LLVM API Documentation
00001 //===-- AlphaAsmPrinter.cpp - Alpha LLVM assembly writer ------------------===// 00002 // 00003 // The LLVM Compiler Infrastructure 00004 // 00005 // This file was developed by the LLVM research group and is distributed under 00006 // the University of Illinois Open Source License. See LICENSE.TXT for details. 00007 // 00008 //===----------------------------------------------------------------------===// 00009 // 00010 // This file contains a printer that converts from our internal representation 00011 // of machine-dependent LLVM code to GAS-format Alpha assembly language. 00012 // 00013 //===----------------------------------------------------------------------===// 00014 00015 #include "Alpha.h" 00016 #include "AlphaInstrInfo.h" 00017 #include "AlphaTargetMachine.h" 00018 #include "llvm/Module.h" 00019 #include "llvm/Type.h" 00020 #include "llvm/Assembly/Writer.h" 00021 #include "llvm/CodeGen/AsmPrinter.h" 00022 #include "llvm/Target/TargetMachine.h" 00023 #include "llvm/Support/Mangler.h" 00024 #include "llvm/ADT/Statistic.h" 00025 #include <iostream> 00026 using namespace llvm; 00027 00028 namespace { 00029 Statistic<> EmittedInsts("asm-printer", "Number of machine instrs printed"); 00030 00031 struct AlphaAsmPrinter : public AsmPrinter { 00032 00033 /// Unique incrementer for label values for referencing Global values. 00034 /// 00035 unsigned LabelNumber; 00036 00037 AlphaAsmPrinter(std::ostream &o, TargetMachine &tm) 00038 : AsmPrinter(o, tm), LabelNumber(0) { 00039 AlignmentIsInBytes = false; 00040 PrivateGlobalPrefix = "$"; 00041 } 00042 00043 /// We name each basic block in a Function with a unique number, so 00044 /// that we can consistently refer to them later. This is cleared 00045 /// at the beginning of each call to runOnMachineFunction(). 00046 /// 00047 typedef std::map<const Value *, unsigned> ValueMapTy; 00048 ValueMapTy NumberForBB; 00049 std::string CurSection; 00050 00051 virtual const char *getPassName() const { 00052 return "Alpha Assembly Printer"; 00053 } 00054 bool printInstruction(const MachineInstr *MI); 00055 void printOp(const MachineOperand &MO, bool IsCallOp = false); 00056 void printOperand(const MachineInstr *MI, int opNum); 00057 void printBaseOffsetPair (const MachineInstr *MI, int i, bool brackets=true); 00058 void printMachineInstruction(const MachineInstr *MI); 00059 bool runOnMachineFunction(MachineFunction &F); 00060 bool doInitialization(Module &M); 00061 bool doFinalization(Module &M); 00062 }; 00063 } // end of anonymous namespace 00064 00065 /// createAlphaCodePrinterPass - Returns a pass that prints the Alpha 00066 /// assembly code for a MachineFunction to the given output stream, 00067 /// using the given target machine description. This should work 00068 /// regardless of whether the function is in SSA form. 00069 /// 00070 FunctionPass *llvm::createAlphaCodePrinterPass (std::ostream &o, 00071 TargetMachine &tm) { 00072 return new AlphaAsmPrinter(o, tm); 00073 } 00074 00075 #include "AlphaGenAsmWriter.inc" 00076 00077 void AlphaAsmPrinter::printOperand(const MachineInstr *MI, int opNum) 00078 { 00079 const MachineOperand &MO = MI->getOperand(opNum); 00080 if (MO.getType() == MachineOperand::MO_MachineRegister) { 00081 assert(MRegisterInfo::isPhysicalRegister(MO.getReg())&&"Not physreg??"); 00082 O << TM.getRegisterInfo()->get(MO.getReg()).Name; 00083 } else if (MO.isImmediate()) { 00084 O << MO.getImmedValue(); 00085 } else { 00086 printOp(MO); 00087 } 00088 } 00089 00090 00091 void AlphaAsmPrinter::printOp(const MachineOperand &MO, bool IsCallOp) { 00092 const MRegisterInfo &RI = *TM.getRegisterInfo(); 00093 int new_symbol; 00094 00095 switch (MO.getType()) { 00096 case MachineOperand::MO_VirtualRegister: 00097 if (Value *V = MO.getVRegValueOrNull()) { 00098 O << "<" << V->getName() << ">"; 00099 return; 00100 } 00101 // FALLTHROUGH 00102 case MachineOperand::MO_MachineRegister: 00103 case MachineOperand::MO_CCRegister: 00104 O << RI.get(MO.getReg()).Name; 00105 return; 00106 00107 case MachineOperand::MO_SignExtendedImmed: 00108 case MachineOperand::MO_UnextendedImmed: 00109 std::cerr << "printOp() does not handle immediate values\n"; 00110 abort(); 00111 return; 00112 00113 case MachineOperand::MO_PCRelativeDisp: 00114 std::cerr << "Shouldn't use addPCDisp() when building Alpha MachineInstrs"; 00115 abort(); 00116 return; 00117 00118 case MachineOperand::MO_MachineBasicBlock: { 00119 MachineBasicBlock *MBBOp = MO.getMachineBasicBlock(); 00120 O << PrivateGlobalPrefix << "LBB" 00121 << Mang->getValueName(MBBOp->getParent()->getFunction()) 00122 << "_" << MBBOp->getNumber() << "\t" << CommentString << " " 00123 << MBBOp->getBasicBlock()->getName(); 00124 return; 00125 } 00126 00127 case MachineOperand::MO_ConstantPoolIndex: 00128 O << PrivateGlobalPrefix << "CPI" << getFunctionNumber() << "_" 00129 << MO.getConstantPoolIndex(); 00130 return; 00131 00132 case MachineOperand::MO_ExternalSymbol: 00133 O << MO.getSymbolName(); 00134 return; 00135 00136 case MachineOperand::MO_GlobalAddress: 00137 //Abuse PCrel to specify pcrel calls 00138 //calls are the only thing that use this flag 00139 // if (MO.isPCRelative()) 00140 // O << PrivateGlobalPrefix << Mang->getValueName(MO.getGlobal()) << "..ng"; 00141 // else 00142 O << Mang->getValueName(MO.getGlobal()); 00143 return; 00144 00145 default: 00146 O << "<unknown operand type: " << MO.getType() << ">"; 00147 return; 00148 } 00149 } 00150 00151 /// printMachineInstruction -- Print out a single Alpha MI to 00152 /// the current output stream. 00153 /// 00154 void AlphaAsmPrinter::printMachineInstruction(const MachineInstr *MI) { 00155 ++EmittedInsts; 00156 if (printInstruction(MI)) 00157 return; // Printer was automatically generated 00158 00159 assert(0 && "Unhandled instruction in asm writer!"); 00160 abort(); 00161 return; 00162 } 00163 00164 00165 /// runOnMachineFunction - This uses the printMachineInstruction() 00166 /// method to print assembly for each instruction. 00167 /// 00168 bool AlphaAsmPrinter::runOnMachineFunction(MachineFunction &MF) { 00169 SetupMachineFunction(MF); 00170 O << "\n\n"; 00171 00172 // Print out constants referenced by the function 00173 EmitConstantPool(MF.getConstantPool()); 00174 00175 // Print out labels for the function. 00176 const Function *F = MF.getFunction(); 00177 SwitchSection(".text", F); 00178 EmitAlignment(4, F); 00179 switch (F->getLinkage()) { 00180 default: assert(0 && "Unknown linkage type!"); 00181 case Function::InternalLinkage: // Symbols default to internal. 00182 break; 00183 case Function::ExternalLinkage: 00184 O << "\t.globl " << CurrentFnName << "\n"; 00185 break; 00186 case Function::WeakLinkage: 00187 case Function::LinkOnceLinkage: 00188 O << "\t.weak " << CurrentFnName << "\n"; 00189 break; 00190 } 00191 00192 O << "\t.ent " << CurrentFnName << "\n"; 00193 00194 O << CurrentFnName << ":\n"; 00195 00196 // Print out code for the function. 00197 for (MachineFunction::const_iterator I = MF.begin(), E = MF.end(); 00198 I != E; ++I) { 00199 // Print a label for the basic block. 00200 O << PrivateGlobalPrefix << "LBB" << CurrentFnName << "_" << I->getNumber() 00201 << ":\t" << CommentString << " " << I->getBasicBlock()->getName() << "\n"; 00202 for (MachineBasicBlock::const_iterator II = I->begin(), E = I->end(); 00203 II != E; ++II) { 00204 // Print the assembly for the instruction. 00205 O << "\t"; 00206 printMachineInstruction(II); 00207 } 00208 } 00209 ++LabelNumber; 00210 00211 O << "\t.end " << CurrentFnName << "\n"; 00212 00213 // We didn't modify anything. 00214 return false; 00215 } 00216 00217 bool AlphaAsmPrinter::doInitialization(Module &M) 00218 { 00219 AsmPrinter::doInitialization(M); 00220 if(TM.getSubtarget<AlphaSubtarget>().hasF2I() 00221 || TM.getSubtarget<AlphaSubtarget>().hasCT()) 00222 O << "\t.arch ev6\n"; 00223 else 00224 O << "\t.arch ev56\n"; 00225 O << "\t.set noat\n"; 00226 return false; 00227 } 00228 00229 bool AlphaAsmPrinter::doFinalization(Module &M) { 00230 const TargetData &TD = TM.getTargetData(); 00231 00232 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); I != E; ++I) 00233 if (I->hasInitializer()) { // External global require no code 00234 // Check to see if this is a special global used by LLVM, if so, emit it. 00235 if (EmitSpecialLLVMGlobal(I)) 00236 continue; 00237 00238 O << "\n\n"; 00239 std::string name = Mang->getValueName(I); 00240 Constant *C = I->getInitializer(); 00241 unsigned Size = TD.getTypeSize(C->getType()); 00242 // unsigned Align = TD.getTypeAlignmentShift(C->getType()); 00243 unsigned Align = getPreferredAlignmentLog(I); 00244 00245 if (C->isNullValue() && 00246 (I->hasLinkOnceLinkage() || I->hasInternalLinkage() || 00247 I->hasWeakLinkage() /* FIXME: Verify correct */)) { 00248 SwitchSection("\t.section .data", I); 00249 if (I->hasInternalLinkage()) 00250 O << "\t.local " << name << "\n"; 00251 00252 O << "\t.comm " << name << "," << TD.getTypeSize(C->getType()) 00253 << "," << (1 << Align) 00254 << "\n"; 00255 } else { 00256 switch (I->getLinkage()) { 00257 case GlobalValue::LinkOnceLinkage: 00258 case GlobalValue::WeakLinkage: // FIXME: Verify correct for weak. 00259 // Nonnull linkonce -> weak 00260 O << "\t.weak " << name << "\n"; 00261 O << "\t.section\t.llvm.linkonce.d." << name << ",\"aw\",@progbits\n"; 00262 SwitchSection("", I); 00263 break; 00264 case GlobalValue::AppendingLinkage: 00265 // FIXME: appending linkage variables should go into a section of 00266 // their name or something. For now, just emit them as external. 00267 case GlobalValue::ExternalLinkage: 00268 // If external or appending, declare as a global symbol 00269 O << "\t.globl " << name << "\n"; 00270 // FALL THROUGH 00271 case GlobalValue::InternalLinkage: 00272 SwitchSection(C->isNullValue() ? "\t.section .bss" : 00273 "\t.section .data", I); 00274 break; 00275 case GlobalValue::GhostLinkage: 00276 std::cerr << "GhostLinkage cannot appear in AlphaAsmPrinter!\n"; 00277 abort(); 00278 } 00279 00280 EmitAlignment(Align); 00281 O << "\t.type " << name << ",@object\n"; 00282 O << "\t.size " << name << "," << Size << "\n"; 00283 O << name << ":\n"; 00284 EmitGlobalConstant(C); 00285 } 00286 } 00287 00288 AsmPrinter::doFinalization(M); 00289 return false; 00290 }