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 "MipsInstrInfo.h" 18 #include "MipsRelocations.h" 19 #include "MipsSubtarget.h" 20 #include "MipsTargetMachine.h" 21 #include "MCTargetDesc/MipsBaseInfo.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/Constants.h" 32 #include "llvm/DerivedTypes.h" 33 #include "llvm/Function.h" 34 #include "llvm/PassManager.h" 35 #include "llvm/Support/Debug.h" 36 #include "llvm/Support/ErrorHandling.h" 37 #include "llvm/Support/raw_ostream.h" 38 #ifndef NDEBUG 39 #include <iomanip> 40 #endif 41 42 using namespace llvm; 43 44 STATISTIC(NumEmitted, "Number of machine instructions emitted"); 45 46 namespace { 47 48 class MipsCodeEmitter : public MachineFunctionPass { 49 MipsJITInfo *JTI; 50 const MipsInstrInfo *II; 51 const TargetData *TD; 52 const MipsSubtarget *Subtarget; 53 TargetMachine &TM; 54 JITCodeEmitter &MCE; 55 const std::vector<MachineConstantPoolEntry> *MCPEs; 56 const std::vector<MachineJumpTableEntry> *MJTEs; 57 bool IsPIC; 58 59 void getAnalysisUsage(AnalysisUsage &AU) const { 60 AU.addRequired<MachineModuleInfo> (); 61 MachineFunctionPass::getAnalysisUsage(AU); 62 } 63 64 static char ID; 65 66 public: 67 MipsCodeEmitter(TargetMachine &tm, JITCodeEmitter &mce) : 68 MachineFunctionPass(ID), JTI(0), 69 II((const MipsInstrInfo *) tm.getInstrInfo()), 70 TD(tm.getTargetData()), TM(tm), MCE(mce), MCPEs(0), MJTEs(0), 71 IsPIC(TM.getRelocationModel() == Reloc::PIC_) { 72 } 73 74 bool runOnMachineFunction(MachineFunction &MF); 75 76 virtual const char *getPassName() const { 77 return "Mips Machine Code Emitter"; 78 } 79 80 /// getBinaryCodeForInstr - This function, generated by the 81 /// CodeEmitterGenerator using TableGen, produces the binary encoding for 82 /// machine instructions. 83 uint64_t getBinaryCodeForInstr(const MachineInstr &MI) const; 84 85 void emitInstruction(const MachineInstr &MI); 86 87 private: 88 89 void emitWordLE(unsigned Word); 90 91 /// Routines that handle operands which add machine relocations which are 92 /// fixed up by the relocation stage. 93 void emitGlobalAddress(const GlobalValue *GV, unsigned Reloc, 94 bool MayNeedFarStub) const; 95 void emitExternalSymbolAddress(const char *ES, unsigned Reloc) const; 96 void emitConstPoolAddress(unsigned CPI, unsigned Reloc) const; 97 void emitJumpTableAddress(unsigned JTIndex, unsigned Reloc) const; 98 void emitMachineBasicBlock(MachineBasicBlock *BB, unsigned Reloc) const; 99 100 /// getMachineOpValue - Return binary encoding of operand. If the machine 101 /// operand requires relocation, record the relocation and return zero. 102 unsigned getMachineOpValue(const MachineInstr &MI, 103 const MachineOperand &MO) const; 104 105 unsigned getRelocation(const MachineInstr &MI, 106 const MachineOperand &MO) const; 107 108 unsigned getJumpTargetOpValue(const MachineInstr &MI, unsigned OpNo) const; 109 110 unsigned getBranchTargetOpValue(const MachineInstr &MI, 111 unsigned OpNo) const; 112 unsigned getMemEncoding(const MachineInstr &MI, unsigned OpNo) const; 113 unsigned getSizeExtEncoding(const MachineInstr &MI, unsigned OpNo) const; 114 unsigned getSizeInsEncoding(const MachineInstr &MI, unsigned OpNo) const; 115 116 int emitULW(const MachineInstr &MI); 117 int emitUSW(const MachineInstr &MI); 118 int emitULH(const MachineInstr &MI); 119 int emitULHu(const MachineInstr &MI); 120 int emitUSH(const MachineInstr &MI); 121 122 void emitGlobalAddressUnaligned(const GlobalValue *GV, unsigned Reloc, 123 int Offset) const; 124 }; 125 } 126 127 char MipsCodeEmitter::ID = 0; 128 129 bool MipsCodeEmitter::runOnMachineFunction(MachineFunction &MF) { 130 JTI = ((MipsTargetMachine&) MF.getTarget()).getJITInfo(); 131 II = ((const MipsTargetMachine&) MF.getTarget()).getInstrInfo(); 132 TD = ((const MipsTargetMachine&) MF.getTarget()).getTargetData(); 133 Subtarget = &TM.getSubtarget<MipsSubtarget> (); 134 MCPEs = &MF.getConstantPool()->getConstants(); 135 MJTEs = 0; 136 if (MF.getJumpTableInfo()) MJTEs = &MF.getJumpTableInfo()->getJumpTables(); 137 JTI->Initialize(MF, IsPIC); 138 MCE.setModuleInfo(&getAnalysis<MachineModuleInfo> ()); 139 140 do { 141 DEBUG(errs() << "JITTing function '" 142 << MF.getFunction()->getName() << "'\n"); 143 MCE.startFunction(MF); 144 145 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end(); 146 MBB != E; ++MBB){ 147 MCE.StartMachineBasicBlock(MBB); 148 for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end(); 149 I != E; ++I) 150 emitInstruction(*I); 151 } 152 } while (MCE.finishFunction(MF)); 153 154 return false; 155 } 156 157 unsigned MipsCodeEmitter::getRelocation(const MachineInstr &MI, 158 const MachineOperand &MO) const { 159 // NOTE: This relocations are for static. 160 uint64_t TSFlags = MI.getDesc().TSFlags; 161 uint64_t Form = TSFlags & MipsII::FormMask; 162 if (Form == MipsII::FrmJ) 163 return Mips::reloc_mips_26; 164 if ((Form == MipsII::FrmI || Form == MipsII::FrmFI) 165 && MI.isBranch()) 166 return Mips::reloc_mips_pc16; 167 if (Form == MipsII::FrmI && MI.getOpcode() == Mips::LUi) 168 return Mips::reloc_mips_hi; 169 return Mips::reloc_mips_lo; 170 } 171 172 unsigned MipsCodeEmitter::getJumpTargetOpValue(const MachineInstr &MI, 173 unsigned OpNo) const { 174 MachineOperand MO = MI.getOperand(OpNo); 175 if (MO.isGlobal()) 176 emitGlobalAddress(MO.getGlobal(), getRelocation(MI, MO), true); 177 else if (MO.isSymbol()) 178 emitExternalSymbolAddress(MO.getSymbolName(), getRelocation(MI, MO)); 179 else if (MO.isMBB()) 180 emitMachineBasicBlock(MO.getMBB(), getRelocation(MI, MO)); 181 else 182 llvm_unreachable("Unexpected jump target operand kind."); 183 return 0; 184 } 185 186 unsigned MipsCodeEmitter::getBranchTargetOpValue(const MachineInstr &MI, 187 unsigned OpNo) const { 188 MachineOperand MO = MI.getOperand(OpNo); 189 emitMachineBasicBlock(MO.getMBB(), getRelocation(MI, MO)); 190 return 0; 191 } 192 193 unsigned MipsCodeEmitter::getMemEncoding(const MachineInstr &MI, 194 unsigned OpNo) const { 195 // Base register is encoded in bits 20-16, offset is encoded in bits 15-0. 196 assert(MI.getOperand(OpNo).isReg()); 197 unsigned RegBits = getMachineOpValue(MI, MI.getOperand(OpNo)) << 16; 198 return (getMachineOpValue(MI, MI.getOperand(OpNo+1)) & 0xFFFF) | RegBits; 199 } 200 201 unsigned MipsCodeEmitter::getSizeExtEncoding(const MachineInstr &MI, 202 unsigned OpNo) const { 203 // size is encoded as size-1. 204 return getMachineOpValue(MI, MI.getOperand(OpNo)) - 1; 205 } 206 207 unsigned MipsCodeEmitter::getSizeInsEncoding(const MachineInstr &MI, 208 unsigned OpNo) const { 209 // size is encoded as pos+size-1. 210 return getMachineOpValue(MI, MI.getOperand(OpNo-1)) + 211 getMachineOpValue(MI, MI.getOperand(OpNo)) - 1; 212 } 213 214 /// getMachineOpValue - Return binary encoding of operand. If the machine 215 /// operand requires relocation, record the relocation and return zero. 216 unsigned MipsCodeEmitter::getMachineOpValue(const MachineInstr &MI, 217 const MachineOperand &MO) const { 218 if (MO.isReg()) 219 return getMipsRegisterNumbering(MO.getReg()); 220 else if (MO.isImm()) 221 return static_cast<unsigned>(MO.getImm()); 222 else if (MO.isGlobal()) { 223 if (MI.getOpcode() == Mips::ULW || MI.getOpcode() == Mips::USW || 224 MI.getOpcode() == Mips::ULH || MI.getOpcode() == Mips::ULHu) 225 emitGlobalAddressUnaligned(MO.getGlobal(), getRelocation(MI, MO), 4); 226 else if (MI.getOpcode() == Mips::USH) 227 emitGlobalAddressUnaligned(MO.getGlobal(), getRelocation(MI, MO), 8); 228 else 229 emitGlobalAddress(MO.getGlobal(), getRelocation(MI, MO), true); 230 } else if (MO.isSymbol()) 231 emitExternalSymbolAddress(MO.getSymbolName(), getRelocation(MI, MO)); 232 else if (MO.isCPI()) 233 emitConstPoolAddress(MO.getIndex(), getRelocation(MI, MO)); 234 else if (MO.isJTI()) 235 emitJumpTableAddress(MO.getIndex(), getRelocation(MI, MO)); 236 else if (MO.isMBB()) 237 emitMachineBasicBlock(MO.getMBB(), getRelocation(MI, MO)); 238 else 239 llvm_unreachable("Unable to encode MachineOperand!"); 240 return 0; 241 } 242 243 void MipsCodeEmitter::emitGlobalAddress(const GlobalValue *GV, unsigned Reloc, 244 bool MayNeedFarStub) const { 245 MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc, 246 const_cast<GlobalValue *>(GV), 0, 247 MayNeedFarStub)); 248 } 249 250 void MipsCodeEmitter::emitGlobalAddressUnaligned(const GlobalValue *GV, 251 unsigned Reloc, int Offset) const { 252 MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset(), Reloc, 253 const_cast<GlobalValue *>(GV), 0, false)); 254 MCE.addRelocation(MachineRelocation::getGV(MCE.getCurrentPCOffset() + Offset, 255 Reloc, const_cast<GlobalValue *>(GV), 0, false)); 256 } 257 258 void MipsCodeEmitter:: 259 emitExternalSymbolAddress(const char *ES, unsigned Reloc) const { 260 MCE.addRelocation(MachineRelocation::getExtSym(MCE.getCurrentPCOffset(), 261 Reloc, ES, 0, 0, false)); 262 } 263 264 void MipsCodeEmitter::emitConstPoolAddress(unsigned CPI, unsigned Reloc) const { 265 MCE.addRelocation(MachineRelocation::getConstPool(MCE.getCurrentPCOffset(), 266 Reloc, CPI, 0, false)); 267 } 268 269 void MipsCodeEmitter:: 270 emitJumpTableAddress(unsigned JTIndex, unsigned Reloc) const { 271 MCE.addRelocation(MachineRelocation::getJumpTable(MCE.getCurrentPCOffset(), 272 Reloc, JTIndex, 0, false)); 273 } 274 275 void MipsCodeEmitter::emitMachineBasicBlock(MachineBasicBlock *BB, 276 unsigned Reloc) const { 277 MCE.addRelocation(MachineRelocation::getBB(MCE.getCurrentPCOffset(), 278 Reloc, BB)); 279 } 280 281 int MipsCodeEmitter::emitUSW(const MachineInstr &MI) { 282 unsigned src = getMachineOpValue(MI, MI.getOperand(0)); 283 unsigned base = getMachineOpValue(MI, MI.getOperand(1)); 284 unsigned offset = getMachineOpValue(MI, MI.getOperand(2)); 285 // swr src, offset(base) 286 // swl src, offset+3(base) 287 MCE.emitWordLE( 288 (0x2e << 26) | (base << 21) | (src << 16) | (offset & 0xffff)); 289 MCE.emitWordLE( 290 (0x2a << 26) | (base << 21) | (src << 16) | ((offset+3) & 0xffff)); 291 return 2; 292 } 293 294 int MipsCodeEmitter::emitULW(const MachineInstr &MI) { 295 unsigned dst = getMachineOpValue(MI, MI.getOperand(0)); 296 unsigned base = getMachineOpValue(MI, MI.getOperand(1)); 297 unsigned offset = getMachineOpValue(MI, MI.getOperand(2)); 298 unsigned at = 1; 299 if (dst != base) { 300 // lwr dst, offset(base) 301 // lwl dst, offset+3(base) 302 MCE.emitWordLE( 303 (0x26 << 26) | (base << 21) | (dst << 16) | (offset & 0xffff)); 304 MCE.emitWordLE( 305 (0x22 << 26) | (base << 21) | (dst << 16) | ((offset+3) & 0xffff)); 306 return 2; 307 } else { 308 // lwr at, offset(base) 309 // lwl at, offset+3(base) 310 // addu dst, at, $zero 311 MCE.emitWordLE( 312 (0x26 << 26) | (base << 21) | (at << 16) | (offset & 0xffff)); 313 MCE.emitWordLE( 314 (0x22 << 26) | (base << 21) | (at << 16) | ((offset+3) & 0xffff)); 315 MCE.emitWordLE( 316 (0x0 << 26) | (at << 21) | (0x0 << 16) | (dst << 11) | (0x0 << 6) | 0x21); 317 return 3; 318 } 319 } 320 321 int MipsCodeEmitter::emitUSH(const MachineInstr &MI) { 322 unsigned src = getMachineOpValue(MI, MI.getOperand(0)); 323 unsigned base = getMachineOpValue(MI, MI.getOperand(1)); 324 unsigned offset = getMachineOpValue(MI, MI.getOperand(2)); 325 unsigned at = 1; 326 // sb src, offset(base) 327 // srl at,src,8 328 // sb at, offset+1(base) 329 MCE.emitWordLE( 330 (0x28 << 26) | (base << 21) | (src << 16) | (offset & 0xffff)); 331 MCE.emitWordLE( 332 (0x0 << 26) | (0x0 << 21) | (src << 16) | (at << 11) | (0x8 << 6) | 0x2); 333 MCE.emitWordLE( 334 (0x28 << 26) | (base << 21) | (at << 16) | ((offset+1) & 0xffff)); 335 return 3; 336 } 337 338 int MipsCodeEmitter::emitULH(const MachineInstr &MI) { 339 unsigned dst = getMachineOpValue(MI, MI.getOperand(0)); 340 unsigned base = getMachineOpValue(MI, MI.getOperand(1)); 341 unsigned offset = getMachineOpValue(MI, MI.getOperand(2)); 342 unsigned at = 1; 343 // lbu at, offset(base) 344 // lb dst, offset+1(base) 345 // sll dst,dst,8 346 // or dst,dst,at 347 MCE.emitWordLE( 348 (0x24 << 26) | (base << 21) | (at << 16) | (offset & 0xffff)); 349 MCE.emitWordLE( 350 (0x20 << 26) | (base << 21) | (dst << 16) | ((offset+1) & 0xffff)); 351 MCE.emitWordLE( 352 (0x0 << 26) | (0x0 << 21) | (dst << 16) | (dst << 11) | (0x8 << 6) | 0x0); 353 MCE.emitWordLE( 354 (0x0 << 26) | (dst << 21) | (at << 16) | (dst << 11) | (0x0 << 6) | 0x25); 355 return 4; 356 } 357 358 int MipsCodeEmitter::emitULHu(const MachineInstr &MI) { 359 unsigned dst = getMachineOpValue(MI, MI.getOperand(0)); 360 unsigned base = getMachineOpValue(MI, MI.getOperand(1)); 361 unsigned offset = getMachineOpValue(MI, MI.getOperand(2)); 362 unsigned at = 1; 363 // lbu at, offset(base) 364 // lbu dst, offset+1(base) 365 // sll dst,dst,8 366 // or dst,dst,at 367 MCE.emitWordLE( 368 (0x24 << 26) | (base << 21) | (at << 16) | (offset & 0xffff)); 369 MCE.emitWordLE( 370 (0x24 << 26) | (base << 21) | (dst << 16) | ((offset+1) & 0xffff)); 371 MCE.emitWordLE( 372 (0x0 << 26) | (0x0 << 21) | (dst << 16) | (dst << 11) | (0x8 << 6) | 0x0); 373 MCE.emitWordLE( 374 (0x0 << 26) | (dst << 21) | (at << 16) | (dst << 11) | (0x0 << 6) | 0x25); 375 return 4; 376 } 377 378 void MipsCodeEmitter::emitInstruction(const MachineInstr &MI) { 379 DEBUG(errs() << "JIT: " << (void*)MCE.getCurrentPCValue() << ":\t" << MI); 380 381 MCE.processDebugLoc(MI.getDebugLoc(), true); 382 383 // Skip pseudo instructions. 384 if ((MI.getDesc().TSFlags & MipsII::FormMask) == MipsII::Pseudo) 385 return; 386 387 388 switch (MI.getOpcode()) { 389 case Mips::USW: 390 NumEmitted += emitUSW(MI); 391 break; 392 case Mips::ULW: 393 NumEmitted += emitULW(MI); 394 break; 395 case Mips::ULH: 396 NumEmitted += emitULH(MI); 397 break; 398 case Mips::ULHu: 399 NumEmitted += emitULHu(MI); 400 break; 401 case Mips::USH: 402 NumEmitted += emitUSH(MI); 403 break; 404 405 default: 406 emitWordLE(getBinaryCodeForInstr(MI)); 407 ++NumEmitted; // Keep track of the # of mi's emitted 408 break; 409 } 410 411 MCE.processDebugLoc(MI.getDebugLoc(), false); 412 } 413 414 void MipsCodeEmitter::emitWordLE(unsigned Word) { 415 DEBUG(errs() << " 0x"; 416 errs().write_hex(Word) << "\n"); 417 MCE.emitWordLE(Word); 418 } 419 420 /// createMipsJITCodeEmitterPass - Return a pass that emits the collected Mips 421 /// code to the specified MCE object. 422 FunctionPass *llvm::createMipsJITCodeEmitterPass(MipsTargetMachine &TM, 423 JITCodeEmitter &JCE) { 424 return new MipsCodeEmitter(TM, JCE); 425 } 426 427 #include "MipsGenCodeEmitter.inc" 428
