lib/Target/IA64/IA64AsmPrinter.cpp

   1 //===-- IA64AsmPrinter.cpp - Print out IA64 LLVM as assembly --------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file was developed by Duraid Madina and is distributed under the
   6 // 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 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/MachineFunctionPass.h"
  26 #include "llvm/Target/TargetAsmInfo.h"
  27 #include "llvm/Target/TargetMachine.h"
  28 #include "llvm/Support/Mangler.h"
  29 #include "llvm/ADT/Statistic.h"
  30 using namespace llvm;
  31
  32 STATISTIC(EmittedInsts, "Number of machine instrs printed");
  33
  34 namespace {
  35   struct IA64AsmPrinter : public AsmPrinter {
  36     std::set<std::string> ExternalFunctionNames, ExternalObjectNames;
  37
  38     IA64AsmPrinter(std::ostream &O, TargetMachine &TM, const TargetAsmInfo *T)
  39       : AsmPrinter(O, TM, T) {
  40     }
  41
  42     virtual const char *getPassName() const {
  43       return "IA64 Assembly Printer";
  44     }
  45
  46     /// printInstruction - This method is automatically generated by tablegen
  47     /// from the instruction set description.  This method returns true if the
  48     /// machine instruction was sufficiently described to print it, otherwise it
  49     /// returns false.
  50     bool printInstruction(const MachineInstr *MI);
  51
  52     // This method is used by the tablegen'erated instruction printer.
  53     void printOperand(const MachineInstr *MI, unsigned OpNo){
  54       const MachineOperand &MO = MI->getOperand(OpNo);
  55       if (MO.getType() == MachineOperand::MO_Register) {
  56         assert(MRegisterInfo::isPhysicalRegister(MO.getReg())&&"Not physref??");
  57         //XXX Bug Workaround: See note in Printer::doInitialization about %.
  58         O << TM.getRegisterInfo()->get(MO.getReg()).Name;
  59       } else {
  60         printOp(MO);
  61       }
  62     }
  63
  64     void printS8ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  65       int val=(unsigned int)MI->getOperand(OpNo).getImmedValue();
  66       if(val>=128) val=val-256; // if negative, flip sign
  67       O << val;
  68     }
  69     void printS14ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  70       int val=(unsigned int)MI->getOperand(OpNo).getImmedValue();
  71       if(val>=8192) val=val-16384; // if negative, flip sign
  72       O << val;
  73     }
  74     void printS22ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  75       int val=(unsigned int)MI->getOperand(OpNo).getImmedValue();
  76       if(val>=2097152) val=val-4194304; // if negative, flip sign
  77       O << val;
  78     }
  79     void printU64ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  80       O << (uint64_t)MI->getOperand(OpNo).getImmedValue();
  81     }
  82     void printS64ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  83 // XXX : nasty hack to avoid GPREL22 "relocation truncated to fit" linker
  84 // errors - instead of add rX = @gprel(CPI<whatever>), r1;; we now
  85 // emit movl rX = @gprel(CPI<whatever);;
  86 //      add  rX = rX, r1;
  87 // this gives us 64 bits instead of 22 (for the add long imm) to play
  88 // with, which shuts up the linker. The problem is that the constant
  89 // pool entries aren't immediates at this stage, so we check here.
  90 // If it's an immediate, print it the old fashioned way. If it's
  91 // not, we print it as a constant pool index.
  92       if(MI->getOperand(OpNo).isImmediate()) {
  93         O << (int64_t)MI->getOperand(OpNo).getImmedValue();
  94       } else { // this is a constant pool reference: FIXME: assert this
  95         printOp(MI->getOperand(OpNo));
  96       }
  97     }
  98
  99     void printGlobalOperand(const MachineInstr *MI, unsigned OpNo) {
 100       printOp(MI->getOperand(OpNo), false); // this is NOT a br.call instruction
 101     }
 102
 103     void printCallOperand(const MachineInstr *MI, unsigned OpNo) {
 104       printOp(MI->getOperand(OpNo), true); // this is a br.call instruction
 105     }
 106
 107     std::string getSectionForFunction(const Function &F) const;
 108
 109     void printMachineInstruction(const MachineInstr *MI);
 110     void printOp(const MachineOperand &MO, bool isBRCALLinsn= false);
 111     bool runOnMachineFunction(MachineFunction &F);
 112     bool doInitialization(Module &M);
 113     bool doFinalization(Module &M);
 114   };
 115 } // end of anonymous namespace
 116
 117
 118 // Include the auto-generated portion of the assembly writer.
 119 #include "IA64GenAsmWriter.inc"
 120
 121
 122 std::string IA64AsmPrinter::getSectionForFunction(const Function &F) const {
 123   // This means "Allocated instruXions in mem, initialized".
 124   return "\n\t.section .text, \"ax\", \"progbits\"\n";
 125 }
 126
 127 /// runOnMachineFunction - This uses the printMachineInstruction()
 128 /// method to print assembly for each instruction.
 129 ///
 130 bool IA64AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
 131   SetupMachineFunction(MF);
 132   O << "\n\n";
 133
 134   // Print out constants referenced by the function
 135   EmitConstantPool(MF.getConstantPool());
 136
 137   const Function *F = MF.getFunction();
 138   SwitchToTextSection(getSectionForFunction(*F).c_str(), F);
 139
 140   // Print out labels for the function.
 141   EmitAlignment(5);
 142   O << "\t.global\t" << CurrentFnName << "\n";
 143   O << "\t.type\t" << CurrentFnName << ", @function\n";
 144   O << CurrentFnName << ":\n";
 145
 146   // Print out code for the function.
 147   for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
 148        I != E; ++I) {
 149     // Print a label for the basic block if there are any predecessors.
 150     if (I->pred_begin() != I->pred_end()) {
 151       printBasicBlockLabel(I, true);
 152       O << '\n';
 153     }
 154     for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
 155          II != E; ++II) {
 156       // Print the assembly for the instruction.
 157       O << "\t";
 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 MRegisterInfo &RI = *TM.getRegisterInfo();
 169   switch (MO.getType()) {
 170   case MachineOperand::MO_Register:
 171     O << RI.get(MO.getReg()).Name;
 172     return;
 173
 174   case MachineOperand::MO_Immediate:
 175     O << MO.getImmedValue();
 176     return;
 177   case MachineOperand::MO_MachineBasicBlock:
 178     printBasicBlockLabel(MO.getMachineBasicBlock());
 179     return;
 180   case MachineOperand::MO_ConstantPoolIndex: {
 181     O << "@gprel(" << TAI->getPrivateGlobalPrefix()
 182       << "CPI" << getFunctionNumber() << "_"
 183       << MO.getConstantPoolIndex() << ")";
 184     return;
 185   }
 186
 187   case MachineOperand::MO_GlobalAddress: {
 188
 189     // functions need @ltoff(@fptr(fn_name)) form
 190     GlobalValue *GV = MO.getGlobal();
 191     Function *F = dyn_cast<Function>(GV);
 192
 193     bool Needfptr=false; // if we're computing an address @ltoff(X), do
 194                          // we need to decorate it so it becomes
 195                          // @ltoff(@fptr(X)) ?
 196     if (F && !isBRCALLinsn /*&& F->isDeclaration()*/)
 197       Needfptr=true;
 198
 199     // if this is the target of a call instruction, we should define
 200     // the function somewhere (GNU gas has no problem without this, but
 201     // Intel ias rightly complains of an 'undefined symbol')
 202
 203     if (F /*&& isBRCALLinsn*/ && F->isDeclaration())
 204       ExternalFunctionNames.insert(Mang->getValueName(MO.getGlobal()));
 205     else
 206       if (GV->isDeclaration()) // e.g. stuff like 'stdin'
 207         ExternalObjectNames.insert(Mang->getValueName(MO.getGlobal()));
 208
 209     if (!isBRCALLinsn)
 210       O << "@ltoff(";
 211     if (Needfptr)
 212       O << "@fptr(";
 213     O << Mang->getValueName(MO.getGlobal());
 214
 215     if (Needfptr && !isBRCALLinsn)
 216       O << "#))"; // close both fptr( and ltoff(
 217     else {
 218       if (Needfptr)
 219         O << "#)"; // close only fptr(
 220       if (!isBRCALLinsn)
 221         O << "#)"; // close only ltoff(
 222     }
 223
 224     int Offset = MO.getOffset();
 225     if (Offset > 0)
 226       O << " + " << Offset;
 227     else if (Offset < 0)
 228       O << " - " << -Offset;
 229     return;
 230   }
 231   case MachineOperand::MO_ExternalSymbol:
 232     O << MO.getSymbolName();
 233     ExternalFunctionNames.insert(MO.getSymbolName());
 234     return;
 235   default:
 236     O << "<AsmPrinter: unknown operand type: " << MO.getType() << " >"; return;
 237   }
 238 }
 239
 240 /// printMachineInstruction -- Print out a single IA64 LLVM instruction
 241 /// MI to the current output stream.
 242 ///
 243 void IA64AsmPrinter::printMachineInstruction(const MachineInstr *MI) {
 244   ++EmittedInsts;
 245
 246   // Call the autogenerated instruction printer routines.
 247   printInstruction(MI);
 248 }
 249
 250 bool IA64AsmPrinter::doInitialization(Module &M) {
 251   bool Result = AsmPrinter::doInitialization(M);
 252
 253   O << "\n.ident \"LLVM-ia64\"\n\n"
 254     << "\t.psr    lsb\n"  // should be "msb" on HP-UX, for starters
 255     << "\t.radix  C\n"
 256     << "\t.psr    abi64\n"; // we only support 64 bits for now
 257   return Result;
 258 }
 259
 260 bool IA64AsmPrinter::doFinalization(Module &M) {
 261   const TargetData *TD = TM.getTargetData();
 262
 263   // Print out module-level global variables here.
 264   for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
 265        I != E; ++I)
 266     if (I->hasInitializer()) {   // External global require no code
 267       // Check to see if this is a special global used by LLVM, if so, emit it.
 268       if (EmitSpecialLLVMGlobal(I))
 269         continue;
 270
 271       O << "\n\n";
 272       std::string name = Mang->getValueName(I);
 273       Constant *C = I->getInitializer();
 274       unsigned Size = TD->getTypeSize(C->getType());
 275       unsigned Align = TD->getPreferredTypeAlignmentShift(C->getType());
 276
 277       if (C->isNullValue() &&
 278           (I->hasLinkOnceLinkage() || I->hasInternalLinkage() ||
 279            I->hasWeakLinkage() /* FIXME: Verify correct */)) {
 280         SwitchToDataSection(".data", I);
 281         if (I->hasInternalLinkage()) {
 282           O << "\t.lcomm " << name << "#," << TD->getTypeSize(C->getType())
 283           << "," << (1 << Align);
 284           O << "\n";
 285         } else {
 286           O << "\t.common " << name << "#," << TD->getTypeSize(C->getType())
 287           << "," << (1 << Align);
 288           O << "\n";
 289         }
 290       } else {
 291         switch (I->getLinkage()) {
 292           case GlobalValue::LinkOnceLinkage:
 293           case GlobalValue::WeakLinkage:   // FIXME: Verify correct for weak.
 294                                            // Nonnull linkonce -> weak
 295             O << "\t.weak " << name << "\n";
 296             O << "\t.section\t.llvm.linkonce.d." << name
 297               << ", \"aw\", \"progbits\"\n";
 298             SwitchToDataSection("", I);
 299             break;
 300           case GlobalValue::AppendingLinkage:
 301             // FIXME: appending linkage variables should go into a section of
 302             // their name or something.  For now, just emit them as external.
 303           case GlobalValue::ExternalLinkage:
 304             // If external or appending, declare as a global symbol
 305             O << "\t.global " << name << "\n";
 306             // FALL THROUGH
 307           case GlobalValue::InternalLinkage:
 308             SwitchToDataSection(C->isNullValue() ? ".bss" : ".data", I);
 309             break;
 310           case GlobalValue::GhostLinkage:
 311             cerr << "GhostLinkage cannot appear in IA64AsmPrinter!\n";
 312             abort();
 313           case GlobalValue::DLLImportLinkage:
 314             cerr << "DLLImport linkage is not supported by this target!\n";
 315             abort();
 316           case GlobalValue::DLLExportLinkage:
 317             cerr << "DLLExport linkage is not supported by this target!\n";
 318             abort();
 319           default:
 320             assert(0 && "Unknown linkage type!");
 321         }
 322
 323         EmitAlignment(Align);
 324         O << "\t.type " << name << ",@object\n";
 325         O << "\t.size " << name << "," << Size << "\n";
 326         O << name << ":\t\t\t\t// " << *C << "\n";
 327         EmitGlobalConstant(C);
 328       }
 329     }
 330
 331       // we print out ".global X \n .type X, @function" for each external function
 332       O << "\n\n// br.call targets referenced (and not defined) above: \n";
 333   for (std::set<std::string>::iterator i = ExternalFunctionNames.begin(),
 334        e = ExternalFunctionNames.end(); i!=e; ++i) {
 335     O << "\t.global " << *i << "\n\t.type " << *i << ", @function\n";
 336   }
 337   O << "\n\n";
 338
 339   // we print out ".global X \n .type X, @object" for each external object
 340   O << "\n\n// (external) symbols referenced (and not defined) above: \n";
 341   for (std::set<std::string>::iterator i = ExternalObjectNames.begin(),
 342        e = ExternalObjectNames.end(); i!=e; ++i) {
 343     O << "\t.global " << *i << "\n\t.type " << *i << ", @object\n";
 344   }
 345   O << "\n\n";
 346
 347   return AsmPrinter::doFinalization(M);
 348 }
 349
 350 /// createIA64CodePrinterPass - Returns a pass that prints the IA64
 351 /// assembly code for a MachineFunction to the given output stream, using
 352 /// the given target machine description.
 353 ///
 354 FunctionPass *llvm::createIA64CodePrinterPass(std::ostream &o,
 355                                               IA64TargetMachine &tm) {
 356   return new IA64AsmPrinter(o, tm, tm.getTargetAsmInfo());
 357 }
 358
 359