MipsCodeEmitter.cpp revision 1b235a26f530623d07b49ab861fcd4adb4e62b4f
1//===-- Mips/MipsCodeEmitter.cpp - Convert Mips Code to Machine Code ------===// 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 the pass that transforms the Mips machine instructions 11// into relocatable machine code. 12// 13//===---------------------------------------------------------------------===// 14 15#define DEBUG_TYPE "jit" 16#include "Mips.h" 17#include "MCTargetDesc/MipsBaseInfo.h" 18#include "MipsInstrInfo.h" 19#include "MipsRelocations.h" 20#include "MipsSubtarget.h" 21#include "MipsTargetMachine.h" 22#include "llvm/ADT/Statistic.h" 23#include "llvm/CodeGen/JITCodeEmitter.h" 24#include "llvm/CodeGen/MachineConstantPool.h" 25#include "llvm/CodeGen/MachineFunctionPass.h" 26#include "llvm/CodeGen/MachineInstr.h" 27#include "llvm/CodeGen/MachineJumpTableInfo.h" 28#include "llvm/CodeGen/MachineModuleInfo.h" 29#include "llvm/CodeGen/MachineOperand.h" 30#include "llvm/CodeGen/Passes.h" 31#include "llvm/IR/Constants.h" 32#include "llvm/IR/DerivedTypes.h" 33#include "llvm/PassManager.h" 34#include "llvm/Support/Debug.h" 35#include "llvm/Support/ErrorHandling.h" 36#include "llvm/Support/raw_ostream.h" 37#ifndef NDEBUG 38#include <iomanip> 39#endif 40 41using namespace llvm; 42 43STATISTIC(NumEmitted, "Number of machine instructions emitted"); 44 45namespace { 46 47class MipsCodeEmitter : public MachineFunctionPass { 48 MipsJITInfo *JTI; 49 const MipsInstrInfo *II; 50 const DataLayout *TD; 51 const MipsSubtarget *Subtarget; 52 TargetMachine &TM; 53 JITCodeEmitter &MCE; 54 const std::vector<MachineConstantPoolEntry> *MCPEs; 55 const std::vector<MachineJumpTableEntry> *MJTEs; 56 bool IsPIC; 57 58 void getAnalysisUsage(AnalysisUsage &AU) const { 59 AU.addRequired<MachineModuleInfo> (); 60 MachineFunctionPass::getAnalysisUsage(AU); 61 } 62 63 static char ID; 64 65public: 66 MipsCodeEmitter(TargetMachine &tm, JITCodeEmitter &mce) 67 : MachineFunctionPass(ID), JTI(0), 68 II((const MipsInstrInfo *) tm.getInstrInfo()), TD(tm.getDataLayout()), 69 TM(tm), MCE(mce), MCPEs(0), MJTEs(0), 70 IsPIC(TM.getRelocationModel() == Reloc::PIC_) {} 71 72 bool runOnMachineFunction(MachineFunction &MF); 73 74 virtual const char *getPassName() const { 75 return "Mips Machine Code Emitter"; 76 } 77 78 /// getBinaryCodeForInstr - This function, generated by the 79 /// CodeEmitterGenerator using TableGen, produces the binary encoding for 80 /// machine instructions. 81 uint64_t getBinaryCodeForInstr(const MachineInstr &MI) const; 82 83 void emitInstruction(const MachineInstr &MI); 84 85private: 86 87 void emitWord(unsigned Word); 88 89 /// Routines that handle operands which add machine relocations which are 90 /// fixed up by the relocation stage. 91 void emitGlobalAddress(const GlobalValue *GV, unsigned Reloc, 92 bool MayNeedFarStub) const; 93 void emitExternalSymbolAddress(const char *ES, unsigned Reloc) const; 94 void emitConstPoolAddress(unsigned CPI, unsigned Reloc) const; 95 void emitJumpTableAddress(unsigned JTIndex, unsigned Reloc) const; 96 void emitMachineBasicBlock(MachineBasicBlock *BB, unsigned Reloc) const; 97 98 /// getMachineOpValue - Return binary encoding of operand. If the machine 99 /// operand requires relocation, record the relocation and return zero. 100 unsigned getMachineOpValue(const MachineInstr &MI, 101 const MachineOperand &MO) const; 102 103 unsigned getRelocation(const MachineInstr &MI, 104 const MachineOperand &MO) const; 105 106 unsigned getJumpTargetOpValue(const MachineInstr &MI, unsigned OpNo) const; 107 108 unsigned getBranchTargetOpValue(const MachineInstr &MI, unsigned OpNo) const; 109 unsigned getMemEncoding(const MachineInstr &MI, unsigned OpNo) const; 110 unsigned getSizeExtEncoding(const MachineInstr &MI, unsigned OpNo) const; 111 unsigned getSizeInsEncoding(const MachineInstr &MI, unsigned OpNo) const; 112 113 void emitGlobalAddressUnaligned(const GlobalValue *GV, unsigned Reloc, 114 int Offset) const; 115}; 116} 117 118char MipsCodeEmitter::ID = 0; 119 120bool MipsCodeEmitter::runOnMachineFunction(MachineFunction &MF) { 121 MipsTargetMachine &Target = static_cast<MipsTargetMachine &>( 122 const_cast<TargetMachine &>(MF.getTarget())); 123 124 JTI = Target.getJITInfo(); 125 II = Target.getInstrInfo(); 126 TD = Target.getDataLayout(); 127 Subtarget = &TM.getSubtarget<MipsSubtarget> (); 128 MCPEs = &MF.getConstantPool()->getConstants(); 129 MJTEs = 0; 130 if (MF.getJumpTableInfo()) MJTEs = &MF.getJumpTableInfo()->getJumpTables(); 131 JTI->Initialize(MF, IsPIC, Subtarget->isLittle()); 132 MCE.setModuleInfo(&getAnalysis<MachineModuleInfo> ()); 133 134 do { 135 DEBUG(errs() << "JITTing function '" 136 << MF.getName() << "'\n"); 137 MCE.startFunction(MF); 138 139 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end(); 140 MBB != E; ++MBB){ 141 MCE.StartMachineBasicBlock(MBB); 142 for (MachineBasicBlock::instr_iterator I = MBB->instr_begin(), 143 E = MBB->instr_end(); I != E; ++I) 144 emitInstruction(*I); 145 } 146 } while (MCE.finishFunction(MF)); 147 148 return false; 149} 150 151unsigned MipsCodeEmitter::getRelocation(const MachineInstr &MI, 152 const MachineOperand &MO) const { 153 // NOTE: This relocations are for static. 154 uint64_t TSFlags = MI.getDesc().TSFlags; 155 uint64_t Form = TSFlags & MipsII::FormMask; 156 if (Form == MipsII::FrmJ) 157 return Mips::reloc_mips_26; 158 if ((Form == MipsII::FrmI || Form == MipsII::FrmFI) 159 && MI.isBranch()) 160 return Mips::reloc_mips_pc16; 161 if (Form == MipsII::FrmI && MI.getOpcode() == Mips::LUi) 162 return Mips::reloc_mips_hi; 163 return Mips::reloc_mips_lo; 164} 165 166unsigned MipsCodeEmitter::getJumpTargetOpValue(const MachineInstr &MI, 167 unsigned OpNo) const { 168 MachineOperand MO = MI.getOperand(OpNo); 169 if (MO.isGlobal()) 170 emitGlobalAddress(MO.getGlobal(), getRelocation(MI, MO), true); 171 else if (MO.isSymbol()) 172 emitExternalSymbolAddress(MO.getSymbolName(), getRelocation(MI, MO)); 173 else if (MO.isMBB()) 174 emitMachineBasicBlock(MO.getMBB(), getRelocation(MI, MO)); 175 else 176 llvm_unreachable("Unexpected jump target operand kind."); 177 return 0; 178} 179 180unsigned MipsCodeEmitter::getBranchTargetOpValue(const MachineInstr &MI, 181 unsigned OpNo) const { 182 MachineOperand MO = MI.getOperand(OpNo); 183 emitMachineBasicBlock(MO.getMBB(), getRelocation(MI, MO)); 184 return 0; 185} 186 187unsigned MipsCodeEmitter::getMemEncoding(const MachineInstr &MI, 188 unsigned OpNo) const { 189 // Base register is encoded in bits 20-16, offset is encoded in bits 15-0. 190 assert(MI.getOperand(OpNo).isReg()); 191 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo)) << 16; 192 return (getMachineOpValue(MI, MI.getOperand(OpNo+1)) & 0xFFFF) | RegBits; 193} 194 195unsigned MipsCodeEmitter::getSizeExtEncoding(const MachineInstr &MI, 196 unsigned OpNo) const { 197 // size is encoded as size-1. 198 return getMachineOpValue(MI, MI.getOperand(OpNo)) - 1; 199} 200 201unsigned MipsCodeEmitter::getSizeInsEncoding(const MachineInstr &MI, 202 unsigned OpNo) const { 203 // size is encoded as pos+size-1. 204 return getMachineOpValue(MI, MI.getOperand(OpNo-1)) + 205 getMachineOpValue(MI, MI.getOperand(OpNo)) - 1; 206} 207 208/// getMachineOpValue - Return binary encoding of operand. If the machine 209/// operand requires relocation, record the relocation and return zero. 210unsigned MipsCodeEmitter::getMachineOpValue(const MachineInstr &MI, 211 const MachineOperand &MO) const { 212 if (MO.isReg()) 213 return TM.getRegisterInfo()->getEncodingValue(MO.getReg()); 214 else if (MO.isImm()) 215 return static_cast<unsigned>(MO.getImm()); 216 else if (MO.isGlobal()) 217 emitGlobalAddress(MO.getGlobal(), getRelocation(MI, MO), true); 218 else if (MO.isSymbol()) 219 emitExternalSymbolAddress(MO.getSymbolName(), getRelocation(MI, MO)); 220 else if (MO.isCPI()) 221 emitConstPoolAddress(MO.getIndex(), getRelocation(MI, MO)); 222 else if (MO.isJTI()) 223 emitJumpTableAddress(MO.getIndex(), getRelocation(MI, MO)); 224 else if (MO.isMBB()) 225 emitMachineBasicBlock(MO.getMBB(), getRelocation(MI, MO)); 226 else 227 llvm_unreachable("Unable to encode MachineOperand!"); 228 return 0; 229} 230 231void MipsCodeEmitter::emitGlobalAddress(const GlobalValue *GV, unsigned Reloc, 232 bool MayNeedFarStub) const { 233 MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc, 234 const_cast<GlobalValue *>(GV), 0, 235 MayNeedFarStub)); 236} 237 238void MipsCodeEmitter::emitGlobalAddressUnaligned(const GlobalValue *GV, 239 unsigned Reloc, int Offset) const { 240 MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc, 241 const_cast<GlobalValue *>(GV), 0, false)); 242 MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset() + Offset, 243 Reloc, const_cast<GlobalValue *>(GV), 0, false)); 244} 245 246void MipsCodeEmitter:: 247emitExternalSymbolAddress(const char *ES, unsigned Reloc) const { 248 MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(), 249 Reloc, ES, 0, 0)); 250} 251 252void MipsCodeEmitter::emitConstPoolAddress(unsigned CPI, unsigned Reloc) const { 253 MCE.addRelocation(MachineRelocation::getConstPool(MCE.getCurrentPCOffset(), 254 Reloc, CPI, 0, false)); 255} 256 257void MipsCodeEmitter:: 258emitJumpTableAddress(unsigned JTIndex, unsigned Reloc) const { 259 MCE.addRelocation(MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(), 260 Reloc, JTIndex, 0, false)); 261} 262 263void MipsCodeEmitter::emitMachineBasicBlock(MachineBasicBlock *BB, 264 unsigned Reloc) const { 265 MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(), 266 Reloc, BB)); 267} 268 269void MipsCodeEmitter::emitInstruction(const MachineInstr &MI) { 270 DEBUG(errs() << "JIT: " << (void*)MCE.getCurrentPCValue() << ":\t" << MI); 271 272 MCE.processDebugLoc(MI.getDebugLoc(), true); 273 274 // Skip pseudo instructions. 275 if ((MI.getDesc().TSFlags & MipsII::FormMask) == MipsII::Pseudo) 276 return; 277 278 emitWord(getBinaryCodeForInstr(MI)); 279 ++NumEmitted; // Keep track of the # of mi's emitted 280 281 MCE.processDebugLoc(MI.getDebugLoc(), false); 282} 283 284void MipsCodeEmitter::emitWord(unsigned Word) { 285 DEBUG(errs() << " 0x"; 286 errs().write_hex(Word) << "\n"); 287 if (Subtarget->isLittle()) 288 MCE.emitWordLE(Word); 289 else 290 MCE.emitWordBE(Word); 291} 292 293/// createMipsJITCodeEmitterPass - Return a pass that emits the collected Mips 294/// code to the specified MCE object. 295FunctionPass *llvm::createMipsJITCodeEmitterPass(MipsTargetMachine &TM, 296 JITCodeEmitter &JCE) { 297 return new MipsCodeEmitter(TM, JCE); 298} 299 300#include "MipsGenCodeEmitter.inc" 301