lib/Target/SystemZ/AsmPrinter/SystemZAsmPrinter.cpp

   1 //===-- SystemZAsmPrinter.cpp - SystemZ LLVM assembly writer ---------------===//
   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 the SystemZ assembly language.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #define DEBUG_TYPE "asm-printer"
  16 #include "SystemZ.h"
  17 #include "SystemZInstrInfo.h"
  18 #include "SystemZTargetMachine.h"
  19 #include "llvm/Constants.h"
  20 #include "llvm/DerivedTypes.h"
  21 #include "llvm/Module.h"
  22 #include "llvm/CodeGen/AsmPrinter.h"
  23 #include "llvm/CodeGen/DwarfWriter.h"
  24 #include "llvm/CodeGen/MachineModuleInfo.h"
  25 #include "llvm/CodeGen/MachineFunctionPass.h"
  26 #include "llvm/CodeGen/MachineConstantPool.h"
  27 #include "llvm/CodeGen/MachineInstr.h"
  28 #include "llvm/Target/TargetAsmInfo.h"
  29 #include "llvm/Target/TargetData.h"
  30 #include "llvm/Target/TargetRegistry.h"
  31 #include "llvm/ADT/Statistic.h"
  32 #include "llvm/Support/Compiler.h"
  33 #include "llvm/Support/FormattedStream.h"
  34 #include "llvm/Support/Mangler.h"
  35
  36 using namespace llvm;
  37
  38 STATISTIC(EmittedInsts, "Number of machine instrs printed");
  39
  40 namespace {
  41   class VISIBILITY_HIDDEN SystemZAsmPrinter : public AsmPrinter {
  42   public:
  43     SystemZAsmPrinter(formatted_raw_ostream &O, TargetMachine &TM,
  44                       const TargetAsmInfo *TAI, bool V)
  45       : AsmPrinter(O, TM, TAI, V) {}
  46
  47     virtual const char *getPassName() const {
  48       return "SystemZ Assembly Printer";
  49     }
  50
  51     void printOperand(const MachineInstr *MI, int OpNum,
  52                       const char* Modifier = 0);
  53     void printPCRelImmOperand(const MachineInstr *MI, int OpNum);
  54     void printRIAddrOperand(const MachineInstr *MI, int OpNum,
  55                             const char* Modifier = 0);
  56     void printRRIAddrOperand(const MachineInstr *MI, int OpNum,
  57                              const char* Modifier = 0);
  58     void printS16ImmOperand(const MachineInstr *MI, int OpNum) {
  59       O << (int16_t)MI->getOperand(OpNum).getImm();
  60     }
  61     void printS32ImmOperand(const MachineInstr *MI, int OpNum) {
  62       O << (int32_t)MI->getOperand(OpNum).getImm();
  63     }
  64
  65     bool printInstruction(const MachineInstr *MI);  // autogenerated.
  66     void printMachineInstruction(const MachineInstr * MI);
  67
  68     void emitFunctionHeader(const MachineFunction &MF);
  69     bool runOnMachineFunction(MachineFunction &F);
  70     bool doInitialization(Module &M);
  71     bool doFinalization(Module &M);
  72     void printModuleLevelGV(const GlobalVariable* GVar);
  73
  74     void getAnalysisUsage(AnalysisUsage &AU) const {
  75       AsmPrinter::getAnalysisUsage(AU);
  76       AU.setPreservesAll();
  77     }
  78   };
  79 } // end of anonymous namespace
  80
  81 #include "SystemZGenAsmWriter.inc"
  82
  83 /// createSystemZCodePrinterPass - Returns a pass that prints the SystemZ
  84 /// assembly code for a MachineFunction to the given output stream,
  85 /// using the given target machine description.  This should work
  86 /// regardless of whether the function is in SSA form.
  87 ///
  88 FunctionPass *llvm::createSystemZCodePrinterPass(formatted_raw_ostream &o,
  89                                                  TargetMachine &tm,
  90                                                  bool verbose) {
  91   return new SystemZAsmPrinter(o, tm, tm.getTargetAsmInfo(), verbose);
  92 }
  93
  94 bool SystemZAsmPrinter::doInitialization(Module &M) {
  95   Mang = new Mangler(M, "", TAI->getPrivateGlobalPrefix());
  96   return false; // success
  97 }
  98
  99
 100 bool SystemZAsmPrinter::doFinalization(Module &M) {
 101   // Print out module-level global variables here.
 102   for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
 103        I != E; ++I)
 104     printModuleLevelGV(I);
 105
 106   return AsmPrinter::doFinalization(M);
 107 }
 108
 109 void SystemZAsmPrinter::emitFunctionHeader(const MachineFunction &MF) {
 110   unsigned FnAlign = MF.getAlignment();
 111   const Function *F = MF.getFunction();
 112
 113   SwitchToSection(TAI->SectionForGlobal(F));
 114
 115   EmitAlignment(FnAlign, F);
 116
 117   switch (F->getLinkage()) {
 118   default: assert(0 && "Unknown linkage type!");
 119   case Function::InternalLinkage:  // Symbols default to internal.
 120   case Function::PrivateLinkage:
 121     break;
 122   case Function::ExternalLinkage:
 123     O << "\t.globl\t" << CurrentFnName << '\n';
 124     break;
 125   case Function::LinkOnceAnyLinkage:
 126   case Function::LinkOnceODRLinkage:
 127   case Function::WeakAnyLinkage:
 128   case Function::WeakODRLinkage:
 129     O << "\t.weak\t" << CurrentFnName << '\n';
 130     break;
 131   }
 132
 133   printVisibility(CurrentFnName, F->getVisibility());
 134
 135   O << "\t.type\t" << CurrentFnName << ",@function\n"
 136     << CurrentFnName << ":\n";
 137 }
 138
 139 bool SystemZAsmPrinter::runOnMachineFunction(MachineFunction &MF) {
 140   SetupMachineFunction(MF);
 141   O << "\n\n";
 142
 143   // Print out constants referenced by the function
 144   EmitConstantPool(MF.getConstantPool());
 145
 146   // Print the 'header' of function
 147   emitFunctionHeader(MF);
 148
 149   // Print out code for the function.
 150   for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
 151        I != E; ++I) {
 152     // Print a label for the basic block.
 153     if (!VerboseAsm && (I->pred_empty() || I->isOnlyReachableByFallthrough())) {
 154       // This is an entry block or a block that's only reachable via a
 155       // fallthrough edge. In non-VerboseAsm mode, don't print the label.
 156     } else {
 157       printBasicBlockLabel(I, true, true, VerboseAsm);
 158       O << '\n';
 159     }
 160
 161     for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
 162          II != E; ++II)
 163       // Print the assembly for the instruction.
 164       printMachineInstruction(II);
 165   }
 166
 167   if (TAI->hasDotTypeDotSizeDirective())
 168     O << "\t.size\t" << CurrentFnName << ", .-" << CurrentFnName << '\n';
 169
 170   // Print out jump tables referenced by the function.
 171   EmitJumpTableInfo(MF.getJumpTableInfo(), MF);
 172
 173   O.flush();
 174
 175   // We didn't modify anything
 176   return false;
 177 }
 178
 179 void SystemZAsmPrinter::printMachineInstruction(const MachineInstr *MI) {
 180   ++EmittedInsts;
 181
 182   // Call the autogenerated instruction printer routines.
 183   if (printInstruction(MI))
 184     return;
 185
 186   assert(0 && "Should not happen");
 187 }
 188
 189 void SystemZAsmPrinter::printPCRelImmOperand(const MachineInstr *MI, int OpNum) {
 190   const MachineOperand &MO = MI->getOperand(OpNum);
 191   switch (MO.getType()) {
 192   case MachineOperand::MO_Immediate:
 193     O << MO.getImm();
 194     return;
 195   case MachineOperand::MO_MachineBasicBlock:
 196     printBasicBlockLabel(MO.getMBB(), false, false, VerboseAsm);
 197     return;
 198   case MachineOperand::MO_GlobalAddress: {
 199     const GlobalValue *GV = MO.getGlobal();
 200     std::string Name = Mang->getMangledName(GV);
 201
 202     O << Name;
 203
 204     // Assemble calls via PLT for externally visible symbols if PIC.
 205     if (TM.getRelocationModel() == Reloc::PIC_ &&
 206         !GV->hasHiddenVisibility() && !GV->hasProtectedVisibility() &&
 207         !GV->hasLocalLinkage())
 208       O << "@PLT";
 209
 210     printOffset(MO.getOffset());
 211     return;
 212   }
 213   case MachineOperand::MO_ExternalSymbol: {
 214     std::string Name(TAI->getGlobalPrefix());
 215     Name += MO.getSymbolName();
 216     O << Name;
 217
 218     if (TM.getRelocationModel() == Reloc::PIC_)
 219       O << "@PLT";
 220
 221     return;
 222   }
 223   default:
 224     assert(0 && "Not implemented yet!");
 225   }
 226 }
 227
 228
 229 void SystemZAsmPrinter::printOperand(const MachineInstr *MI, int OpNum,
 230                                      const char* Modifier) {
 231   const MachineOperand &MO = MI->getOperand(OpNum);
 232   switch (MO.getType()) {
 233   case MachineOperand::MO_Register: {
 234     assert (TargetRegisterInfo::isPhysicalRegister(MO.getReg()) &&
 235             "Virtual registers should be already mapped!");
 236     unsigned Reg = MO.getReg();
 237     if (Modifier && strncmp(Modifier, "subreg", 6) == 0) {
 238       if (strncmp(Modifier + 7, "even", 4) == 0)
 239         Reg = TRI->getSubReg(Reg, SystemZ::SUBREG_EVEN);
 240       else if (strncmp(Modifier + 7, "odd", 3) == 0)
 241         Reg = TRI->getSubReg(Reg, SystemZ::SUBREG_ODD);
 242       else
 243         assert(0 && "Invalid subreg modifier");
 244     }
 245
 246     O << '%' << TRI->getAsmName(Reg);
 247     return;
 248   }
 249   case MachineOperand::MO_Immediate:
 250     O << MO.getImm();
 251     return;
 252   case MachineOperand::MO_MachineBasicBlock:
 253     printBasicBlockLabel(MO.getMBB());
 254     return;
 255   case MachineOperand::MO_JumpTableIndex:
 256     O << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber() << '_'
 257       << MO.getIndex();
 258
 259     return;
 260   case MachineOperand::MO_ConstantPoolIndex:
 261     O << TAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << '_'
 262       << MO.getIndex();
 263
 264     printOffset(MO.getOffset());
 265     break;
 266   case MachineOperand::MO_GlobalAddress: {
 267     const GlobalValue *GV = MO.getGlobal();
 268     std::string Name = Mang->getMangledName(GV);
 269
 270     O << Name;
 271     break;
 272   }
 273   case MachineOperand::MO_ExternalSymbol: {
 274     std::string Name(TAI->getGlobalPrefix());
 275     Name += MO.getSymbolName();
 276     O << Name;
 277     break;
 278   }
 279   default:
 280     assert(0 && "Not implemented yet!");
 281   }
 282
 283   switch (MO.getTargetFlags()) {
 284   default:
 285     assert(0 && "Unknown target flag on GV operand");
 286   case SystemZII::MO_NO_FLAG:
 287     break;
 288   case SystemZII::MO_GOTENT:    O << "@GOTENT";    break;
 289   case SystemZII::MO_PLT:       O << "@PLT";       break;
 290   }
 291
 292   printOffset(MO.getOffset());
 293 }
 294
 295 void SystemZAsmPrinter::printRIAddrOperand(const MachineInstr *MI, int OpNum,
 296                                            const char* Modifier) {
 297   const MachineOperand &Base = MI->getOperand(OpNum);
 298
 299   // Print displacement operand.
 300   printOperand(MI, OpNum+1);
 301
 302   // Print base operand (if any)
 303   if (Base.getReg()) {
 304     O << '(';
 305     printOperand(MI, OpNum);
 306     O << ')';
 307   }
 308 }
 309
 310 void SystemZAsmPrinter::printRRIAddrOperand(const MachineInstr *MI, int OpNum,
 311                                             const char* Modifier) {
 312   const MachineOperand &Base = MI->getOperand(OpNum);
 313   const MachineOperand &Index = MI->getOperand(OpNum+2);
 314
 315   // Print displacement operand.
 316   printOperand(MI, OpNum+1);
 317
 318   // Print base operand (if any)
 319   if (Base.getReg()) {
 320     O << '(';
 321     printOperand(MI, OpNum);
 322     if (Index.getReg()) {
 323       O << ',';
 324       printOperand(MI, OpNum+2);
 325     }
 326     O << ')';
 327   } else
 328     assert(!Index.getReg() && "Should allocate base register first!");
 329 }
 330
 331 /// PrintUnmangledNameSafely - Print out the printable characters in the name.
 332 /// Don't print things like \\n or \\0.
 333 static void PrintUnmangledNameSafely(const Value *V, formatted_raw_ostream &OS) {
 334   for (const char *Name = V->getNameStart(), *E = Name+V->getNameLen();
 335        Name != E; ++Name)
 336     if (isprint(*Name))
 337       OS << *Name;
 338 }
 339
 340 void SystemZAsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
 341   const TargetData *TD = TM.getTargetData();
 342
 343   if (!GVar->hasInitializer())
 344     return;   // External global require no code
 345
 346   // Check to see if this is a special global used by LLVM, if so, emit it.
 347   if (EmitSpecialLLVMGlobal(GVar))
 348     return;
 349
 350   std::string name = Mang->getMangledName(GVar);
 351   Constant *C = GVar->getInitializer();
 352   unsigned Size = TD->getTypeAllocSize(C->getType());
 353   unsigned Align = std::max(1U, TD->getPreferredAlignmentLog(GVar));
 354
 355   printVisibility(name, GVar->getVisibility());
 356
 357   O << "\t.type\t" << name << ",@object\n";
 358
 359   SwitchToSection(TAI->SectionForGlobal(GVar));
 360
 361   if (C->isNullValue() && !GVar->hasSection() &&
 362       !GVar->isThreadLocal() &&
 363       (GVar->hasLocalLinkage() || GVar->isWeakForLinker())) {
 364
 365     if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
 366
 367     if (GVar->hasLocalLinkage())
 368       O << "\t.local\t" << name << '\n';
 369
 370     O << TAI->getCOMMDirective()  << name << ',' << Size;
 371     if (TAI->getCOMMDirectiveTakesAlignment())
 372       O << ',' << (TAI->getAlignmentIsInBytes() ? (1 << Align) : Align);
 373
 374     if (VerboseAsm) {
 375       O << "\t\t" << TAI->getCommentString() << ' ';
 376       PrintUnmangledNameSafely(GVar, O);
 377     }
 378     O << '\n';
 379     return;
 380   }
 381
 382   switch (GVar->getLinkage()) {
 383   case GlobalValue::CommonLinkage:
 384   case GlobalValue::LinkOnceAnyLinkage:
 385   case GlobalValue::LinkOnceODRLinkage:
 386   case GlobalValue::WeakAnyLinkage:
 387   case GlobalValue::WeakODRLinkage:
 388     O << "\t.weak\t" << name << '\n';
 389     break;
 390   case GlobalValue::DLLExportLinkage:
 391   case GlobalValue::AppendingLinkage:
 392     // FIXME: appending linkage variables should go into a section of
 393     // their name or something.  For now, just emit them as external.
 394   case GlobalValue::ExternalLinkage:
 395     // If external or appending, declare as a global symbol
 396     O << "\t.globl " << name << '\n';
 397     // FALL THROUGH
 398   case GlobalValue::PrivateLinkage:
 399   case GlobalValue::InternalLinkage:
 400      break;
 401   default:
 402     assert(0 && "Unknown linkage type!");
 403   }
 404
 405   // Use 16-bit alignment by default to simplify bunch of stuff
 406   EmitAlignment(Align, GVar, 1);
 407   O << name << ":";
 408   if (VerboseAsm) {
 409     O << "\t\t\t\t" << TAI->getCommentString() << ' ';
 410     PrintUnmangledNameSafely(GVar, O);
 411   }
 412   O << '\n';
 413   if (TAI->hasDotTypeDotSizeDirective())
 414     O << "\t.size\t" << name << ", " << Size << '\n';
 415
 416   EmitGlobalConstant(C);
 417 }
 418
 419 // Force static initialization.
 420 extern "C" void LLVMInitializeSystemZAsmPrinter() {
 421   extern Target TheSystemZTarget;
 422   TargetRegistry::RegisterAsmPrinter(TheSystemZTarget,
 423                                      createSystemZCodePrinterPass);
 424 }