lib/Target/X86/AsmPrinter/X86IntelAsmPrinter.cpp

   1 //===-- X86IntelAsmPrinter.cpp - Convert X86 LLVM code to Intel assembly --===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // 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 Intel format assembly language.
  12 // This printer is the output mechanism used by `llc'.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #define DEBUG_TYPE "asm-printer"
  17 #include "X86IntelAsmPrinter.h"
  18 #include "X86InstrInfo.h"
  19 #include "X86TargetAsmInfo.h"
  20 #include "X86.h"
  21 #include "llvm/CallingConv.h"
  22 #include "llvm/Constants.h"
  23 #include "llvm/DerivedTypes.h"
  24 #include "llvm/Module.h"
  25 #include "llvm/ADT/Statistic.h"
  26 #include "llvm/ADT/StringExtras.h"
  27 #include "llvm/Assembly/Writer.h"
  28 #include "llvm/CodeGen/DwarfWriter.h"
  29 #include "llvm/Support/ErrorHandling.h"
  30 #include "llvm/Support/Mangler.h"
  31 #include "llvm/Target/TargetAsmInfo.h"
  32 #include "llvm/Target/TargetOptions.h"
  33 using namespace llvm;
  34
  35 STATISTIC(EmittedInsts, "Number of machine instrs printed");
  36
  37 static X86MachineFunctionInfo calculateFunctionInfo(const Function *F,
  38                                                     const TargetData *TD) {
  39   X86MachineFunctionInfo Info;
  40   uint64_t Size = 0;
  41
  42   switch (F->getCallingConv()) {
  43   case CallingConv::X86_StdCall:
  44     Info.setDecorationStyle(StdCall);
  45     break;
  46   case CallingConv::X86_FastCall:
  47     Info.setDecorationStyle(FastCall);
  48     break;
  49   default:
  50     return Info;
  51   }
  52
  53   unsigned argNum = 1;
  54   for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
  55        AI != AE; ++AI, ++argNum) {
  56     const Type* Ty = AI->getType();
  57
  58     // 'Dereference' type in case of byval parameter attribute
  59     if (F->paramHasAttr(argNum, Attribute::ByVal))
  60       Ty = cast<PointerType>(Ty)->getElementType();
  61
  62     // Size should be aligned to DWORD boundary
  63     Size += ((TD->getTypeAllocSize(Ty) + 3)/4)*4;
  64   }
  65
  66   // We're not supporting tooooo huge arguments :)
  67   Info.setBytesToPopOnReturn((unsigned int)Size);
  68   return Info;
  69 }
  70
  71
  72 /// decorateName - Query FunctionInfoMap and use this information for various
  73 /// name decoration.
  74 void X86IntelAsmPrinter::decorateName(std::string &Name,
  75                                       const GlobalValue *GV) {
  76   const Function *F = dyn_cast<Function>(GV);
  77   if (!F) return;
  78
  79   // We don't want to decorate non-stdcall or non-fastcall functions right now
  80   unsigned CC = F->getCallingConv();
  81   if (CC != CallingConv::X86_StdCall && CC != CallingConv::X86_FastCall)
  82     return;
  83
  84   FMFInfoMap::const_iterator info_item = FunctionInfoMap.find(F);
  85
  86   const X86MachineFunctionInfo *Info;
  87   if (info_item == FunctionInfoMap.end()) {
  88     // Calculate apropriate function info and populate map
  89     FunctionInfoMap[F] = calculateFunctionInfo(F, TM.getTargetData());
  90     Info = &FunctionInfoMap[F];
  91   } else {
  92     Info = &info_item->second;
  93   }
  94
  95   const FunctionType *FT = F->getFunctionType();
  96   switch (Info->getDecorationStyle()) {
  97   case None:
  98     break;
  99   case StdCall:
 100     // "Pure" variadic functions do not receive @0 suffix.
 101     if (!FT->isVarArg() || (FT->getNumParams() == 0) ||
 102         (FT->getNumParams() == 1 && F->hasStructRetAttr()))
 103       Name += '@' + utostr_32(Info->getBytesToPopOnReturn());
 104     break;
 105   case FastCall:
 106     // "Pure" variadic functions do not receive @0 suffix.
 107     if (!FT->isVarArg() || (FT->getNumParams() == 0) ||
 108         (FT->getNumParams() == 1 && F->hasStructRetAttr()))
 109       Name += '@' + utostr_32(Info->getBytesToPopOnReturn());
 110
 111     if (Name[0] == '_')
 112       Name[0] = '@';
 113     else
 114       Name = '@' + Name;
 115
 116     break;
 117   default:
 118     llvm_unreachable("Unsupported DecorationStyle");
 119   }
 120 }
 121
 122 /// runOnMachineFunction - This uses the printMachineInstruction()
 123 /// method to print assembly for each instruction.
 124 ///
 125 bool X86IntelAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
 126   this->MF = &MF;
 127   SetupMachineFunction(MF);
 128   O << "\n\n";
 129
 130   // Print out constants referenced by the function
 131   EmitConstantPool(MF.getConstantPool());
 132
 133   // Print out labels for the function.
 134   const Function *F = MF.getFunction();
 135   unsigned CC = F->getCallingConv();
 136   unsigned FnAlign = MF.getAlignment();
 137
 138   // Populate function information map.  Actually, We don't want to populate
 139   // non-stdcall or non-fastcall functions' information right now.
 140   if (CC == CallingConv::X86_StdCall || CC == CallingConv::X86_FastCall)
 141     FunctionInfoMap[F] = *MF.getInfo<X86MachineFunctionInfo>();
 142
 143   decorateName(CurrentFnName, F);
 144
 145   SwitchToTextSection("_text", F);
 146   switch (F->getLinkage()) {
 147   default: llvm_unreachable("Unsupported linkage type!");
 148   case Function::PrivateLinkage:
 149   case Function::InternalLinkage:
 150     EmitAlignment(FnAlign);
 151     break;
 152   case Function::DLLExportLinkage:
 153     DLLExportedFns.insert(CurrentFnName);
 154     //FALLS THROUGH
 155   case Function::ExternalLinkage:
 156     O << "\tpublic " << CurrentFnName << "\n";
 157     EmitAlignment(FnAlign);
 158     break;
 159   }
 160
 161   O << CurrentFnName << "\tproc near\n";
 162
 163   // Print out code for the function.
 164   for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
 165        I != E; ++I) {
 166     // Print a label for the basic block if there are any predecessors.
 167     if (!I->pred_empty()) {
 168       printBasicBlockLabel(I, true, true);
 169       O << '\n';
 170     }
 171     for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
 172          II != E; ++II) {
 173       // Print the assembly for the instruction.
 174       printMachineInstruction(II);
 175     }
 176   }
 177
 178   // Print out jump tables referenced by the function.
 179   EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
 180
 181   O << CurrentFnName << "\tendp\n";
 182
 183   O.flush();
 184
 185   // We didn't modify anything.
 186   return false;
 187 }
 188
 189 void X86IntelAsmPrinter::printSSECC(const MachineInstr *MI, unsigned Op) {
 190   unsigned char value = MI->getOperand(Op).getImm();
 191   assert(value <= 7 && "Invalid ssecc argument!");
 192   switch (value) {
 193   case 0: O << "eq"; break;
 194   case 1: O << "lt"; break;
 195   case 2: O << "le"; break;
 196   case 3: O << "unord"; break;
 197   case 4: O << "neq"; break;
 198   case 5: O << "nlt"; break;
 199   case 6: O << "nle"; break;
 200   case 7: O << "ord"; break;
 201   }
 202 }
 203
 204 void X86IntelAsmPrinter::printOp(const MachineOperand &MO,
 205                                  const char *Modifier) {
 206   switch (MO.getType()) {
 207   case MachineOperand::MO_Register: {
 208     if (TargetRegisterInfo::isPhysicalRegister(MO.getReg())) {
 209       unsigned Reg = MO.getReg();
 210       if (Modifier && strncmp(Modifier, "subreg", strlen("subreg")) == 0) {
 211         MVT VT = (strcmp(Modifier,"subreg64") == 0) ?
 212           MVT::i64 : ((strcmp(Modifier, "subreg32") == 0) ? MVT::i32 :
 213                       ((strcmp(Modifier,"subreg16") == 0) ? MVT::i16 :MVT::i8));
 214         Reg = getX86SubSuperRegister(Reg, VT);
 215       }
 216       O << TRI->getName(Reg);
 217     } else
 218       O << "reg" << MO.getReg();
 219     return;
 220   }
 221   case MachineOperand::MO_Immediate:
 222     O << MO.getImm();
 223     return;
 224   case MachineOperand::MO_JumpTableIndex: {
 225     bool isMemOp  = Modifier && !strcmp(Modifier, "mem");
 226     if (!isMemOp) O << "OFFSET ";
 227     O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
 228       << "_" << MO.getIndex();
 229     return;
 230   }
 231   case MachineOperand::MO_ConstantPoolIndex: {
 232     bool isMemOp  = Modifier && !strcmp(Modifier, "mem");
 233     if (!isMemOp) O << "OFFSET ";
 234     O << "[" << TAI->getPrivateGlobalPrefix() << "CPI"
 235       << getFunctionNumber() << "_" << MO.getIndex();
 236     printOffset(MO.getOffset());
 237     O << "]";
 238     return;
 239   }
 240   case MachineOperand::MO_GlobalAddress: {
 241     bool isMemOp  = Modifier && !strcmp(Modifier, "mem");
 242     GlobalValue *GV = MO.getGlobal();
 243     std::string Name = Mang->getMangledName(GV);
 244     decorateName(Name, GV);
 245
 246     if (!isMemOp) O << "OFFSET ";
 247
 248     // Handle dllimport linkage.
 249     // FIXME: This should be fixed with full support of stdcall & fastcall
 250     // CC's
 251     if (MO.getTargetFlags() == X86II::MO_DLLIMPORT)
 252       O << "__imp_";
 253
 254     O << Name;
 255     printOffset(MO.getOffset());
 256     return;
 257   }
 258   case MachineOperand::MO_ExternalSymbol: {
 259     O << TAI->getGlobalPrefix() << MO.getSymbolName();
 260     return;
 261   }
 262   default:
 263     O << "<unknown operand type>"; return;
 264   }
 265 }
 266
 267 void X86IntelAsmPrinter::print_pcrel_imm(const MachineInstr *MI, unsigned OpNo){
 268   const MachineOperand &MO = MI->getOperand(OpNo);
 269   switch (MO.getType()) {
 270   default: llvm_unreachable("Unknown pcrel immediate operand");
 271   case MachineOperand::MO_Immediate:
 272     O << MO.getImm();
 273     return;
 274   case MachineOperand::MO_MachineBasicBlock:
 275     printBasicBlockLabel(MO.getMBB());
 276     return;
 277
 278   case MachineOperand::MO_GlobalAddress: {
 279     GlobalValue *GV = MO.getGlobal();
 280     std::string Name = Mang->getMangledName(GV);
 281     decorateName(Name, GV);
 282
 283     // Handle dllimport linkage.
 284     // FIXME: This should be fixed with full support of stdcall & fastcall
 285     // CC's
 286     if (MO.getTargetFlags() == X86II::MO_DLLIMPORT)
 287       O << "__imp_";
 288     O << Name;
 289     printOffset(MO.getOffset());
 290     return;
 291   }
 292
 293   case MachineOperand::MO_ExternalSymbol:
 294     O << TAI->getGlobalPrefix() << MO.getSymbolName();
 295     return;
 296   }
 297 }
 298
 299
 300 void X86IntelAsmPrinter::printLeaMemReference(const MachineInstr *MI,
 301                                               unsigned Op,
 302                                               const char *Modifier) {
 303   const MachineOperand &BaseReg  = MI->getOperand(Op);
 304   int ScaleVal                   = MI->getOperand(Op+1).getImm();
 305   const MachineOperand &IndexReg = MI->getOperand(Op+2);
 306   const MachineOperand &DispSpec = MI->getOperand(Op+3);
 307
 308   O << "[";
 309   bool NeedPlus = false;
 310   if (BaseReg.getReg()) {
 311     printOp(BaseReg, Modifier);
 312     NeedPlus = true;
 313   }
 314
 315   if (IndexReg.getReg()) {
 316     if (NeedPlus) O << " + ";
 317     if (ScaleVal != 1)
 318       O << ScaleVal << "*";
 319     printOp(IndexReg, Modifier);
 320     NeedPlus = true;
 321   }
 322
 323   if (DispSpec.isGlobal() || DispSpec.isCPI() ||
 324       DispSpec.isJTI()) {
 325     if (NeedPlus)
 326       O << " + ";
 327     printOp(DispSpec, "mem");
 328   } else {
 329     int DispVal = DispSpec.getImm();
 330     if (DispVal || (!BaseReg.getReg() && !IndexReg.getReg())) {
 331       if (NeedPlus) {
 332         if (DispVal > 0)
 333           O << " + ";
 334         else {
 335           O << " - ";
 336           DispVal = -DispVal;
 337         }
 338       }
 339       O << DispVal;
 340     }
 341   }
 342   O << "]";
 343 }
 344
 345 void X86IntelAsmPrinter::printMemReference(const MachineInstr *MI, unsigned Op,
 346                                            const char *Modifier) {
 347   assert(isMem(MI, Op) && "Invalid memory reference!");
 348   MachineOperand Segment = MI->getOperand(Op+4);
 349   if (Segment.getReg()) {
 350       printOperand(MI, Op+4, Modifier);
 351       O << ':';
 352     }
 353   printLeaMemReference(MI, Op, Modifier);
 354 }
 355
 356 void X86IntelAsmPrinter::printPICJumpTableSetLabel(unsigned uid,
 357                                            const MachineBasicBlock *MBB) const {
 358   if (!TAI->getSetDirective())
 359     return;
 360
 361   O << TAI->getSetDirective() << ' ' << TAI->getPrivateGlobalPrefix()
 362     << getFunctionNumber() << '_' << uid << "_set_" << MBB->getNumber() << ',';
 363   printBasicBlockLabel(MBB, false, false, false);
 364   O << '-' << "\"L" << getFunctionNumber() << "$pb\"'\n";
 365 }
 366
 367 void X86IntelAsmPrinter::printPICLabel(const MachineInstr *MI, unsigned Op) {
 368   O << "L" << getFunctionNumber() << "$pb\n";
 369   O << "L" << getFunctionNumber() << "$pb:";
 370 }
 371
 372 bool X86IntelAsmPrinter::printAsmMRegister(const MachineOperand &MO,
 373                                            const char Mode) {
 374   unsigned Reg = MO.getReg();
 375   switch (Mode) {
 376   default: return true;  // Unknown mode.
 377   case 'b': // Print QImode register
 378     Reg = getX86SubSuperRegister(Reg, MVT::i8);
 379     break;
 380   case 'h': // Print QImode high register
 381     Reg = getX86SubSuperRegister(Reg, MVT::i8, true);
 382     break;
 383   case 'w': // Print HImode register
 384     Reg = getX86SubSuperRegister(Reg, MVT::i16);
 385     break;
 386   case 'k': // Print SImode register
 387     Reg = getX86SubSuperRegister(Reg, MVT::i32);
 388     break;
 389   }
 390
 391   O << TRI->getName(Reg);
 392   return false;
 393 }
 394
 395 /// PrintAsmOperand - Print out an operand for an inline asm expression.
 396 ///
 397 bool X86IntelAsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
 398                                          unsigned AsmVariant,
 399                                          const char *ExtraCode) {
 400   // Does this asm operand have a single letter operand modifier?
 401   if (ExtraCode && ExtraCode[0]) {
 402     if (ExtraCode[1] != 0) return true; // Unknown modifier.
 403
 404     switch (ExtraCode[0]) {
 405     default: return true;  // Unknown modifier.
 406     case 'b': // Print QImode register
 407     case 'h': // Print QImode high register
 408     case 'w': // Print HImode register
 409     case 'k': // Print SImode register
 410       return printAsmMRegister(MI->getOperand(OpNo), ExtraCode[0]);
 411     }
 412   }
 413
 414   printOperand(MI, OpNo);
 415   return false;
 416 }
 417
 418 bool X86IntelAsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI,
 419                                                unsigned OpNo,
 420                                                unsigned AsmVariant,
 421                                                const char *ExtraCode) {
 422   if (ExtraCode && ExtraCode[0])
 423     return true; // Unknown modifier.
 424   printMemReference(MI, OpNo);
 425   return false;
 426 }
 427
 428 /// printMachineInstruction -- Print out a single X86 LLVM instruction
 429 /// MI in Intel syntax to the current output stream.
 430 ///
 431 void X86IntelAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
 432   ++EmittedInsts;
 433
 434   // Call the autogenerated instruction printer routines.
 435   printInstruction(MI);
 436 }
 437
 438 bool X86IntelAsmPrinter::doInitialization(Module &M) {
 439   bool Result = AsmPrinter::doInitialization(M);
 440
 441   Mang->markCharUnacceptable('.');
 442
 443   O << "\t.686\n\t.MMX\n\t.XMM\n\t.model flat\n\n";
 444
 445   // Emit declarations for external functions.
 446   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
 447     if (I->isDeclaration()) {
 448       std::string Name = Mang->getMangledName(I);
 449       decorateName(Name, I);
 450
 451       O << "\tEXTERN " ;
 452       if (I->hasDLLImportLinkage()) {
 453         O << "__imp_";
 454       }
 455       O << Name << ":near\n";
 456     }
 457
 458   // Emit declarations for external globals.  Note that VC++ always declares
 459   // external globals to have type byte, and if that's good enough for VC++...
 460   for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
 461        I != E; ++I) {
 462     if (I->isDeclaration()) {
 463       std::string Name = Mang->getMangledName(I);
 464
 465       O << "\tEXTERN " ;
 466       if (I->hasDLLImportLinkage()) {
 467         O << "__imp_";
 468       }
 469       O << Name << ":byte\n";
 470     }
 471   }
 472
 473   return Result;
 474 }
 475
 476 bool X86IntelAsmPrinter::doFinalization(Module &M) {
 477   const TargetData *TD = TM.getTargetData();
 478
 479   // Print out module-level global variables here.
 480   for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
 481        I != E; ++I) {
 482     if (I->isDeclaration()) continue;   // External global require no code
 483
 484     // Check to see if this is a special global used by LLVM, if so, emit it.
 485     if (EmitSpecialLLVMGlobal(I))
 486       continue;
 487
 488     std::string name = Mang->getMangledName(I);
 489     Constant *C = I->getInitializer();
 490     unsigned Align = TD->getPreferredAlignmentLog(I);
 491     bool bCustomSegment = false;
 492
 493     switch (I->getLinkage()) {
 494     case GlobalValue::CommonLinkage:
 495     case GlobalValue::LinkOnceAnyLinkage:
 496     case GlobalValue::LinkOnceODRLinkage:
 497     case GlobalValue::WeakAnyLinkage:
 498     case GlobalValue::WeakODRLinkage:
 499       SwitchToDataSection("");
 500       O << name << "?\tSEGEMNT PARA common 'COMMON'\n";
 501       bCustomSegment = true;
 502       // FIXME: the default alignment is 16 bytes, but 1, 2, 4, and 256
 503       // are also available.
 504       break;
 505     case GlobalValue::AppendingLinkage:
 506       SwitchToDataSection("");
 507       O << name << "?\tSEGMENT PARA public 'DATA'\n";
 508       bCustomSegment = true;
 509       // FIXME: the default alignment is 16 bytes, but 1, 2, 4, and 256
 510       // are also available.
 511       break;
 512     case GlobalValue::DLLExportLinkage:
 513       DLLExportedGVs.insert(name);
 514       // FALL THROUGH
 515     case GlobalValue::ExternalLinkage:
 516       O << "\tpublic " << name << "\n";
 517       // FALL THROUGH
 518     case GlobalValue::InternalLinkage:
 519       SwitchToSection(TAI->getDataSection());
 520       break;
 521     default:
 522       llvm_unreachable("Unknown linkage type!");
 523     }
 524
 525     if (!bCustomSegment)
 526       EmitAlignment(Align, I);
 527
 528     O << name << ":";
 529     if (VerboseAsm)
 530       O << "\t\t\t\t" << TAI->getCommentString()
 531         << " " << I->getName();
 532     O << '\n';
 533
 534     EmitGlobalConstant(C);
 535
 536     if (bCustomSegment)
 537       O << name << "?\tends\n";
 538   }
 539
 540     // Output linker support code for dllexported globals
 541   if (!DLLExportedGVs.empty() || !DLLExportedFns.empty()) {
 542     SwitchToDataSection("");
 543     O << "; WARNING: The following code is valid only with MASM v8.x"
 544       << "and (possible) higher\n"
 545       << "; This version of MASM is usually shipped with Microsoft "
 546       << "Visual Studio 2005\n"
 547       << "; or (possible) further versions. Unfortunately, there is no "
 548       << "way to support\n"
 549       << "; dllexported symbols in the earlier versions of MASM in fully "
 550       << "automatic way\n\n";
 551     O << "_drectve\t segment info alias('.drectve')\n";
 552   }
 553
 554   for (StringSet<>::iterator i = DLLExportedGVs.begin(),
 555          e = DLLExportedGVs.end();
 556          i != e; ++i)
 557     O << "\t db ' /EXPORT:" << i->getKeyData() << ",data'\n";
 558
 559   for (StringSet<>::iterator i = DLLExportedFns.begin(),
 560          e = DLLExportedFns.end();
 561          i != e; ++i)
 562     O << "\t db ' /EXPORT:" << i->getKeyData() << "'\n";
 563
 564   if (!DLLExportedGVs.empty() || !DLLExportedFns.empty())
 565     O << "_drectve\t ends\n";
 566
 567   // Bypass X86SharedAsmPrinter::doFinalization().
 568   bool Result = AsmPrinter::doFinalization(M);
 569   SwitchToDataSection("");
 570   O << "\tend\n";
 571   return Result;
 572 }
 573
 574 void X86IntelAsmPrinter::EmitString(const ConstantArray *CVA) const {
 575   unsigned NumElts = CVA->getNumOperands();
 576   if (NumElts) {
 577     // ML does not have escape sequences except '' for '.  It also has a maximum
 578     // string length of 255.
 579     unsigned len = 0;
 580     bool inString = false;
 581     for (unsigned i = 0; i < NumElts; i++) {
 582       int n = cast<ConstantInt>(CVA->getOperand(i))->getZExtValue() & 255;
 583       if (len == 0)
 584         O << "\tdb ";
 585
 586       if (n >= 32 && n <= 127) {
 587         if (!inString) {
 588           if (len > 0) {
 589             O << ",'";
 590             len += 2;
 591           } else {
 592             O << "'";
 593             len++;
 594           }
 595           inString = true;
 596         }
 597         if (n == '\'') {
 598           O << "'";
 599           len++;
 600         }
 601         O << char(n);
 602       } else {
 603         if (inString) {
 604           O << "'";
 605           len++;
 606           inString = false;
 607         }
 608         if (len > 0) {
 609           O << ",";
 610           len++;
 611         }
 612         O << n;
 613         len += 1 + (n > 9) + (n > 99);
 614       }
 615
 616       if (len > 60) {
 617         if (inString) {
 618           O << "'";
 619           inString = false;
 620         }
 621         O << "\n";
 622         len = 0;
 623       }
 624     }
 625
 626     if (len > 0) {
 627       if (inString)
 628         O << "'";
 629       O << "\n";
 630     }
 631   }
 632 }
 633
 634 // Include the auto-generated portion of the assembly writer.
 635 #include "X86GenAsmWriter1.inc"