lib/Target/IA64/AsmPrinter/IA64AsmPrinter.cpp

   1 //===-- IA64AsmPrinter.cpp - Print out IA64 LLVM as 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 assembly accepted by the GNU binutils 'gas'
  12 // assembler. The Intel 'ias' and HP-UX 'as' assemblers *may* choke on this
  13 // output, but if so that's a bug I'd like to hear about: please file a bug
  14 // report in bugzilla. FYI, the not too bad 'ias' assembler is bundled with
  15 // the Intel C/C++ compiler for Itanium Linux.
  16 //
  17 //===----------------------------------------------------------------------===//
  18
  19 #define DEBUG_TYPE "asm-printer"
  20 #include "IA64.h"
  21 #include "IA64TargetMachine.h"
  22 #include "llvm/Module.h"
  23 #include "llvm/Type.h"
  24 #include "llvm/CodeGen/AsmPrinter.h"
  25 #include "llvm/CodeGen/DwarfWriter.h"
  26 #include "llvm/CodeGen/MachineFunctionPass.h"
  27 #include "llvm/Target/TargetAsmInfo.h"
  28 #include "llvm/Support/Mangler.h"
  29 #include "llvm/Support/raw_ostream.h"
  30 #include "llvm/ADT/Statistic.h"
  31 using namespace llvm;
  32
  33 STATISTIC(EmittedInsts, "Number of machine instrs printed");
  34
  35 namespace {
  36   class IA64AsmPrinter : public AsmPrinter {
  37     std::set<std::string> ExternalFunctionNames, ExternalObjectNames;
  38   public:
  39     explicit IA64AsmPrinter(raw_ostream &O, TargetMachine &TM,
  40                             const TargetAsmInfo *T, CodeGenOpt::Level OL,
  41                             bool V)
  42       : AsmPrinter(O, TM, T, OL, V) {}
  43
  44     virtual const char *getPassName() const {
  45       return "IA64 Assembly Printer";
  46     }
  47
  48     /// printInstruction - This method is automatically generated by tablegen
  49     /// from the instruction set description.  This method returns true if the
  50     /// machine instruction was sufficiently described to print it, otherwise it
  51     /// returns false.
  52     bool printInstruction(const MachineInstr *MI);
  53
  54     // This method is used by the tablegen'erated instruction printer.
  55     void printOperand(const MachineInstr *MI, unsigned OpNo){
  56       const MachineOperand &MO = MI->getOperand(OpNo);
  57       if (MO.getType() == MachineOperand::MO_Register) {
  58         assert(TargetRegisterInfo::isPhysicalRegister(MO.getReg()) &&
  59                "Not physref??");
  60         //XXX Bug Workaround: See note in Printer::doInitialization about %.
  61         O << TM.getRegisterInfo()->get(MO.getReg()).AsmName;
  62       } else {
  63         printOp(MO);
  64       }
  65     }
  66
  67     void printS8ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  68       int val=(unsigned int)MI->getOperand(OpNo).getImm();
  69       if(val>=128) val=val-256; // if negative, flip sign
  70       O << val;
  71     }
  72     void printS14ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  73       int val=(unsigned int)MI->getOperand(OpNo).getImm();
  74       if(val>=8192) val=val-16384; // if negative, flip sign
  75       O << val;
  76     }
  77     void printS22ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  78       int val=(unsigned int)MI->getOperand(OpNo).getImm();
  79       if(val>=2097152) val=val-4194304; // if negative, flip sign
  80       O << val;
  81     }
  82     void printU64ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  83       O << (uint64_t)MI->getOperand(OpNo).getImm();
  84     }
  85     void printS64ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  86 // XXX : nasty hack to avoid GPREL22 "relocation truncated to fit" linker
  87 // errors - instead of add rX = @gprel(CPI<whatever>), r1;; we now
  88 // emit movl rX = @gprel(CPI<whatever);;
  89 //      add  rX = rX, r1;
  90 // this gives us 64 bits instead of 22 (for the add long imm) to play
  91 // with, which shuts up the linker. The problem is that the constant
  92 // pool entries aren't immediates at this stage, so we check here.
  93 // If it's an immediate, print it the old fashioned way. If it's
  94 // not, we print it as a constant pool index.
  95       if (MI->getOperand(OpNo).isImm()) {
  96         O << (int64_t)MI->getOperand(OpNo).getImm();
  97       } else { // this is a constant pool reference: FIXME: assert this
  98         printOp(MI->getOperand(OpNo));
  99       }
 100     }
 101
 102     void printGlobalOperand(const MachineInstr *MI, unsigned OpNo) {
 103       printOp(MI->getOperand(OpNo), false); // this is NOT a br.call instruction
 104     }
 105
 106     void printCallOperand(const MachineInstr *MI, unsigned OpNo) {
 107       printOp(MI->getOperand(OpNo), true); // this is a br.call instruction
 108     }
 109
 110     void printMachineInstruction(const MachineInstr *MI);
 111     void printOp(const MachineOperand &MO, bool isBRCALLinsn= false);
 112     void printModuleLevelGV(const GlobalVariable* GVar);
 113     bool runOnMachineFunction(MachineFunction &F);
 114     bool doInitialization(Module &M);
 115     bool doFinalization(Module &M);
 116   };
 117 } // end of anonymous namespace
 118
 119
 120 // Include the auto-generated portion of the assembly writer.
 121 #include "IA64GenAsmWriter.inc"
 122
 123 /// runOnMachineFunction - This uses the printMachineInstruction()
 124 /// method to print assembly for each instruction.
 125 ///
 126 bool IA64AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
 127   this->MF = &MF;
 128
 129   SetupMachineFunction(MF);
 130   O << "\n\n";
 131
 132   // Print out constants referenced by the function
 133   EmitConstantPool(MF.getConstantPool());
 134
 135   const Function *F = MF.getFunction();
 136   SwitchToSection(TAI->SectionForGlobal(F));
 137
 138   // Print out labels for the function.
 139   EmitAlignment(5);
 140   O << "\t.global\t" << CurrentFnName << '\n';
 141
 142   printVisibility(CurrentFnName, F->getVisibility());
 143
 144   O << "\t.type\t" << CurrentFnName << ", @function\n";
 145   O << CurrentFnName << ":\n";
 146
 147   // Print out code for the function.
 148   for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
 149        I != E; ++I) {
 150     // Print a label for the basic block if there are any predecessors.
 151     if (!I->pred_empty()) {
 152       printBasicBlockLabel(I, true, true);
 153       O << '\n';
 154     }
 155     for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
 156          II != E; ++II) {
 157       // Print the assembly for the instruction.
 158       printMachineInstruction(II);
 159     }
 160   }
 161
 162   // We didn't modify anything.
 163   return false;
 164 }
 165
 166 void IA64AsmPrinter::printOp(const MachineOperand &MO,
 167                              bool isBRCALLinsn /* = false */) {
 168   const TargetRegisterInfo &RI = *TM.getRegisterInfo();
 169   switch (MO.getType()) {
 170   case MachineOperand::MO_Register:
 171     O << RI.get(MO.getReg()).AsmName;
 172     return;
 173
 174   case MachineOperand::MO_Immediate:
 175     O << MO.getImm();
 176     return;
 177   case MachineOperand::MO_MachineBasicBlock:
 178     printBasicBlockLabel(MO.getMBB());
 179     return;
 180   case MachineOperand::MO_ConstantPoolIndex: {
 181     O << "@gprel(" << TAI->getPrivateGlobalPrefix()
 182       << "CPI" << getFunctionNumber() << "_" << MO.getIndex() << ")";
 183     return;
 184   }
 185
 186   case MachineOperand::MO_GlobalAddress: {
 187
 188     // functions need @ltoff(@fptr(fn_name)) form
 189     GlobalValue *GV = MO.getGlobal();
 190     Function *F = dyn_cast<Function>(GV);
 191
 192     bool Needfptr=false; // if we're computing an address @ltoff(X), do
 193                          // we need to decorate it so it becomes
 194                          // @ltoff(@fptr(X)) ?
 195     if (F && !isBRCALLinsn /*&& F->isDeclaration()*/)
 196       Needfptr=true;
 197
 198     // if this is the target of a call instruction, we should define
 199     // the function somewhere (GNU gas has no problem without this, but
 200     // Intel ias rightly complains of an 'undefined symbol')
 201
 202     if (F /*&& isBRCALLinsn*/ && F->isDeclaration())
 203       ExternalFunctionNames.insert(Mang->getValueName(MO.getGlobal()));
 204     else
 205       if (GV->isDeclaration()) // e.g. stuff like 'stdin'
 206         ExternalObjectNames.insert(Mang->getValueName(MO.getGlobal()));
 207
 208     if (!isBRCALLinsn)
 209       O << "@ltoff(";
 210     if (Needfptr)
 211       O << "@fptr(";
 212     O << Mang->getValueName(MO.getGlobal());
 213
 214     if (Needfptr && !isBRCALLinsn)
 215       O << "#))"; // close both fptr( and ltoff(
 216     else {
 217       if (Needfptr)
 218         O << "#)"; // close only fptr(
 219       if (!isBRCALLinsn)
 220         O << "#)"; // close only ltoff(
 221     }
 222
 223     int Offset = MO.getOffset();
 224     if (Offset > 0)
 225       O << " + " << Offset;
 226     else if (Offset < 0)
 227       O << " - " << -Offset;
 228     return;
 229   }
 230   case MachineOperand::MO_ExternalSymbol:
 231     O << MO.getSymbolName();
 232     ExternalFunctionNames.insert(MO.getSymbolName());
 233     return;
 234   default:
 235     O << "<AsmPrinter: unknown operand type: " << MO.getType() << " >"; return;
 236   }
 237 }
 238
 239 /// printMachineInstruction -- Print out a single IA64 LLVM instruction
 240 /// MI to the current output stream.
 241 ///
 242 void IA64AsmPrinter::printMachineInstruction(const MachineInstr *MI) {
 243   ++EmittedInsts;
 244
 245   // Call the autogenerated instruction printer routines.
 246   printInstruction(MI);
 247 }
 248
 249 bool IA64AsmPrinter::doInitialization(Module &M) {
 250   bool Result = AsmPrinter::doInitialization(M);
 251
 252   O << "\n.ident \"LLVM-ia64\"\n\n"
 253     << "\t.psr    lsb\n"  // should be "msb" on HP-UX, for starters
 254     << "\t.radix  C\n"
 255     << "\t.psr    abi64\n"; // we only support 64 bits for now
 256   return Result;
 257 }
 258
 259 void IA64AsmPrinter::printModuleLevelGV(const GlobalVariable* GVar) {
 260   const TargetData *TD = TM.getTargetData();
 261
 262   if (!GVar->hasInitializer())
 263     return; // External global require no code
 264
 265   // Check to see if this is a special global used by LLVM, if so, emit it.
 266   if (EmitSpecialLLVMGlobal(GVar))
 267     return;
 268
 269   O << "\n\n";
 270   std::string name = Mang->getValueName(GVar);
 271   Constant *C = GVar->getInitializer();
 272   unsigned Size = TD->getTypeAllocSize(C->getType());
 273   unsigned Align = TD->getPreferredAlignmentLog(GVar);
 274
 275   printVisibility(name, GVar->getVisibility());
 276
 277   SwitchToSection(TAI->SectionForGlobal(GVar));
 278
 279   if (C->isNullValue() && !GVar->hasSection()) {
 280     if (!GVar->isThreadLocal() &&
 281         (GVar->hasLocalLinkage() || GVar->isWeakForLinker())) {
 282       if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
 283
 284       if (GVar->hasLocalLinkage()) {
 285         O << "\t.lcomm " << name << "#," << Size
 286           << ',' << (1 << Align);
 287         O << '\n';
 288       } else {
 289         O << "\t.common " << name << "#," << Size
 290           << ',' << (1 << Align);
 291         O << '\n';
 292       }
 293
 294       return;
 295     }
 296   }
 297
 298   switch (GVar->getLinkage()) {
 299    case GlobalValue::LinkOnceAnyLinkage:
 300    case GlobalValue::LinkOnceODRLinkage:
 301    case GlobalValue::CommonLinkage:
 302    case GlobalValue::WeakAnyLinkage:
 303    case GlobalValue::WeakODRLinkage:
 304     // Nonnull linkonce -> weak
 305     O << "\t.weak " << name << '\n';
 306     break;
 307    case GlobalValue::AppendingLinkage:
 308     // FIXME: appending linkage variables should go into a section of
 309     // their name or something.  For now, just emit them as external.
 310    case GlobalValue::ExternalLinkage:
 311     // If external or appending, declare as a global symbol
 312     O << TAI->getGlobalDirective() << name << '\n';
 313     // FALL THROUGH
 314    case GlobalValue::InternalLinkage:
 315    case GlobalValue::PrivateLinkage:
 316     break;
 317    case GlobalValue::GhostLinkage:
 318     cerr << "GhostLinkage cannot appear in IA64AsmPrinter!\n";
 319     abort();
 320    case GlobalValue::DLLImportLinkage:
 321     cerr << "DLLImport linkage is not supported by this target!\n";
 322     abort();
 323    case GlobalValue::DLLExportLinkage:
 324     cerr << "DLLExport linkage is not supported by this target!\n";
 325     abort();
 326    default:
 327     assert(0 && "Unknown linkage type!");
 328   }
 329
 330   EmitAlignment(Align, GVar);
 331
 332   if (TAI->hasDotTypeDotSizeDirective()) {
 333     O << "\t.type " << name << ",@object\n";
 334     O << "\t.size " << name << ',' << Size << '\n';
 335   }
 336
 337   O << name << ":\n";
 338   EmitGlobalConstant(C);
 339 }
 340
 341
 342 bool IA64AsmPrinter::doFinalization(Module &M) {
 343   // Print out module-level global variables here.
 344   for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
 345        I != E; ++I)
 346     printModuleLevelGV(I);
 347
 348   // we print out ".global X \n .type X, @function" for each external function
 349   O << "\n\n// br.call targets referenced (and not defined) above: \n";
 350   for (std::set<std::string>::iterator i = ExternalFunctionNames.begin(),
 351        e = ExternalFunctionNames.end(); i!=e; ++i) {
 352     O << "\t.global " << *i << "\n\t.type " << *i << ", @function\n";
 353   }
 354   O << "\n\n";
 355
 356   // we print out ".global X \n .type X, @object" for each external object
 357   O << "\n\n// (external) symbols referenced (and not defined) above: \n";
 358   for (std::set<std::string>::iterator i = ExternalObjectNames.begin(),
 359        e = ExternalObjectNames.end(); i!=e; ++i) {
 360     O << "\t.global " << *i << "\n\t.type " << *i << ", @object\n";
 361   }
 362   O << "\n\n";
 363
 364   return AsmPrinter::doFinalization(M);
 365 }
 366
 367 /// createIA64CodePrinterPass - Returns a pass that prints the IA64
 368 /// assembly code for a MachineFunction to the given output stream, using
 369 /// the given target machine description.
 370 ///
 371 FunctionPass *llvm::createIA64CodePrinterPass(raw_ostream &o,
 372                                               IA64TargetMachine &tm,
 373                                               CodeGenOpt::Level OptLevel,
 374                                               bool verbose) {
 375   return new IA64AsmPrinter(o, tm, tm.getTargetAsmInfo(), OptLevel, verbose);
 376 }