val))
 543           << "\t" << CommentString << " double least significant word " << Val
 544           << "\n";
 545         O << Data32bitsDirective << unsigned(DoubleToBits(Val) >> 32)
 546           << "\t" << CommentString << " double most significant word " << Val
 547           << "\n";
 548       }
 549       return;
 550     } else {
 551       O << Data32bitsDirective << FloatToBits(Val) << "\t" << CommentString
 552         << " float " << Val << "\n";
 553       return;
 554     }
 555   } else if (CV->getType() == Type::ULongTy || CV->getType() == Type::LongTy) {
 556     if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
 557       uint64_t Val = CI->getRawValue();
 558
 559       if (Data64bitsDirective)
 560         O << Data64bitsDirective << Val << "\n";
 561       else if (TD->isBigEndian()) {
 562         O << Data32bitsDirective << unsigned(Val >> 32)
 563           << "\t" << CommentString << " Double-word most significant word "
 564           << Val << "\n";
 565         O << Data32bitsDirective << unsigned(Val)
 566           << "\t" << CommentString << " Double-word least significant word "
 567           << Val << "\n";
 568       } else {
 569         O << Data32bitsDirective << unsigned(Val)
 570           << "\t" << CommentString << " Double-word least significant word "
 571           << Val << "\n";
 572         O << Data32bitsDirective << unsigned(Val >> 32)
 573           << "\t" << CommentString << " Double-word most significant word "
 574           << Val << "\n";
 575       }
 576       return;
 577     }
 578   } else if (const ConstantPacked *CP = dyn_cast<ConstantPacked>(CV)) {
 579     const PackedType *PTy = CP->getType();
 580
 581     for (unsigned I = 0, E = PTy->getNumElements(); I < E; ++I)
 582       EmitGlobalConstant(CP->getOperand(I));
 583
 584     return;
 585   }
 586
 587   const Type *type = CV->getType();
 588   switch (type->getTypeID()) {
 589   case Type::BoolTyID:
 590   case Type::UByteTyID: case Type::SByteTyID:
 591     O << Data8bitsDirective;
 592     break;
 593   case Type::UShortTyID: case Type::ShortTyID:
 594     O << Data16bitsDirective;
 595     break;
 596   case Type::PointerTyID:
 597     if (TD->getPointerSize() == 8) {
 598       assert(Data64bitsDirective &&
 599              "Target cannot handle 64-bit pointer exprs!");
 600       O << Data64bitsDirective;
 601       break;
 602     }
 603     //Fall through for pointer size == int size
 604   case Type::UIntTyID: case Type::IntTyID:
 605     O << Data32bitsDirective;
 606     break;
 607   case Type::ULongTyID: case Type::LongTyID:
 608     assert(Data64bitsDirective &&"Target cannot handle 64-bit constant exprs!");
 609     O << Data64bitsDirective;
 610     break;
 611   case Type::FloatTyID: case Type::DoubleTyID:
 612     assert (0 && "Should have already output floating point constant.");
 613   default:
 614     assert (0 && "Can't handle printing this type of thing");
 615     break;
 616   }
 617   EmitConstantValueOnly(CV);
 618   O << "\n";
 619 }
 620
 621 /// printInlineAsm - This method formats and prints the specified machine
 622 /// instruction that is an inline asm.
 623 void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
 624   unsigned NumOperands = MI->getNumOperands();
 625
 626   // Count the number of register definitions.
 627   unsigned NumDefs = 0;
 628   for (; MI->getOperand(NumDefs).isDef(); ++NumDefs)
 629     assert(NumDefs != NumOperands-1 && "No asm string?");
 630
 631   assert(MI->getOperand(NumDefs).isExternalSymbol() && "No asm string?");
 632
 633   // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
 634   const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
 635
 636   // If this asmstr is empty, don't bother printing the #APP/#NOAPP markers.
 637   if (AsmStr[0] == 0) {
 638     O << "\n";  // Tab already printed, avoid double indenting next instr.
 639     return;
 640   }
 641
 642   O << InlineAsmStart << "\n\t";
 643
 644   // The variant of the current asmprinter: FIXME: change.
 645   int AsmPrinterVariant = 0;
 646
 647   int CurVariant = -1;            // The number of the {.|.|.} region we are in.
 648   const char *LastEmitted = AsmStr; // One past the last character emitted.
 649
 650   while (*LastEmitted) {
 651     switch (*LastEmitted) {
 652     default: {
 653       // Not a special case, emit the string section literally.
 654       const char *LiteralEnd = LastEmitted+1;
 655       while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
 656              *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
 657         ++LiteralEnd;
 658       if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
 659         O.write(LastEmitted, LiteralEnd-LastEmitted);
 660       LastEmitted = LiteralEnd;
 661       break;
 662     }
 663     case '\n':
 664       ++LastEmitted;   // Consume newline character.
 665       O << "\n\t";     // Indent code with newline.
 666       break;
 667     case '$': {
 668       ++LastEmitted;   // Consume '$' character.
 669       if (*LastEmitted == '$') { // $$ -> $
 670         if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
 671           O << '$';
 672         ++LastEmitted;  // Consume second '$' character.
 673         break;
 674       }
 675
 676       bool HasCurlyBraces = false;
 677       if (*LastEmitted == '{') {     // ${variable}
 678         ++LastEmitted;               // Consume '{' character.
 679         HasCurlyBraces = true;
 680       }
 681
 682       const char *IDStart = LastEmitted;
 683       char *IDEnd;
 684       long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
 685       if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
 686         std::cerr << "Bad $ operand number in inline asm string: '"
 687                   << AsmStr << "'\n";
 688         exit(1);
 689       }
 690       LastEmitted = IDEnd;
 691
 692       char Modifier[2] = { 0, 0 };
 693
 694       if (HasCurlyBraces) {
 695         // If we have curly braces, check for a modifier character.  This
 696         // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
 697         if (*LastEmitted == ':') {
 698           ++LastEmitted;    // Consume ':' character.
 699           if (*LastEmitted == 0) {
 700             std::cerr << "Bad ${:} expression in inline asm string: '"
 701                       << AsmStr << "'\n";
 702             exit(1);
 703           }
 704
 705           Modifier[0] = *LastEmitted;
 706           ++LastEmitted;    // Consume modifier character.
 707         }
 708
 709         if (*LastEmitted != '}') {
 710           std::cerr << "Bad ${} expression in inline asm string: '"
 711                     << AsmStr << "'\n";
 712           exit(1);
 713         }
 714         ++LastEmitted;    // Consume '}' character.
 715       }
 716
 717       if ((unsigned)Val >= NumOperands-1) {
 718         std::cerr << "Invalid $ operand number in inline asm string: '"
 719                   << AsmStr << "'\n";
 720         exit(1);
 721       }
 722
 723       // Okay, we finally have a value number.  Ask the target to print this
 724       // operand!
 725       if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
 726         unsigned OpNo = 1;
 727
 728         bool Error = false;
 729
 730         // Scan to find the machine operand number for the operand.
 731         for (; Val; --Val) {
 732           if (OpNo >= MI->getNumOperands()) break;
 733           unsigned OpFlags = MI->getOperand(OpNo).getImmedValue();
 734           OpNo += (OpFlags >> 3) + 1;
 735         }
 736
 737         if (OpNo >= MI->getNumOperands()) {
 738           Error = true;
 739         } else {
 740           unsigned OpFlags = MI->getOperand(OpNo).getImmedValue();
 741           ++OpNo;  // Skip over the ID number.
 742
 743           AsmPrinter *AP = const_cast<AsmPrinter*>(this);
 744           if ((OpFlags & 7) == 4 /*ADDR MODE*/) {
 745             Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
 746                                               Modifier[0] ? Modifier : 0);
 747           } else {
 748             Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
 749                                         Modifier[0] ? Modifier : 0);
 750           }
 751         }
 752         if (Error) {
 753           std::cerr << "Invalid operand found in inline asm: '"
 754                     << AsmStr << "'\n";
 755           MI->dump();
 756           exit(1);
 757         }
 758       }
 759       break;
 760     }
 761     case '{':
 762       ++LastEmitted;      // Consume '{' character.
 763       if (CurVariant != -1) {
 764         std::cerr << "Nested variants found in inline asm string: '"
 765                   << AsmStr << "'\n";
 766         exit(1);
 767       }
 768       CurVariant = 0;     // We're in the first variant now.
 769       break;
 770     case '|':
 771       ++LastEmitted;  // consume '|' character.
 772       if (CurVariant == -1) {
 773         std::cerr << "Found '|' character outside of variant in inline asm "
 774                   << "string: '" << AsmStr << "'\n";
 775         exit(1);
 776       }
 777       ++CurVariant;   // We're in the next variant.
 778       break;
 779     case '}':
 780       ++LastEmitted;  // consume '}' character.
 781       if (CurVariant == -1) {
 782         std::cerr << "Found '}' character outside of variant in inline asm "
 783                   << "string: '" << AsmStr << "'\n";
 784         exit(1);
 785       }
 786       CurVariant = -1;
 787       break;
 788     }
 789   }
 790   O << "\n\t" << InlineAsmEnd << "\n";
 791 }
 792
 793 /// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
 794 /// instruction, using the specified assembler variant.  Targets should
 795 /// overried this to format as appropriate.
 796 bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
 797                                  unsigned AsmVariant, const char *ExtraCode) {
 798   // Target doesn't support this yet!
 799   return true;
 800 }
 801
 802 bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
 803                                        unsigned AsmVariant,
 804                                        const char *ExtraCode) {
 805   // Target doesn't support this yet!
 806   return true;
 807 }
 808
 809 /// printBasicBlockLabel - This method prints the label for the specified
 810 /// MachineBasicBlock
 811 void AsmPrinter::printBasicBlockLabel(const MachineBasicBlock *MBB,
 812                                       bool printColon,
 813                                       bool printComment) const {
 814   O << PrivateGlobalPrefix << "BB" << FunctionNumber << "_"
 815     << MBB->getNumber();
 816   if (printColon)
 817     O << ':';
 818   if (printComment)
 819     O << '\t' << CommentString << MBB->getBasicBlock()->getName();
 820 }