1 //===- SPUInstrInfo.cpp - Cell SPU Instruction Information ----------------===// 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 Cell SPU implementation of the TargetInstrInfo class. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "SPUInstrInfo.h" 15 #include "SPUInstrBuilder.h" 16 #include "SPUTargetMachine.h" 17 #include "SPUHazardRecognizers.h" 18 #include "llvm/CodeGen/MachineInstrBuilder.h" 19 #include "llvm/MC/MCContext.h" 20 #include "llvm/Support/Debug.h" 21 #include "llvm/Support/ErrorHandling.h" 22 #include "llvm/Support/TargetRegistry.h" 23 #include "llvm/Support/raw_ostream.h" 24 25 #define GET_INSTRINFO_CTOR 26 #include "SPUGenInstrInfo.inc" 27 28 using namespace llvm; 29 30 namespace { 31 //! Predicate for an unconditional branch instruction 32 inline bool isUncondBranch(const MachineInstr *I) { 33 unsigned opc = I->getOpcode(); 34 35 return (opc == SPU::BR 36 || opc == SPU::BRA 37 || opc == SPU::BI); 38 } 39 40 //! Predicate for a conditional branch instruction 41 inline bool isCondBranch(const MachineInstr *I) { 42 unsigned opc = I->getOpcode(); 43 44 return (opc == SPU::BRNZr32 45 || opc == SPU::BRNZv4i32 46 || opc == SPU::BRZr32 47 || opc == SPU::BRZv4i32 48 || opc == SPU::BRHNZr16 49 || opc == SPU::BRHNZv8i16 50 || opc == SPU::BRHZr16 51 || opc == SPU::BRHZv8i16); 52 } 53 } 54 55 SPUInstrInfo::SPUInstrInfo(SPUTargetMachine &tm) 56 : SPUGenInstrInfo(SPU::ADJCALLSTACKDOWN, SPU::ADJCALLSTACKUP), 57 TM(tm), 58 RI(*TM.getSubtargetImpl(), *this) 59 { /* NOP */ } 60 61 /// CreateTargetHazardRecognizer - Return the hazard recognizer to use for 62 /// this target when scheduling the DAG. 63 ScheduleHazardRecognizer *SPUInstrInfo::CreateTargetHazardRecognizer( 64 const TargetMachine *TM, 65 const ScheduleDAG *DAG) const { 66 const TargetInstrInfo *TII = TM->getInstrInfo(); 67 assert(TII && "No InstrInfo?"); 68 return new SPUHazardRecognizer(*TII); 69 } 70 71 unsigned 72 SPUInstrInfo::isLoadFromStackSlot(const MachineInstr *MI, 73 int &FrameIndex) const { 74 switch (MI->getOpcode()) { 75 default: break; 76 case SPU::LQDv16i8: 77 case SPU::LQDv8i16: 78 case SPU::LQDv4i32: 79 case SPU::LQDv4f32: 80 case SPU::LQDv2f64: 81 case SPU::LQDr128: 82 case SPU::LQDr64: 83 case SPU::LQDr32: 84 case SPU::LQDr16: { 85 const MachineOperand MOp1 = MI->getOperand(1); 86 const MachineOperand MOp2 = MI->getOperand(2); 87 if (MOp1.isImm() && MOp2.isFI()) { 88 FrameIndex = MOp2.getIndex(); 89 return MI->getOperand(0).getReg(); 90 } 91 break; 92 } 93 } 94 return 0; 95 } 96 97 unsigned 98 SPUInstrInfo::isStoreToStackSlot(const MachineInstr *MI, 99 int &FrameIndex) const { 100 switch (MI->getOpcode()) { 101 default: break; 102 case SPU::STQDv16i8: 103 case SPU::STQDv8i16: 104 case SPU::STQDv4i32: 105 case SPU::STQDv4f32: 106 case SPU::STQDv2f64: 107 case SPU::STQDr128: 108 case SPU::STQDr64: 109 case SPU::STQDr32: 110 case SPU::STQDr16: 111 case SPU::STQDr8: { 112 const MachineOperand MOp1 = MI->getOperand(1); 113 const MachineOperand MOp2 = MI->getOperand(2); 114 if (MOp1.isImm() && MOp2.isFI()) { 115 FrameIndex = MOp2.getIndex(); 116 return MI->getOperand(0).getReg(); 117 } 118 break; 119 } 120 } 121 return 0; 122 } 123 124 void SPUInstrInfo::copyPhysReg(MachineBasicBlock &MBB, 125 MachineBasicBlock::iterator I, DebugLoc DL, 126 unsigned DestReg, unsigned SrcReg, 127 bool KillSrc) const 128 { 129 // We support cross register class moves for our aliases, such as R3 in any 130 // reg class to any other reg class containing R3. This is required because 131 // we instruction select bitconvert i64 -> f64 as a noop for example, so our 132 // types have no specific meaning. 133 134 BuildMI(MBB, I, DL, get(SPU::LRr128), DestReg) 135 .addReg(SrcReg, getKillRegState(KillSrc)); 136 } 137 138 void 139 SPUInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB, 140 MachineBasicBlock::iterator MI, 141 unsigned SrcReg, bool isKill, int FrameIdx, 142 const TargetRegisterClass *RC, 143 const TargetRegisterInfo *TRI) const 144 { 145 unsigned opc; 146 bool isValidFrameIdx = (FrameIdx < SPUFrameLowering::maxFrameOffset()); 147 if (RC == SPU::GPRCRegisterClass) { 148 opc = (isValidFrameIdx ? SPU::STQDr128 : SPU::STQXr128); 149 } else if (RC == SPU::R64CRegisterClass) { 150 opc = (isValidFrameIdx ? SPU::STQDr64 : SPU::STQXr64); 151 } else if (RC == SPU::R64FPRegisterClass) { 152 opc = (isValidFrameIdx ? SPU::STQDr64 : SPU::STQXr64); 153 } else if (RC == SPU::R32CRegisterClass) { 154 opc = (isValidFrameIdx ? SPU::STQDr32 : SPU::STQXr32); 155 } else if (RC == SPU::R32FPRegisterClass) { 156 opc = (isValidFrameIdx ? SPU::STQDr32 : SPU::STQXr32); 157 } else if (RC == SPU::R16CRegisterClass) { 158 opc = (isValidFrameIdx ? SPU::STQDr16 : SPU::STQXr16); 159 } else if (RC == SPU::R8CRegisterClass) { 160 opc = (isValidFrameIdx ? SPU::STQDr8 : SPU::STQXr8); 161 } else if (RC == SPU::VECREGRegisterClass) { 162 opc = (isValidFrameIdx) ? SPU::STQDv16i8 : SPU::STQXv16i8; 163 } else { 164 llvm_unreachable("Unknown regclass!"); 165 } 166 167 DebugLoc DL; 168 if (MI != MBB.end()) DL = MI->getDebugLoc(); 169 addFrameReference(BuildMI(MBB, MI, DL, get(opc)) 170 .addReg(SrcReg, getKillRegState(isKill)), FrameIdx); 171 } 172 173 void 174 SPUInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB, 175 MachineBasicBlock::iterator MI, 176 unsigned DestReg, int FrameIdx, 177 const TargetRegisterClass *RC, 178 const TargetRegisterInfo *TRI) const 179 { 180 unsigned opc; 181 bool isValidFrameIdx = (FrameIdx < SPUFrameLowering::maxFrameOffset()); 182 if (RC == SPU::GPRCRegisterClass) { 183 opc = (isValidFrameIdx ? SPU::LQDr128 : SPU::LQXr128); 184 } else if (RC == SPU::R64CRegisterClass) { 185 opc = (isValidFrameIdx ? SPU::LQDr64 : SPU::LQXr64); 186 } else if (RC == SPU::R64FPRegisterClass) { 187 opc = (isValidFrameIdx ? SPU::LQDr64 : SPU::LQXr64); 188 } else if (RC == SPU::R32CRegisterClass) { 189 opc = (isValidFrameIdx ? SPU::LQDr32 : SPU::LQXr32); 190 } else if (RC == SPU::R32FPRegisterClass) { 191 opc = (isValidFrameIdx ? SPU::LQDr32 : SPU::LQXr32); 192 } else if (RC == SPU::R16CRegisterClass) { 193 opc = (isValidFrameIdx ? SPU::LQDr16 : SPU::LQXr16); 194 } else if (RC == SPU::R8CRegisterClass) { 195 opc = (isValidFrameIdx ? SPU::LQDr8 : SPU::LQXr8); 196 } else if (RC == SPU::VECREGRegisterClass) { 197 opc = (isValidFrameIdx) ? SPU::LQDv16i8 : SPU::LQXv16i8; 198 } else { 199 llvm_unreachable("Unknown regclass in loadRegFromStackSlot!"); 200 } 201 202 DebugLoc DL; 203 if (MI != MBB.end()) DL = MI->getDebugLoc(); 204 addFrameReference(BuildMI(MBB, MI, DL, get(opc), DestReg), FrameIdx); 205 } 206 207 //! Branch analysis 208 /*! 209 \note This code was kiped from PPC. There may be more branch analysis for 210 CellSPU than what's currently done here. 211 */ 212 bool 213 SPUInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB, 214 MachineBasicBlock *&FBB, 215 SmallVectorImpl<MachineOperand> &Cond, 216 bool AllowModify) const { 217 // If the block has no terminators, it just falls into the block after it. 218 MachineBasicBlock::iterator I = MBB.end(); 219 if (I == MBB.begin()) 220 return false; 221 --I; 222 while (I->isDebugValue()) { 223 if (I == MBB.begin()) 224 return false; 225 --I; 226 } 227 if (!isUnpredicatedTerminator(I)) 228 return false; 229 230 // Get the last instruction in the block. 231 MachineInstr *LastInst = I; 232 233 // If there is only one terminator instruction, process it. 234 if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) { 235 if (isUncondBranch(LastInst)) { 236 // Check for jump tables 237 if (!LastInst->getOperand(0).isMBB()) 238 return true; 239 TBB = LastInst->getOperand(0).getMBB(); 240 return false; 241 } else if (isCondBranch(LastInst)) { 242 // Block ends with fall-through condbranch. 243 TBB = LastInst->getOperand(1).getMBB(); 244 DEBUG(errs() << "Pushing LastInst: "); 245 DEBUG(LastInst->dump()); 246 Cond.push_back(MachineOperand::CreateImm(LastInst->getOpcode())); 247 Cond.push_back(LastInst->getOperand(0)); 248 return false; 249 } 250 // Otherwise, don't know what this is. 251 return true; 252 } 253 254 // Get the instruction before it if it's a terminator. 255 MachineInstr *SecondLastInst = I; 256 257 // If there are three terminators, we don't know what sort of block this is. 258 if (SecondLastInst && I != MBB.begin() && 259 isUnpredicatedTerminator(--I)) 260 return true; 261 262 // If the block ends with a conditional and unconditional branch, handle it. 263 if (isCondBranch(SecondLastInst) && isUncondBranch(LastInst)) { 264 TBB = SecondLastInst->getOperand(1).getMBB(); 265 DEBUG(errs() << "Pushing SecondLastInst: "); 266 DEBUG(SecondLastInst->dump()); 267 Cond.push_back(MachineOperand::CreateImm(SecondLastInst->getOpcode())); 268 Cond.push_back(SecondLastInst->getOperand(0)); 269 FBB = LastInst->getOperand(0).getMBB(); 270 return false; 271 } 272 273 // If the block ends with two unconditional branches, handle it. The second 274 // one is not executed, so remove it. 275 if (isUncondBranch(SecondLastInst) && isUncondBranch(LastInst)) { 276 TBB = SecondLastInst->getOperand(0).getMBB(); 277 I = LastInst; 278 if (AllowModify) 279 I->eraseFromParent(); 280 return false; 281 } 282 283 // Otherwise, can't handle this. 284 return true; 285 } 286 287 // search MBB for branch hint labels and branch hit ops 288 static void removeHBR( MachineBasicBlock &MBB) { 289 for (MachineBasicBlock::iterator I = MBB.begin(); I != MBB.end(); ++I){ 290 if (I->getOpcode() == SPU::HBRA || 291 I->getOpcode() == SPU::HBR_LABEL){ 292 I=MBB.erase(I); 293 if (I == MBB.end()) 294 break; 295 } 296 } 297 } 298 299 unsigned 300 SPUInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const { 301 MachineBasicBlock::iterator I = MBB.end(); 302 removeHBR(MBB); 303 if (I == MBB.begin()) 304 return 0; 305 --I; 306 while (I->isDebugValue()) { 307 if (I == MBB.begin()) 308 return 0; 309 --I; 310 } 311 if (!isCondBranch(I) && !isUncondBranch(I)) 312 return 0; 313 314 // Remove the first branch. 315 DEBUG(errs() << "Removing branch: "); 316 DEBUG(I->dump()); 317 I->eraseFromParent(); 318 I = MBB.end(); 319 if (I == MBB.begin()) 320 return 1; 321 322 --I; 323 if (!(isCondBranch(I) || isUncondBranch(I))) 324 return 1; 325 326 // Remove the second branch. 327 DEBUG(errs() << "Removing second branch: "); 328 DEBUG(I->dump()); 329 I->eraseFromParent(); 330 return 2; 331 } 332 333 /** Find the optimal position for a hint branch instruction in a basic block. 334 * This should take into account: 335 * -the branch hint delays 336 * -congestion of the memory bus 337 * -dual-issue scheduling (i.e. avoid insertion of nops) 338 * Current implementation is rather simplistic. 339 */ 340 static MachineBasicBlock::iterator findHBRPosition(MachineBasicBlock &MBB) 341 { 342 MachineBasicBlock::iterator J = MBB.end(); 343 for( int i=0; i<8; i++) { 344 if( J == MBB.begin() ) return J; 345 J--; 346 } 347 return J; 348 } 349 350 unsigned 351 SPUInstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB, 352 MachineBasicBlock *FBB, 353 const SmallVectorImpl<MachineOperand> &Cond, 354 DebugLoc DL) const { 355 // Shouldn't be a fall through. 356 assert(TBB && "InsertBranch must not be told to insert a fallthrough"); 357 assert((Cond.size() == 2 || Cond.size() == 0) && 358 "SPU branch conditions have two components!"); 359 360 MachineInstrBuilder MIB; 361 //TODO: make a more accurate algorithm. 362 bool haveHBR = MBB.size()>8; 363 364 removeHBR(MBB); 365 MCSymbol *branchLabel = MBB.getParent()->getContext().CreateTempSymbol(); 366 // Add a label just before the branch 367 if (haveHBR) 368 MIB = BuildMI(&MBB, DL, get(SPU::HBR_LABEL)).addSym(branchLabel); 369 370 // One-way branch. 371 if (FBB == 0) { 372 if (Cond.empty()) { 373 // Unconditional branch 374 MIB = BuildMI(&MBB, DL, get(SPU::BR)); 375 MIB.addMBB(TBB); 376 377 DEBUG(errs() << "Inserted one-way uncond branch: "); 378 DEBUG((*MIB).dump()); 379 380 // basic blocks have just one branch so it is safe to add the hint a its 381 if (haveHBR) { 382 MIB = BuildMI( MBB, findHBRPosition(MBB), DL, get(SPU::HBRA)); 383 MIB.addSym(branchLabel); 384 MIB.addMBB(TBB); 385 } 386 } else { 387 // Conditional branch 388 MIB = BuildMI(&MBB, DL, get(Cond[0].getImm())); 389 MIB.addReg(Cond[1].getReg()).addMBB(TBB); 390 391 if (haveHBR) { 392 MIB = BuildMI(MBB, findHBRPosition(MBB), DL, get(SPU::HBRA)); 393 MIB.addSym(branchLabel); 394 MIB.addMBB(TBB); 395 } 396 397 DEBUG(errs() << "Inserted one-way cond branch: "); 398 DEBUG((*MIB).dump()); 399 } 400 return 1; 401 } else { 402 MIB = BuildMI(&MBB, DL, get(Cond[0].getImm())); 403 MachineInstrBuilder MIB2 = BuildMI(&MBB, DL, get(SPU::BR)); 404 405 // Two-way Conditional Branch. 406 MIB.addReg(Cond[1].getReg()).addMBB(TBB); 407 MIB2.addMBB(FBB); 408 409 if (haveHBR) { 410 MIB = BuildMI( MBB, findHBRPosition(MBB), DL, get(SPU::HBRA)); 411 MIB.addSym(branchLabel); 412 MIB.addMBB(FBB); 413 } 414 415 DEBUG(errs() << "Inserted conditional branch: "); 416 DEBUG((*MIB).dump()); 417 DEBUG(errs() << "part 2: "); 418 DEBUG((*MIB2).dump()); 419 return 2; 420 } 421 } 422 423 //! Reverses a branch's condition, returning false on success. 424 bool 425 SPUInstrInfo::ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) 426 const { 427 // Pretty brainless way of inverting the condition, but it works, considering 428 // there are only two conditions... 429 static struct { 430 unsigned Opc; //! The incoming opcode 431 unsigned RevCondOpc; //! The reversed condition opcode 432 } revconds[] = { 433 { SPU::BRNZr32, SPU::BRZr32 }, 434 { SPU::BRNZv4i32, SPU::BRZv4i32 }, 435 { SPU::BRZr32, SPU::BRNZr32 }, 436 { SPU::BRZv4i32, SPU::BRNZv4i32 }, 437 { SPU::BRHNZr16, SPU::BRHZr16 }, 438 { SPU::BRHNZv8i16, SPU::BRHZv8i16 }, 439 { SPU::BRHZr16, SPU::BRHNZr16 }, 440 { SPU::BRHZv8i16, SPU::BRHNZv8i16 } 441 }; 442 443 unsigned Opc = unsigned(Cond[0].getImm()); 444 // Pretty dull mapping between the two conditions that SPU can generate: 445 for (int i = sizeof(revconds)/sizeof(revconds[0]) - 1; i >= 0; --i) { 446 if (revconds[i].Opc == Opc) { 447 Cond[0].setImm(revconds[i].RevCondOpc); 448 return false; 449 } 450 } 451 452 return true; 453 } 454
