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 #include "IA64.h"
  20 #include "IA64TargetMachine.h"
  21 #include "llvm/Module.h"
  22 #include "llvm/Type.h"
  23 #include "llvm/Assembly/Writer.h"
  24 #include "llvm/CodeGen/AsmPrinter.h"
  25 #include "llvm/CodeGen/MachineFunctionPass.h"
  26 #include "llvm/Target/TargetMachine.h"
  27 #include "llvm/Support/Mangler.h"
  28 #include "llvm/ADT/Statistic.h"
  29 #include <iostream>
  30 using namespace llvm;
  31
  32 namespace {
  33   Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed");
  34
  35   struct IA64AsmPrinter : public AsmPrinter {
  36     std::set<std::string> ExternalFunctionNames, ExternalObjectNames;
  37
  38     IA64AsmPrinter(std::ostream &O, TargetMachine &TM) : AsmPrinter(O, TM) {
  39       CommentString = "//";
  40       Data8bitsDirective = "\tdata1\t";     // FIXME: check that we are
  41       Data16bitsDirective = "\tdata2.ua\t"; // disabling auto-alignment
  42       Data32bitsDirective = "\tdata4.ua\t"; // properly
  43       Data64bitsDirective = "\tdata8.ua\t";
  44       ZeroDirective = "\t.skip\t";
  45       AsciiDirective = "\tstring\t";
  46
  47       GlobalVarAddrPrefix="";
  48       GlobalVarAddrSuffix="";
  49       FunctionAddrPrefix="@fptr(";
  50       FunctionAddrSuffix=")";
  51
  52       // FIXME: would be nice to have rodata (no 'w') when appropriate?
  53       ConstantPoolSection = "\n\t.section .data, \"aw\", \"progbits\"\n";
  54     }
  55
  56     virtual const char *getPassName() const {
  57       return "IA64 Assembly Printer";
  58     }
  59
  60     /// printInstruction - This method is automatically generated by tablegen
  61     /// from the instruction set description.  This method returns true if the
  62     /// machine instruction was sufficiently described to print it, otherwise it
  63     /// returns false.
  64     bool printInstruction(const MachineInstr *MI);
  65
  66     // This method is used by the tablegen'erated instruction printer.
  67     void printOperand(const MachineInstr *MI, unsigned OpNo){
  68       const MachineOperand &MO = MI->getOperand(OpNo);
  69       if (MO.getType() == MachineOperand::MO_MachineRegister) {
  70         assert(MRegisterInfo::isPhysicalRegister(MO.getReg())&&"Not physref??");
  71         //XXX Bug Workaround: See note in Printer::doInitialization about %.
  72         O << TM.getRegisterInfo()->get(MO.getReg()).Name;
  73       } else {
  74         printOp(MO);
  75       }
  76     }
  77
  78     void printS8ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  79       int val=(unsigned int)MI->getOperand(OpNo).getImmedValue();
  80       if(val>=128) val=val-256; // if negative, flip sign
  81       O << val;
  82     }
  83     void printS14ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  84       int val=(unsigned int)MI->getOperand(OpNo).getImmedValue();
  85       if(val>=8192) val=val-16384; // if negative, flip sign
  86       O << val;
  87     }
  88     void printS22ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  89       int val=(unsigned int)MI->getOperand(OpNo).getImmedValue();
  90       if(val>=2097152) val=val-4194304; // if negative, flip sign
  91       O << val;
  92     }
  93     void printU64ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  94       O << (uint64_t)MI->getOperand(OpNo).getImmedValue();
  95     }
  96     void printS64ImmOperand(const MachineInstr *MI, unsigned OpNo) {
  97 // XXX : nasty hack to avoid GPREL22 "relocation truncated to fit" linker
  98 // errors - instead of add rX = @gprel(CPI<whatever>), r1;; we now
  99 // emit movl rX = @gprel(CPI<whatever);;
 100 //      add  rX = rX, r1;
 101 // this gives us 64 bits instead of 22 (for the add long imm) to play
 102 // with, which shuts up the linker. The problem is that the constant
 103 // pool entries aren't immediates at this stage, so we check here.
 104 // If it's an immediate, print it the old fashioned way. If it's
 105 // not, we print it as a constant pool index.
 106       if(MI->getOperand(OpNo).isImmediate()) {
 107         O << (int64_t)MI->getOperand(OpNo).getImmedValue();
 108       } else { // this is a constant pool reference: FIXME: assert this
 109         printOp(MI->getOperand(OpNo));
 110       }
 111     }
 112
 113     void printGlobalOperand(const MachineInstr *MI, unsigned OpNo) {
 114       printOp(MI->getOperand(OpNo), false); // this is NOT a br.call instruction
 115     }
 116
 117     void printCallOperand(const MachineInstr *MI, unsigned OpNo) {
 118       printOp(MI->getOperand(OpNo), true); // this is a br.call instruction
 119     }
 120
 121     void printMachineInstruction(const MachineInstr *MI);
 122     void printOp(const MachineOperand &MO, bool isBRCALLinsn= false);
 123     bool runOnMachineFunction(MachineFunction &F);
 124     bool doInitialization(Module &M);
 125     bool doFinalization(Module &M);
 126   };
 127 } // end of anonymous namespace
 128
 129
 130 // Include the auto-generated portion of the assembly writer.
 131 #include "IA64GenAsmWriter.inc"
 132
 133
 134 /// runOnMachineFunction - This uses the printMachineInstruction()
 135 /// method to print assembly for each instruction.
 136 ///
 137 bool IA64AsmPrinter::runOnMachineFunction(MachineFunction &MF) {
 138   SetupMachineFunction(MF);
 139   O << "\n\n";
 140
 141   // Print out constants referenced by the function
 142   EmitConstantPool(MF.getConstantPool());
 143
 144   // Print out labels for the function.
 145   SwitchSection("\n\t.section .text, \"ax\", \"progbits\"\n", MF.getFunction());
 146   // ^^  means "Allocated instruXions in mem, initialized"
 147   EmitAlignment(5);
 148   O << "\t.global\t" << CurrentFnName << "\n";
 149   O << "\t.type\t" << CurrentFnName << ", @function\n";
 150   O << CurrentFnName << ":\n";
 151
 152   // Print out code for the function.
 153   for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
 154        I != E; ++I) {
 155     // Print a label for the basic block if there are any predecessors.
 156     if (I->pred_begin() != I->pred_end())
 157       O << PrivateGlobalPrefix << "LBB" << CurrentFnName << "_"
 158         << I->getNumber() << ":\t"
 159         << CommentString << " " << I->getBasicBlock()->getName() << "\n";
 160     for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end();
 161          II != E; ++II) {
 162       // Print the assembly for the instruction.
 163       O << "\t";
 164       printMachineInstruction(II);
 165     }
 166   }
 167
 168   // We didn't modify anything.
 169   return false;
 170 }
 171
 172 void IA64AsmPrinter::printOp(const MachineOperand &MO,
 173                                  bool isBRCALLinsn /* = false */) {
 174   const MRegisterInfo &RI = *TM.getRegisterInfo();
 175   switch (MO.getType()) {
 176   case MachineOperand::MO_VirtualRegister:
 177     if (Value *V = MO.getVRegValueOrNull()) {
 178       O << "<" << V->getName() << ">";
 179       return;
 180     }
 181     // FALLTHROUGH
 182   case MachineOperand::MO_MachineRegister:
 183   case MachineOperand::MO_CCRegister: {
 184     O << RI.get(MO.getReg()).Name;
 185     return;
 186   }
 187
 188   case MachineOperand::MO_SignExtendedImmed:
 189   case MachineOperand::MO_UnextendedImmed:
 190     O << /*(unsigned int)*/MO.getImmedValue();
 191     return;
 192   case MachineOperand::MO_MachineBasicBlock: {
 193     MachineBasicBlock *MBBOp = MO.getMachineBasicBlock();
 194     O << PrivateGlobalPrefix << "LBB"
 195       << Mang->getValueName(MBBOp->getParent()->getFunction())
 196       << "_" << MBBOp->getNumber () << "\t// "
 197       << MBBOp->getBasicBlock ()->getName ();
 198     return;
 199   }
 200   case MachineOperand::MO_PCRelativeDisp:
 201     std::cerr << "Shouldn't use addPCDisp() when building IA64 MachineInstrs";
 202     abort ();
 203     return;
 204
 205   case MachineOperand::MO_ConstantPoolIndex: {
 206     O << "@gprel(" << PrivateGlobalPrefix << "CPI" << getFunctionNumber() << "_"
 207       << MO.getConstantPoolIndex() << ")";
 208     return;
 209   }
 210
 211   case MachineOperand::MO_GlobalAddress: {
 212
 213     // functions need @ltoff(@fptr(fn_name)) form
 214     GlobalValue *GV = MO.getGlobal();
 215     Function *F = dyn_cast<Function>(GV);
 216
 217     bool Needfptr=false; // if we're computing an address @ltoff(X), do
 218                          // we need to decorate it so it becomes
 219                          // @ltoff(@fptr(X)) ?
 220     if (F && !isBRCALLinsn /*&& F->isExternal()*/)
 221       Needfptr=true;
 222
 223     // if this is the target of a call instruction, we should define
 224     // the function somewhere (GNU gas has no problem without this, but
 225     // Intel ias rightly complains of an 'undefined symbol')
 226
 227     if (F /*&& isBRCALLinsn*/ && F->isExternal())
 228       ExternalFunctionNames.insert(Mang->getValueName(MO.getGlobal()));
 229     else
 230       if (GV->isExternal()) // e.g. stuff like 'stdin'
 231         ExternalObjectNames.insert(Mang->getValueName(MO.getGlobal()));
 232
 233     if (!isBRCALLinsn)
 234       O << "@ltoff(";
 235     if (Needfptr)
 236       O << "@fptr(";
 237     O << Mang->getValueName(MO.getGlobal());
 238
 239     if (Needfptr && !isBRCALLinsn)
 240       O << "#))"; // close both fptr( and ltoff(
 241     else {
 242       if (Needfptr)
 243         O << "#)"; // close only fptr(
 244       if (!isBRCALLinsn)
 245         O << "#)"; // close only ltoff(
 246     }
 247
 248     int Offset = MO.getOffset();
 249     if (Offset > 0)
 250       O << " + " << Offset;
 251     else if (Offset < 0)
 252       O << " - " << -Offset;
 253     return;
 254   }
 255   case MachineOperand::MO_ExternalSymbol:
 256     O << MO.getSymbolName();
 257     ExternalFunctionNames.insert(MO.getSymbolName());
 258     return;
 259   default:
 260     O << "<AsmPrinter: unknown operand type: " << MO.getType() << " >"; return;
 261   }
 262 }
 263
 264 /// printMachineInstruction -- Print out a single IA64 LLVM instruction
 265 /// MI to the current output stream.
 266 ///
 267 void IA64AsmPrinter::printMachineInstruction(const MachineInstr *MI) {
 268   ++EmittedInsts;
 269
 270   // Call the autogenerated instruction printer routines.
 271   printInstruction(MI);
 272 }
 273
 274 bool IA64AsmPrinter::doInitialization(Module &M) {
 275   AsmPrinter::doInitialization(M);
 276
 277   O << "\n.ident \"LLVM-ia64\"\n\n"
 278     << "\t.psr    lsb\n"  // should be "msb" on HP-UX, for starters
 279     << "\t.radix  C\n"
 280     << "\t.psr    abi64\n"; // we only support 64 bits for now
 281   return false;
 282 }
 283
 284 bool IA64AsmPrinter::doFinalization(Module &M) {
 285   const TargetData &TD = TM.getTargetData();
 286
 287   // Print out module-level global variables here.
 288   for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
 289        I != E; ++I)
 290     if (I->hasInitializer()) {   // External global require no code
 291       // Check to see if this is a special global used by LLVM, if so, emit it.
 292       if (EmitSpecialLLVMGlobal(I))
 293         continue;
 294
 295       O << "\n\n";
 296       std::string name = Mang->getValueName(I);
 297       Constant *C = I->getInitializer();
 298       unsigned Size = TD.getTypeSize(C->getType());
 299       unsigned Align = TD.getTypeAlignmentShift(C->getType());
 300
 301       if (C->isNullValue() &&
 302           (I->hasLinkOnceLinkage() || I->hasInternalLinkage() ||
 303            I->hasWeakLinkage() /* FIXME: Verify correct */)) {
 304         SwitchSection(".data", I);
 305         if (I->hasInternalLinkage()) {
 306           O << "\t.lcomm " << name << "#," << TD.getTypeSize(C->getType())
 307           << "," << (1 << Align);
 308           O << "\t\t// ";
 309         } else {
 310           O << "\t.common " << name << "#," << TD.getTypeSize(C->getType())
 311           << "," << (1 << Align);
 312           O << "\t\t// ";
 313         }
 314         WriteAsOperand(O, I, true, true, &M);
 315         O << "\n";
 316       } else {
 317         switch (I->getLinkage()) {
 318           case GlobalValue::LinkOnceLinkage:
 319           case GlobalValue::WeakLinkage:   // FIXME: Verify correct for weak.
 320                                            // Nonnull linkonce -> weak
 321             O << "\t.weak " << name << "\n";
 322             O << "\t.section\t.llvm.linkonce.d." << name
 323               << ", \"aw\", \"progbits\"\n";
 324             SwitchSection("", I);
 325             break;
 326           case GlobalValue::AppendingLinkage:
 327             // FIXME: appending linkage variables should go into a section of
 328             // their name or something.  For now, just emit them as external.
 329           case GlobalValue::ExternalLinkage:
 330             // If external or appending, declare as a global symbol
 331             O << "\t.global " << name << "\n";
 332             // FALL THROUGH
 333           case GlobalValue::InternalLinkage:
 334             SwitchSection(C->isNullValue() ? ".bss" : ".data", I);
 335             break;
 336           case GlobalValue::GhostLinkage:
 337             std::cerr << "GhostLinkage cannot appear in IA64AsmPrinter!\n";
 338             abort();
 339         }
 340
 341         EmitAlignment(Align);
 342         O << "\t.type " << name << ",@object\n";
 343         O << "\t.size " << name << "," << Size << "\n";
 344         O << name << ":\t\t\t\t// ";
 345         WriteAsOperand(O, I, true, true, &M);
 346         O << " = ";
 347         WriteAsOperand(O, C, false, false, &M);
 348         O << "\n";
 349         EmitGlobalConstant(C);
 350       }
 351     }
 352
 353       // we print out ".global X \n .type X, @function" for each external function
 354       O << "\n\n// br.call targets referenced (and not defined) above: \n";
 355   for (std::set<std::string>::iterator i = ExternalFunctionNames.begin(),
 356        e = ExternalFunctionNames.end(); i!=e; ++i) {
 357     O << "\t.global " << *i << "\n\t.type " << *i << ", @function\n";
 358   }
 359   O << "\n\n";
 360
 361   // we print out ".global X \n .type X, @object" for each external object
 362   O << "\n\n// (external) symbols referenced (and not defined) above: \n";
 363   for (std::set<std::string>::iterator i = ExternalObjectNames.begin(),
 364        e = ExternalObjectNames.end(); i!=e; ++i) {
 365     O << "\t.global " << *i << "\n\t.type " << *i << ", @object\n";
 366   }
 367   O << "\n\n";
 368
 369   AsmPrinter::doFinalization(M);
 370   return false; // success
 371 }
 372
 373 /// createIA64CodePrinterPass - Returns a pass that prints the IA64
 374 /// assembly code for a MachineFunction to the given output stream, using
 375 /// the given target machine description.
 376 ///
 377 FunctionPass *llvm::createIA64CodePrinterPass(std::ostream &o,
 378                                               IA64TargetMachine &tm) {
 379   return new IA64AsmPrinter(o, tm);
 380 }
 381
 382