SelectionDAGISel.cpp revision bb466331e7e50d03497ce40ee344870236fd9c32
1//===-- SelectionDAGISel.cpp - Implement the SelectionDAGISel class -------===// 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 implements the SelectionDAGISel class. 11// 12//===----------------------------------------------------------------------===// 13 14#define DEBUG_TYPE "isel" 15#include "llvm/CodeGen/SelectionDAGISel.h" 16#include "llvm/ADT/BitVector.h" 17#include "llvm/Analysis/AliasAnalysis.h" 18#include "llvm/Constants.h" 19#include "llvm/CallingConv.h" 20#include "llvm/DerivedTypes.h" 21#include "llvm/Function.h" 22#include "llvm/GlobalVariable.h" 23#include "llvm/InlineAsm.h" 24#include "llvm/Instructions.h" 25#include "llvm/Intrinsics.h" 26#include "llvm/IntrinsicInst.h" 27#include "llvm/ParameterAttributes.h" 28#include "llvm/CodeGen/FastISel.h" 29#include "llvm/CodeGen/GCStrategy.h" 30#include "llvm/CodeGen/GCMetadata.h" 31#include "llvm/CodeGen/MachineFunction.h" 32#include "llvm/CodeGen/MachineFrameInfo.h" 33#include "llvm/CodeGen/MachineInstrBuilder.h" 34#include "llvm/CodeGen/MachineJumpTableInfo.h" 35#include "llvm/CodeGen/MachineModuleInfo.h" 36#include "llvm/CodeGen/MachineRegisterInfo.h" 37#include "llvm/CodeGen/ScheduleDAG.h" 38#include "llvm/CodeGen/SchedulerRegistry.h" 39#include "llvm/CodeGen/SelectionDAG.h" 40#include "llvm/Target/TargetRegisterInfo.h" 41#include "llvm/Target/TargetData.h" 42#include "llvm/Target/TargetFrameInfo.h" 43#include "llvm/Target/TargetInstrInfo.h" 44#include "llvm/Target/TargetLowering.h" 45#include "llvm/Target/TargetMachine.h" 46#include "llvm/Target/TargetOptions.h" 47#include "llvm/Support/Compiler.h" 48#include "llvm/Support/Debug.h" 49#include "llvm/Support/MathExtras.h" 50#include "llvm/Support/Timer.h" 51#include <algorithm> 52using namespace llvm; 53 54static cl::opt<bool> 55EnableValueProp("enable-value-prop", cl::Hidden); 56static cl::opt<bool> 57EnableLegalizeTypes("enable-legalize-types", cl::Hidden); 58static cl::opt<bool> 59EnableFastISel("fast-isel", cl::Hidden, 60 cl::desc("Enable the experimental \"fast\" instruction selector")); 61static cl::opt<bool> 62DisableFastISelAbort("fast-isel-no-abort", cl::Hidden, 63 cl::desc("Use the SelectionDAGISel when \"fast\" instruction " 64 "selection fails")); 65 66#ifndef NDEBUG 67static cl::opt<bool> 68ViewDAGCombine1("view-dag-combine1-dags", cl::Hidden, 69 cl::desc("Pop up a window to show dags before the first " 70 "dag combine pass")); 71static cl::opt<bool> 72ViewLegalizeTypesDAGs("view-legalize-types-dags", cl::Hidden, 73 cl::desc("Pop up a window to show dags before legalize types")); 74static cl::opt<bool> 75ViewLegalizeDAGs("view-legalize-dags", cl::Hidden, 76 cl::desc("Pop up a window to show dags before legalize")); 77static cl::opt<bool> 78ViewDAGCombine2("view-dag-combine2-dags", cl::Hidden, 79 cl::desc("Pop up a window to show dags before the second " 80 "dag combine pass")); 81static cl::opt<bool> 82ViewISelDAGs("view-isel-dags", cl::Hidden, 83 cl::desc("Pop up a window to show isel dags as they are selected")); 84static cl::opt<bool> 85ViewSchedDAGs("view-sched-dags", cl::Hidden, 86 cl::desc("Pop up a window to show sched dags as they are processed")); 87static cl::opt<bool> 88ViewSUnitDAGs("view-sunit-dags", cl::Hidden, 89 cl::desc("Pop up a window to show SUnit dags after they are processed")); 90#else 91static const bool ViewDAGCombine1 = false, 92 ViewLegalizeTypesDAGs = false, ViewLegalizeDAGs = false, 93 ViewDAGCombine2 = false, 94 ViewISelDAGs = false, ViewSchedDAGs = false, 95 ViewSUnitDAGs = false; 96#endif 97 98//===---------------------------------------------------------------------===// 99/// 100/// RegisterScheduler class - Track the registration of instruction schedulers. 101/// 102//===---------------------------------------------------------------------===// 103MachinePassRegistry RegisterScheduler::Registry; 104 105//===---------------------------------------------------------------------===// 106/// 107/// ISHeuristic command line option for instruction schedulers. 108/// 109//===---------------------------------------------------------------------===// 110static cl::opt<RegisterScheduler::FunctionPassCtor, false, 111 RegisterPassParser<RegisterScheduler> > 112ISHeuristic("pre-RA-sched", 113 cl::init(&createDefaultScheduler), 114 cl::desc("Instruction schedulers available (before register" 115 " allocation):")); 116 117static RegisterScheduler 118defaultListDAGScheduler("default", " Best scheduler for the target", 119 createDefaultScheduler); 120 121namespace { struct SDISelAsmOperandInfo; } 122 123/// ComputeLinearIndex - Given an LLVM IR aggregate type and a sequence 124/// insertvalue or extractvalue indices that identify a member, return 125/// the linearized index of the start of the member. 126/// 127static unsigned ComputeLinearIndex(const TargetLowering &TLI, const Type *Ty, 128 const unsigned *Indices, 129 const unsigned *IndicesEnd, 130 unsigned CurIndex = 0) { 131 // Base case: We're done. 132 if (Indices && Indices == IndicesEnd) 133 return CurIndex; 134 135 // Given a struct type, recursively traverse the elements. 136 if (const StructType *STy = dyn_cast<StructType>(Ty)) { 137 for (StructType::element_iterator EB = STy->element_begin(), 138 EI = EB, 139 EE = STy->element_end(); 140 EI != EE; ++EI) { 141 if (Indices && *Indices == unsigned(EI - EB)) 142 return ComputeLinearIndex(TLI, *EI, Indices+1, IndicesEnd, CurIndex); 143 CurIndex = ComputeLinearIndex(TLI, *EI, 0, 0, CurIndex); 144 } 145 } 146 // Given an array type, recursively traverse the elements. 147 else if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) { 148 const Type *EltTy = ATy->getElementType(); 149 for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i) { 150 if (Indices && *Indices == i) 151 return ComputeLinearIndex(TLI, EltTy, Indices+1, IndicesEnd, CurIndex); 152 CurIndex = ComputeLinearIndex(TLI, EltTy, 0, 0, CurIndex); 153 } 154 } 155 // We haven't found the type we're looking for, so keep searching. 156 return CurIndex + 1; 157} 158 159/// ComputeValueVTs - Given an LLVM IR type, compute a sequence of 160/// MVTs that represent all the individual underlying 161/// non-aggregate types that comprise it. 162/// 163/// If Offsets is non-null, it points to a vector to be filled in 164/// with the in-memory offsets of each of the individual values. 165/// 166static void ComputeValueVTs(const TargetLowering &TLI, const Type *Ty, 167 SmallVectorImpl<MVT> &ValueVTs, 168 SmallVectorImpl<uint64_t> *Offsets = 0, 169 uint64_t StartingOffset = 0) { 170 // Given a struct type, recursively traverse the elements. 171 if (const StructType *STy = dyn_cast<StructType>(Ty)) { 172 const StructLayout *SL = TLI.getTargetData()->getStructLayout(STy); 173 for (StructType::element_iterator EB = STy->element_begin(), 174 EI = EB, 175 EE = STy->element_end(); 176 EI != EE; ++EI) 177 ComputeValueVTs(TLI, *EI, ValueVTs, Offsets, 178 StartingOffset + SL->getElementOffset(EI - EB)); 179 return; 180 } 181 // Given an array type, recursively traverse the elements. 182 if (const ArrayType *ATy = dyn_cast<ArrayType>(Ty)) { 183 const Type *EltTy = ATy->getElementType(); 184 uint64_t EltSize = TLI.getTargetData()->getABITypeSize(EltTy); 185 for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i) 186 ComputeValueVTs(TLI, EltTy, ValueVTs, Offsets, 187 StartingOffset + i * EltSize); 188 return; 189 } 190 // Base case: we can get an MVT for this LLVM IR type. 191 ValueVTs.push_back(TLI.getValueType(Ty)); 192 if (Offsets) 193 Offsets->push_back(StartingOffset); 194} 195 196namespace { 197 /// RegsForValue - This struct represents the registers (physical or virtual) 198 /// that a particular set of values is assigned, and the type information about 199 /// the value. The most common situation is to represent one value at a time, 200 /// but struct or array values are handled element-wise as multiple values. 201 /// The splitting of aggregates is performed recursively, so that we never 202 /// have aggregate-typed registers. The values at this point do not necessarily 203 /// have legal types, so each value may require one or more registers of some 204 /// legal type. 205 /// 206 struct VISIBILITY_HIDDEN RegsForValue { 207 /// TLI - The TargetLowering object. 208 /// 209 const TargetLowering *TLI; 210 211 /// ValueVTs - The value types of the values, which may not be legal, and 212 /// may need be promoted or synthesized from one or more registers. 213 /// 214 SmallVector<MVT, 4> ValueVTs; 215 216 /// RegVTs - The value types of the registers. This is the same size as 217 /// ValueVTs and it records, for each value, what the type of the assigned 218 /// register or registers are. (Individual values are never synthesized 219 /// from more than one type of register.) 220 /// 221 /// With virtual registers, the contents of RegVTs is redundant with TLI's 222 /// getRegisterType member function, however when with physical registers 223 /// it is necessary to have a separate record of the types. 224 /// 225 SmallVector<MVT, 4> RegVTs; 226 227 /// Regs - This list holds the registers assigned to the values. 228 /// Each legal or promoted value requires one register, and each 229 /// expanded value requires multiple registers. 230 /// 231 SmallVector<unsigned, 4> Regs; 232 233 RegsForValue() : TLI(0) {} 234 235 RegsForValue(const TargetLowering &tli, 236 const SmallVector<unsigned, 4> ®s, 237 MVT regvt, MVT valuevt) 238 : TLI(&tli), ValueVTs(1, valuevt), RegVTs(1, regvt), Regs(regs) {} 239 RegsForValue(const TargetLowering &tli, 240 const SmallVector<unsigned, 4> ®s, 241 const SmallVector<MVT, 4> ®vts, 242 const SmallVector<MVT, 4> &valuevts) 243 : TLI(&tli), ValueVTs(valuevts), RegVTs(regvts), Regs(regs) {} 244 RegsForValue(const TargetLowering &tli, 245 unsigned Reg, const Type *Ty) : TLI(&tli) { 246 ComputeValueVTs(tli, Ty, ValueVTs); 247 248 for (unsigned Value = 0, e = ValueVTs.size(); Value != e; ++Value) { 249 MVT ValueVT = ValueVTs[Value]; 250 unsigned NumRegs = TLI->getNumRegisters(ValueVT); 251 MVT RegisterVT = TLI->getRegisterType(ValueVT); 252 for (unsigned i = 0; i != NumRegs; ++i) 253 Regs.push_back(Reg + i); 254 RegVTs.push_back(RegisterVT); 255 Reg += NumRegs; 256 } 257 } 258 259 /// append - Add the specified values to this one. 260 void append(const RegsForValue &RHS) { 261 TLI = RHS.TLI; 262 ValueVTs.append(RHS.ValueVTs.begin(), RHS.ValueVTs.end()); 263 RegVTs.append(RHS.RegVTs.begin(), RHS.RegVTs.end()); 264 Regs.append(RHS.Regs.begin(), RHS.Regs.end()); 265 } 266 267 268 /// getCopyFromRegs - Emit a series of CopyFromReg nodes that copies from 269 /// this value and returns the result as a ValueVTs value. This uses 270 /// Chain/Flag as the input and updates them for the output Chain/Flag. 271 /// If the Flag pointer is NULL, no flag is used. 272 SDValue getCopyFromRegs(SelectionDAG &DAG, 273 SDValue &Chain, SDValue *Flag) const; 274 275 /// getCopyToRegs - Emit a series of CopyToReg nodes that copies the 276 /// specified value into the registers specified by this object. This uses 277 /// Chain/Flag as the input and updates them for the output Chain/Flag. 278 /// If the Flag pointer is NULL, no flag is used. 279 void getCopyToRegs(SDValue Val, SelectionDAG &DAG, 280 SDValue &Chain, SDValue *Flag) const; 281 282 /// AddInlineAsmOperands - Add this value to the specified inlineasm node 283 /// operand list. This adds the code marker and includes the number of 284 /// values added into it. 285 void AddInlineAsmOperands(unsigned Code, SelectionDAG &DAG, 286 std::vector<SDValue> &Ops) const; 287 }; 288} 289 290namespace llvm { 291 //===--------------------------------------------------------------------===// 292 /// createDefaultScheduler - This creates an instruction scheduler appropriate 293 /// for the target. 294 ScheduleDAG* createDefaultScheduler(SelectionDAGISel *IS, 295 SelectionDAG *DAG, 296 MachineBasicBlock *BB, 297 bool Fast) { 298 TargetLowering &TLI = IS->getTargetLowering(); 299 300 if (TLI.getSchedulingPreference() == TargetLowering::SchedulingForLatency) { 301 return createTDListDAGScheduler(IS, DAG, BB, Fast); 302 } else { 303 assert(TLI.getSchedulingPreference() == 304 TargetLowering::SchedulingForRegPressure && "Unknown sched type!"); 305 return createBURRListDAGScheduler(IS, DAG, BB, Fast); 306 } 307 } 308 309 310 //===--------------------------------------------------------------------===// 311 /// FunctionLoweringInfo - This contains information that is global to a 312 /// function that is used when lowering a region of the function. 313 class FunctionLoweringInfo { 314 public: 315 TargetLowering &TLI; 316 Function &Fn; 317 MachineFunction &MF; 318 MachineRegisterInfo &RegInfo; 319 320 FunctionLoweringInfo(TargetLowering &TLI, Function &Fn,MachineFunction &MF); 321 322 /// MBBMap - A mapping from LLVM basic blocks to their machine code entry. 323 std::map<const BasicBlock*, MachineBasicBlock *> MBBMap; 324 325 /// ValueMap - Since we emit code for the function a basic block at a time, 326 /// we must remember which virtual registers hold the values for 327 /// cross-basic-block values. 328 DenseMap<const Value*, unsigned> ValueMap; 329 330 /// StaticAllocaMap - Keep track of frame indices for fixed sized allocas in 331 /// the entry block. This allows the allocas to be efficiently referenced 332 /// anywhere in the function. 333 std::map<const AllocaInst*, int> StaticAllocaMap; 334 335#ifndef NDEBUG 336 SmallSet<Instruction*, 8> CatchInfoLost; 337 SmallSet<Instruction*, 8> CatchInfoFound; 338#endif 339 340 unsigned MakeReg(MVT VT) { 341 return RegInfo.createVirtualRegister(TLI.getRegClassFor(VT)); 342 } 343 344 /// isExportedInst - Return true if the specified value is an instruction 345 /// exported from its block. 346 bool isExportedInst(const Value *V) { 347 return ValueMap.count(V); 348 } 349 350 unsigned CreateRegForValue(const Value *V); 351 352 unsigned InitializeRegForValue(const Value *V) { 353 unsigned &R = ValueMap[V]; 354 assert(R == 0 && "Already initialized this value register!"); 355 return R = CreateRegForValue(V); 356 } 357 358 struct LiveOutInfo { 359 unsigned NumSignBits; 360 APInt KnownOne, KnownZero; 361 LiveOutInfo() : NumSignBits(0) {} 362 }; 363 364 /// LiveOutRegInfo - Information about live out vregs, indexed by their 365 /// register number offset by 'FirstVirtualRegister'. 366 std::vector<LiveOutInfo> LiveOutRegInfo; 367 }; 368} 369 370/// isSelector - Return true if this instruction is a call to the 371/// eh.selector intrinsic. 372static bool isSelector(Instruction *I) { 373 if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(I)) 374 return (II->getIntrinsicID() == Intrinsic::eh_selector_i32 || 375 II->getIntrinsicID() == Intrinsic::eh_selector_i64); 376 return false; 377} 378 379/// isUsedOutsideOfDefiningBlock - Return true if this instruction is used by 380/// PHI nodes or outside of the basic block that defines it, or used by a 381/// switch or atomic instruction, which may expand to multiple basic blocks. 382static bool isUsedOutsideOfDefiningBlock(Instruction *I) { 383 if (isa<PHINode>(I)) return true; 384 BasicBlock *BB = I->getParent(); 385 for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E; ++UI) 386 if (cast<Instruction>(*UI)->getParent() != BB || isa<PHINode>(*UI) || 387 // FIXME: Remove switchinst special case. 388 isa<SwitchInst>(*UI)) 389 return true; 390 return false; 391} 392 393/// isOnlyUsedInEntryBlock - If the specified argument is only used in the 394/// entry block, return true. This includes arguments used by switches, since 395/// the switch may expand into multiple basic blocks. 396static bool isOnlyUsedInEntryBlock(Argument *A) { 397 BasicBlock *Entry = A->getParent()->begin(); 398 for (Value::use_iterator UI = A->use_begin(), E = A->use_end(); UI != E; ++UI) 399 if (cast<Instruction>(*UI)->getParent() != Entry || isa<SwitchInst>(*UI)) 400 return false; // Use not in entry block. 401 return true; 402} 403 404FunctionLoweringInfo::FunctionLoweringInfo(TargetLowering &tli, 405 Function &fn, MachineFunction &mf) 406 : TLI(tli), Fn(fn), MF(mf), RegInfo(MF.getRegInfo()) { 407 408 // Create a vreg for each argument register that is not dead and is used 409 // outside of the entry block for the function. 410 for (Function::arg_iterator AI = Fn.arg_begin(), E = Fn.arg_end(); 411 AI != E; ++AI) 412 if (!isOnlyUsedInEntryBlock(AI)) 413 InitializeRegForValue(AI); 414 415 // Initialize the mapping of values to registers. This is only set up for 416 // instruction values that are used outside of the block that defines 417 // them. 418 Function::iterator BB = Fn.begin(), EB = Fn.end(); 419 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) 420 if (AllocaInst *AI = dyn_cast<AllocaInst>(I)) 421 if (ConstantInt *CUI = dyn_cast<ConstantInt>(AI->getArraySize())) { 422 const Type *Ty = AI->getAllocatedType(); 423 uint64_t TySize = TLI.getTargetData()->getABITypeSize(Ty); 424 unsigned Align = 425 std::max((unsigned)TLI.getTargetData()->getPrefTypeAlignment(Ty), 426 AI->getAlignment()); 427 428 TySize *= CUI->getZExtValue(); // Get total allocated size. 429 if (TySize == 0) TySize = 1; // Don't create zero-sized stack objects. 430 StaticAllocaMap[AI] = 431 MF.getFrameInfo()->CreateStackObject(TySize, Align); 432 } 433 434 for (; BB != EB; ++BB) 435 for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) 436 if (!I->use_empty() && isUsedOutsideOfDefiningBlock(I)) 437 if (!isa<AllocaInst>(I) || 438 !StaticAllocaMap.count(cast<AllocaInst>(I))) 439 InitializeRegForValue(I); 440 441 // Create an initial MachineBasicBlock for each LLVM BasicBlock in F. This 442 // also creates the initial PHI MachineInstrs, though none of the input 443 // operands are populated. 444 for (BB = Fn.begin(), EB = Fn.end(); BB != EB; ++BB) { 445 MachineBasicBlock *MBB = mf.CreateMachineBasicBlock(BB); 446 MBBMap[BB] = MBB; 447 MF.push_back(MBB); 448 449 // Create Machine PHI nodes for LLVM PHI nodes, lowering them as 450 // appropriate. 451 PHINode *PN; 452 for (BasicBlock::iterator I = BB->begin();(PN = dyn_cast<PHINode>(I)); ++I){ 453 if (PN->use_empty()) continue; 454 455 unsigned PHIReg = ValueMap[PN]; 456 assert(PHIReg && "PHI node does not have an assigned virtual register!"); 457 458 SmallVector<MVT, 4> ValueVTs; 459 ComputeValueVTs(TLI, PN->getType(), ValueVTs); 460 for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) { 461 MVT VT = ValueVTs[vti]; 462 unsigned NumRegisters = TLI.getNumRegisters(VT); 463 const TargetInstrInfo *TII = TLI.getTargetMachine().getInstrInfo(); 464 for (unsigned i = 0; i != NumRegisters; ++i) 465 BuildMI(MBB, TII->get(TargetInstrInfo::PHI), PHIReg+i); 466 PHIReg += NumRegisters; 467 } 468 } 469 } 470} 471 472/// CreateRegForValue - Allocate the appropriate number of virtual registers of 473/// the correctly promoted or expanded types. Assign these registers 474/// consecutive vreg numbers and return the first assigned number. 475/// 476/// In the case that the given value has struct or array type, this function 477/// will assign registers for each member or element. 478/// 479unsigned FunctionLoweringInfo::CreateRegForValue(const Value *V) { 480 SmallVector<MVT, 4> ValueVTs; 481 ComputeValueVTs(TLI, V->getType(), ValueVTs); 482 483 unsigned FirstReg = 0; 484 for (unsigned Value = 0, e = ValueVTs.size(); Value != e; ++Value) { 485 MVT ValueVT = ValueVTs[Value]; 486 MVT RegisterVT = TLI.getRegisterType(ValueVT); 487 488 unsigned NumRegs = TLI.getNumRegisters(ValueVT); 489 for (unsigned i = 0; i != NumRegs; ++i) { 490 unsigned R = MakeReg(RegisterVT); 491 if (!FirstReg) FirstReg = R; 492 } 493 } 494 return FirstReg; 495} 496 497//===----------------------------------------------------------------------===// 498/// SelectionDAGLowering - This is the common target-independent lowering 499/// implementation that is parameterized by a TargetLowering object. 500/// Also, targets can overload any lowering method. 501/// 502namespace llvm { 503class SelectionDAGLowering { 504 MachineBasicBlock *CurMBB; 505 506 DenseMap<const Value*, SDValue> NodeMap; 507 508 /// PendingLoads - Loads are not emitted to the program immediately. We bunch 509 /// them up and then emit token factor nodes when possible. This allows us to 510 /// get simple disambiguation between loads without worrying about alias 511 /// analysis. 512 SmallVector<SDValue, 8> PendingLoads; 513 514 /// PendingExports - CopyToReg nodes that copy values to virtual registers 515 /// for export to other blocks need to be emitted before any terminator 516 /// instruction, but they have no other ordering requirements. We bunch them 517 /// up and the emit a single tokenfactor for them just before terminator 518 /// instructions. 519 std::vector<SDValue> PendingExports; 520 521 /// Case - A struct to record the Value for a switch case, and the 522 /// case's target basic block. 523 struct Case { 524 Constant* Low; 525 Constant* High; 526 MachineBasicBlock* BB; 527 528 Case() : Low(0), High(0), BB(0) { } 529 Case(Constant* low, Constant* high, MachineBasicBlock* bb) : 530 Low(low), High(high), BB(bb) { } 531 uint64_t size() const { 532 uint64_t rHigh = cast<ConstantInt>(High)->getSExtValue(); 533 uint64_t rLow = cast<ConstantInt>(Low)->getSExtValue(); 534 return (rHigh - rLow + 1ULL); 535 } 536 }; 537 538 struct CaseBits { 539 uint64_t Mask; 540 MachineBasicBlock* BB; 541 unsigned Bits; 542 543 CaseBits(uint64_t mask, MachineBasicBlock* bb, unsigned bits): 544 Mask(mask), BB(bb), Bits(bits) { } 545 }; 546 547 typedef std::vector<Case> CaseVector; 548 typedef std::vector<CaseBits> CaseBitsVector; 549 typedef CaseVector::iterator CaseItr; 550 typedef std::pair<CaseItr, CaseItr> CaseRange; 551 552 /// CaseRec - A struct with ctor used in lowering switches to a binary tree 553 /// of conditional branches. 554 struct CaseRec { 555 CaseRec(MachineBasicBlock *bb, Constant *lt, Constant *ge, CaseRange r) : 556 CaseBB(bb), LT(lt), GE(ge), Range(r) {} 557 558 /// CaseBB - The MBB in which to emit the compare and branch 559 MachineBasicBlock *CaseBB; 560 /// LT, GE - If nonzero, we know the current case value must be less-than or 561 /// greater-than-or-equal-to these Constants. 562 Constant *LT; 563 Constant *GE; 564 /// Range - A pair of iterators representing the range of case values to be 565 /// processed at this point in the binary search tree. 566 CaseRange Range; 567 }; 568 569 typedef std::vector<CaseRec> CaseRecVector; 570 571 /// The comparison function for sorting the switch case values in the vector. 572 /// WARNING: Case ranges should be disjoint! 573 struct CaseCmp { 574 bool operator () (const Case& C1, const Case& C2) { 575 assert(isa<ConstantInt>(C1.Low) && isa<ConstantInt>(C2.High)); 576 const ConstantInt* CI1 = cast<const ConstantInt>(C1.Low); 577 const ConstantInt* CI2 = cast<const ConstantInt>(C2.High); 578 return CI1->getValue().slt(CI2->getValue()); 579 } 580 }; 581 582 struct CaseBitsCmp { 583 bool operator () (const CaseBits& C1, const CaseBits& C2) { 584 return C1.Bits > C2.Bits; 585 } 586 }; 587 588 unsigned Clusterify(CaseVector& Cases, const SwitchInst &SI); 589 590public: 591 // TLI - This is information that describes the available target features we 592 // need for lowering. This indicates when operations are unavailable, 593 // implemented with a libcall, etc. 594 TargetLowering &TLI; 595 SelectionDAG &DAG; 596 const TargetData *TD; 597 AliasAnalysis &AA; 598 599 /// SwitchCases - Vector of CaseBlock structures used to communicate 600 /// SwitchInst code generation information. 601 std::vector<SelectionDAGISel::CaseBlock> SwitchCases; 602 /// JTCases - Vector of JumpTable structures used to communicate 603 /// SwitchInst code generation information. 604 std::vector<SelectionDAGISel::JumpTableBlock> JTCases; 605 std::vector<SelectionDAGISel::BitTestBlock> BitTestCases; 606 607 /// FuncInfo - Information about the function as a whole. 608 /// 609 FunctionLoweringInfo &FuncInfo; 610 611 /// GFI - Garbage collection metadata for the function. 612 GCFunctionInfo *GFI; 613 614 SelectionDAGLowering(SelectionDAG &dag, TargetLowering &tli, 615 AliasAnalysis &aa, 616 FunctionLoweringInfo &funcinfo, 617 GCFunctionInfo *gfi) 618 : TLI(tli), DAG(dag), TD(DAG.getTarget().getTargetData()), AA(aa), 619 FuncInfo(funcinfo), GFI(gfi) { 620 } 621 622 /// getRoot - Return the current virtual root of the Selection DAG, 623 /// flushing any PendingLoad items. This must be done before emitting 624 /// a store or any other node that may need to be ordered after any 625 /// prior load instructions. 626 /// 627 SDValue getRoot() { 628 if (PendingLoads.empty()) 629 return DAG.getRoot(); 630 631 if (PendingLoads.size() == 1) { 632 SDValue Root = PendingLoads[0]; 633 DAG.setRoot(Root); 634 PendingLoads.clear(); 635 return Root; 636 } 637 638 // Otherwise, we have to make a token factor node. 639 SDValue Root = DAG.getNode(ISD::TokenFactor, MVT::Other, 640 &PendingLoads[0], PendingLoads.size()); 641 PendingLoads.clear(); 642 DAG.setRoot(Root); 643 return Root; 644 } 645 646 /// getControlRoot - Similar to getRoot, but instead of flushing all the 647 /// PendingLoad items, flush all the PendingExports items. It is necessary 648 /// to do this before emitting a terminator instruction. 649 /// 650 SDValue getControlRoot() { 651 SDValue Root = DAG.getRoot(); 652 653 if (PendingExports.empty()) 654 return Root; 655 656 // Turn all of the CopyToReg chains into one factored node. 657 if (Root.getOpcode() != ISD::EntryToken) { 658 unsigned i = 0, e = PendingExports.size(); 659 for (; i != e; ++i) { 660 assert(PendingExports[i].Val->getNumOperands() > 1); 661 if (PendingExports[i].Val->getOperand(0) == Root) 662 break; // Don't add the root if we already indirectly depend on it. 663 } 664 665 if (i == e) 666 PendingExports.push_back(Root); 667 } 668 669 Root = DAG.getNode(ISD::TokenFactor, MVT::Other, 670 &PendingExports[0], 671 PendingExports.size()); 672 PendingExports.clear(); 673 DAG.setRoot(Root); 674 return Root; 675 } 676 677 void CopyValueToVirtualRegister(Value *V, unsigned Reg); 678 679 void visit(Instruction &I) { visit(I.getOpcode(), I); } 680 681 void visit(unsigned Opcode, User &I) { 682 // Note: this doesn't use InstVisitor, because it has to work with 683 // ConstantExpr's in addition to instructions. 684 switch (Opcode) { 685 default: assert(0 && "Unknown instruction type encountered!"); 686 abort(); 687 // Build the switch statement using the Instruction.def file. 688#define HANDLE_INST(NUM, OPCODE, CLASS) \ 689 case Instruction::OPCODE:return visit##OPCODE((CLASS&)I); 690#include "llvm/Instruction.def" 691 } 692 } 693 694 void setCurrentBasicBlock(MachineBasicBlock *MBB) { CurMBB = MBB; } 695 696 SDValue getValue(const Value *V); 697 698 void setValue(const Value *V, SDValue NewN) { 699 SDValue &N = NodeMap[V]; 700 assert(N.Val == 0 && "Already set a value for this node!"); 701 N = NewN; 702 } 703 704 void GetRegistersForValue(SDISelAsmOperandInfo &OpInfo, bool HasEarlyClobber, 705 std::set<unsigned> &OutputRegs, 706 std::set<unsigned> &InputRegs); 707 708 void FindMergedConditions(Value *Cond, MachineBasicBlock *TBB, 709 MachineBasicBlock *FBB, MachineBasicBlock *CurBB, 710 unsigned Opc); 711 bool isExportableFromCurrentBlock(Value *V, const BasicBlock *FromBB); 712 void ExportFromCurrentBlock(Value *V); 713 void LowerCallTo(CallSite CS, SDValue Callee, bool IsTailCall, 714 MachineBasicBlock *LandingPad = NULL); 715 716 // Terminator instructions. 717 void visitRet(ReturnInst &I); 718 void visitBr(BranchInst &I); 719 void visitSwitch(SwitchInst &I); 720 void visitUnreachable(UnreachableInst &I) { /* noop */ } 721 722 // Helpers for visitSwitch 723 bool handleSmallSwitchRange(CaseRec& CR, 724 CaseRecVector& WorkList, 725 Value* SV, 726 MachineBasicBlock* Default); 727 bool handleJTSwitchCase(CaseRec& CR, 728 CaseRecVector& WorkList, 729 Value* SV, 730 MachineBasicBlock* Default); 731 bool handleBTSplitSwitchCase(CaseRec& CR, 732 CaseRecVector& WorkList, 733 Value* SV, 734 MachineBasicBlock* Default); 735 bool handleBitTestsSwitchCase(CaseRec& CR, 736 CaseRecVector& WorkList, 737 Value* SV, 738 MachineBasicBlock* Default); 739 void visitSwitchCase(SelectionDAGISel::CaseBlock &CB); 740 void visitBitTestHeader(SelectionDAGISel::BitTestBlock &B); 741 void visitBitTestCase(MachineBasicBlock* NextMBB, 742 unsigned Reg, 743 SelectionDAGISel::BitTestCase &B); 744 void visitJumpTable(SelectionDAGISel::JumpTable &JT); 745 void visitJumpTableHeader(SelectionDAGISel::JumpTable &JT, 746 SelectionDAGISel::JumpTableHeader &JTH); 747 748 // These all get lowered before this pass. 749 void visitInvoke(InvokeInst &I); 750 void visitUnwind(UnwindInst &I); 751 752 void visitBinary(User &I, unsigned OpCode); 753 void visitShift(User &I, unsigned Opcode); 754 void visitAdd(User &I) { 755 if (I.getType()->isFPOrFPVector()) 756 visitBinary(I, ISD::FADD); 757 else 758 visitBinary(I, ISD::ADD); 759 } 760 void visitSub(User &I); 761 void visitMul(User &I) { 762 if (I.getType()->isFPOrFPVector()) 763 visitBinary(I, ISD::FMUL); 764 else 765 visitBinary(I, ISD::MUL); 766 } 767 void visitURem(User &I) { visitBinary(I, ISD::UREM); } 768 void visitSRem(User &I) { visitBinary(I, ISD::SREM); } 769 void visitFRem(User &I) { visitBinary(I, ISD::FREM); } 770 void visitUDiv(User &I) { visitBinary(I, ISD::UDIV); } 771 void visitSDiv(User &I) { visitBinary(I, ISD::SDIV); } 772 void visitFDiv(User &I) { visitBinary(I, ISD::FDIV); } 773 void visitAnd (User &I) { visitBinary(I, ISD::AND); } 774 void visitOr (User &I) { visitBinary(I, ISD::OR); } 775 void visitXor (User &I) { visitBinary(I, ISD::XOR); } 776 void visitShl (User &I) { visitShift(I, ISD::SHL); } 777 void visitLShr(User &I) { visitShift(I, ISD::SRL); } 778 void visitAShr(User &I) { visitShift(I, ISD::SRA); } 779 void visitICmp(User &I); 780 void visitFCmp(User &I); 781 void visitVICmp(User &I); 782 void visitVFCmp(User &I); 783 // Visit the conversion instructions 784 void visitTrunc(User &I); 785 void visitZExt(User &I); 786 void visitSExt(User &I); 787 void visitFPTrunc(User &I); 788 void visitFPExt(User &I); 789 void visitFPToUI(User &I); 790 void visitFPToSI(User &I); 791 void visitUIToFP(User &I); 792 void visitSIToFP(User &I); 793 void visitPtrToInt(User &I); 794 void visitIntToPtr(User &I); 795 void visitBitCast(User &I); 796 797 void visitExtractElement(User &I); 798 void visitInsertElement(User &I); 799 void visitShuffleVector(User &I); 800 801 void visitExtractValue(ExtractValueInst &I); 802 void visitInsertValue(InsertValueInst &I); 803 804 void visitGetElementPtr(User &I); 805 void visitSelect(User &I); 806 807 void visitMalloc(MallocInst &I); 808 void visitFree(FreeInst &I); 809 void visitAlloca(AllocaInst &I); 810 void visitLoad(LoadInst &I); 811 void visitStore(StoreInst &I); 812 void visitPHI(PHINode &I) { } // PHI nodes are handled specially. 813 void visitCall(CallInst &I); 814 void visitInlineAsm(CallSite CS); 815 const char *visitIntrinsicCall(CallInst &I, unsigned Intrinsic); 816 void visitTargetIntrinsic(CallInst &I, unsigned Intrinsic); 817 818 void visitVAStart(CallInst &I); 819 void visitVAArg(VAArgInst &I); 820 void visitVAEnd(CallInst &I); 821 void visitVACopy(CallInst &I); 822 823 void visitUserOp1(Instruction &I) { 824 assert(0 && "UserOp1 should not exist at instruction selection time!"); 825 abort(); 826 } 827 void visitUserOp2(Instruction &I) { 828 assert(0 && "UserOp2 should not exist at instruction selection time!"); 829 abort(); 830 } 831 832private: 833 inline const char *implVisitBinaryAtomic(CallInst& I, ISD::NodeType Op); 834 835}; 836} // end namespace llvm 837 838 839/// getCopyFromParts - Create a value that contains the specified legal parts 840/// combined into the value they represent. If the parts combine to a type 841/// larger then ValueVT then AssertOp can be used to specify whether the extra 842/// bits are known to be zero (ISD::AssertZext) or sign extended from ValueVT 843/// (ISD::AssertSext). 844static SDValue getCopyFromParts(SelectionDAG &DAG, 845 const SDValue *Parts, 846 unsigned NumParts, 847 MVT PartVT, 848 MVT ValueVT, 849 ISD::NodeType AssertOp = ISD::DELETED_NODE) { 850 assert(NumParts > 0 && "No parts to assemble!"); 851 TargetLowering &TLI = DAG.getTargetLoweringInfo(); 852 SDValue Val = Parts[0]; 853 854 if (NumParts > 1) { 855 // Assemble the value from multiple parts. 856 if (!ValueVT.isVector()) { 857 unsigned PartBits = PartVT.getSizeInBits(); 858 unsigned ValueBits = ValueVT.getSizeInBits(); 859 860 // Assemble the power of 2 part. 861 unsigned RoundParts = NumParts & (NumParts - 1) ? 862 1 << Log2_32(NumParts) : NumParts; 863 unsigned RoundBits = PartBits * RoundParts; 864 MVT RoundVT = RoundBits == ValueBits ? 865 ValueVT : MVT::getIntegerVT(RoundBits); 866 SDValue Lo, Hi; 867 868 if (RoundParts > 2) { 869 MVT HalfVT = MVT::getIntegerVT(RoundBits/2); 870 Lo = getCopyFromParts(DAG, Parts, RoundParts/2, PartVT, HalfVT); 871 Hi = getCopyFromParts(DAG, Parts+RoundParts/2, RoundParts/2, 872 PartVT, HalfVT); 873 } else { 874 Lo = Parts[0]; 875 Hi = Parts[1]; 876 } 877 if (TLI.isBigEndian()) 878 std::swap(Lo, Hi); 879 Val = DAG.getNode(ISD::BUILD_PAIR, RoundVT, Lo, Hi); 880 881 if (RoundParts < NumParts) { 882 // Assemble the trailing non-power-of-2 part. 883 unsigned OddParts = NumParts - RoundParts; 884 MVT OddVT = MVT::getIntegerVT(OddParts * PartBits); 885 Hi = getCopyFromParts(DAG, Parts+RoundParts, OddParts, PartVT, OddVT); 886 887 // Combine the round and odd parts. 888 Lo = Val; 889 if (TLI.isBigEndian()) 890 std::swap(Lo, Hi); 891 MVT TotalVT = MVT::getIntegerVT(NumParts * PartBits); 892 Hi = DAG.getNode(ISD::ANY_EXTEND, TotalVT, Hi); 893 Hi = DAG.getNode(ISD::SHL, TotalVT, Hi, 894 DAG.getConstant(Lo.getValueType().getSizeInBits(), 895 TLI.getShiftAmountTy())); 896 Lo = DAG.getNode(ISD::ZERO_EXTEND, TotalVT, Lo); 897 Val = DAG.getNode(ISD::OR, TotalVT, Lo, Hi); 898 } 899 } else { 900 // Handle a multi-element vector. 901 MVT IntermediateVT, RegisterVT; 902 unsigned NumIntermediates; 903 unsigned NumRegs = 904 TLI.getVectorTypeBreakdown(ValueVT, IntermediateVT, NumIntermediates, 905 RegisterVT); 906 assert(NumRegs == NumParts && "Part count doesn't match vector breakdown!"); 907 NumParts = NumRegs; // Silence a compiler warning. 908 assert(RegisterVT == PartVT && "Part type doesn't match vector breakdown!"); 909 assert(RegisterVT == Parts[0].getValueType() && 910 "Part type doesn't match part!"); 911 912 // Assemble the parts into intermediate operands. 913 SmallVector<SDValue, 8> Ops(NumIntermediates); 914 if (NumIntermediates == NumParts) { 915 // If the register was not expanded, truncate or copy the value, 916 // as appropriate. 917 for (unsigned i = 0; i != NumParts; ++i) 918 Ops[i] = getCopyFromParts(DAG, &Parts[i], 1, 919 PartVT, IntermediateVT); 920 } else if (NumParts > 0) { 921 // If the intermediate type was expanded, build the intermediate operands 922 // from the parts. 923 assert(NumParts % NumIntermediates == 0 && 924 "Must expand into a divisible number of parts!"); 925 unsigned Factor = NumParts / NumIntermediates; 926 for (unsigned i = 0; i != NumIntermediates; ++i) 927 Ops[i] = getCopyFromParts(DAG, &Parts[i * Factor], Factor, 928 PartVT, IntermediateVT); 929 } 930 931 // Build a vector with BUILD_VECTOR or CONCAT_VECTORS from the intermediate 932 // operands. 933 Val = DAG.getNode(IntermediateVT.isVector() ? 934 ISD::CONCAT_VECTORS : ISD::BUILD_VECTOR, 935 ValueVT, &Ops[0], NumIntermediates); 936 } 937 } 938 939 // There is now one part, held in Val. Correct it to match ValueVT. 940 PartVT = Val.getValueType(); 941 942 if (PartVT == ValueVT) 943 return Val; 944 945 if (PartVT.isVector()) { 946 assert(ValueVT.isVector() && "Unknown vector conversion!"); 947 return DAG.getNode(ISD::BIT_CONVERT, ValueVT, Val); 948 } 949 950 if (ValueVT.isVector()) { 951 assert(ValueVT.getVectorElementType() == PartVT && 952 ValueVT.getVectorNumElements() == 1 && 953 "Only trivial scalar-to-vector conversions should get here!"); 954 return DAG.getNode(ISD::BUILD_VECTOR, ValueVT, Val); 955 } 956 957 if (PartVT.isInteger() && 958 ValueVT.isInteger()) { 959 if (ValueVT.bitsLT(PartVT)) { 960 // For a truncate, see if we have any information to 961 // indicate whether the truncated bits will always be 962 // zero or sign-extension. 963 if (AssertOp != ISD::DELETED_NODE) 964 Val = DAG.getNode(AssertOp, PartVT, Val, 965 DAG.getValueType(ValueVT)); 966 return DAG.getNode(ISD::TRUNCATE, ValueVT, Val); 967 } else { 968 return DAG.getNode(ISD::ANY_EXTEND, ValueVT, Val); 969 } 970 } 971 972 if (PartVT.isFloatingPoint() && ValueVT.isFloatingPoint()) { 973 if (ValueVT.bitsLT(Val.getValueType())) 974 // FP_ROUND's are always exact here. 975 return DAG.getNode(ISD::FP_ROUND, ValueVT, Val, 976 DAG.getIntPtrConstant(1)); 977 return DAG.getNode(ISD::FP_EXTEND, ValueVT, Val); 978 } 979 980 if (PartVT.getSizeInBits() == ValueVT.getSizeInBits()) 981 return DAG.getNode(ISD::BIT_CONVERT, ValueVT, Val); 982 983 assert(0 && "Unknown mismatch!"); 984 return SDValue(); 985} 986 987/// getCopyToParts - Create a series of nodes that contain the specified value 988/// split into legal parts. If the parts contain more bits than Val, then, for 989/// integers, ExtendKind can be used to specify how to generate the extra bits. 990static void getCopyToParts(SelectionDAG &DAG, 991 SDValue Val, 992 SDValue *Parts, 993 unsigned NumParts, 994 MVT PartVT, 995 ISD::NodeType ExtendKind = ISD::ANY_EXTEND) { 996 TargetLowering &TLI = DAG.getTargetLoweringInfo(); 997 MVT PtrVT = TLI.getPointerTy(); 998 MVT ValueVT = Val.getValueType(); 999 unsigned PartBits = PartVT.getSizeInBits(); 1000 assert(TLI.isTypeLegal(PartVT) && "Copying to an illegal type!"); 1001 1002 if (!NumParts) 1003 return; 1004 1005 if (!ValueVT.isVector()) { 1006 if (PartVT == ValueVT) { 1007 assert(NumParts == 1 && "No-op copy with multiple parts!"); 1008 Parts[0] = Val; 1009 return; 1010 } 1011 1012 if (NumParts * PartBits > ValueVT.getSizeInBits()) { 1013 // If the parts cover more bits than the value has, promote the value. 1014 if (PartVT.isFloatingPoint() && ValueVT.isFloatingPoint()) { 1015 assert(NumParts == 1 && "Do not know what to promote to!"); 1016 Val = DAG.getNode(ISD::FP_EXTEND, PartVT, Val); 1017 } else if (PartVT.isInteger() && ValueVT.isInteger()) { 1018 ValueVT = MVT::getIntegerVT(NumParts * PartBits); 1019 Val = DAG.getNode(ExtendKind, ValueVT, Val); 1020 } else { 1021 assert(0 && "Unknown mismatch!"); 1022 } 1023 } else if (PartBits == ValueVT.getSizeInBits()) { 1024 // Different types of the same size. 1025 assert(NumParts == 1 && PartVT != ValueVT); 1026 Val = DAG.getNode(ISD::BIT_CONVERT, PartVT, Val); 1027 } else if (NumParts * PartBits < ValueVT.getSizeInBits()) { 1028 // If the parts cover less bits than value has, truncate the value. 1029 if (PartVT.isInteger() && ValueVT.isInteger()) { 1030 ValueVT = MVT::getIntegerVT(NumParts * PartBits); 1031 Val = DAG.getNode(ISD::TRUNCATE, ValueVT, Val); 1032 } else { 1033 assert(0 && "Unknown mismatch!"); 1034 } 1035 } 1036 1037 // The value may have changed - recompute ValueVT. 1038 ValueVT = Val.getValueType(); 1039 assert(NumParts * PartBits == ValueVT.getSizeInBits() && 1040 "Failed to tile the value with PartVT!"); 1041 1042 if (NumParts == 1) { 1043 assert(PartVT == ValueVT && "Type conversion failed!"); 1044 Parts[0] = Val; 1045 return; 1046 } 1047 1048 // Expand the value into multiple parts. 1049 if (NumParts & (NumParts - 1)) { 1050 // The number of parts is not a power of 2. Split off and copy the tail. 1051 assert(PartVT.isInteger() && ValueVT.isInteger() && 1052 "Do not know what to expand to!"); 1053 unsigned RoundParts = 1 << Log2_32(NumParts); 1054 unsigned RoundBits = RoundParts * PartBits; 1055 unsigned OddParts = NumParts - RoundParts; 1056 SDValue OddVal = DAG.getNode(ISD::SRL, ValueVT, Val, 1057 DAG.getConstant(RoundBits, 1058 TLI.getShiftAmountTy())); 1059 getCopyToParts(DAG, OddVal, Parts + RoundParts, OddParts, PartVT); 1060 if (TLI.isBigEndian()) 1061 // The odd parts were reversed by getCopyToParts - unreverse them. 1062 std::reverse(Parts + RoundParts, Parts + NumParts); 1063 NumParts = RoundParts; 1064 ValueVT = MVT::getIntegerVT(NumParts * PartBits); 1065 Val = DAG.getNode(ISD::TRUNCATE, ValueVT, Val); 1066 } 1067 1068 // The number of parts is a power of 2. Repeatedly bisect the value using 1069 // EXTRACT_ELEMENT. 1070 Parts[0] = DAG.getNode(ISD::BIT_CONVERT, 1071 MVT::getIntegerVT(ValueVT.getSizeInBits()), 1072 Val); 1073 for (unsigned StepSize = NumParts; StepSize > 1; StepSize /= 2) { 1074 for (unsigned i = 0; i < NumParts; i += StepSize) { 1075 unsigned ThisBits = StepSize * PartBits / 2; 1076 MVT ThisVT = MVT::getIntegerVT (ThisBits); 1077 SDValue &Part0 = Parts[i]; 1078 SDValue &Part1 = Parts[i+StepSize/2]; 1079 1080 Part1 = DAG.getNode(ISD::EXTRACT_ELEMENT, ThisVT, Part0, 1081 DAG.getConstant(1, PtrVT)); 1082 Part0 = DAG.getNode(ISD::EXTRACT_ELEMENT, ThisVT, Part0, 1083 DAG.getConstant(0, PtrVT)); 1084 1085 if (ThisBits == PartBits && ThisVT != PartVT) { 1086 Part0 = DAG.getNode(ISD::BIT_CONVERT, PartVT, Part0); 1087 Part1 = DAG.getNode(ISD::BIT_CONVERT, PartVT, Part1); 1088 } 1089 } 1090 } 1091 1092 if (TLI.isBigEndian()) 1093 std::reverse(Parts, Parts + NumParts); 1094 1095 return; 1096 } 1097 1098 // Vector ValueVT. 1099 if (NumParts == 1) { 1100 if (PartVT != ValueVT) { 1101 if (PartVT.isVector()) { 1102 Val = DAG.getNode(ISD::BIT_CONVERT, PartVT, Val); 1103 } else { 1104 assert(ValueVT.getVectorElementType() == PartVT && 1105 ValueVT.getVectorNumElements() == 1 && 1106 "Only trivial vector-to-scalar conversions should get here!"); 1107 Val = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, PartVT, Val, 1108 DAG.getConstant(0, PtrVT)); 1109 } 1110 } 1111 1112 Parts[0] = Val; 1113 return; 1114 } 1115 1116 // Handle a multi-element vector. 1117 MVT IntermediateVT, RegisterVT; 1118 unsigned NumIntermediates; 1119 unsigned NumRegs = 1120 DAG.getTargetLoweringInfo() 1121 .getVectorTypeBreakdown(ValueVT, IntermediateVT, NumIntermediates, 1122 RegisterVT); 1123 unsigned NumElements = ValueVT.getVectorNumElements(); 1124 1125 assert(NumRegs == NumParts && "Part count doesn't match vector breakdown!"); 1126 NumParts = NumRegs; // Silence a compiler warning. 1127 assert(RegisterVT == PartVT && "Part type doesn't match vector breakdown!"); 1128 1129 // Split the vector into intermediate operands. 1130 SmallVector<SDValue, 8> Ops(NumIntermediates); 1131 for (unsigned i = 0; i != NumIntermediates; ++i) 1132 if (IntermediateVT.isVector()) 1133 Ops[i] = DAG.getNode(ISD::EXTRACT_SUBVECTOR, 1134 IntermediateVT, Val, 1135 DAG.getConstant(i * (NumElements / NumIntermediates), 1136 PtrVT)); 1137 else 1138 Ops[i] = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, 1139 IntermediateVT, Val, 1140 DAG.getConstant(i, PtrVT)); 1141 1142 // Split the intermediate operands into legal parts. 1143 if (NumParts == NumIntermediates) { 1144 // If the register was not expanded, promote or copy the value, 1145 // as appropriate. 1146 for (unsigned i = 0; i != NumParts; ++i) 1147 getCopyToParts(DAG, Ops[i], &Parts[i], 1, PartVT); 1148 } else if (NumParts > 0) { 1149 // If the intermediate type was expanded, split each the value into 1150 // legal parts. 1151 assert(NumParts % NumIntermediates == 0 && 1152 "Must expand into a divisible number of parts!"); 1153 unsigned Factor = NumParts / NumIntermediates; 1154 for (unsigned i = 0; i != NumIntermediates; ++i) 1155 getCopyToParts(DAG, Ops[i], &Parts[i * Factor], Factor, PartVT); 1156 } 1157} 1158 1159 1160SDValue SelectionDAGLowering::getValue(const Value *V) { 1161 SDValue &N = NodeMap[V]; 1162 if (N.Val) return N; 1163 1164 if (Constant *C = const_cast<Constant*>(dyn_cast<Constant>(V))) { 1165 MVT VT = TLI.getValueType(V->getType(), true); 1166 1167 if (ConstantInt *CI = dyn_cast<ConstantInt>(C)) 1168 return N = DAG.getConstant(CI->getValue(), VT); 1169 1170 if (GlobalValue *GV = dyn_cast<GlobalValue>(C)) 1171 return N = DAG.getGlobalAddress(GV, VT); 1172 1173 if (isa<ConstantPointerNull>(C)) 1174 return N = DAG.getConstant(0, TLI.getPointerTy()); 1175 1176 if (ConstantFP *CFP = dyn_cast<ConstantFP>(C)) 1177 return N = DAG.getConstantFP(CFP->getValueAPF(), VT); 1178 1179 if (isa<UndefValue>(C) && !isa<VectorType>(V->getType()) && 1180 !V->getType()->isAggregateType()) 1181 return N = DAG.getNode(ISD::UNDEF, VT); 1182 1183 if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) { 1184 visit(CE->getOpcode(), *CE); 1185 SDValue N1 = NodeMap[V]; 1186 assert(N1.Val && "visit didn't populate the ValueMap!"); 1187 return N1; 1188 } 1189 1190 if (isa<ConstantStruct>(C) || isa<ConstantArray>(C)) { 1191 SmallVector<SDValue, 4> Constants; 1192 for (User::const_op_iterator OI = C->op_begin(), OE = C->op_end(); 1193 OI != OE; ++OI) { 1194 SDNode *Val = getValue(*OI).Val; 1195 for (unsigned i = 0, e = Val->getNumValues(); i != e; ++i) 1196 Constants.push_back(SDValue(Val, i)); 1197 } 1198 return DAG.getMergeValues(&Constants[0], Constants.size()); 1199 } 1200 1201 if (isa<StructType>(C->getType()) || isa<ArrayType>(C->getType())) { 1202 assert((isa<ConstantAggregateZero>(C) || isa<UndefValue>(C)) && 1203 "Unknown struct or array constant!"); 1204 1205 SmallVector<MVT, 4> ValueVTs; 1206 ComputeValueVTs(TLI, C->getType(), ValueVTs); 1207 unsigned NumElts = ValueVTs.size(); 1208 if (NumElts == 0) 1209 return SDValue(); // empty struct 1210 SmallVector<SDValue, 4> Constants(NumElts); 1211 for (unsigned i = 0; i != NumElts; ++i) { 1212 MVT EltVT = ValueVTs[i]; 1213 if (isa<UndefValue>(C)) 1214 Constants[i] = DAG.getNode(ISD::UNDEF, EltVT); 1215 else if (EltVT.isFloatingPoint()) 1216 Constants[i] = DAG.getConstantFP(0, EltVT); 1217 else 1218 Constants[i] = DAG.getConstant(0, EltVT); 1219 } 1220 return DAG.getMergeValues(&Constants[0], NumElts); 1221 } 1222 1223 const VectorType *VecTy = cast<VectorType>(V->getType()); 1224 unsigned NumElements = VecTy->getNumElements(); 1225 1226 // Now that we know the number and type of the elements, get that number of 1227 // elements into the Ops array based on what kind of constant it is. 1228 SmallVector<SDValue, 16> Ops; 1229 if (ConstantVector *CP = dyn_cast<ConstantVector>(C)) { 1230 for (unsigned i = 0; i != NumElements; ++i) 1231 Ops.push_back(getValue(CP->getOperand(i))); 1232 } else { 1233 assert((isa<ConstantAggregateZero>(C) || isa<UndefValue>(C)) && 1234 "Unknown vector constant!"); 1235 MVT EltVT = TLI.getValueType(VecTy->getElementType()); 1236 1237 SDValue Op; 1238 if (isa<UndefValue>(C)) 1239 Op = DAG.getNode(ISD::UNDEF, EltVT); 1240 else if (EltVT.isFloatingPoint()) 1241 Op = DAG.getConstantFP(0, EltVT); 1242 else 1243 Op = DAG.getConstant(0, EltVT); 1244 Ops.assign(NumElements, Op); 1245 } 1246 1247 // Create a BUILD_VECTOR node. 1248 return NodeMap[V] = DAG.getNode(ISD::BUILD_VECTOR, VT, &Ops[0], Ops.size()); 1249 } 1250 1251 // If this is a static alloca, generate it as the frameindex instead of 1252 // computation. 1253 if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) { 1254 std::map<const AllocaInst*, int>::iterator SI = 1255 FuncInfo.StaticAllocaMap.find(AI); 1256 if (SI != FuncInfo.StaticAllocaMap.end()) 1257 return DAG.getFrameIndex(SI->second, TLI.getPointerTy()); 1258 } 1259 1260 unsigned InReg = FuncInfo.ValueMap[V]; 1261 assert(InReg && "Value not in map!"); 1262 1263 RegsForValue RFV(TLI, InReg, V->getType()); 1264 SDValue Chain = DAG.getEntryNode(); 1265 return RFV.getCopyFromRegs(DAG, Chain, NULL); 1266} 1267 1268 1269void SelectionDAGLowering::visitRet(ReturnInst &I) { 1270 if (I.getNumOperands() == 0) { 1271 DAG.setRoot(DAG.getNode(ISD::RET, MVT::Other, getControlRoot())); 1272 return; 1273 } 1274 1275 SmallVector<SDValue, 8> NewValues; 1276 NewValues.push_back(getControlRoot()); 1277 for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i) { 1278 SDValue RetOp = getValue(I.getOperand(i)); 1279 1280 SmallVector<MVT, 4> ValueVTs; 1281 ComputeValueVTs(TLI, I.getOperand(i)->getType(), ValueVTs); 1282 for (unsigned j = 0, f = ValueVTs.size(); j != f; ++j) { 1283 MVT VT = ValueVTs[j]; 1284 1285 // FIXME: C calling convention requires the return type to be promoted to 1286 // at least 32-bit. But this is not necessary for non-C calling conventions. 1287 if (VT.isInteger()) { 1288 MVT MinVT = TLI.getRegisterType(MVT::i32); 1289 if (VT.bitsLT(MinVT)) 1290 VT = MinVT; 1291 } 1292 1293 unsigned NumParts = TLI.getNumRegisters(VT); 1294 MVT PartVT = TLI.getRegisterType(VT); 1295 SmallVector<SDValue, 4> Parts(NumParts); 1296 ISD::NodeType ExtendKind = ISD::ANY_EXTEND; 1297 1298 const Function *F = I.getParent()->getParent(); 1299 if (F->paramHasAttr(0, ParamAttr::SExt)) 1300 ExtendKind = ISD::SIGN_EXTEND; 1301 else if (F->paramHasAttr(0, ParamAttr::ZExt)) 1302 ExtendKind = ISD::ZERO_EXTEND; 1303 1304 getCopyToParts(DAG, SDValue(RetOp.Val, RetOp.ResNo + j), 1305 &Parts[0], NumParts, PartVT, ExtendKind); 1306 1307 for (unsigned i = 0; i < NumParts; ++i) { 1308 NewValues.push_back(Parts[i]); 1309 NewValues.push_back(DAG.getArgFlags(ISD::ArgFlagsTy())); 1310 } 1311 } 1312 } 1313 DAG.setRoot(DAG.getNode(ISD::RET, MVT::Other, 1314 &NewValues[0], NewValues.size())); 1315} 1316 1317/// ExportFromCurrentBlock - If this condition isn't known to be exported from 1318/// the current basic block, add it to ValueMap now so that we'll get a 1319/// CopyTo/FromReg. 1320void SelectionDAGLowering::ExportFromCurrentBlock(Value *V) { 1321 // No need to export constants. 1322 if (!isa<Instruction>(V) && !isa<Argument>(V)) return; 1323 1324 // Already exported? 1325 if (FuncInfo.isExportedInst(V)) return; 1326 1327 unsigned Reg = FuncInfo.InitializeRegForValue(V); 1328 CopyValueToVirtualRegister(V, Reg); 1329} 1330 1331bool SelectionDAGLowering::isExportableFromCurrentBlock(Value *V, 1332 const BasicBlock *FromBB) { 1333 // The operands of the setcc have to be in this block. We don't know 1334 // how to export them from some other block. 1335 if (Instruction *VI = dyn_cast<Instruction>(V)) { 1336 // Can export from current BB. 1337 if (VI->getParent() == FromBB) 1338 return true; 1339 1340 // Is already exported, noop. 1341 return FuncInfo.isExportedInst(V); 1342 } 1343 1344 // If this is an argument, we can export it if the BB is the entry block or 1345 // if it is already exported. 1346 if (isa<Argument>(V)) { 1347 if (FromBB == &FromBB->getParent()->getEntryBlock()) 1348 return true; 1349 1350 // Otherwise, can only export this if it is already exported. 1351 return FuncInfo.isExportedInst(V); 1352 } 1353 1354 // Otherwise, constants can always be exported. 1355 return true; 1356} 1357 1358static bool InBlock(const Value *V, const BasicBlock *BB) { 1359 if (const Instruction *I = dyn_cast<Instruction>(V)) 1360 return I->getParent() == BB; 1361 return true; 1362} 1363 1364/// FindMergedConditions - If Cond is an expression like 1365void SelectionDAGLowering::FindMergedConditions(Value *Cond, 1366 MachineBasicBlock *TBB, 1367 MachineBasicBlock *FBB, 1368 MachineBasicBlock *CurBB, 1369 unsigned Opc) { 1370 // If this node is not part of the or/and tree, emit it as a branch. 1371 Instruction *BOp = dyn_cast<Instruction>(Cond); 1372 1373 if (!BOp || !(isa<BinaryOperator>(BOp) || isa<CmpInst>(BOp)) || 1374 (unsigned)BOp->getOpcode() != Opc || !BOp->hasOneUse() || 1375 BOp->getParent() != CurBB->getBasicBlock() || 1376 !InBlock(BOp->getOperand(0), CurBB->getBasicBlock()) || 1377 !InBlock(BOp->getOperand(1), CurBB->getBasicBlock())) { 1378 const BasicBlock *BB = CurBB->getBasicBlock(); 1379 1380 // If the leaf of the tree is a comparison, merge the condition into 1381 // the caseblock. 1382 if ((isa<ICmpInst>(Cond) || isa<FCmpInst>(Cond)) && 1383 // The operands of the cmp have to be in this block. We don't know 1384 // how to export them from some other block. If this is the first block 1385 // of the sequence, no exporting is needed. 1386 (CurBB == CurMBB || 1387 (isExportableFromCurrentBlock(BOp->getOperand(0), BB) && 1388 isExportableFromCurrentBlock(BOp->getOperand(1), BB)))) { 1389 BOp = cast<Instruction>(Cond); 1390 ISD::CondCode Condition; 1391 if (ICmpInst *IC = dyn_cast<ICmpInst>(Cond)) { 1392 switch (IC->getPredicate()) { 1393 default: assert(0 && "Unknown icmp predicate opcode!"); 1394 case ICmpInst::ICMP_EQ: Condition = ISD::SETEQ; break; 1395 case ICmpInst::ICMP_NE: Condition = ISD::SETNE; break; 1396 case ICmpInst::ICMP_SLE: Condition = ISD::SETLE; break; 1397 case ICmpInst::ICMP_ULE: Condition = ISD::SETULE; break; 1398 case ICmpInst::ICMP_SGE: Condition = ISD::SETGE; break; 1399 case ICmpInst::ICMP_UGE: Condition = ISD::SETUGE; break; 1400 case ICmpInst::ICMP_SLT: Condition = ISD::SETLT; break; 1401 case ICmpInst::ICMP_ULT: Condition = ISD::SETULT; break; 1402 case ICmpInst::ICMP_SGT: Condition = ISD::SETGT; break; 1403 case ICmpInst::ICMP_UGT: Condition = ISD::SETUGT; break; 1404 } 1405 } else if (FCmpInst *FC = dyn_cast<FCmpInst>(Cond)) { 1406 ISD::CondCode FPC, FOC; 1407 switch (FC->getPredicate()) { 1408 default: assert(0 && "Unknown fcmp predicate opcode!"); 1409 case FCmpInst::FCMP_FALSE: FOC = FPC = ISD::SETFALSE; break; 1410 case FCmpInst::FCMP_OEQ: FOC = ISD::SETEQ; FPC = ISD::SETOEQ; break; 1411 case FCmpInst::FCMP_OGT: FOC = ISD::SETGT; FPC = ISD::SETOGT; break; 1412 case FCmpInst::FCMP_OGE: FOC = ISD::SETGE; FPC = ISD::SETOGE; break; 1413 case FCmpInst::FCMP_OLT: FOC = ISD::SETLT; FPC = ISD::SETOLT; break; 1414 case FCmpInst::FCMP_OLE: FOC = ISD::SETLE; FPC = ISD::SETOLE; break; 1415 case FCmpInst::FCMP_ONE: FOC = ISD::SETNE; FPC = ISD::SETONE; break; 1416 case FCmpInst::FCMP_ORD: FOC = FPC = ISD::SETO; break; 1417 case FCmpInst::FCMP_UNO: FOC = FPC = ISD::SETUO; break; 1418 case FCmpInst::FCMP_UEQ: FOC = ISD::SETEQ; FPC = ISD::SETUEQ; break; 1419 case FCmpInst::FCMP_UGT: FOC = ISD::SETGT; FPC = ISD::SETUGT; break; 1420 case FCmpInst::FCMP_UGE: FOC = ISD::SETGE; FPC = ISD::SETUGE; break; 1421 case FCmpInst::FCMP_ULT: FOC = ISD::SETLT; FPC = ISD::SETULT; break; 1422 case FCmpInst::FCMP_ULE: FOC = ISD::SETLE; FPC = ISD::SETULE; break; 1423 case FCmpInst::FCMP_UNE: FOC = ISD::SETNE; FPC = ISD::SETUNE; break; 1424 case FCmpInst::FCMP_TRUE: FOC = FPC = ISD::SETTRUE; break; 1425 } 1426 if (FiniteOnlyFPMath()) 1427 Condition = FOC; 1428 else 1429 Condition = FPC; 1430 } else { 1431 Condition = ISD::SETEQ; // silence warning. 1432 assert(0 && "Unknown compare instruction"); 1433 } 1434 1435 SelectionDAGISel::CaseBlock CB(Condition, BOp->getOperand(0), 1436 BOp->getOperand(1), NULL, TBB, FBB, CurBB); 1437 SwitchCases.push_back(CB); 1438 return; 1439 } 1440 1441 // Create a CaseBlock record representing this branch. 1442 SelectionDAGISel::CaseBlock CB(ISD::SETEQ, Cond, ConstantInt::getTrue(), 1443 NULL, TBB, FBB, CurBB); 1444 SwitchCases.push_back(CB); 1445 return; 1446 } 1447 1448 1449 // Create TmpBB after CurBB. 1450 MachineFunction::iterator BBI = CurBB; 1451 MachineFunction &MF = DAG.getMachineFunction(); 1452 MachineBasicBlock *TmpBB = MF.CreateMachineBasicBlock(CurBB->getBasicBlock()); 1453 CurBB->getParent()->insert(++BBI, TmpBB); 1454 1455 if (Opc == Instruction::Or) { 1456 // Codegen X | Y as: 1457 // jmp_if_X TBB 1458 // jmp TmpBB 1459 // TmpBB: 1460 // jmp_if_Y TBB 1461 // jmp FBB 1462 // 1463 1464 // Emit the LHS condition. 1465 FindMergedConditions(BOp->getOperand(0), TBB, TmpBB, CurBB, Opc); 1466 1467 // Emit the RHS condition into TmpBB. 1468 FindMergedConditions(BOp->getOperand(1), TBB, FBB, TmpBB, Opc); 1469 } else { 1470 assert(Opc == Instruction::And && "Unknown merge op!"); 1471 // Codegen X & Y as: 1472 // jmp_if_X TmpBB 1473 // jmp FBB 1474 // TmpBB: 1475 // jmp_if_Y TBB 1476 // jmp FBB 1477 // 1478 // This requires creation of TmpBB after CurBB. 1479 1480 // Emit the LHS condition. 1481 FindMergedConditions(BOp->getOperand(0), TmpBB, FBB, CurBB, Opc); 1482 1483 // Emit the RHS condition into TmpBB. 1484 FindMergedConditions(BOp->getOperand(1), TBB, FBB, TmpBB, Opc); 1485 } 1486} 1487 1488/// If the set of cases should be emitted as a series of branches, return true. 1489/// If we should emit this as a bunch of and/or'd together conditions, return 1490/// false. 1491static bool 1492ShouldEmitAsBranches(const std::vector<SelectionDAGISel::CaseBlock> &Cases) { 1493 if (Cases.size() != 2) return true; 1494 1495 // If this is two comparisons of the same values or'd or and'd together, they 1496 // will get folded into a single comparison, so don't emit two blocks. 1497 if ((Cases[0].CmpLHS == Cases[1].CmpLHS && 1498 Cases[0].CmpRHS == Cases[1].CmpRHS) || 1499 (Cases[0].CmpRHS == Cases[1].CmpLHS && 1500 Cases[0].CmpLHS == Cases[1].CmpRHS)) { 1501 return false; 1502 } 1503 1504 return true; 1505} 1506 1507void SelectionDAGLowering::visitBr(BranchInst &I) { 1508 // Update machine-CFG edges. 1509 MachineBasicBlock *Succ0MBB = FuncInfo.MBBMap[I.getSuccessor(0)]; 1510 1511 // Figure out which block is immediately after the current one. 1512 MachineBasicBlock *NextBlock = 0; 1513 MachineFunction::iterator BBI = CurMBB; 1514 if (++BBI != CurMBB->getParent()->end()) 1515 NextBlock = BBI; 1516 1517 if (I.isUnconditional()) { 1518 // Update machine-CFG edges. 1519 CurMBB->addSuccessor(Succ0MBB); 1520 1521 // If this is not a fall-through branch, emit the branch. 1522 if (Succ0MBB != NextBlock) 1523 DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, getControlRoot(), 1524 DAG.getBasicBlock(Succ0MBB))); 1525 return; 1526 } 1527 1528 // If this condition is one of the special cases we handle, do special stuff 1529 // now. 1530 Value *CondVal = I.getCondition(); 1531 MachineBasicBlock *Succ1MBB = FuncInfo.MBBMap[I.getSuccessor(1)]; 1532 1533 // If this is a series of conditions that are or'd or and'd together, emit 1534 // this as a sequence of branches instead of setcc's with and/or operations. 1535 // For example, instead of something like: 1536 // cmp A, B 1537 // C = seteq 1538 // cmp D, E 1539 // F = setle 1540 // or C, F 1541 // jnz foo 1542 // Emit: 1543 // cmp A, B 1544 // je foo 1545 // cmp D, E 1546 // jle foo 1547 // 1548 if (BinaryOperator *BOp = dyn_cast<BinaryOperator>(CondVal)) { 1549 if (BOp->hasOneUse() && 1550 (BOp->getOpcode() == Instruction::And || 1551 BOp->getOpcode() == Instruction::Or)) { 1552 FindMergedConditions(BOp, Succ0MBB, Succ1MBB, CurMBB, BOp->getOpcode()); 1553 // If the compares in later blocks need to use values not currently 1554 // exported from this block, export them now. This block should always 1555 // be the first entry. 1556 assert(SwitchCases[0].ThisBB == CurMBB && "Unexpected lowering!"); 1557 1558 // Allow some cases to be rejected. 1559 if (ShouldEmitAsBranches(SwitchCases)) { 1560 for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i) { 1561 ExportFromCurrentBlock(SwitchCases[i].CmpLHS); 1562 ExportFromCurrentBlock(SwitchCases[i].CmpRHS); 1563 } 1564 1565 // Emit the branch for this block. 1566 visitSwitchCase(SwitchCases[0]); 1567 SwitchCases.erase(SwitchCases.begin()); 1568 return; 1569 } 1570 1571 // Okay, we decided not to do this, remove any inserted MBB's and clear 1572 // SwitchCases. 1573 for (unsigned i = 1, e = SwitchCases.size(); i != e; ++i) 1574 CurMBB->getParent()->erase(SwitchCases[i].ThisBB); 1575 1576 SwitchCases.clear(); 1577 } 1578 } 1579 1580 // Create a CaseBlock record representing this branch. 1581 SelectionDAGISel::CaseBlock CB(ISD::SETEQ, CondVal, ConstantInt::getTrue(), 1582 NULL, Succ0MBB, Succ1MBB, CurMBB); 1583 // Use visitSwitchCase to actually insert the fast branch sequence for this 1584 // cond branch. 1585 visitSwitchCase(CB); 1586} 1587 1588/// visitSwitchCase - Emits the necessary code to represent a single node in 1589/// the binary search tree resulting from lowering a switch instruction. 1590void SelectionDAGLowering::visitSwitchCase(SelectionDAGISel::CaseBlock &CB) { 1591 SDValue Cond; 1592 SDValue CondLHS = getValue(CB.CmpLHS); 1593 1594 // Build the setcc now. 1595 if (CB.CmpMHS == NULL) { 1596 // Fold "(X == true)" to X and "(X == false)" to !X to 1597 // handle common cases produced by branch lowering. 1598 if (CB.CmpRHS == ConstantInt::getTrue() && CB.CC == ISD::SETEQ) 1599 Cond = CondLHS; 1600 else if (CB.CmpRHS == ConstantInt::getFalse() && CB.CC == ISD::SETEQ) { 1601 SDValue True = DAG.getConstant(1, CondLHS.getValueType()); 1602 Cond = DAG.getNode(ISD::XOR, CondLHS.getValueType(), CondLHS, True); 1603 } else 1604 Cond = DAG.getSetCC(MVT::i1, CondLHS, getValue(CB.CmpRHS), CB.CC); 1605 } else { 1606 assert(CB.CC == ISD::SETLE && "Can handle only LE ranges now"); 1607 1608 uint64_t Low = cast<ConstantInt>(CB.CmpLHS)->getSExtValue(); 1609 uint64_t High = cast<ConstantInt>(CB.CmpRHS)->getSExtValue(); 1610 1611 SDValue CmpOp = getValue(CB.CmpMHS); 1612 MVT VT = CmpOp.getValueType(); 1613 1614 if (cast<ConstantInt>(CB.CmpLHS)->isMinValue(true)) { 1615 Cond = DAG.getSetCC(MVT::i1, CmpOp, DAG.getConstant(High, VT), ISD::SETLE); 1616 } else { 1617 SDValue SUB = DAG.getNode(ISD::SUB, VT, CmpOp, DAG.getConstant(Low, VT)); 1618 Cond = DAG.getSetCC(MVT::i1, SUB, 1619 DAG.getConstant(High-Low, VT), ISD::SETULE); 1620 } 1621 } 1622 1623 // Update successor info 1624 CurMBB->addSuccessor(CB.TrueBB); 1625 CurMBB->addSuccessor(CB.FalseBB); 1626 1627 // Set NextBlock to be the MBB immediately after the current one, if any. 1628 // This is used to avoid emitting unnecessary branches to the next block. 1629 MachineBasicBlock *NextBlock = 0; 1630 MachineFunction::iterator BBI = CurMBB; 1631 if (++BBI != CurMBB->getParent()->end()) 1632 NextBlock = BBI; 1633 1634 // If the lhs block is the next block, invert the condition so that we can 1635 // fall through to the lhs instead of the rhs block. 1636 if (CB.TrueBB == NextBlock) { 1637 std::swap(CB.TrueBB, CB.FalseBB); 1638 SDValue True = DAG.getConstant(1, Cond.getValueType()); 1639 Cond = DAG.getNode(ISD::XOR, Cond.getValueType(), Cond, True); 1640 } 1641 SDValue BrCond = DAG.getNode(ISD::BRCOND, MVT::Other, getControlRoot(), Cond, 1642 DAG.getBasicBlock(CB.TrueBB)); 1643 1644 // If the branch was constant folded, fix up the CFG. 1645 if (BrCond.getOpcode() == ISD::BR) { 1646 CurMBB->removeSuccessor(CB.FalseBB); 1647 DAG.setRoot(BrCond); 1648 } else { 1649 // Otherwise, go ahead and insert the false branch. 1650 if (BrCond == getControlRoot()) 1651 CurMBB->removeSuccessor(CB.TrueBB); 1652 1653 if (CB.FalseBB == NextBlock) 1654 DAG.setRoot(BrCond); 1655 else 1656 DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, BrCond, 1657 DAG.getBasicBlock(CB.FalseBB))); 1658 } 1659} 1660 1661/// visitJumpTable - Emit JumpTable node in the current MBB 1662void SelectionDAGLowering::visitJumpTable(SelectionDAGISel::JumpTable &JT) { 1663 // Emit the code for the jump table 1664 assert(JT.Reg != -1U && "Should lower JT Header first!"); 1665 MVT PTy = TLI.getPointerTy(); 1666 SDValue Index = DAG.getCopyFromReg(getControlRoot(), JT.Reg, PTy); 1667 SDValue Table = DAG.getJumpTable(JT.JTI, PTy); 1668 DAG.setRoot(DAG.getNode(ISD::BR_JT, MVT::Other, Index.getValue(1), 1669 Table, Index)); 1670 return; 1671} 1672 1673/// visitJumpTableHeader - This function emits necessary code to produce index 1674/// in the JumpTable from switch case. 1675void SelectionDAGLowering::visitJumpTableHeader(SelectionDAGISel::JumpTable &JT, 1676 SelectionDAGISel::JumpTableHeader &JTH) { 1677 // Subtract the lowest switch case value from the value being switched on 1678 // and conditional branch to default mbb if the result is greater than the 1679 // difference between smallest and largest cases. 1680 SDValue SwitchOp = getValue(JTH.SValue); 1681 MVT VT = SwitchOp.getValueType(); 1682 SDValue SUB = DAG.getNode(ISD::SUB, VT, SwitchOp, 1683 DAG.getConstant(JTH.First, VT)); 1684 1685 // The SDNode we just created, which holds the value being switched on 1686 // minus the the smallest case value, needs to be copied to a virtual 1687 // register so it can be used as an index into the jump table in a 1688 // subsequent basic block. This value may be smaller or larger than the 1689 // target's pointer type, and therefore require extension or truncating. 1690 if (VT.bitsGT(TLI.getPointerTy())) 1691 SwitchOp = DAG.getNode(ISD::TRUNCATE, TLI.getPointerTy(), SUB); 1692 else 1693 SwitchOp = DAG.getNode(ISD::ZERO_EXTEND, TLI.getPointerTy(), SUB); 1694 1695 unsigned JumpTableReg = FuncInfo.MakeReg(TLI.getPointerTy()); 1696 SDValue CopyTo = DAG.getCopyToReg(getControlRoot(), JumpTableReg, SwitchOp); 1697 JT.Reg = JumpTableReg; 1698 1699 // Emit the range check for the jump table, and branch to the default 1700 // block for the switch statement if the value being switched on exceeds 1701 // the largest case in the switch. 1702 SDValue CMP = DAG.getSetCC(TLI.getSetCCResultType(SUB), SUB, 1703 DAG.getConstant(JTH.Last-JTH.First,VT), 1704 ISD::SETUGT); 1705 1706 // Set NextBlock to be the MBB immediately after the current one, if any. 1707 // This is used to avoid emitting unnecessary branches to the next block. 1708 MachineBasicBlock *NextBlock = 0; 1709 MachineFunction::iterator BBI = CurMBB; 1710 if (++BBI != CurMBB->getParent()->end()) 1711 NextBlock = BBI; 1712 1713 SDValue BrCond = DAG.getNode(ISD::BRCOND, MVT::Other, CopyTo, CMP, 1714 DAG.getBasicBlock(JT.Default)); 1715 1716 if (JT.MBB == NextBlock) 1717 DAG.setRoot(BrCond); 1718 else 1719 DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, BrCond, 1720 DAG.getBasicBlock(JT.MBB))); 1721 1722 return; 1723} 1724 1725/// visitBitTestHeader - This function emits necessary code to produce value 1726/// suitable for "bit tests" 1727void SelectionDAGLowering::visitBitTestHeader(SelectionDAGISel::BitTestBlock &B) { 1728 // Subtract the minimum value 1729 SDValue SwitchOp = getValue(B.SValue); 1730 MVT VT = SwitchOp.getValueType(); 1731 SDValue SUB = DAG.getNode(ISD::SUB, VT, SwitchOp, 1732 DAG.getConstant(B.First, VT)); 1733 1734 // Check range 1735 SDValue RangeCmp = DAG.getSetCC(TLI.getSetCCResultType(SUB), SUB, 1736 DAG.getConstant(B.Range, VT), 1737 ISD::SETUGT); 1738 1739 SDValue ShiftOp; 1740 if (VT.bitsGT(TLI.getShiftAmountTy())) 1741 ShiftOp = DAG.getNode(ISD::TRUNCATE, TLI.getShiftAmountTy(), SUB); 1742 else 1743 ShiftOp = DAG.getNode(ISD::ZERO_EXTEND, TLI.getShiftAmountTy(), SUB); 1744 1745 // Make desired shift 1746 SDValue SwitchVal = DAG.getNode(ISD::SHL, TLI.getPointerTy(), 1747 DAG.getConstant(1, TLI.getPointerTy()), 1748 ShiftOp); 1749 1750 unsigned SwitchReg = FuncInfo.MakeReg(TLI.getPointerTy()); 1751 SDValue CopyTo = DAG.getCopyToReg(getControlRoot(), SwitchReg, SwitchVal); 1752 B.Reg = SwitchReg; 1753 1754 // Set NextBlock to be the MBB immediately after the current one, if any. 1755 // This is used to avoid emitting unnecessary branches to the next block. 1756 MachineBasicBlock *NextBlock = 0; 1757 MachineFunction::iterator BBI = CurMBB; 1758 if (++BBI != CurMBB->getParent()->end()) 1759 NextBlock = BBI; 1760 1761 MachineBasicBlock* MBB = B.Cases[0].ThisBB; 1762 1763 CurMBB->addSuccessor(B.Default); 1764 CurMBB->addSuccessor(MBB); 1765 1766 SDValue BrRange = DAG.getNode(ISD::BRCOND, MVT::Other, CopyTo, RangeCmp, 1767 DAG.getBasicBlock(B.Default)); 1768 1769 if (MBB == NextBlock) 1770 DAG.setRoot(BrRange); 1771 else 1772 DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, CopyTo, 1773 DAG.getBasicBlock(MBB))); 1774 1775 return; 1776} 1777 1778/// visitBitTestCase - this function produces one "bit test" 1779void SelectionDAGLowering::visitBitTestCase(MachineBasicBlock* NextMBB, 1780 unsigned Reg, 1781 SelectionDAGISel::BitTestCase &B) { 1782 // Emit bit tests and jumps 1783 SDValue SwitchVal = DAG.getCopyFromReg(getControlRoot(), Reg, 1784 TLI.getPointerTy()); 1785 1786 SDValue AndOp = DAG.getNode(ISD::AND, TLI.getPointerTy(), SwitchVal, 1787 DAG.getConstant(B.Mask, TLI.getPointerTy())); 1788 SDValue AndCmp = DAG.getSetCC(TLI.getSetCCResultType(AndOp), AndOp, 1789 DAG.getConstant(0, TLI.getPointerTy()), 1790 ISD::SETNE); 1791 1792 CurMBB->addSuccessor(B.TargetBB); 1793 CurMBB->addSuccessor(NextMBB); 1794 1795 SDValue BrAnd = DAG.getNode(ISD::BRCOND, MVT::Other, getControlRoot(), 1796 AndCmp, DAG.getBasicBlock(B.TargetBB)); 1797 1798 // Set NextBlock to be the MBB immediately after the current one, if any. 1799 // This is used to avoid emitting unnecessary branches to the next block. 1800 MachineBasicBlock *NextBlock = 0; 1801 MachineFunction::iterator BBI = CurMBB; 1802 if (++BBI != CurMBB->getParent()->end()) 1803 NextBlock = BBI; 1804 1805 if (NextMBB == NextBlock) 1806 DAG.setRoot(BrAnd); 1807 else 1808 DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, BrAnd, 1809 DAG.getBasicBlock(NextMBB))); 1810 1811 return; 1812} 1813 1814void SelectionDAGLowering::visitInvoke(InvokeInst &I) { 1815 // Retrieve successors. 1816 MachineBasicBlock *Return = FuncInfo.MBBMap[I.getSuccessor(0)]; 1817 MachineBasicBlock *LandingPad = FuncInfo.MBBMap[I.getSuccessor(1)]; 1818 1819 if (isa<InlineAsm>(I.getCalledValue())) 1820 visitInlineAsm(&I); 1821 else 1822 LowerCallTo(&I, getValue(I.getOperand(0)), false, LandingPad); 1823 1824 // If the value of the invoke is used outside of its defining block, make it 1825 // available as a virtual register. 1826 if (!I.use_empty()) { 1827 DenseMap<const Value*, unsigned>::iterator VMI = FuncInfo.ValueMap.find(&I); 1828 if (VMI != FuncInfo.ValueMap.end()) 1829 CopyValueToVirtualRegister(&I, VMI->second); 1830 } 1831 1832 // Update successor info 1833 CurMBB->addSuccessor(Return); 1834 CurMBB->addSuccessor(LandingPad); 1835 1836 // Drop into normal successor. 1837 DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, getControlRoot(), 1838 DAG.getBasicBlock(Return))); 1839} 1840 1841void SelectionDAGLowering::visitUnwind(UnwindInst &I) { 1842} 1843 1844/// handleSmallSwitchCaseRange - Emit a series of specific tests (suitable for 1845/// small case ranges). 1846bool SelectionDAGLowering::handleSmallSwitchRange(CaseRec& CR, 1847 CaseRecVector& WorkList, 1848 Value* SV, 1849 MachineBasicBlock* Default) { 1850 Case& BackCase = *(CR.Range.second-1); 1851 1852 // Size is the number of Cases represented by this range. 1853 unsigned Size = CR.Range.second - CR.Range.first; 1854 if (Size > 3) 1855 return false; 1856 1857 // Get the MachineFunction which holds the current MBB. This is used when 1858 // inserting any additional MBBs necessary to represent the switch. 1859 MachineFunction *CurMF = CurMBB->getParent(); 1860 1861 // Figure out which block is immediately after the current one. 1862 MachineBasicBlock *NextBlock = 0; 1863 MachineFunction::iterator BBI = CR.CaseBB; 1864 1865 if (++BBI != CurMBB->getParent()->end()) 1866 NextBlock = BBI; 1867 1868 // TODO: If any two of the cases has the same destination, and if one value 1869 // is the same as the other, but has one bit unset that the other has set, 1870 // use bit manipulation to do two compares at once. For example: 1871 // "if (X == 6 || X == 4)" -> "if ((X|2) == 6)" 1872 1873 // Rearrange the case blocks so that the last one falls through if possible. 1874 if (NextBlock && Default != NextBlock && BackCase.BB != NextBlock) { 1875 // The last case block won't fall through into 'NextBlock' if we emit the 1876 // branches in this order. See if rearranging a case value would help. 1877 for (CaseItr I = CR.Range.first, E = CR.Range.second-1; I != E; ++I) { 1878 if (I->BB == NextBlock) { 1879 std::swap(*I, BackCase); 1880 break; 1881 } 1882 } 1883 } 1884 1885 // Create a CaseBlock record representing a conditional branch to 1886 // the Case's target mbb if the value being switched on SV is equal 1887 // to C. 1888 MachineBasicBlock *CurBlock = CR.CaseBB; 1889 for (CaseItr I = CR.Range.first, E = CR.Range.second; I != E; ++I) { 1890 MachineBasicBlock *FallThrough; 1891 if (I != E-1) { 1892 FallThrough = CurMF->CreateMachineBasicBlock(CurBlock->getBasicBlock()); 1893 CurMF->insert(BBI, FallThrough); 1894 } else { 1895 // If the last case doesn't match, go to the default block. 1896 FallThrough = Default; 1897 } 1898 1899 Value *RHS, *LHS, *MHS; 1900 ISD::CondCode CC; 1901 if (I->High == I->Low) { 1902 // This is just small small case range :) containing exactly 1 case 1903 CC = ISD::SETEQ; 1904 LHS = SV; RHS = I->High; MHS = NULL; 1905 } else { 1906 CC = ISD::SETLE; 1907 LHS = I->Low; MHS = SV; RHS = I->High; 1908 } 1909 SelectionDAGISel::CaseBlock CB(CC, LHS, RHS, MHS, 1910 I->BB, FallThrough, CurBlock); 1911 1912 // If emitting the first comparison, just call visitSwitchCase to emit the 1913 // code into the current block. Otherwise, push the CaseBlock onto the 1914 // vector to be later processed by SDISel, and insert the node's MBB 1915 // before the next MBB. 1916 if (CurBlock == CurMBB) 1917 visitSwitchCase(CB); 1918 else 1919 SwitchCases.push_back(CB); 1920 1921 CurBlock = FallThrough; 1922 } 1923 1924 return true; 1925} 1926 1927static inline bool areJTsAllowed(const TargetLowering &TLI) { 1928 return !DisableJumpTables && 1929 (TLI.isOperationLegal(ISD::BR_JT, MVT::Other) || 1930 TLI.isOperationLegal(ISD::BRIND, MVT::Other)); 1931} 1932 1933/// handleJTSwitchCase - Emit jumptable for current switch case range 1934bool SelectionDAGLowering::handleJTSwitchCase(CaseRec& CR, 1935 CaseRecVector& WorkList, 1936 Value* SV, 1937 MachineBasicBlock* Default) { 1938 Case& FrontCase = *CR.Range.first; 1939 Case& BackCase = *(CR.Range.second-1); 1940 1941 int64_t First = cast<ConstantInt>(FrontCase.Low)->getSExtValue(); 1942 int64_t Last = cast<ConstantInt>(BackCase.High)->getSExtValue(); 1943 1944 uint64_t TSize = 0; 1945 for (CaseItr I = CR.Range.first, E = CR.Range.second; 1946 I!=E; ++I) 1947 TSize += I->size(); 1948 1949 if (!areJTsAllowed(TLI) || TSize <= 3) 1950 return false; 1951 1952 double Density = (double)TSize / (double)((Last - First) + 1ULL); 1953 if (Density < 0.4) 1954 return false; 1955 1956 DOUT << "Lowering jump table\n" 1957 << "First entry: " << First << ". Last entry: " << Last << "\n" 1958 << "Size: " << TSize << ". Density: " << Density << "\n\n"; 1959 1960 // Get the MachineFunction which holds the current MBB. This is used when 1961 // inserting any additional MBBs necessary to represent the switch. 1962 MachineFunction *CurMF = CurMBB->getParent(); 1963 1964 // Figure out which block is immediately after the current one. 1965 MachineBasicBlock *NextBlock = 0; 1966 MachineFunction::iterator BBI = CR.CaseBB; 1967 1968 if (++BBI != CurMBB->getParent()->end()) 1969 NextBlock = BBI; 1970 1971 const BasicBlock *LLVMBB = CR.CaseBB->getBasicBlock(); 1972 1973 // Create a new basic block to hold the code for loading the address 1974 // of the jump table, and jumping to it. Update successor information; 1975 // we will either branch to the default case for the switch, or the jump 1976 // table. 1977 MachineBasicBlock *JumpTableBB = CurMF->CreateMachineBasicBlock(LLVMBB); 1978 CurMF->insert(BBI, JumpTableBB); 1979 CR.CaseBB->addSuccessor(Default); 1980 CR.CaseBB->addSuccessor(JumpTableBB); 1981 1982 // Build a vector of destination BBs, corresponding to each target 1983 // of the jump table. If the value of the jump table slot corresponds to 1984 // a case statement, push the case's BB onto the vector, otherwise, push 1985 // the default BB. 1986 std::vector<MachineBasicBlock*> DestBBs; 1987 int64_t TEI = First; 1988 for (CaseItr I = CR.Range.first, E = CR.Range.second; I != E; ++TEI) { 1989 int64_t Low = cast<ConstantInt>(I->Low)->getSExtValue(); 1990 int64_t High = cast<ConstantInt>(I->High)->getSExtValue(); 1991 1992 if ((Low <= TEI) && (TEI <= High)) { 1993 DestBBs.push_back(I->BB); 1994 if (TEI==High) 1995 ++I; 1996 } else { 1997 DestBBs.push_back(Default); 1998 } 1999 } 2000 2001 // Update successor info. Add one edge to each unique successor. 2002 BitVector SuccsHandled(CR.CaseBB->getParent()->getNumBlockIDs()); 2003 for (std::vector<MachineBasicBlock*>::iterator I = DestBBs.begin(), 2004 E = DestBBs.end(); I != E; ++I) { 2005 if (!SuccsHandled[(*I)->getNumber()]) { 2006 SuccsHandled[(*I)->getNumber()] = true; 2007 JumpTableBB->addSuccessor(*I); 2008 } 2009 } 2010 2011 // Create a jump table index for this jump table, or return an existing 2012 // one. 2013 unsigned JTI = CurMF->getJumpTableInfo()->getJumpTableIndex(DestBBs); 2014 2015 // Set the jump table information so that we can codegen it as a second 2016 // MachineBasicBlock 2017 SelectionDAGISel::JumpTable JT(-1U, JTI, JumpTableBB, Default); 2018 SelectionDAGISel::JumpTableHeader JTH(First, Last, SV, CR.CaseBB, 2019 (CR.CaseBB == CurMBB)); 2020 if (CR.CaseBB == CurMBB) 2021 visitJumpTableHeader(JT, JTH); 2022 2023 JTCases.push_back(SelectionDAGISel::JumpTableBlock(JTH, JT)); 2024 2025 return true; 2026} 2027 2028/// handleBTSplitSwitchCase - emit comparison and split binary search tree into 2029/// 2 subtrees. 2030bool SelectionDAGLowering::handleBTSplitSwitchCase(CaseRec& CR, 2031 CaseRecVector& WorkList, 2032 Value* SV, 2033 MachineBasicBlock* Default) { 2034 // Get the MachineFunction which holds the current MBB. This is used when 2035 // inserting any additional MBBs necessary to represent the switch. 2036 MachineFunction *CurMF = CurMBB->getParent(); 2037 2038 // Figure out which block is immediately after the current one. 2039 MachineBasicBlock *NextBlock = 0; 2040 MachineFunction::iterator BBI = CR.CaseBB; 2041 2042 if (++BBI != CurMBB->getParent()->end()) 2043 NextBlock = BBI; 2044 2045 Case& FrontCase = *CR.Range.first; 2046 Case& BackCase = *(CR.Range.second-1); 2047 const BasicBlock *LLVMBB = CR.CaseBB->getBasicBlock(); 2048 2049 // Size is the number of Cases represented by this range. 2050 unsigned Size = CR.Range.second - CR.Range.first; 2051 2052 int64_t First = cast<ConstantInt>(FrontCase.Low)->getSExtValue(); 2053 int64_t Last = cast<ConstantInt>(BackCase.High)->getSExtValue(); 2054 double FMetric = 0; 2055 CaseItr Pivot = CR.Range.first + Size/2; 2056 2057 // Select optimal pivot, maximizing sum density of LHS and RHS. This will 2058 // (heuristically) allow us to emit JumpTable's later. 2059 uint64_t TSize = 0; 2060 for (CaseItr I = CR.Range.first, E = CR.Range.second; 2061 I!=E; ++I) 2062 TSize += I->size(); 2063 2064 uint64_t LSize = FrontCase.size(); 2065 uint64_t RSize = TSize-LSize; 2066 DOUT << "Selecting best pivot: \n" 2067 << "First: " << First << ", Last: " << Last <<"\n" 2068 << "LSize: " << LSize << ", RSize: " << RSize << "\n"; 2069 for (CaseItr I = CR.Range.first, J=I+1, E = CR.Range.second; 2070 J!=E; ++I, ++J) { 2071 int64_t LEnd = cast<ConstantInt>(I->High)->getSExtValue(); 2072 int64_t RBegin = cast<ConstantInt>(J->Low)->getSExtValue(); 2073 assert((RBegin-LEnd>=1) && "Invalid case distance"); 2074 double LDensity = (double)LSize / (double)((LEnd - First) + 1ULL); 2075 double RDensity = (double)RSize / (double)((Last - RBegin) + 1ULL); 2076 double Metric = Log2_64(RBegin-LEnd)*(LDensity+RDensity); 2077 // Should always split in some non-trivial place 2078 DOUT <<"=>Step\n" 2079 << "LEnd: " << LEnd << ", RBegin: " << RBegin << "\n" 2080 << "LDensity: " << LDensity << ", RDensity: " << RDensity << "\n" 2081 << "Metric: " << Metric << "\n"; 2082 if (FMetric < Metric) { 2083 Pivot = J; 2084 FMetric = Metric; 2085 DOUT << "Current metric set to: " << FMetric << "\n"; 2086 } 2087 2088 LSize += J->size(); 2089 RSize -= J->size(); 2090 } 2091 if (areJTsAllowed(TLI)) { 2092 // If our case is dense we *really* should handle it earlier! 2093 assert((FMetric > 0) && "Should handle dense range earlier!"); 2094 } else { 2095 Pivot = CR.Range.first + Size/2; 2096 } 2097 2098 CaseRange LHSR(CR.Range.first, Pivot); 2099 CaseRange RHSR(Pivot, CR.Range.second); 2100 Constant *C = Pivot->Low; 2101 MachineBasicBlock *FalseBB = 0, *TrueBB = 0; 2102 2103 // We know that we branch to the LHS if the Value being switched on is 2104 // less than the Pivot value, C. We use this to optimize our binary 2105 // tree a bit, by recognizing that if SV is greater than or equal to the 2106 // LHS's Case Value, and that Case Value is exactly one less than the 2107 // Pivot's Value, then we can branch directly to the LHS's Target, 2108 // rather than creating a leaf node for it. 2109 if ((LHSR.second - LHSR.first) == 1 && 2110 LHSR.first->High == CR.GE && 2111 cast<ConstantInt>(C)->getSExtValue() == 2112 (cast<ConstantInt>(CR.GE)->getSExtValue() + 1LL)) { 2113 TrueBB = LHSR.first->BB; 2114 } else { 2115 TrueBB = CurMF->CreateMachineBasicBlock(LLVMBB); 2116 CurMF->insert(BBI, TrueBB); 2117 WorkList.push_back(CaseRec(TrueBB, C, CR.GE, LHSR)); 2118 } 2119 2120 // Similar to the optimization above, if the Value being switched on is 2121 // known to be less than the Constant CR.LT, and the current Case Value 2122 // is CR.LT - 1, then we can branch directly to the target block for 2123 // the current Case Value, rather than emitting a RHS leaf node for it. 2124 if ((RHSR.second - RHSR.first) == 1 && CR.LT && 2125 cast<ConstantInt>(RHSR.first->Low)->getSExtValue() == 2126 (cast<ConstantInt>(CR.LT)->getSExtValue() - 1LL)) { 2127 FalseBB = RHSR.first->BB; 2128 } else { 2129 FalseBB = CurMF->CreateMachineBasicBlock(LLVMBB); 2130 CurMF->insert(BBI, FalseBB); 2131 WorkList.push_back(CaseRec(FalseBB,CR.LT,C,RHSR)); 2132 } 2133 2134 // Create a CaseBlock record representing a conditional branch to 2135 // the LHS node if the value being switched on SV is less than C. 2136 // Otherwise, branch to LHS. 2137 SelectionDAGISel::CaseBlock CB(ISD::SETLT, SV, C, NULL, 2138 TrueBB, FalseBB, CR.CaseBB); 2139 2140 if (CR.CaseBB == CurMBB) 2141 visitSwitchCase(CB); 2142 else 2143 SwitchCases.push_back(CB); 2144 2145 return true; 2146} 2147 2148/// handleBitTestsSwitchCase - if current case range has few destination and 2149/// range span less, than machine word bitwidth, encode case range into series 2150/// of masks and emit bit tests with these masks. 2151bool SelectionDAGLowering::handleBitTestsSwitchCase(CaseRec& CR, 2152 CaseRecVector& WorkList, 2153 Value* SV, 2154 MachineBasicBlock* Default){ 2155 unsigned IntPtrBits = TLI.getPointerTy().getSizeInBits(); 2156 2157 Case& FrontCase = *CR.Range.first; 2158 Case& BackCase = *(CR.Range.second-1); 2159 2160 // Get the MachineFunction which holds the current MBB. This is used when 2161 // inserting any additional MBBs necessary to represent the switch. 2162 MachineFunction *CurMF = CurMBB->getParent(); 2163 2164 unsigned numCmps = 0; 2165 for (CaseItr I = CR.Range.first, E = CR.Range.second; 2166 I!=E; ++I) { 2167 // Single case counts one, case range - two. 2168 if (I->Low == I->High) 2169 numCmps +=1; 2170 else 2171 numCmps +=2; 2172 } 2173 2174 // Count unique destinations 2175 SmallSet<MachineBasicBlock*, 4> Dests; 2176 for (CaseItr I = CR.Range.first, E = CR.Range.second; I!=E; ++I) { 2177 Dests.insert(I->BB); 2178 if (Dests.size() > 3) 2179 // Don't bother the code below, if there are too much unique destinations 2180 return false; 2181 } 2182 DOUT << "Total number of unique destinations: " << Dests.size() << "\n" 2183 << "Total number of comparisons: " << numCmps << "\n"; 2184 2185 // Compute span of values. 2186 Constant* minValue = FrontCase.Low; 2187 Constant* maxValue = BackCase.High; 2188 uint64_t range = cast<ConstantInt>(maxValue)->getSExtValue() - 2189 cast<ConstantInt>(minValue)->getSExtValue(); 2190 DOUT << "Compare range: " << range << "\n" 2191 << "Low bound: " << cast<ConstantInt>(minValue)->getSExtValue() << "\n" 2192 << "High bound: " << cast<ConstantInt>(maxValue)->getSExtValue() << "\n"; 2193 2194 if (range>=IntPtrBits || 2195 (!(Dests.size() == 1 && numCmps >= 3) && 2196 !(Dests.size() == 2 && numCmps >= 5) && 2197 !(Dests.size() >= 3 && numCmps >= 6))) 2198 return false; 2199 2200 DOUT << "Emitting bit tests\n"; 2201 int64_t lowBound = 0; 2202 2203 // Optimize the case where all the case values fit in a 2204 // word without having to subtract minValue. In this case, 2205 // we can optimize away the subtraction. 2206 if (cast<ConstantInt>(minValue)->getSExtValue() >= 0 && 2207 cast<ConstantInt>(maxValue)->getSExtValue() < IntPtrBits) { 2208 range = cast<ConstantInt>(maxValue)->getSExtValue(); 2209 } else { 2210 lowBound = cast<ConstantInt>(minValue)->getSExtValue(); 2211 } 2212 2213 CaseBitsVector CasesBits; 2214 unsigned i, count = 0; 2215 2216 for (CaseItr I = CR.Range.first, E = CR.Range.second; I!=E; ++I) { 2217 MachineBasicBlock* Dest = I->BB; 2218 for (i = 0; i < count; ++i) 2219 if (Dest == CasesBits[i].BB) 2220 break; 2221 2222 if (i == count) { 2223 assert((count < 3) && "Too much destinations to test!"); 2224 CasesBits.push_back(CaseBits(0, Dest, 0)); 2225 count++; 2226 } 2227 2228 uint64_t lo = cast<ConstantInt>(I->Low)->getSExtValue() - lowBound; 2229 uint64_t hi = cast<ConstantInt>(I->High)->getSExtValue() - lowBound; 2230 2231 for (uint64_t j = lo; j <= hi; j++) { 2232 CasesBits[i].Mask |= 1ULL << j; 2233 CasesBits[i].Bits++; 2234 } 2235 2236 } 2237 std::sort(CasesBits.begin(), CasesBits.end(), CaseBitsCmp()); 2238 2239 SelectionDAGISel::BitTestInfo BTC; 2240 2241 // Figure out which block is immediately after the current one. 2242 MachineFunction::iterator BBI = CR.CaseBB; 2243 ++BBI; 2244 2245 const BasicBlock *LLVMBB = CR.CaseBB->getBasicBlock(); 2246 2247 DOUT << "Cases:\n"; 2248 for (unsigned i = 0, e = CasesBits.size(); i!=e; ++i) { 2249 DOUT << "Mask: " << CasesBits[i].Mask << ", Bits: " << CasesBits[i].Bits 2250 << ", BB: " << CasesBits[i].BB << "\n"; 2251 2252 MachineBasicBlock *CaseBB = CurMF->CreateMachineBasicBlock(LLVMBB); 2253 CurMF->insert(BBI, CaseBB); 2254 BTC.push_back(SelectionDAGISel::BitTestCase(CasesBits[i].Mask, 2255 CaseBB, 2256 CasesBits[i].BB)); 2257 } 2258 2259 SelectionDAGISel::BitTestBlock BTB(lowBound, range, SV, 2260 -1U, (CR.CaseBB == CurMBB), 2261 CR.CaseBB, Default, BTC); 2262 2263 if (CR.CaseBB == CurMBB) 2264 visitBitTestHeader(BTB); 2265 2266 BitTestCases.push_back(BTB); 2267 2268 return true; 2269} 2270 2271 2272/// Clusterify - Transform simple list of Cases into list of CaseRange's 2273unsigned SelectionDAGLowering::Clusterify(CaseVector& Cases, 2274 const SwitchInst& SI) { 2275 unsigned numCmps = 0; 2276 2277 // Start with "simple" cases 2278 for (unsigned i = 1; i < SI.getNumSuccessors(); ++i) { 2279 MachineBasicBlock *SMBB = FuncInfo.MBBMap[SI.getSuccessor(i)]; 2280 Cases.push_back(Case(SI.getSuccessorValue(i), 2281 SI.getSuccessorValue(i), 2282 SMBB)); 2283 } 2284 std::sort(Cases.begin(), Cases.end(), CaseCmp()); 2285 2286 // Merge case into clusters 2287 if (Cases.size()>=2) 2288 // Must recompute end() each iteration because it may be 2289 // invalidated by erase if we hold on to it 2290 for (CaseItr I=Cases.begin(), J=++(Cases.begin()); J!=Cases.end(); ) { 2291 int64_t nextValue = cast<ConstantInt>(J->Low)->getSExtValue(); 2292 int64_t currentValue = cast<ConstantInt>(I->High)->getSExtValue(); 2293 MachineBasicBlock* nextBB = J->BB; 2294 MachineBasicBlock* currentBB = I->BB; 2295 2296 // If the two neighboring cases go to the same destination, merge them 2297 // into a single case. 2298 if ((nextValue-currentValue==1) && (currentBB == nextBB)) { 2299 I->High = J->High; 2300 J = Cases.erase(J); 2301 } else { 2302 I = J++; 2303 } 2304 } 2305 2306 for (CaseItr I=Cases.begin(), E=Cases.end(); I!=E; ++I, ++numCmps) { 2307 if (I->Low != I->High) 2308 // A range counts double, since it requires two compares. 2309 ++numCmps; 2310 } 2311 2312 return numCmps; 2313} 2314 2315void SelectionDAGLowering::visitSwitch(SwitchInst &SI) { 2316 // Figure out which block is immediately after the current one. 2317 MachineBasicBlock *NextBlock = 0; 2318 MachineFunction::iterator BBI = CurMBB; 2319 2320 MachineBasicBlock *Default = FuncInfo.MBBMap[SI.getDefaultDest()]; 2321 2322 // If there is only the default destination, branch to it if it is not the 2323 // next basic block. Otherwise, just fall through. 2324 if (SI.getNumOperands() == 2) { 2325 // Update machine-CFG edges. 2326 2327 // If this is not a fall-through branch, emit the branch. 2328 CurMBB->addSuccessor(Default); 2329 if (Default != NextBlock) 2330 DAG.setRoot(DAG.getNode(ISD::BR, MVT::Other, getControlRoot(), 2331 DAG.getBasicBlock(Default))); 2332 2333 return; 2334 } 2335 2336 // If there are any non-default case statements, create a vector of Cases 2337 // representing each one, and sort the vector so that we can efficiently 2338 // create a binary search tree from them. 2339 CaseVector Cases; 2340 unsigned numCmps = Clusterify(Cases, SI); 2341 DOUT << "Clusterify finished. Total clusters: " << Cases.size() 2342 << ". Total compares: " << numCmps << "\n"; 2343 2344 // Get the Value to be switched on and default basic blocks, which will be 2345 // inserted into CaseBlock records, representing basic blocks in the binary 2346 // search tree. 2347 Value *SV = SI.getOperand(0); 2348 2349 // Push the initial CaseRec onto the worklist 2350 CaseRecVector WorkList; 2351 WorkList.push_back(CaseRec(CurMBB,0,0,CaseRange(Cases.begin(),Cases.end()))); 2352 2353 while (!WorkList.empty()) { 2354 // Grab a record representing a case range to process off the worklist 2355 CaseRec CR = WorkList.back(); 2356 WorkList.pop_back(); 2357 2358 if (handleBitTestsSwitchCase(CR, WorkList, SV, Default)) 2359 continue; 2360 2361 // If the range has few cases (two or less) emit a series of specific 2362 // tests. 2363 if (handleSmallSwitchRange(CR, WorkList, SV, Default)) 2364 continue; 2365 2366 // If the switch has more than 5 blocks, and at least 40% dense, and the 2367 // target supports indirect branches, then emit a jump table rather than 2368 // lowering the switch to a binary tree of conditional branches. 2369 if (handleJTSwitchCase(CR, WorkList, SV, Default)) 2370 continue; 2371 2372 // Emit binary tree. We need to pick a pivot, and push left and right ranges 2373 // onto the worklist. Leafs are handled via handleSmallSwitchRange() call. 2374 handleBTSplitSwitchCase(CR, WorkList, SV, Default); 2375 } 2376} 2377 2378 2379void SelectionDAGLowering::visitSub(User &I) { 2380 // -0.0 - X --> fneg 2381 const Type *Ty = I.getType(); 2382 if (isa<VectorType>(Ty)) { 2383 if (ConstantVector *CV = dyn_cast<ConstantVector>(I.getOperand(0))) { 2384 const VectorType *DestTy = cast<VectorType>(I.getType()); 2385 const Type *ElTy = DestTy->getElementType(); 2386 if (ElTy->isFloatingPoint()) { 2387 unsigned VL = DestTy->getNumElements(); 2388 std::vector<Constant*> NZ(VL, ConstantFP::getNegativeZero(ElTy)); 2389 Constant *CNZ = ConstantVector::get(&NZ[0], NZ.size()); 2390 if (CV == CNZ) { 2391 SDValue Op2 = getValue(I.getOperand(1)); 2392 setValue(&I, DAG.getNode(ISD::FNEG, Op2.getValueType(), Op2)); 2393 return; 2394 } 2395 } 2396 } 2397 } 2398 if (Ty->isFloatingPoint()) { 2399 if (ConstantFP *CFP = dyn_cast<ConstantFP>(I.getOperand(0))) 2400 if (CFP->isExactlyValue(ConstantFP::getNegativeZero(Ty)->getValueAPF())) { 2401 SDValue Op2 = getValue(I.getOperand(1)); 2402 setValue(&I, DAG.getNode(ISD::FNEG, Op2.getValueType(), Op2)); 2403 return; 2404 } 2405 } 2406 2407 visitBinary(I, Ty->isFPOrFPVector() ? ISD::FSUB : ISD::SUB); 2408} 2409 2410void SelectionDAGLowering::visitBinary(User &I, unsigned OpCode) { 2411 SDValue Op1 = getValue(I.getOperand(0)); 2412 SDValue Op2 = getValue(I.getOperand(1)); 2413 2414 setValue(&I, DAG.getNode(OpCode, Op1.getValueType(), Op1, Op2)); 2415} 2416 2417void SelectionDAGLowering::visitShift(User &I, unsigned Opcode) { 2418 SDValue Op1 = getValue(I.getOperand(0)); 2419 SDValue Op2 = getValue(I.getOperand(1)); 2420 if (!isa<VectorType>(I.getType())) { 2421 if (TLI.getShiftAmountTy().bitsLT(Op2.getValueType())) 2422 Op2 = DAG.getNode(ISD::TRUNCATE, TLI.getShiftAmountTy(), Op2); 2423 else if (TLI.getShiftAmountTy().bitsGT(Op2.getValueType())) 2424 Op2 = DAG.getNode(ISD::ANY_EXTEND, TLI.getShiftAmountTy(), Op2); 2425 } 2426 2427 setValue(&I, DAG.getNode(Opcode, Op1.getValueType(), Op1, Op2)); 2428} 2429 2430void SelectionDAGLowering::visitICmp(User &I) { 2431 ICmpInst::Predicate predicate = ICmpInst::BAD_ICMP_PREDICATE; 2432 if (ICmpInst *IC = dyn_cast<ICmpInst>(&I)) 2433 predicate = IC->getPredicate(); 2434 else if (ConstantExpr *IC = dyn_cast<ConstantExpr>(&I)) 2435 predicate = ICmpInst::Predicate(IC->getPredicate()); 2436 SDValue Op1 = getValue(I.getOperand(0)); 2437 SDValue Op2 = getValue(I.getOperand(1)); 2438 ISD::CondCode Opcode; 2439 switch (predicate) { 2440 case ICmpInst::ICMP_EQ : Opcode = ISD::SETEQ; break; 2441 case ICmpInst::ICMP_NE : Opcode = ISD::SETNE; break; 2442 case ICmpInst::ICMP_UGT : Opcode = ISD::SETUGT; break; 2443 case ICmpInst::ICMP_UGE : Opcode = ISD::SETUGE; break; 2444 case ICmpInst::ICMP_ULT : Opcode = ISD::SETULT; break; 2445 case ICmpInst::ICMP_ULE : Opcode = ISD::SETULE; break; 2446 case ICmpInst::ICMP_SGT : Opcode = ISD::SETGT; break; 2447 case ICmpInst::ICMP_SGE : Opcode = ISD::SETGE; break; 2448 case ICmpInst::ICMP_SLT : Opcode = ISD::SETLT; break; 2449 case ICmpInst::ICMP_SLE : Opcode = ISD::SETLE; break; 2450 default: 2451 assert(!"Invalid ICmp predicate value"); 2452 Opcode = ISD::SETEQ; 2453 break; 2454 } 2455 setValue(&I, DAG.getSetCC(MVT::i1, Op1, Op2, Opcode)); 2456} 2457 2458void SelectionDAGLowering::visitFCmp(User &I) { 2459 FCmpInst::Predicate predicate = FCmpInst::BAD_FCMP_PREDICATE; 2460 if (FCmpInst *FC = dyn_cast<FCmpInst>(&I)) 2461 predicate = FC->getPredicate(); 2462 else if (ConstantExpr *FC = dyn_cast<ConstantExpr>(&I)) 2463 predicate = FCmpInst::Predicate(FC->getPredicate()); 2464 SDValue Op1 = getValue(I.getOperand(0)); 2465 SDValue Op2 = getValue(I.getOperand(1)); 2466 ISD::CondCode Condition, FOC, FPC; 2467 switch (predicate) { 2468 case FCmpInst::FCMP_FALSE: FOC = FPC = ISD::SETFALSE; break; 2469 case FCmpInst::FCMP_OEQ: FOC = ISD::SETEQ; FPC = ISD::SETOEQ; break; 2470 case FCmpInst::FCMP_OGT: FOC = ISD::SETGT; FPC = ISD::SETOGT; break; 2471 case FCmpInst::FCMP_OGE: FOC = ISD::SETGE; FPC = ISD::SETOGE; break; 2472 case FCmpInst::FCMP_OLT: FOC = ISD::SETLT; FPC = ISD::SETOLT; break; 2473 case FCmpInst::FCMP_OLE: FOC = ISD::SETLE; FPC = ISD::SETOLE; break; 2474 case FCmpInst::FCMP_ONE: FOC = ISD::SETNE; FPC = ISD::SETONE; break; 2475 case FCmpInst::FCMP_ORD: FOC = FPC = ISD::SETO; break; 2476 case FCmpInst::FCMP_UNO: FOC = FPC = ISD::SETUO; break; 2477 case FCmpInst::FCMP_UEQ: FOC = ISD::SETEQ; FPC = ISD::SETUEQ; break; 2478 case FCmpInst::FCMP_UGT: FOC = ISD::SETGT; FPC = ISD::SETUGT; break; 2479 case FCmpInst::FCMP_UGE: FOC = ISD::SETGE; FPC = ISD::SETUGE; break; 2480 case FCmpInst::FCMP_ULT: FOC = ISD::SETLT; FPC = ISD::SETULT; break; 2481 case FCmpInst::FCMP_ULE: FOC = ISD::SETLE; FPC = ISD::SETULE; break; 2482 case FCmpInst::FCMP_UNE: FOC = ISD::SETNE; FPC = ISD::SETUNE; break; 2483 case FCmpInst::FCMP_TRUE: FOC = FPC = ISD::SETTRUE; break; 2484 default: 2485 assert(!"Invalid FCmp predicate value"); 2486 FOC = FPC = ISD::SETFALSE; 2487 break; 2488 } 2489 if (FiniteOnlyFPMath()) 2490 Condition = FOC; 2491 else 2492 Condition = FPC; 2493 setValue(&I, DAG.getSetCC(MVT::i1, Op1, Op2, Condition)); 2494} 2495 2496void SelectionDAGLowering::visitVICmp(User &I) { 2497 ICmpInst::Predicate predicate = ICmpInst::BAD_ICMP_PREDICATE; 2498 if (VICmpInst *IC = dyn_cast<VICmpInst>(&I)) 2499 predicate = IC->getPredicate(); 2500 else if (ConstantExpr *IC = dyn_cast<ConstantExpr>(&I)) 2501 predicate = ICmpInst::Predicate(IC->getPredicate()); 2502 SDValue Op1 = getValue(I.getOperand(0)); 2503 SDValue Op2 = getValue(I.getOperand(1)); 2504 ISD::CondCode Opcode; 2505 switch (predicate) { 2506 case ICmpInst::ICMP_EQ : Opcode = ISD::SETEQ; break; 2507 case ICmpInst::ICMP_NE : Opcode = ISD::SETNE; break; 2508 case ICmpInst::ICMP_UGT : Opcode = ISD::SETUGT; break; 2509 case ICmpInst::ICMP_UGE : Opcode = ISD::SETUGE; break; 2510 case ICmpInst::ICMP_ULT : Opcode = ISD::SETULT; break; 2511 case ICmpInst::ICMP_ULE : Opcode = ISD::SETULE; break; 2512 case ICmpInst::ICMP_SGT : Opcode = ISD::SETGT; break; 2513 case ICmpInst::ICMP_SGE : Opcode = ISD::SETGE; break; 2514 case ICmpInst::ICMP_SLT : Opcode = ISD::SETLT; break; 2515 case ICmpInst::ICMP_SLE : Opcode = ISD::SETLE; break; 2516 default: 2517 assert(!"Invalid ICmp predicate value"); 2518 Opcode = ISD::SETEQ; 2519 break; 2520 } 2521 setValue(&I, DAG.getVSetCC(Op1.getValueType(), Op1, Op2, Opcode)); 2522} 2523 2524void SelectionDAGLowering::visitVFCmp(User &I) { 2525 FCmpInst::Predicate predicate = FCmpInst::BAD_FCMP_PREDICATE; 2526 if (VFCmpInst *FC = dyn_cast<VFCmpInst>(&I)) 2527 predicate = FC->getPredicate(); 2528 else if (ConstantExpr *FC = dyn_cast<ConstantExpr>(&I)) 2529 predicate = FCmpInst::Predicate(FC->getPredicate()); 2530 SDValue Op1 = getValue(I.getOperand(0)); 2531 SDValue Op2 = getValue(I.getOperand(1)); 2532 ISD::CondCode Condition, FOC, FPC; 2533 switch (predicate) { 2534 case FCmpInst::FCMP_FALSE: FOC = FPC = ISD::SETFALSE; break; 2535 case FCmpInst::FCMP_OEQ: FOC = ISD::SETEQ; FPC = ISD::SETOEQ; break; 2536 case FCmpInst::FCMP_OGT: FOC = ISD::SETGT; FPC = ISD::SETOGT; break; 2537 case FCmpInst::FCMP_OGE: FOC = ISD::SETGE; FPC = ISD::SETOGE; break; 2538 case FCmpInst::FCMP_OLT: FOC = ISD::SETLT; FPC = ISD::SETOLT; break; 2539 case FCmpInst::FCMP_OLE: FOC = ISD::SETLE; FPC = ISD::SETOLE; break; 2540 case FCmpInst::FCMP_ONE: FOC = ISD::SETNE; FPC = ISD::SETONE; break; 2541 case FCmpInst::FCMP_ORD: FOC = FPC = ISD::SETO; break; 2542 case FCmpInst::FCMP_UNO: FOC = FPC = ISD::SETUO; break; 2543 case FCmpInst::FCMP_UEQ: FOC = ISD::SETEQ; FPC = ISD::SETUEQ; break; 2544 case FCmpInst::FCMP_UGT: FOC = ISD::SETGT; FPC = ISD::SETUGT; break; 2545 case FCmpInst::FCMP_UGE: FOC = ISD::SETGE; FPC = ISD::SETUGE; break; 2546 case FCmpInst::FCMP_ULT: FOC = ISD::SETLT; FPC = ISD::SETULT; break; 2547 case FCmpInst::FCMP_ULE: FOC = ISD::SETLE; FPC = ISD::SETULE; break; 2548 case FCmpInst::FCMP_UNE: FOC = ISD::SETNE; FPC = ISD::SETUNE; break; 2549 case FCmpInst::FCMP_TRUE: FOC = FPC = ISD::SETTRUE; break; 2550 default: 2551 assert(!"Invalid VFCmp predicate value"); 2552 FOC = FPC = ISD::SETFALSE; 2553 break; 2554 } 2555 if (FiniteOnlyFPMath()) 2556 Condition = FOC; 2557 else 2558 Condition = FPC; 2559 2560 MVT DestVT = TLI.getValueType(I.getType()); 2561 2562 setValue(&I, DAG.getVSetCC(DestVT, Op1, Op2, Condition)); 2563} 2564 2565void SelectionDAGLowering::visitSelect(User &I) { 2566 SDValue Cond = getValue(I.getOperand(0)); 2567 SDValue TrueVal = getValue(I.getOperand(1)); 2568 SDValue FalseVal = getValue(I.getOperand(2)); 2569 setValue(&I, DAG.getNode(ISD::SELECT, TrueVal.getValueType(), Cond, 2570 TrueVal, FalseVal)); 2571} 2572 2573 2574void SelectionDAGLowering::visitTrunc(User &I) { 2575 // TruncInst cannot be a no-op cast because sizeof(src) > sizeof(dest). 2576 SDValue N = getValue(I.getOperand(0)); 2577 MVT DestVT = TLI.getValueType(I.getType()); 2578 setValue(&I, DAG.getNode(ISD::TRUNCATE, DestVT, N)); 2579} 2580 2581void SelectionDAGLowering::visitZExt(User &I) { 2582 // ZExt cannot be a no-op cast because sizeof(src) < sizeof(dest). 2583 // ZExt also can't be a cast to bool for same reason. So, nothing much to do 2584 SDValue N = getValue(I.getOperand(0)); 2585 MVT DestVT = TLI.getValueType(I.getType()); 2586 setValue(&I, DAG.getNode(ISD::ZERO_EXTEND, DestVT, N)); 2587} 2588 2589void SelectionDAGLowering::visitSExt(User &I) { 2590 // SExt cannot be a no-op cast because sizeof(src) < sizeof(dest). 2591 // SExt also can't be a cast to bool for same reason. So, nothing much to do 2592 SDValue N = getValue(I.getOperand(0)); 2593 MVT DestVT = TLI.getValueType(I.getType()); 2594 setValue(&I, DAG.getNode(ISD::SIGN_EXTEND, DestVT, N)); 2595} 2596 2597void SelectionDAGLowering::visitFPTrunc(User &I) { 2598 // FPTrunc is never a no-op cast, no need to check 2599 SDValue N = getValue(I.getOperand(0)); 2600 MVT DestVT = TLI.getValueType(I.getType()); 2601 setValue(&I, DAG.getNode(ISD::FP_ROUND, DestVT, N, DAG.getIntPtrConstant(0))); 2602} 2603 2604void SelectionDAGLowering::visitFPExt(User &I){ 2605 // FPTrunc is never a no-op cast, no need to check 2606 SDValue N = getValue(I.getOperand(0)); 2607 MVT DestVT = TLI.getValueType(I.getType()); 2608 setValue(&I, DAG.getNode(ISD::FP_EXTEND, DestVT, N)); 2609} 2610 2611void SelectionDAGLowering::visitFPToUI(User &I) { 2612 // FPToUI is never a no-op cast, no need to check 2613 SDValue N = getValue(I.getOperand(0)); 2614 MVT DestVT = TLI.getValueType(I.getType()); 2615 setValue(&I, DAG.getNode(ISD::FP_TO_UINT, DestVT, N)); 2616} 2617 2618void SelectionDAGLowering::visitFPToSI(User &I) { 2619 // FPToSI is never a no-op cast, no need to check 2620 SDValue N = getValue(I.getOperand(0)); 2621 MVT DestVT = TLI.getValueType(I.getType()); 2622 setValue(&I, DAG.getNode(ISD::FP_TO_SINT, DestVT, N)); 2623} 2624 2625void SelectionDAGLowering::visitUIToFP(User &I) { 2626 // UIToFP is never a no-op cast, no need to check 2627 SDValue N = getValue(I.getOperand(0)); 2628 MVT DestVT = TLI.getValueType(I.getType()); 2629 setValue(&I, DAG.getNode(ISD::UINT_TO_FP, DestVT, N)); 2630} 2631 2632void SelectionDAGLowering::visitSIToFP(User &I){ 2633 // UIToFP is never a no-op cast, no need to check 2634 SDValue N = getValue(I.getOperand(0)); 2635 MVT DestVT = TLI.getValueType(I.getType()); 2636 setValue(&I, DAG.getNode(ISD::SINT_TO_FP, DestVT, N)); 2637} 2638 2639void SelectionDAGLowering::visitPtrToInt(User &I) { 2640 // What to do depends on the size of the integer and the size of the pointer. 2641 // We can either truncate, zero extend, or no-op, accordingly. 2642 SDValue N = getValue(I.getOperand(0)); 2643 MVT SrcVT = N.getValueType(); 2644 MVT DestVT = TLI.getValueType(I.getType()); 2645 SDValue Result; 2646 if (DestVT.bitsLT(SrcVT)) 2647 Result = DAG.getNode(ISD::TRUNCATE, DestVT, N); 2648 else 2649 // Note: ZERO_EXTEND can handle cases where the sizes are equal too 2650 Result = DAG.getNode(ISD::ZERO_EXTEND, DestVT, N); 2651 setValue(&I, Result); 2652} 2653 2654void SelectionDAGLowering::visitIntToPtr(User &I) { 2655 // What to do depends on the size of the integer and the size of the pointer. 2656 // We can either truncate, zero extend, or no-op, accordingly. 2657 SDValue N = getValue(I.getOperand(0)); 2658 MVT SrcVT = N.getValueType(); 2659 MVT DestVT = TLI.getValueType(I.getType()); 2660 if (DestVT.bitsLT(SrcVT)) 2661 setValue(&I, DAG.getNode(ISD::TRUNCATE, DestVT, N)); 2662 else 2663 // Note: ZERO_EXTEND can handle cases where the sizes are equal too 2664 setValue(&I, DAG.getNode(ISD::ZERO_EXTEND, DestVT, N)); 2665} 2666 2667void SelectionDAGLowering::visitBitCast(User &I) { 2668 SDValue N = getValue(I.getOperand(0)); 2669 MVT DestVT = TLI.getValueType(I.getType()); 2670 2671 // BitCast assures us that source and destination are the same size so this 2672 // is either a BIT_CONVERT or a no-op. 2673 if (DestVT != N.getValueType()) 2674 setValue(&I, DAG.getNode(ISD::BIT_CONVERT, DestVT, N)); // convert types 2675 else 2676 setValue(&I, N); // noop cast. 2677} 2678 2679void SelectionDAGLowering::visitInsertElement(User &I) { 2680 SDValue InVec = getValue(I.getOperand(0)); 2681 SDValue InVal = getValue(I.getOperand(1)); 2682 SDValue InIdx = DAG.getNode(ISD::ZERO_EXTEND, TLI.getPointerTy(), 2683 getValue(I.getOperand(2))); 2684 2685 setValue(&I, DAG.getNode(ISD::INSERT_VECTOR_ELT, 2686 TLI.getValueType(I.getType()), 2687 InVec, InVal, InIdx)); 2688} 2689 2690void SelectionDAGLowering::visitExtractElement(User &I) { 2691 SDValue InVec = getValue(I.getOperand(0)); 2692 SDValue InIdx = DAG.getNode(ISD::ZERO_EXTEND, TLI.getPointerTy(), 2693 getValue(I.getOperand(1))); 2694 setValue(&I, DAG.getNode(ISD::EXTRACT_VECTOR_ELT, 2695 TLI.getValueType(I.getType()), InVec, InIdx)); 2696} 2697 2698void SelectionDAGLowering::visitShuffleVector(User &I) { 2699 SDValue V1 = getValue(I.getOperand(0)); 2700 SDValue V2 = getValue(I.getOperand(1)); 2701 SDValue Mask = getValue(I.getOperand(2)); 2702 2703 setValue(&I, DAG.getNode(ISD::VECTOR_SHUFFLE, 2704 TLI.getValueType(I.getType()), 2705 V1, V2, Mask)); 2706} 2707 2708void SelectionDAGLowering::visitInsertValue(InsertValueInst &I) { 2709 const Value *Op0 = I.getOperand(0); 2710 const Value *Op1 = I.getOperand(1); 2711 const Type *AggTy = I.getType(); 2712 const Type *ValTy = Op1->getType(); 2713 bool IntoUndef = isa<UndefValue>(Op0); 2714 bool FromUndef = isa<UndefValue>(Op1); 2715 2716 unsigned LinearIndex = ComputeLinearIndex(TLI, AggTy, 2717 I.idx_begin(), I.idx_end()); 2718 2719 SmallVector<MVT, 4> AggValueVTs; 2720 ComputeValueVTs(TLI, AggTy, AggValueVTs); 2721 SmallVector<MVT, 4> ValValueVTs; 2722 ComputeValueVTs(TLI, ValTy, ValValueVTs); 2723 2724 unsigned NumAggValues = AggValueVTs.size(); 2725 unsigned NumValValues = ValValueVTs.size(); 2726 SmallVector<SDValue, 4> Values(NumAggValues); 2727 2728 SDValue Agg = getValue(Op0); 2729 SDValue Val = getValue(Op1); 2730 unsigned i = 0; 2731 // Copy the beginning value(s) from the original aggregate. 2732 for (; i != LinearIndex; ++i) 2733 Values[i] = IntoUndef ? DAG.getNode(ISD::UNDEF, AggValueVTs[i]) : 2734 SDValue(Agg.Val, Agg.ResNo + i); 2735 // Copy values from the inserted value(s). 2736 for (; i != LinearIndex + NumValValues; ++i) 2737 Values[i] = FromUndef ? DAG.getNode(ISD::UNDEF, AggValueVTs[i]) : 2738 SDValue(Val.Val, Val.ResNo + i - LinearIndex); 2739 // Copy remaining value(s) from the original aggregate. 2740 for (; i != NumAggValues; ++i) 2741 Values[i] = IntoUndef ? DAG.getNode(ISD::UNDEF, AggValueVTs[i]) : 2742 SDValue(Agg.Val, Agg.ResNo + i); 2743 2744 setValue(&I, DAG.getMergeValues(DAG.getVTList(&AggValueVTs[0], NumAggValues), 2745 &Values[0], NumAggValues)); 2746} 2747 2748void SelectionDAGLowering::visitExtractValue(ExtractValueInst &I) { 2749 const Value *Op0 = I.getOperand(0); 2750 const Type *AggTy = Op0->getType(); 2751 const Type *ValTy = I.getType(); 2752 bool OutOfUndef = isa<UndefValue>(Op0); 2753 2754 unsigned LinearIndex = ComputeLinearIndex(TLI, AggTy, 2755 I.idx_begin(), I.idx_end()); 2756 2757 SmallVector<MVT, 4> ValValueVTs; 2758 ComputeValueVTs(TLI, ValTy, ValValueVTs); 2759 2760 unsigned NumValValues = ValValueVTs.size(); 2761 SmallVector<SDValue, 4> Values(NumValValues); 2762 2763 SDValue Agg = getValue(Op0); 2764 // Copy out the selected value(s). 2765 for (unsigned i = LinearIndex; i != LinearIndex + NumValValues; ++i) 2766 Values[i - LinearIndex] = 2767 OutOfUndef ? DAG.getNode(ISD::UNDEF, Agg.Val->getValueType(Agg.ResNo + i)) : 2768 SDValue(Agg.Val, Agg.ResNo + i); 2769 2770 setValue(&I, DAG.getMergeValues(DAG.getVTList(&ValValueVTs[0], NumValValues), 2771 &Values[0], NumValValues)); 2772} 2773 2774 2775void SelectionDAGLowering::visitGetElementPtr(User &I) { 2776 SDValue N = getValue(I.getOperand(0)); 2777 const Type *Ty = I.getOperand(0)->getType(); 2778 2779 for (GetElementPtrInst::op_iterator OI = I.op_begin()+1, E = I.op_end(); 2780 OI != E; ++OI) { 2781 Value *Idx = *OI; 2782 if (const StructType *StTy = dyn_cast<StructType>(Ty)) { 2783 unsigned Field = cast<ConstantInt>(Idx)->getZExtValue(); 2784 if (Field) { 2785 // N = N + Offset 2786 uint64_t Offset = TD->getStructLayout(StTy)->getElementOffset(Field); 2787 N = DAG.getNode(ISD::ADD, N.getValueType(), N, 2788 DAG.getIntPtrConstant(Offset)); 2789 } 2790 Ty = StTy->getElementType(Field); 2791 } else { 2792 Ty = cast<SequentialType>(Ty)->getElementType(); 2793 2794 // If this is a constant subscript, handle it quickly. 2795 if (ConstantInt *CI = dyn_cast<ConstantInt>(Idx)) { 2796 if (CI->getZExtValue() == 0) continue; 2797 uint64_t Offs = 2798 TD->getABITypeSize(Ty)*cast<ConstantInt>(CI)->getSExtValue(); 2799 N = DAG.getNode(ISD::ADD, N.getValueType(), N, 2800 DAG.getIntPtrConstant(Offs)); 2801 continue; 2802 } 2803 2804 // N = N + Idx * ElementSize; 2805 uint64_t ElementSize = TD->getABITypeSize(Ty); 2806 SDValue IdxN = getValue(Idx); 2807 2808 // If the index is smaller or larger than intptr_t, truncate or extend 2809 // it. 2810 if (IdxN.getValueType().bitsLT(N.getValueType())) { 2811 IdxN = DAG.getNode(ISD::SIGN_EXTEND, N.getValueType(), IdxN); 2812 } else if (IdxN.getValueType().bitsGT(N.getValueType())) 2813 IdxN = DAG.getNode(ISD::TRUNCATE, N.getValueType(), IdxN); 2814 2815 // If this is a multiply by a power of two, turn it into a shl 2816 // immediately. This is a very common case. 2817 if (isPowerOf2_64(ElementSize)) { 2818 unsigned Amt = Log2_64(ElementSize); 2819 IdxN = DAG.getNode(ISD::SHL, N.getValueType(), IdxN, 2820 DAG.getConstant(Amt, TLI.getShiftAmountTy())); 2821 N = DAG.getNode(ISD::ADD, N.getValueType(), N, IdxN); 2822 continue; 2823 } 2824 2825 SDValue Scale = DAG.getIntPtrConstant(ElementSize); 2826 IdxN = DAG.getNode(ISD::MUL, N.getValueType(), IdxN, Scale); 2827 N = DAG.getNode(ISD::ADD, N.getValueType(), N, IdxN); 2828 } 2829 } 2830 setValue(&I, N); 2831} 2832 2833void SelectionDAGLowering::visitAlloca(AllocaInst &I) { 2834 // If this is a fixed sized alloca in the entry block of the function, 2835 // allocate it statically on the stack. 2836 if (FuncInfo.StaticAllocaMap.count(&I)) 2837 return; // getValue will auto-populate this. 2838 2839 const Type *Ty = I.getAllocatedType(); 2840 uint64_t TySize = TLI.getTargetData()->getABITypeSize(Ty); 2841 unsigned Align = 2842 std::max((unsigned)TLI.getTargetData()->getPrefTypeAlignment(Ty), 2843 I.getAlignment()); 2844 2845 SDValue AllocSize = getValue(I.getArraySize()); 2846 MVT IntPtr = TLI.getPointerTy(); 2847 if (IntPtr.bitsLT(AllocSize.getValueType())) 2848 AllocSize = DAG.getNode(ISD::TRUNCATE, IntPtr, AllocSize); 2849 else if (IntPtr.bitsGT(AllocSize.getValueType())) 2850 AllocSize = DAG.getNode(ISD::ZERO_EXTEND, IntPtr, AllocSize); 2851 2852 AllocSize = DAG.getNode(ISD::MUL, IntPtr, AllocSize, 2853 DAG.getIntPtrConstant(TySize)); 2854 2855 // Handle alignment. If the requested alignment is less than or equal to 2856 // the stack alignment, ignore it. If the size is greater than or equal to 2857 // the stack alignment, we note this in the DYNAMIC_STACKALLOC node. 2858 unsigned StackAlign = 2859 TLI.getTargetMachine().getFrameInfo()->getStackAlignment(); 2860 if (Align <= StackAlign) 2861 Align = 0; 2862 2863 // Round the size of the allocation up to the stack alignment size 2864 // by add SA-1 to the size. 2865 AllocSize = DAG.getNode(ISD::ADD, AllocSize.getValueType(), AllocSize, 2866 DAG.getIntPtrConstant(StackAlign-1)); 2867 // Mask out the low bits for alignment purposes. 2868 AllocSize = DAG.getNode(ISD::AND, AllocSize.getValueType(), AllocSize, 2869 DAG.getIntPtrConstant(~(uint64_t)(StackAlign-1))); 2870 2871 SDValue Ops[] = { getRoot(), AllocSize, DAG.getIntPtrConstant(Align) }; 2872 const MVT *VTs = DAG.getNodeValueTypes(AllocSize.getValueType(), 2873 MVT::Other); 2874 SDValue DSA = DAG.getNode(ISD::DYNAMIC_STACKALLOC, VTs, 2, Ops, 3); 2875 setValue(&I, DSA); 2876 DAG.setRoot(DSA.getValue(1)); 2877 2878 // Inform the Frame Information that we have just allocated a variable-sized 2879 // object. 2880 CurMBB->getParent()->getFrameInfo()->CreateVariableSizedObject(); 2881} 2882 2883void SelectionDAGLowering::visitLoad(LoadInst &I) { 2884 const Value *SV = I.getOperand(0); 2885 SDValue Ptr = getValue(SV); 2886 2887 const Type *Ty = I.getType(); 2888 bool isVolatile = I.isVolatile(); 2889 unsigned Alignment = I.getAlignment(); 2890 2891 SmallVector<MVT, 4> ValueVTs; 2892 SmallVector<uint64_t, 4> Offsets; 2893 ComputeValueVTs(TLI, Ty, ValueVTs, &Offsets); 2894 unsigned NumValues = ValueVTs.size(); 2895 if (NumValues == 0) 2896 return; 2897 2898 SDValue Root; 2899 bool ConstantMemory = false; 2900 if (I.isVolatile()) 2901 // Serialize volatile loads with other side effects. 2902 Root = getRoot(); 2903 else if (AA.pointsToConstantMemory(SV)) { 2904 // Do not serialize (non-volatile) loads of constant memory with anything. 2905 Root = DAG.getEntryNode(); 2906 ConstantMemory = true; 2907 } else { 2908 // Do not serialize non-volatile loads against each other. 2909 Root = DAG.getRoot(); 2910 } 2911 2912 SmallVector<SDValue, 4> Values(NumValues); 2913 SmallVector<SDValue, 4> Chains(NumValues); 2914 MVT PtrVT = Ptr.getValueType(); 2915 for (unsigned i = 0; i != NumValues; ++i) { 2916 SDValue L = DAG.getLoad(ValueVTs[i], Root, 2917 DAG.getNode(ISD::ADD, PtrVT, Ptr, 2918 DAG.getConstant(Offsets[i], PtrVT)), 2919 SV, Offsets[i], 2920 isVolatile, Alignment); 2921 Values[i] = L; 2922 Chains[i] = L.getValue(1); 2923 } 2924 2925 if (!ConstantMemory) { 2926 SDValue Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, 2927 &Chains[0], NumValues); 2928 if (isVolatile) 2929 DAG.setRoot(Chain); 2930 else 2931 PendingLoads.push_back(Chain); 2932 } 2933 2934 setValue(&I, DAG.getMergeValues(DAG.getVTList(&ValueVTs[0], NumValues), 2935 &Values[0], NumValues)); 2936} 2937 2938 2939void SelectionDAGLowering::visitStore(StoreInst &I) { 2940 Value *SrcV = I.getOperand(0); 2941 Value *PtrV = I.getOperand(1); 2942 2943 SmallVector<MVT, 4> ValueVTs; 2944 SmallVector<uint64_t, 4> Offsets; 2945 ComputeValueVTs(TLI, SrcV->getType(), ValueVTs, &Offsets); 2946 unsigned NumValues = ValueVTs.size(); 2947 if (NumValues == 0) 2948 return; 2949 2950 // Get the lowered operands. Note that we do this after 2951 // checking if NumResults is zero, because with zero results 2952 // the operands won't have values in the map. 2953 SDValue Src = getValue(SrcV); 2954 SDValue Ptr = getValue(PtrV); 2955 2956 SDValue Root = getRoot(); 2957 SmallVector<SDValue, 4> Chains(NumValues); 2958 MVT PtrVT = Ptr.getValueType(); 2959 bool isVolatile = I.isVolatile(); 2960 unsigned Alignment = I.getAlignment(); 2961 for (unsigned i = 0; i != NumValues; ++i) 2962 Chains[i] = DAG.getStore(Root, SDValue(Src.Val, Src.ResNo + i), 2963 DAG.getNode(ISD::ADD, PtrVT, Ptr, 2964 DAG.getConstant(Offsets[i], PtrVT)), 2965 PtrV, Offsets[i], 2966 isVolatile, Alignment); 2967 2968 DAG.setRoot(DAG.getNode(ISD::TokenFactor, MVT::Other, &Chains[0], NumValues)); 2969} 2970 2971/// visitTargetIntrinsic - Lower a call of a target intrinsic to an INTRINSIC 2972/// node. 2973void SelectionDAGLowering::visitTargetIntrinsic(CallInst &I, 2974 unsigned Intrinsic) { 2975 bool HasChain = !I.doesNotAccessMemory(); 2976 bool OnlyLoad = HasChain && I.onlyReadsMemory(); 2977 2978 // Build the operand list. 2979 SmallVector<SDValue, 8> Ops; 2980 if (HasChain) { // If this intrinsic has side-effects, chainify it. 2981 if (OnlyLoad) { 2982 // We don't need to serialize loads against other loads. 2983 Ops.push_back(DAG.getRoot()); 2984 } else { 2985 Ops.push_back(getRoot()); 2986 } 2987 } 2988 2989 // Add the intrinsic ID as an integer operand. 2990 Ops.push_back(DAG.getConstant(Intrinsic, TLI.getPointerTy())); 2991 2992 // Add all operands of the call to the operand list. 2993 for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i) { 2994 SDValue Op = getValue(I.getOperand(i)); 2995 assert(TLI.isTypeLegal(Op.getValueType()) && 2996 "Intrinsic uses a non-legal type?"); 2997 Ops.push_back(Op); 2998 } 2999 3000 std::vector<MVT> VTs; 3001 if (I.getType() != Type::VoidTy) { 3002 MVT VT = TLI.getValueType(I.getType()); 3003 if (VT.isVector()) { 3004 const VectorType *DestTy = cast<VectorType>(I.getType()); 3005 MVT EltVT = TLI.getValueType(DestTy->getElementType()); 3006 3007 VT = MVT::getVectorVT(EltVT, DestTy->getNumElements()); 3008 assert(VT != MVT::Other && "Intrinsic uses a non-legal type?"); 3009 } 3010 3011 assert(TLI.isTypeLegal(VT) && "Intrinsic uses a non-legal type?"); 3012 VTs.push_back(VT); 3013 } 3014 if (HasChain) 3015 VTs.push_back(MVT::Other); 3016 3017 const MVT *VTList = DAG.getNodeValueTypes(VTs); 3018 3019 // Create the node. 3020 SDValue Result; 3021 if (!HasChain) 3022 Result = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, VTList, VTs.size(), 3023 &Ops[0], Ops.size()); 3024 else if (I.getType() != Type::VoidTy) 3025 Result = DAG.getNode(ISD::INTRINSIC_W_CHAIN, VTList, VTs.size(), 3026 &Ops[0], Ops.size()); 3027 else 3028 Result = DAG.getNode(ISD::INTRINSIC_VOID, VTList, VTs.size(), 3029 &Ops[0], Ops.size()); 3030 3031 if (HasChain) { 3032 SDValue Chain = Result.getValue(Result.Val->getNumValues()-1); 3033 if (OnlyLoad) 3034 PendingLoads.push_back(Chain); 3035 else 3036 DAG.setRoot(Chain); 3037 } 3038 if (I.getType() != Type::VoidTy) { 3039 if (const VectorType *PTy = dyn_cast<VectorType>(I.getType())) { 3040 MVT VT = TLI.getValueType(PTy); 3041 Result = DAG.getNode(ISD::BIT_CONVERT, VT, Result); 3042 } 3043 setValue(&I, Result); 3044 } 3045} 3046 3047/// ExtractTypeInfo - Returns the type info, possibly bitcast, encoded in V. 3048static GlobalVariable *ExtractTypeInfo (Value *V) { 3049 V = V->stripPointerCasts(); 3050 GlobalVariable *GV = dyn_cast<GlobalVariable>(V); 3051 assert ((GV || isa<ConstantPointerNull>(V)) && 3052 "TypeInfo must be a global variable or NULL"); 3053 return GV; 3054} 3055 3056/// addCatchInfo - Extract the personality and type infos from an eh.selector 3057/// call, and add them to the specified machine basic block. 3058static void addCatchInfo(CallInst &I, MachineModuleInfo *MMI, 3059 MachineBasicBlock *MBB) { 3060 // Inform the MachineModuleInfo of the personality for this landing pad. 3061 ConstantExpr *CE = cast<ConstantExpr>(I.getOperand(2)); 3062 assert(CE->getOpcode() == Instruction::BitCast && 3063 isa<Function>(CE->getOperand(0)) && 3064 "Personality should be a function"); 3065 MMI->addPersonality(MBB, cast<Function>(CE->getOperand(0))); 3066 3067 // Gather all the type infos for this landing pad and pass them along to 3068 // MachineModuleInfo. 3069 std::vector<GlobalVariable *> TyInfo; 3070 unsigned N = I.getNumOperands(); 3071 3072 for (unsigned i = N - 1; i > 2; --i) { 3073 if (ConstantInt *CI = dyn_cast<ConstantInt>(I.getOperand(i))) { 3074 unsigned FilterLength = CI->getZExtValue(); 3075 unsigned FirstCatch = i + FilterLength + !FilterLength; 3076 assert (FirstCatch <= N && "Invalid filter length"); 3077 3078 if (FirstCatch < N) { 3079 TyInfo.reserve(N - FirstCatch); 3080 for (unsigned j = FirstCatch; j < N; ++j) 3081 TyInfo.push_back(ExtractTypeInfo(I.getOperand(j))); 3082 MMI->addCatchTypeInfo(MBB, TyInfo); 3083 TyInfo.clear(); 3084 } 3085 3086 if (!FilterLength) { 3087 // Cleanup. 3088 MMI->addCleanup(MBB); 3089 } else { 3090 // Filter. 3091 TyInfo.reserve(FilterLength - 1); 3092 for (unsigned j = i + 1; j < FirstCatch; ++j) 3093 TyInfo.push_back(ExtractTypeInfo(I.getOperand(j))); 3094 MMI->addFilterTypeInfo(MBB, TyInfo); 3095 TyInfo.clear(); 3096 } 3097 3098 N = i; 3099 } 3100 } 3101 3102 if (N > 3) { 3103 TyInfo.reserve(N - 3); 3104 for (unsigned j = 3; j < N; ++j) 3105 TyInfo.push_back(ExtractTypeInfo(I.getOperand(j))); 3106 MMI->addCatchTypeInfo(MBB, TyInfo); 3107 } 3108} 3109 3110 3111/// Inlined utility function to implement binary input atomic intrinsics for 3112// visitIntrinsicCall: I is a call instruction 3113// Op is the associated NodeType for I 3114const char * 3115SelectionDAGLowering::implVisitBinaryAtomic(CallInst& I, ISD::NodeType Op) { 3116 SDValue Root = getRoot(); 3117 SDValue L = DAG.getAtomic(Op, Root, 3118 getValue(I.getOperand(1)), 3119 getValue(I.getOperand(2)), 3120 I.getOperand(1)); 3121 setValue(&I, L); 3122 DAG.setRoot(L.getValue(1)); 3123 return 0; 3124} 3125 3126/// visitIntrinsicCall - Lower the call to the specified intrinsic function. If 3127/// we want to emit this as a call to a named external function, return the name 3128/// otherwise lower it and return null. 3129const char * 3130SelectionDAGLowering::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) { 3131 switch (Intrinsic) { 3132 default: 3133 // By default, turn this into a target intrinsic node. 3134 visitTargetIntrinsic(I, Intrinsic); 3135 return 0; 3136 case Intrinsic::vastart: visitVAStart(I); return 0; 3137 case Intrinsic::vaend: visitVAEnd(I); return 0; 3138 case Intrinsic::vacopy: visitVACopy(I); return 0; 3139 case Intrinsic::returnaddress: 3140 setValue(&I, DAG.getNode(ISD::RETURNADDR, TLI.getPointerTy(), 3141 getValue(I.getOperand(1)))); 3142 return 0; 3143 case Intrinsic::frameaddress: 3144 setValue(&I, DAG.getNode(ISD::FRAMEADDR, TLI.getPointerTy(), 3145 getValue(I.getOperand(1)))); 3146 return 0; 3147 case Intrinsic::setjmp: 3148 return "_setjmp"+!TLI.usesUnderscoreSetJmp(); 3149 break; 3150 case Intrinsic::longjmp: 3151 return "_longjmp"+!TLI.usesUnderscoreLongJmp(); 3152 break; 3153 case Intrinsic::memcpy_i32: 3154 case Intrinsic::memcpy_i64: { 3155 SDValue Op1 = getValue(I.getOperand(1)); 3156 SDValue Op2 = getValue(I.getOperand(2)); 3157 SDValue Op3 = getValue(I.getOperand(3)); 3158 unsigned Align = cast<ConstantInt>(I.getOperand(4))->getZExtValue(); 3159 DAG.setRoot(DAG.getMemcpy(getRoot(), Op1, Op2, Op3, Align, false, 3160 I.getOperand(1), 0, I.getOperand(2), 0)); 3161 return 0; 3162 } 3163 case Intrinsic::memset_i32: 3164 case Intrinsic::memset_i64: { 3165 SDValue Op1 = getValue(I.getOperand(1)); 3166 SDValue Op2 = getValue(I.getOperand(2)); 3167 SDValue Op3 = getValue(I.getOperand(3)); 3168 unsigned Align = cast<ConstantInt>(I.getOperand(4))->getZExtValue(); 3169 DAG.setRoot(DAG.getMemset(getRoot(), Op1, Op2, Op3, Align, 3170 I.getOperand(1), 0)); 3171 return 0; 3172 } 3173 case Intrinsic::memmove_i32: 3174 case Intrinsic::memmove_i64: { 3175 SDValue Op1 = getValue(I.getOperand(1)); 3176 SDValue Op2 = getValue(I.getOperand(2)); 3177 SDValue Op3 = getValue(I.getOperand(3)); 3178 unsigned Align = cast<ConstantInt>(I.getOperand(4))->getZExtValue(); 3179 3180 // If the source and destination are known to not be aliases, we can 3181 // lower memmove as memcpy. 3182 uint64_t Size = -1ULL; 3183 if (ConstantSDNode *C = dyn_cast<ConstantSDNode>(Op3)) 3184 Size = C->getValue(); 3185 if (AA.alias(I.getOperand(1), Size, I.getOperand(2), Size) == 3186 AliasAnalysis::NoAlias) { 3187 DAG.setRoot(DAG.getMemcpy(getRoot(), Op1, Op2, Op3, Align, false, 3188 I.getOperand(1), 0, I.getOperand(2), 0)); 3189 return 0; 3190 } 3191 3192 DAG.setRoot(DAG.getMemmove(getRoot(), Op1, Op2, Op3, Align, 3193 I.getOperand(1), 0, I.getOperand(2), 0)); 3194 return 0; 3195 } 3196 case Intrinsic::dbg_stoppoint: { 3197 MachineModuleInfo *MMI = DAG.getMachineModuleInfo(); 3198 DbgStopPointInst &SPI = cast<DbgStopPointInst>(I); 3199 if (MMI && SPI.getContext() && MMI->Verify(SPI.getContext())) { 3200 DebugInfoDesc *DD = MMI->getDescFor(SPI.getContext()); 3201 assert(DD && "Not a debug information descriptor"); 3202 DAG.setRoot(DAG.getDbgStopPoint(getRoot(), 3203 SPI.getLine(), 3204 SPI.getColumn(), 3205 cast<CompileUnitDesc>(DD))); 3206 } 3207 3208 return 0; 3209 } 3210 case Intrinsic::dbg_region_start: { 3211 MachineModuleInfo *MMI = DAG.getMachineModuleInfo(); 3212 DbgRegionStartInst &RSI = cast<DbgRegionStartInst>(I); 3213 if (MMI && RSI.getContext() && MMI->Verify(RSI.getContext())) { 3214 unsigned LabelID = MMI->RecordRegionStart(RSI.getContext()); 3215 DAG.setRoot(DAG.getLabel(ISD::DBG_LABEL, getRoot(), LabelID)); 3216 } 3217 3218 return 0; 3219 } 3220 case Intrinsic::dbg_region_end: { 3221 MachineModuleInfo *MMI = DAG.getMachineModuleInfo(); 3222 DbgRegionEndInst &REI = cast<DbgRegionEndInst>(I); 3223 if (MMI && REI.getContext() && MMI->Verify(REI.getContext())) { 3224 unsigned LabelID = MMI->RecordRegionEnd(REI.getContext()); 3225 DAG.setRoot(DAG.getLabel(ISD::DBG_LABEL, getRoot(), LabelID)); 3226 } 3227 3228 return 0; 3229 } 3230 case Intrinsic::dbg_func_start: { 3231 MachineModuleInfo *MMI = DAG.getMachineModuleInfo(); 3232 if (!MMI) return 0; 3233 DbgFuncStartInst &FSI = cast<DbgFuncStartInst>(I); 3234 Value *SP = FSI.getSubprogram(); 3235 if (SP && MMI->Verify(SP)) { 3236 // llvm.dbg.func.start implicitly defines a dbg_stoppoint which is 3237 // what (most?) gdb expects. 3238 DebugInfoDesc *DD = MMI->getDescFor(SP); 3239 assert(DD && "Not a debug information descriptor"); 3240 SubprogramDesc *Subprogram = cast<SubprogramDesc>(DD); 3241 const CompileUnitDesc *CompileUnit = Subprogram->getFile(); 3242 unsigned SrcFile = MMI->RecordSource(CompileUnit); 3243 // Record the source line but does create a label. It will be emitted 3244 // at asm emission time. 3245 MMI->RecordSourceLine(Subprogram->getLine(), 0, SrcFile); 3246 } 3247 3248 return 0; 3249 } 3250 case Intrinsic::dbg_declare: { 3251 MachineModuleInfo *MMI = DAG.getMachineModuleInfo(); 3252 DbgDeclareInst &DI = cast<DbgDeclareInst>(I); 3253 Value *Variable = DI.getVariable(); 3254 if (MMI && Variable && MMI->Verify(Variable)) 3255 DAG.setRoot(DAG.getNode(ISD::DECLARE, MVT::Other, getRoot(), 3256 getValue(DI.getAddress()), getValue(Variable))); 3257 return 0; 3258 } 3259 3260 case Intrinsic::eh_exception: { 3261 if (!CurMBB->isLandingPad()) { 3262 // FIXME: Mark exception register as live in. Hack for PR1508. 3263 unsigned Reg = TLI.getExceptionAddressRegister(); 3264 if (Reg) CurMBB->addLiveIn(Reg); 3265 } 3266 // Insert the EXCEPTIONADDR instruction. 3267 SDVTList VTs = DAG.getVTList(TLI.getPointerTy(), MVT::Other); 3268 SDValue Ops[1]; 3269 Ops[0] = DAG.getRoot(); 3270 SDValue Op = DAG.getNode(ISD::EXCEPTIONADDR, VTs, Ops, 1); 3271 setValue(&I, Op); 3272 DAG.setRoot(Op.getValue(1)); 3273 return 0; 3274 } 3275 3276 case Intrinsic::eh_selector_i32: 3277 case Intrinsic::eh_selector_i64: { 3278 MachineModuleInfo *MMI = DAG.getMachineModuleInfo(); 3279 MVT VT = (Intrinsic == Intrinsic::eh_selector_i32 ? 3280 MVT::i32 : MVT::i64); 3281 3282 if (MMI) { 3283 if (CurMBB->isLandingPad()) 3284 addCatchInfo(I, MMI, CurMBB); 3285 else { 3286#ifndef NDEBUG 3287 FuncInfo.CatchInfoLost.insert(&I); 3288#endif 3289 // FIXME: Mark exception selector register as live in. Hack for PR1508. 3290 unsigned Reg = TLI.getExceptionSelectorRegister(); 3291 if (Reg) CurMBB->addLiveIn(Reg); 3292 } 3293 3294 // Insert the EHSELECTION instruction. 3295 SDVTList VTs = DAG.getVTList(VT, MVT::Other); 3296 SDValue Ops[2]; 3297 Ops[0] = getValue(I.getOperand(1)); 3298 Ops[1] = getRoot(); 3299 SDValue Op = DAG.getNode(ISD::EHSELECTION, VTs, Ops, 2); 3300 setValue(&I, Op); 3301 DAG.setRoot(Op.getValue(1)); 3302 } else { 3303 setValue(&I, DAG.getConstant(0, VT)); 3304 } 3305 3306 return 0; 3307 } 3308 3309 case Intrinsic::eh_typeid_for_i32: 3310 case Intrinsic::eh_typeid_for_i64: { 3311 MachineModuleInfo *MMI = DAG.getMachineModuleInfo(); 3312 MVT VT = (Intrinsic == Intrinsic::eh_typeid_for_i32 ? 3313 MVT::i32 : MVT::i64); 3314 3315 if (MMI) { 3316 // Find the type id for the given typeinfo. 3317 GlobalVariable *GV = ExtractTypeInfo(I.getOperand(1)); 3318 3319 unsigned TypeID = MMI->getTypeIDFor(GV); 3320 setValue(&I, DAG.getConstant(TypeID, VT)); 3321 } else { 3322 // Return something different to eh_selector. 3323 setValue(&I, DAG.getConstant(1, VT)); 3324 } 3325 3326 return 0; 3327 } 3328 3329 case Intrinsic::eh_return: { 3330 MachineModuleInfo *MMI = DAG.getMachineModuleInfo(); 3331 3332 if (MMI) { 3333 MMI->setCallsEHReturn(true); 3334 DAG.setRoot(DAG.getNode(ISD::EH_RETURN, 3335 MVT::Other, 3336 getControlRoot(), 3337 getValue(I.getOperand(1)), 3338 getValue(I.getOperand(2)))); 3339 } else { 3340 setValue(&I, DAG.getConstant(0, TLI.getPointerTy())); 3341 } 3342 3343 return 0; 3344 } 3345 3346 case Intrinsic::eh_unwind_init: { 3347 if (MachineModuleInfo *MMI = DAG.getMachineModuleInfo()) { 3348 MMI->setCallsUnwindInit(true); 3349 } 3350 3351 return 0; 3352 } 3353 3354 case Intrinsic::eh_dwarf_cfa: { 3355 MVT VT = getValue(I.getOperand(1)).getValueType(); 3356 SDValue CfaArg; 3357 if (VT.bitsGT(TLI.getPointerTy())) 3358 CfaArg = DAG.getNode(ISD::TRUNCATE, 3359 TLI.getPointerTy(), getValue(I.getOperand(1))); 3360 else 3361 CfaArg = DAG.getNode(ISD::SIGN_EXTEND, 3362 TLI.getPointerTy(), getValue(I.getOperand(1))); 3363 3364 SDValue Offset = DAG.getNode(ISD::ADD, 3365 TLI.getPointerTy(), 3366 DAG.getNode(ISD::FRAME_TO_ARGS_OFFSET, 3367 TLI.getPointerTy()), 3368 CfaArg); 3369 setValue(&I, DAG.getNode(ISD::ADD, 3370 TLI.getPointerTy(), 3371 DAG.getNode(ISD::FRAMEADDR, 3372 TLI.getPointerTy(), 3373 DAG.getConstant(0, 3374 TLI.getPointerTy())), 3375 Offset)); 3376 return 0; 3377 } 3378 3379 case Intrinsic::sqrt: 3380 setValue(&I, DAG.getNode(ISD::FSQRT, 3381 getValue(I.getOperand(1)).getValueType(), 3382 getValue(I.getOperand(1)))); 3383 return 0; 3384 case Intrinsic::powi: 3385 setValue(&I, DAG.getNode(ISD::FPOWI, 3386 getValue(I.getOperand(1)).getValueType(), 3387 getValue(I.getOperand(1)), 3388 getValue(I.getOperand(2)))); 3389 return 0; 3390 case Intrinsic::sin: 3391 setValue(&I, DAG.getNode(ISD::FSIN, 3392 getValue(I.getOperand(1)).getValueType(), 3393 getValue(I.getOperand(1)))); 3394 return 0; 3395 case Intrinsic::cos: 3396 setValue(&I, DAG.getNode(ISD::FCOS, 3397 getValue(I.getOperand(1)).getValueType(), 3398 getValue(I.getOperand(1)))); 3399 return 0; 3400 case Intrinsic::pow: 3401 setValue(&I, DAG.getNode(ISD::FPOW, 3402 getValue(I.getOperand(1)).getValueType(), 3403 getValue(I.getOperand(1)), 3404 getValue(I.getOperand(2)))); 3405 return 0; 3406 case Intrinsic::pcmarker: { 3407 SDValue Tmp = getValue(I.getOperand(1)); 3408 DAG.setRoot(DAG.getNode(ISD::PCMARKER, MVT::Other, getRoot(), Tmp)); 3409 return 0; 3410 } 3411 case Intrinsic::readcyclecounter: { 3412 SDValue Op = getRoot(); 3413 SDValue Tmp = DAG.getNode(ISD::READCYCLECOUNTER, 3414 DAG.getNodeValueTypes(MVT::i64, MVT::Other), 2, 3415 &Op, 1); 3416 setValue(&I, Tmp); 3417 DAG.setRoot(Tmp.getValue(1)); 3418 return 0; 3419 } 3420 case Intrinsic::part_select: { 3421 // Currently not implemented: just abort 3422 assert(0 && "part_select intrinsic not implemented"); 3423 abort(); 3424 } 3425 case Intrinsic::part_set: { 3426 // Currently not implemented: just abort 3427 assert(0 && "part_set intrinsic not implemented"); 3428 abort(); 3429 } 3430 case Intrinsic::bswap: 3431 setValue(&I, DAG.getNode(ISD::BSWAP, 3432 getValue(I.getOperand(1)).getValueType(), 3433 getValue(I.getOperand(1)))); 3434 return 0; 3435 case Intrinsic::cttz: { 3436 SDValue Arg = getValue(I.getOperand(1)); 3437 MVT Ty = Arg.getValueType(); 3438 SDValue result = DAG.getNode(ISD::CTTZ, Ty, Arg); 3439 setValue(&I, result); 3440 return 0; 3441 } 3442 case Intrinsic::ctlz: { 3443 SDValue Arg = getValue(I.getOperand(1)); 3444 MVT Ty = Arg.getValueType(); 3445 SDValue result = DAG.getNode(ISD::CTLZ, Ty, Arg); 3446 setValue(&I, result); 3447 return 0; 3448 } 3449 case Intrinsic::ctpop: { 3450 SDValue Arg = getValue(I.getOperand(1)); 3451 MVT Ty = Arg.getValueType(); 3452 SDValue result = DAG.getNode(ISD::CTPOP, Ty, Arg); 3453 setValue(&I, result); 3454 return 0; 3455 } 3456 case Intrinsic::stacksave: { 3457 SDValue Op = getRoot(); 3458 SDValue Tmp = DAG.getNode(ISD::STACKSAVE, 3459 DAG.getNodeValueTypes(TLI.getPointerTy(), MVT::Other), 2, &Op, 1); 3460 setValue(&I, Tmp); 3461 DAG.setRoot(Tmp.getValue(1)); 3462 return 0; 3463 } 3464 case Intrinsic::stackrestore: { 3465 SDValue Tmp = getValue(I.getOperand(1)); 3466 DAG.setRoot(DAG.getNode(ISD::STACKRESTORE, MVT::Other, getRoot(), Tmp)); 3467 return 0; 3468 } 3469 case Intrinsic::var_annotation: 3470 // Discard annotate attributes 3471 return 0; 3472 3473 case Intrinsic::init_trampoline: { 3474 const Function *F = cast<Function>(I.getOperand(2)->stripPointerCasts()); 3475 3476 SDValue Ops[6]; 3477 Ops[0] = getRoot(); 3478 Ops[1] = getValue(I.getOperand(1)); 3479 Ops[2] = getValue(I.getOperand(2)); 3480 Ops[3] = getValue(I.getOperand(3)); 3481 Ops[4] = DAG.getSrcValue(I.getOperand(1)); 3482 Ops[5] = DAG.getSrcValue(F); 3483 3484 SDValue Tmp = DAG.getNode(ISD::TRAMPOLINE, 3485 DAG.getNodeValueTypes(TLI.getPointerTy(), 3486 MVT::Other), 2, 3487 Ops, 6); 3488 3489 setValue(&I, Tmp); 3490 DAG.setRoot(Tmp.getValue(1)); 3491 return 0; 3492 } 3493 3494 case Intrinsic::gcroot: 3495 if (GFI) { 3496 Value *Alloca = I.getOperand(1); 3497 Constant *TypeMap = cast<Constant>(I.getOperand(2)); 3498 3499 FrameIndexSDNode *FI = cast<FrameIndexSDNode>(getValue(Alloca).Val); 3500 GFI->addStackRoot(FI->getIndex(), TypeMap); 3501 } 3502 return 0; 3503 3504 case Intrinsic::gcread: 3505 case Intrinsic::gcwrite: 3506 assert(0 && "GC failed to lower gcread/gcwrite intrinsics!"); 3507 return 0; 3508 3509 case Intrinsic::flt_rounds: { 3510 setValue(&I, DAG.getNode(ISD::FLT_ROUNDS_, MVT::i32)); 3511 return 0; 3512 } 3513 3514 case Intrinsic::trap: { 3515 DAG.setRoot(DAG.getNode(ISD::TRAP, MVT::Other, getRoot())); 3516 return 0; 3517 } 3518 case Intrinsic::prefetch: { 3519 SDValue Ops[4]; 3520 Ops[0] = getRoot(); 3521 Ops[1] = getValue(I.getOperand(1)); 3522 Ops[2] = getValue(I.getOperand(2)); 3523 Ops[3] = getValue(I.getOperand(3)); 3524 DAG.setRoot(DAG.getNode(ISD::PREFETCH, MVT::Other, &Ops[0], 4)); 3525 return 0; 3526 } 3527 3528 case Intrinsic::memory_barrier: { 3529 SDValue Ops[6]; 3530 Ops[0] = getRoot(); 3531 for (int x = 1; x < 6; ++x) 3532 Ops[x] = getValue(I.getOperand(x)); 3533 3534 DAG.setRoot(DAG.getNode(ISD::MEMBARRIER, MVT::Other, &Ops[0], 6)); 3535 return 0; 3536 } 3537 case Intrinsic::atomic_cmp_swap: { 3538 SDValue Root = getRoot(); 3539 SDValue L = DAG.getAtomic(ISD::ATOMIC_CMP_SWAP, Root, 3540 getValue(I.getOperand(1)), 3541 getValue(I.getOperand(2)), 3542 getValue(I.getOperand(3)), 3543 I.getOperand(1)); 3544 setValue(&I, L); 3545 DAG.setRoot(L.getValue(1)); 3546 return 0; 3547 } 3548 case Intrinsic::atomic_load_add: 3549 return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_ADD); 3550 case Intrinsic::atomic_load_sub: 3551 return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_SUB); 3552 case Intrinsic::atomic_load_and: 3553 return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_AND); 3554 case Intrinsic::atomic_load_or: 3555 return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_OR); 3556 case Intrinsic::atomic_load_xor: 3557 return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_XOR); 3558 case Intrinsic::atomic_load_nand: 3559 return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_NAND); 3560 case Intrinsic::atomic_load_min: 3561 return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_MIN); 3562 case Intrinsic::atomic_load_max: 3563 return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_MAX); 3564 case Intrinsic::atomic_load_umin: 3565 return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_UMIN); 3566 case Intrinsic::atomic_load_umax: 3567 return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_UMAX); 3568 case Intrinsic::atomic_swap: 3569 return implVisitBinaryAtomic(I, ISD::ATOMIC_SWAP); 3570 } 3571} 3572 3573 3574void SelectionDAGLowering::LowerCallTo(CallSite CS, SDValue Callee, 3575 bool IsTailCall, 3576 MachineBasicBlock *LandingPad) { 3577 const PointerType *PT = cast<PointerType>(CS.getCalledValue()->getType()); 3578 const FunctionType *FTy = cast<FunctionType>(PT->getElementType()); 3579 MachineModuleInfo *MMI = DAG.getMachineModuleInfo(); 3580 unsigned BeginLabel = 0, EndLabel = 0; 3581 3582 TargetLowering::ArgListTy Args; 3583 TargetLowering::ArgListEntry Entry; 3584 Args.reserve(CS.arg_size()); 3585 for (CallSite::arg_iterator i = CS.arg_begin(), e = CS.arg_end(); 3586 i != e; ++i) { 3587 SDValue ArgNode = getValue(*i); 3588 Entry.Node = ArgNode; Entry.Ty = (*i)->getType(); 3589 3590 unsigned attrInd = i - CS.arg_begin() + 1; 3591 Entry.isSExt = CS.paramHasAttr(attrInd, ParamAttr::SExt); 3592 Entry.isZExt = CS.paramHasAttr(attrInd, ParamAttr::ZExt); 3593 Entry.isInReg = CS.paramHasAttr(attrInd, ParamAttr::InReg); 3594 Entry.isSRet = CS.paramHasAttr(attrInd, ParamAttr::StructRet); 3595 Entry.isNest = CS.paramHasAttr(attrInd, ParamAttr::Nest); 3596 Entry.isByVal = CS.paramHasAttr(attrInd, ParamAttr::ByVal); 3597 Entry.Alignment = CS.getParamAlignment(attrInd); 3598 Args.push_back(Entry); 3599 } 3600 3601 if (LandingPad && MMI) { 3602 // Insert a label before the invoke call to mark the try range. This can be 3603 // used to detect deletion of the invoke via the MachineModuleInfo. 3604 BeginLabel = MMI->NextLabelID(); 3605 // Both PendingLoads and PendingExports must be flushed here; 3606 // this call might not return. 3607 (void)getRoot(); 3608 DAG.setRoot(DAG.getLabel(ISD::EH_LABEL, getControlRoot(), BeginLabel)); 3609 } 3610 3611 std::pair<SDValue,SDValue> Result = 3612 TLI.LowerCallTo(getRoot(), CS.getType(), 3613 CS.paramHasAttr(0, ParamAttr::SExt), 3614 CS.paramHasAttr(0, ParamAttr::ZExt), 3615 FTy->isVarArg(), CS.getCallingConv(), IsTailCall, 3616 Callee, Args, DAG); 3617 if (CS.getType() != Type::VoidTy) 3618 setValue(CS.getInstruction(), Result.first); 3619 DAG.setRoot(Result.second); 3620 3621 if (LandingPad && MMI) { 3622 // Insert a label at the end of the invoke call to mark the try range. This 3623 // can be used to detect deletion of the invoke via the MachineModuleInfo. 3624 EndLabel = MMI->NextLabelID(); 3625 DAG.setRoot(DAG.getLabel(ISD::EH_LABEL, getRoot(), EndLabel)); 3626 3627 // Inform MachineModuleInfo of range. 3628 MMI->addInvoke(LandingPad, BeginLabel, EndLabel); 3629 } 3630} 3631 3632 3633void SelectionDAGLowering::visitCall(CallInst &I) { 3634 const char *RenameFn = 0; 3635 if (Function *F = I.getCalledFunction()) { 3636 if (F->isDeclaration()) { 3637 if (unsigned IID = F->getIntrinsicID()) { 3638 RenameFn = visitIntrinsicCall(I, IID); 3639 if (!RenameFn) 3640 return; 3641 } 3642 } 3643 3644 // Check for well-known libc/libm calls. If the function is internal, it 3645 // can't be a library call. 3646 unsigned NameLen = F->getNameLen(); 3647 if (!F->hasInternalLinkage() && NameLen) { 3648 const char *NameStr = F->getNameStart(); 3649 if (NameStr[0] == 'c' && 3650 ((NameLen == 8 && !strcmp(NameStr, "copysign")) || 3651 (NameLen == 9 && !strcmp(NameStr, "copysignf")))) { 3652 if (I.getNumOperands() == 3 && // Basic sanity checks. 3653 I.getOperand(1)->getType()->isFloatingPoint() && 3654 I.getType() == I.getOperand(1)->getType() && 3655 I.getType() == I.getOperand(2)->getType()) { 3656 SDValue LHS = getValue(I.getOperand(1)); 3657 SDValue RHS = getValue(I.getOperand(2)); 3658 setValue(&I, DAG.getNode(ISD::FCOPYSIGN, LHS.getValueType(), 3659 LHS, RHS)); 3660 return; 3661 } 3662 } else if (NameStr[0] == 'f' && 3663 ((NameLen == 4 && !strcmp(NameStr, "fabs")) || 3664 (NameLen == 5 && !strcmp(NameStr, "fabsf")) || 3665 (NameLen == 5 && !strcmp(NameStr, "fabsl")))) { 3666 if (I.getNumOperands() == 2 && // Basic sanity checks. 3667 I.getOperand(1)->getType()->isFloatingPoint() && 3668 I.getType() == I.getOperand(1)->getType()) { 3669 SDValue Tmp = getValue(I.getOperand(1)); 3670 setValue(&I, DAG.getNode(ISD::FABS, Tmp.getValueType(), Tmp)); 3671 return; 3672 } 3673 } else if (NameStr[0] == 's' && 3674 ((NameLen == 3 && !strcmp(NameStr, "sin")) || 3675 (NameLen == 4 && !strcmp(NameStr, "sinf")) || 3676 (NameLen == 4 && !strcmp(NameStr, "sinl")))) { 3677 if (I.getNumOperands() == 2 && // Basic sanity checks. 3678 I.getOperand(1)->getType()->isFloatingPoint() && 3679 I.getType() == I.getOperand(1)->getType()) { 3680 SDValue Tmp = getValue(I.getOperand(1)); 3681 setValue(&I, DAG.getNode(ISD::FSIN, Tmp.getValueType(), Tmp)); 3682 return; 3683 } 3684 } else if (NameStr[0] == 'c' && 3685 ((NameLen == 3 && !strcmp(NameStr, "cos")) || 3686 (NameLen == 4 && !strcmp(NameStr, "cosf")) || 3687 (NameLen == 4 && !strcmp(NameStr, "cosl")))) { 3688 if (I.getNumOperands() == 2 && // Basic sanity checks. 3689 I.getOperand(1)->getType()->isFloatingPoint() && 3690 I.getType() == I.getOperand(1)->getType()) { 3691 SDValue Tmp = getValue(I.getOperand(1)); 3692 setValue(&I, DAG.getNode(ISD::FCOS, Tmp.getValueType(), Tmp)); 3693 return; 3694 } 3695 } 3696 } 3697 } else if (isa<InlineAsm>(I.getOperand(0))) { 3698 visitInlineAsm(&I); 3699 return; 3700 } 3701 3702 SDValue Callee; 3703 if (!RenameFn) 3704 Callee = getValue(I.getOperand(0)); 3705 else 3706 Callee = DAG.getExternalSymbol(RenameFn, TLI.getPointerTy()); 3707 3708 LowerCallTo(&I, Callee, I.isTailCall()); 3709} 3710 3711 3712/// getCopyFromRegs - Emit a series of CopyFromReg nodes that copies from 3713/// this value and returns the result as a ValueVT value. This uses 3714/// Chain/Flag as the input and updates them for the output Chain/Flag. 3715/// If the Flag pointer is NULL, no flag is used. 3716SDValue RegsForValue::getCopyFromRegs(SelectionDAG &DAG, 3717 SDValue &Chain, 3718 SDValue *Flag) const { 3719 // Assemble the legal parts into the final values. 3720 SmallVector<SDValue, 4> Values(ValueVTs.size()); 3721 SmallVector<SDValue, 8> Parts; 3722 for (unsigned Value = 0, Part = 0, e = ValueVTs.size(); Value != e; ++Value) { 3723 // Copy the legal parts from the registers. 3724 MVT ValueVT = ValueVTs[Value]; 3725 unsigned NumRegs = TLI->getNumRegisters(ValueVT); 3726 MVT RegisterVT = RegVTs[Value]; 3727 3728 Parts.resize(NumRegs); 3729 for (unsigned i = 0; i != NumRegs; ++i) { 3730 SDValue P; 3731 if (Flag == 0) 3732 P = DAG.getCopyFromReg(Chain, Regs[Part+i], RegisterVT); 3733 else { 3734 P = DAG.getCopyFromReg(Chain, Regs[Part+i], RegisterVT, *Flag); 3735 *Flag = P.getValue(2); 3736 } 3737 Chain = P.getValue(1); 3738 3739 // If the source register was virtual and if we know something about it, 3740 // add an assert node. 3741 if (TargetRegisterInfo::isVirtualRegister(Regs[Part+i]) && 3742 RegisterVT.isInteger() && !RegisterVT.isVector()) { 3743 unsigned SlotNo = Regs[Part+i]-TargetRegisterInfo::FirstVirtualRegister; 3744 FunctionLoweringInfo &FLI = DAG.getFunctionLoweringInfo(); 3745 if (FLI.LiveOutRegInfo.size() > SlotNo) { 3746 FunctionLoweringInfo::LiveOutInfo &LOI = FLI.LiveOutRegInfo[SlotNo]; 3747 3748 unsigned RegSize = RegisterVT.getSizeInBits(); 3749 unsigned NumSignBits = LOI.NumSignBits; 3750 unsigned NumZeroBits = LOI.KnownZero.countLeadingOnes(); 3751 3752 // FIXME: We capture more information than the dag can represent. For 3753 // now, just use the tightest assertzext/assertsext possible. 3754 bool isSExt = true; 3755 MVT FromVT(MVT::Other); 3756 if (NumSignBits == RegSize) 3757 isSExt = true, FromVT = MVT::i1; // ASSERT SEXT 1 3758 else if (NumZeroBits >= RegSize-1) 3759 isSExt = false, FromVT = MVT::i1; // ASSERT ZEXT 1 3760 else if (NumSignBits > RegSize-8) 3761 isSExt = true, FromVT = MVT::i8; // ASSERT SEXT 8 3762 else if (NumZeroBits >= RegSize-9) 3763 isSExt = false, FromVT = MVT::i8; // ASSERT ZEXT 8 3764 else if (NumSignBits > RegSize-16) 3765 isSExt = true, FromVT = MVT::i16; // ASSERT SEXT 16 3766 else if (NumZeroBits >= RegSize-17) 3767 isSExt = false, FromVT = MVT::i16; // ASSERT ZEXT 16 3768 else if (NumSignBits > RegSize-32) 3769 isSExt = true, FromVT = MVT::i32; // ASSERT SEXT 32 3770 else if (NumZeroBits >= RegSize-33) 3771 isSExt = false, FromVT = MVT::i32; // ASSERT ZEXT 32 3772 3773 if (FromVT != MVT::Other) { 3774 P = DAG.getNode(isSExt ? ISD::AssertSext : ISD::AssertZext, 3775 RegisterVT, P, DAG.getValueType(FromVT)); 3776 3777 } 3778 } 3779 } 3780 3781 Parts[Part+i] = P; 3782 } 3783 3784 Values[Value] = getCopyFromParts(DAG, &Parts[Part], NumRegs, RegisterVT, 3785 ValueVT); 3786 Part += NumRegs; 3787 } 3788 3789 return DAG.getMergeValues(DAG.getVTList(&ValueVTs[0], ValueVTs.size()), 3790 &Values[0], ValueVTs.size()); 3791} 3792 3793/// getCopyToRegs - Emit a series of CopyToReg nodes that copies the 3794/// specified value into the registers specified by this object. This uses 3795/// Chain/Flag as the input and updates them for the output Chain/Flag. 3796/// If the Flag pointer is NULL, no flag is used. 3797void RegsForValue::getCopyToRegs(SDValue Val, SelectionDAG &DAG, 3798 SDValue &Chain, SDValue *Flag) const { 3799 // Get the list of the values's legal parts. 3800 unsigned NumRegs = Regs.size(); 3801 SmallVector<SDValue, 8> Parts(NumRegs); 3802 for (unsigned Value = 0, Part = 0, e = ValueVTs.size(); Value != e; ++Value) { 3803 MVT ValueVT = ValueVTs[Value]; 3804 unsigned NumParts = TLI->getNumRegisters(ValueVT); 3805 MVT RegisterVT = RegVTs[Value]; 3806 3807 getCopyToParts(DAG, Val.getValue(Val.ResNo + Value), 3808 &Parts[Part], NumParts, RegisterVT); 3809 Part += NumParts; 3810 } 3811 3812 // Copy the parts into the registers. 3813 SmallVector<SDValue, 8> Chains(NumRegs); 3814 for (unsigned i = 0; i != NumRegs; ++i) { 3815 SDValue Part; 3816 if (Flag == 0) 3817 Part = DAG.getCopyToReg(Chain, Regs[i], Parts[i]); 3818 else { 3819 Part = DAG.getCopyToReg(Chain, Regs[i], Parts[i], *Flag); 3820 *Flag = Part.getValue(1); 3821 } 3822 Chains[i] = Part.getValue(0); 3823 } 3824 3825 if (NumRegs == 1 || Flag) 3826 // If NumRegs > 1 && Flag is used then the use of the last CopyToReg is 3827 // flagged to it. That is the CopyToReg nodes and the user are considered 3828 // a single scheduling unit. If we create a TokenFactor and return it as 3829 // chain, then the TokenFactor is both a predecessor (operand) of the 3830 // user as well as a successor (the TF operands are flagged to the user). 3831 // c1, f1 = CopyToReg 3832 // c2, f2 = CopyToReg 3833 // c3 = TokenFactor c1, c2 3834 // ... 3835 // = op c3, ..., f2 3836 Chain = Chains[NumRegs-1]; 3837 else 3838 Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, &Chains[0], NumRegs); 3839} 3840 3841/// AddInlineAsmOperands - Add this value to the specified inlineasm node 3842/// operand list. This adds the code marker and includes the number of 3843/// values added into it. 3844void RegsForValue::AddInlineAsmOperands(unsigned Code, SelectionDAG &DAG, 3845 std::vector<SDValue> &Ops) const { 3846 MVT IntPtrTy = DAG.getTargetLoweringInfo().getPointerTy(); 3847 Ops.push_back(DAG.getTargetConstant(Code | (Regs.size() << 3), IntPtrTy)); 3848 for (unsigned Value = 0, Reg = 0, e = ValueVTs.size(); Value != e; ++Value) { 3849 unsigned NumRegs = TLI->getNumRegisters(ValueVTs[Value]); 3850 MVT RegisterVT = RegVTs[Value]; 3851 for (unsigned i = 0; i != NumRegs; ++i) 3852 Ops.push_back(DAG.getRegister(Regs[Reg++], RegisterVT)); 3853 } 3854} 3855 3856/// isAllocatableRegister - If the specified register is safe to allocate, 3857/// i.e. it isn't a stack pointer or some other special register, return the 3858/// register class for the register. Otherwise, return null. 3859static const TargetRegisterClass * 3860isAllocatableRegister(unsigned Reg, MachineFunction &MF, 3861 const TargetLowering &TLI, 3862 const TargetRegisterInfo *TRI) { 3863 MVT FoundVT = MVT::Other; 3864 const TargetRegisterClass *FoundRC = 0; 3865 for (TargetRegisterInfo::regclass_iterator RCI = TRI->regclass_begin(), 3866 E = TRI->regclass_end(); RCI != E; ++RCI) { 3867 MVT ThisVT = MVT::Other; 3868 3869 const TargetRegisterClass *RC = *RCI; 3870 // If none of the the value types for this register class are valid, we 3871 // can't use it. For example, 64-bit reg classes on 32-bit targets. 3872 for (TargetRegisterClass::vt_iterator I = RC->vt_begin(), E = RC->vt_end(); 3873 I != E; ++I) { 3874 if (TLI.isTypeLegal(*I)) { 3875 // If we have already found this register in a different register class, 3876 // choose the one with the largest VT specified. For example, on 3877 // PowerPC, we favor f64 register classes over f32. 3878 if (FoundVT == MVT::Other || FoundVT.bitsLT(*I)) { 3879 ThisVT = *I; 3880 break; 3881 } 3882 } 3883 } 3884 3885 if (ThisVT == MVT::Other) continue; 3886 3887 // NOTE: This isn't ideal. In particular, this might allocate the 3888 // frame pointer in functions that need it (due to them not being taken 3889 // out of allocation, because a variable sized allocation hasn't been seen 3890 // yet). This is a slight code pessimization, but should still work. 3891 for (TargetRegisterClass::iterator I = RC->allocation_order_begin(MF), 3892 E = RC->allocation_order_end(MF); I != E; ++I) 3893 if (*I == Reg) { 3894 // We found a matching register class. Keep looking at others in case 3895 // we find one with larger registers that this physreg is also in. 3896 FoundRC = RC; 3897 FoundVT = ThisVT; 3898 break; 3899 } 3900 } 3901 return FoundRC; 3902} 3903 3904 3905namespace { 3906/// AsmOperandInfo - This contains information for each constraint that we are 3907/// lowering. 3908struct SDISelAsmOperandInfo : public TargetLowering::AsmOperandInfo { 3909 /// CallOperand - If this is the result output operand or a clobber 3910 /// this is null, otherwise it is the incoming operand to the CallInst. 3911 /// This gets modified as the asm is processed. 3912 SDValue CallOperand; 3913 3914 /// AssignedRegs - If this is a register or register class operand, this 3915 /// contains the set of register corresponding to the operand. 3916 RegsForValue AssignedRegs; 3917 3918 explicit SDISelAsmOperandInfo(const InlineAsm::ConstraintInfo &info) 3919 : TargetLowering::AsmOperandInfo(info), CallOperand(0,0) { 3920 } 3921 3922 /// MarkAllocatedRegs - Once AssignedRegs is set, mark the assigned registers 3923 /// busy in OutputRegs/InputRegs. 3924 void MarkAllocatedRegs(bool isOutReg, bool isInReg, 3925 std::set<unsigned> &OutputRegs, 3926 std::set<unsigned> &InputRegs, 3927 const TargetRegisterInfo &TRI) const { 3928 if (isOutReg) { 3929 for (unsigned i = 0, e = AssignedRegs.Regs.size(); i != e; ++i) 3930 MarkRegAndAliases(AssignedRegs.Regs[i], OutputRegs, TRI); 3931 } 3932 if (isInReg) { 3933 for (unsigned i = 0, e = AssignedRegs.Regs.size(); i != e; ++i) 3934 MarkRegAndAliases(AssignedRegs.Regs[i], InputRegs, TRI); 3935 } 3936 } 3937 3938private: 3939 /// MarkRegAndAliases - Mark the specified register and all aliases in the 3940 /// specified set. 3941 static void MarkRegAndAliases(unsigned Reg, std::set<unsigned> &Regs, 3942 const TargetRegisterInfo &TRI) { 3943 assert(TargetRegisterInfo::isPhysicalRegister(Reg) && "Isn't a physreg"); 3944 Regs.insert(Reg); 3945 if (const unsigned *Aliases = TRI.getAliasSet(Reg)) 3946 for (; *Aliases; ++Aliases) 3947 Regs.insert(*Aliases); 3948 } 3949}; 3950} // end anon namespace. 3951 3952 3953/// GetRegistersForValue - Assign registers (virtual or physical) for the 3954/// specified operand. We prefer to assign virtual registers, to allow the 3955/// register allocator handle the assignment process. However, if the asm uses 3956/// features that we can't model on machineinstrs, we have SDISel do the 3957/// allocation. This produces generally horrible, but correct, code. 3958/// 3959/// OpInfo describes the operand. 3960/// HasEarlyClobber is true if there are any early clobber constraints (=&r) 3961/// or any explicitly clobbered registers. 3962/// Input and OutputRegs are the set of already allocated physical registers. 3963/// 3964void SelectionDAGLowering:: 3965GetRegistersForValue(SDISelAsmOperandInfo &OpInfo, bool HasEarlyClobber, 3966 std::set<unsigned> &OutputRegs, 3967 std::set<unsigned> &InputRegs) { 3968 // Compute whether this value requires an input register, an output register, 3969 // or both. 3970 bool isOutReg = false; 3971 bool isInReg = false; 3972 switch (OpInfo.Type) { 3973 case InlineAsm::isOutput: 3974 isOutReg = true; 3975 3976 // If this is an early-clobber output, or if there is an input 3977 // constraint that matches this, we need to reserve the input register 3978 // so no other inputs allocate to it. 3979 isInReg = OpInfo.isEarlyClobber || OpInfo.hasMatchingInput; 3980 break; 3981 case InlineAsm::isInput: 3982 isInReg = true; 3983 isOutReg = false; 3984 break; 3985 case InlineAsm::isClobber: 3986 isOutReg = true; 3987 isInReg = true; 3988 break; 3989 } 3990 3991 3992 MachineFunction &MF = DAG.getMachineFunction(); 3993 SmallVector<unsigned, 4> Regs; 3994 3995 // If this is a constraint for a single physreg, or a constraint for a 3996 // register class, find it. 3997 std::pair<unsigned, const TargetRegisterClass*> PhysReg = 3998 TLI.getRegForInlineAsmConstraint(OpInfo.ConstraintCode, 3999 OpInfo.ConstraintVT); 4000 4001 unsigned NumRegs = 1; 4002 if (OpInfo.ConstraintVT != MVT::Other) 4003 NumRegs = TLI.getNumRegisters(OpInfo.ConstraintVT); 4004 MVT RegVT; 4005 MVT ValueVT = OpInfo.ConstraintVT; 4006 4007 4008 // If this is a constraint for a specific physical register, like {r17}, 4009 // assign it now. 4010 if (PhysReg.first) { 4011 if (OpInfo.ConstraintVT == MVT::Other) 4012 ValueVT = *PhysReg.second->vt_begin(); 4013 4014 // Get the actual register value type. This is important, because the user 4015 // may have asked for (e.g.) the AX register in i32 type. We need to 4016 // remember that AX is actually i16 to get the right extension. 4017 RegVT = *PhysReg.second->vt_begin(); 4018 4019 // This is a explicit reference to a physical register. 4020 Regs.push_back(PhysReg.first); 4021 4022 // If this is an expanded reference, add the rest of the regs to Regs. 4023 if (NumRegs != 1) { 4024 TargetRegisterClass::iterator I = PhysReg.second->begin(); 4025 for (; *I != PhysReg.first; ++I) 4026 assert(I != PhysReg.second->end() && "Didn't find reg!"); 4027 4028 // Already added the first reg. 4029 --NumRegs; ++I; 4030 for (; NumRegs; --NumRegs, ++I) { 4031 assert(I != PhysReg.second->end() && "Ran out of registers to allocate!"); 4032 Regs.push_back(*I); 4033 } 4034 } 4035 OpInfo.AssignedRegs = RegsForValue(TLI, Regs, RegVT, ValueVT); 4036 const TargetRegisterInfo *TRI = DAG.getTarget().getRegisterInfo(); 4037 OpInfo.MarkAllocatedRegs(isOutReg, isInReg, OutputRegs, InputRegs, *TRI); 4038 return; 4039 } 4040 4041 // Otherwise, if this was a reference to an LLVM register class, create vregs 4042 // for this reference. 4043 std::vector<unsigned> RegClassRegs; 4044 const TargetRegisterClass *RC = PhysReg.second; 4045 if (RC) { 4046 // If this is an early clobber or tied register, our regalloc doesn't know 4047 // how to maintain the constraint. If it isn't, go ahead and create vreg 4048 // and let the regalloc do the right thing. 4049 if (!OpInfo.hasMatchingInput && !OpInfo.isEarlyClobber && 4050 // If there is some other early clobber and this is an input register, 4051 // then we are forced to pre-allocate the input reg so it doesn't 4052 // conflict with the earlyclobber. 4053 !(OpInfo.Type == InlineAsm::isInput && HasEarlyClobber)) { 4054 RegVT = *PhysReg.second->vt_begin(); 4055 4056 if (OpInfo.ConstraintVT == MVT::Other) 4057 ValueVT = RegVT; 4058 4059 // Create the appropriate number of virtual registers. 4060 MachineRegisterInfo &RegInfo = MF.getRegInfo(); 4061 for (; NumRegs; --NumRegs) 4062 Regs.push_back(RegInfo.createVirtualRegister(PhysReg.second)); 4063 4064 OpInfo.AssignedRegs = RegsForValue(TLI, Regs, RegVT, ValueVT); 4065 return; 4066 } 4067 4068 // Otherwise, we can't allocate it. Let the code below figure out how to 4069 // maintain these constraints. 4070 RegClassRegs.assign(PhysReg.second->begin(), PhysReg.second->end()); 4071 4072 } else { 4073 // This is a reference to a register class that doesn't directly correspond 4074 // to an LLVM register class. Allocate NumRegs consecutive, available, 4075 // registers from the class. 4076 RegClassRegs = TLI.getRegClassForInlineAsmConstraint(OpInfo.ConstraintCode, 4077 OpInfo.ConstraintVT); 4078 } 4079 4080 const TargetRegisterInfo *TRI = DAG.getTarget().getRegisterInfo(); 4081 unsigned NumAllocated = 0; 4082 for (unsigned i = 0, e = RegClassRegs.size(); i != e; ++i) { 4083 unsigned Reg = RegClassRegs[i]; 4084 // See if this register is available. 4085 if ((isOutReg && OutputRegs.count(Reg)) || // Already used. 4086 (isInReg && InputRegs.count(Reg))) { // Already used. 4087 // Make sure we find consecutive registers. 4088 NumAllocated = 0; 4089 continue; 4090 } 4091 4092 // Check to see if this register is allocatable (i.e. don't give out the 4093 // stack pointer). 4094 if (RC == 0) { 4095 RC = isAllocatableRegister(Reg, MF, TLI, TRI); 4096 if (!RC) { // Couldn't allocate this register. 4097 // Reset NumAllocated to make sure we return consecutive registers. 4098 NumAllocated = 0; 4099 continue; 4100 } 4101 } 4102 4103 // Okay, this register is good, we can use it. 4104 ++NumAllocated; 4105 4106 // If we allocated enough consecutive registers, succeed. 4107 if (NumAllocated == NumRegs) { 4108 unsigned RegStart = (i-NumAllocated)+1; 4109 unsigned RegEnd = i+1; 4110 // Mark all of the allocated registers used. 4111 for (unsigned i = RegStart; i != RegEnd; ++i) 4112 Regs.push_back(RegClassRegs[i]); 4113 4114 OpInfo.AssignedRegs = RegsForValue(TLI, Regs, *RC->vt_begin(), 4115 OpInfo.ConstraintVT); 4116 OpInfo.MarkAllocatedRegs(isOutReg, isInReg, OutputRegs, InputRegs, *TRI); 4117 return; 4118 } 4119 } 4120 4121 // Otherwise, we couldn't allocate enough registers for this. 4122} 4123 4124 4125/// visitInlineAsm - Handle a call to an InlineAsm object. 4126/// 4127void SelectionDAGLowering::visitInlineAsm(CallSite CS) { 4128 InlineAsm *IA = cast<InlineAsm>(CS.getCalledValue()); 4129 4130 /// ConstraintOperands - Information about all of the constraints. 4131 std::vector<SDISelAsmOperandInfo> ConstraintOperands; 4132 4133 SDValue Chain = getRoot(); 4134 SDValue Flag; 4135 4136 std::set<unsigned> OutputRegs, InputRegs; 4137 4138 // Do a prepass over the constraints, canonicalizing them, and building up the 4139 // ConstraintOperands list. 4140 std::vector<InlineAsm::ConstraintInfo> 4141 ConstraintInfos = IA->ParseConstraints(); 4142 4143 // SawEarlyClobber - Keep track of whether we saw an earlyclobber output 4144 // constraint. If so, we can't let the register allocator allocate any input 4145 // registers, because it will not know to avoid the earlyclobbered output reg. 4146 bool SawEarlyClobber = false; 4147 4148 unsigned ArgNo = 0; // ArgNo - The argument of the CallInst. 4149 unsigned ResNo = 0; // ResNo - The result number of the next output. 4150 for (unsigned i = 0, e = ConstraintInfos.size(); i != e; ++i) { 4151 ConstraintOperands.push_back(SDISelAsmOperandInfo(ConstraintInfos[i])); 4152 SDISelAsmOperandInfo &OpInfo = ConstraintOperands.back(); 4153 4154 MVT OpVT = MVT::Other; 4155 4156 // Compute the value type for each operand. 4157 switch (OpInfo.Type) { 4158 case InlineAsm::isOutput: 4159 // Indirect outputs just consume an argument. 4160 if (OpInfo.isIndirect) { 4161 OpInfo.CallOperandVal = CS.getArgument(ArgNo++); 4162 break; 4163 } 4164 // The return value of the call is this value. As such, there is no 4165 // corresponding argument. 4166 assert(CS.getType() != Type::VoidTy && "Bad inline asm!"); 4167 if (const StructType *STy = dyn_cast<StructType>(CS.getType())) { 4168 OpVT = TLI.getValueType(STy->getElementType(ResNo)); 4169 } else { 4170 assert(ResNo == 0 && "Asm only has one result!"); 4171 OpVT = TLI.getValueType(CS.getType()); 4172 } 4173 ++ResNo; 4174 break; 4175 case InlineAsm::isInput: 4176 OpInfo.CallOperandVal = CS.getArgument(ArgNo++); 4177 break; 4178 case InlineAsm::isClobber: 4179 // Nothing to do. 4180 break; 4181 } 4182 4183 // If this is an input or an indirect output, process the call argument. 4184 // BasicBlocks are labels, currently appearing only in asm's. 4185 if (OpInfo.CallOperandVal) { 4186 if (BasicBlock *BB = dyn_cast<BasicBlock>(OpInfo.CallOperandVal)) 4187 OpInfo.CallOperand = DAG.getBasicBlock(FuncInfo.MBBMap[BB]); 4188 else { 4189 OpInfo.CallOperand = getValue(OpInfo.CallOperandVal); 4190 const Type *OpTy = OpInfo.CallOperandVal->getType(); 4191 // If this is an indirect operand, the operand is a pointer to the 4192 // accessed type. 4193 if (OpInfo.isIndirect) 4194 OpTy = cast<PointerType>(OpTy)->getElementType(); 4195 4196 // If OpTy is not a single value, it may be a struct/union that we 4197 // can tile with integers. 4198 if (!OpTy->isSingleValueType() && OpTy->isSized()) { 4199 unsigned BitSize = TD->getTypeSizeInBits(OpTy); 4200 switch (BitSize) { 4201 default: break; 4202 case 1: 4203 case 8: 4204 case 16: 4205 case 32: 4206 case 64: 4207 OpTy = IntegerType::get(BitSize); 4208 break; 4209 } 4210 } 4211 4212 OpVT = TLI.getValueType(OpTy, true); 4213 } 4214 } 4215 4216 OpInfo.ConstraintVT = OpVT; 4217 4218 // Compute the constraint code and ConstraintType to use. 4219 TLI.ComputeConstraintToUse(OpInfo, OpInfo.CallOperand, &DAG); 4220 4221 // Keep track of whether we see an earlyclobber. 4222 SawEarlyClobber |= OpInfo.isEarlyClobber; 4223 4224 // If we see a clobber of a register, it is an early clobber. 4225 if (!SawEarlyClobber && 4226 OpInfo.Type == InlineAsm::isClobber && 4227 OpInfo.ConstraintType == TargetLowering::C_Register) { 4228 // Note that we want to ignore things that we don't trick here, like 4229 // dirflag, fpsr, flags, etc. 4230 std::pair<unsigned, const TargetRegisterClass*> PhysReg = 4231 TLI.getRegForInlineAsmConstraint(OpInfo.ConstraintCode, 4232 OpInfo.ConstraintVT); 4233 if (PhysReg.first || PhysReg.second) { 4234 // This is a register we know of. 4235 SawEarlyClobber = true; 4236 } 4237 } 4238 4239 // If this is a memory input, and if the operand is not indirect, do what we 4240 // need to to provide an address for the memory input. 4241 if (OpInfo.ConstraintType == TargetLowering::C_Memory && 4242 !OpInfo.isIndirect) { 4243 assert(OpInfo.Type == InlineAsm::isInput && 4244 "Can only indirectify direct input operands!"); 4245 4246 // Memory operands really want the address of the value. If we don't have 4247 // an indirect input, put it in the constpool if we can, otherwise spill 4248 // it to a stack slot. 4249 4250 // If the operand is a float, integer, or vector constant, spill to a 4251 // constant pool entry to get its address. 4252 Value *OpVal = OpInfo.CallOperandVal; 4253 if (isa<ConstantFP>(OpVal) || isa<ConstantInt>(OpVal) || 4254 isa<ConstantVector>(OpVal)) { 4255 OpInfo.CallOperand = DAG.getConstantPool(cast<Constant>(OpVal), 4256 TLI.getPointerTy()); 4257 } else { 4258 // Otherwise, create a stack slot and emit a store to it before the 4259 // asm. 4260 const Type *Ty = OpVal->getType(); 4261 uint64_t TySize = TLI.getTargetData()->getABITypeSize(Ty); 4262 unsigned Align = TLI.getTargetData()->getPrefTypeAlignment(Ty); 4263 MachineFunction &MF = DAG.getMachineFunction(); 4264 int SSFI = MF.getFrameInfo()->CreateStackObject(TySize, Align); 4265 SDValue StackSlot = DAG.getFrameIndex(SSFI, TLI.getPointerTy()); 4266 Chain = DAG.getStore(Chain, OpInfo.CallOperand, StackSlot, NULL, 0); 4267 OpInfo.CallOperand = StackSlot; 4268 } 4269 4270 // There is no longer a Value* corresponding to this operand. 4271 OpInfo.CallOperandVal = 0; 4272 // It is now an indirect operand. 4273 OpInfo.isIndirect = true; 4274 } 4275 4276 // If this constraint is for a specific register, allocate it before 4277 // anything else. 4278 if (OpInfo.ConstraintType == TargetLowering::C_Register) 4279 GetRegistersForValue(OpInfo, SawEarlyClobber, OutputRegs, InputRegs); 4280 } 4281 ConstraintInfos.clear(); 4282 4283 4284 // Second pass - Loop over all of the operands, assigning virtual or physregs 4285 // to registerclass operands. 4286 for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) { 4287 SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i]; 4288 4289 // C_Register operands have already been allocated, Other/Memory don't need 4290 // to be. 4291 if (OpInfo.ConstraintType == TargetLowering::C_RegisterClass) 4292 GetRegistersForValue(OpInfo, SawEarlyClobber, OutputRegs, InputRegs); 4293 } 4294 4295 // AsmNodeOperands - The operands for the ISD::INLINEASM node. 4296 std::vector<SDValue> AsmNodeOperands; 4297 AsmNodeOperands.push_back(SDValue()); // reserve space for input chain 4298 AsmNodeOperands.push_back( 4299 DAG.getTargetExternalSymbol(IA->getAsmString().c_str(), MVT::Other)); 4300 4301 4302 // Loop over all of the inputs, copying the operand values into the 4303 // appropriate registers and processing the output regs. 4304 RegsForValue RetValRegs; 4305 4306 // IndirectStoresToEmit - The set of stores to emit after the inline asm node. 4307 std::vector<std::pair<RegsForValue, Value*> > IndirectStoresToEmit; 4308 4309 for (unsigned i = 0, e = ConstraintOperands.size(); i != e; ++i) { 4310 SDISelAsmOperandInfo &OpInfo = ConstraintOperands[i]; 4311 4312 switch (OpInfo.Type) { 4313 case InlineAsm::isOutput: { 4314 if (OpInfo.ConstraintType != TargetLowering::C_RegisterClass && 4315 OpInfo.ConstraintType != TargetLowering::C_Register) { 4316 // Memory output, or 'other' output (e.g. 'X' constraint). 4317 assert(OpInfo.isIndirect && "Memory output must be indirect operand"); 4318 4319 // Add information to the INLINEASM node to know about this output. 4320 unsigned ResOpType = 4/*MEM*/ | (1 << 3); 4321 AsmNodeOperands.push_back(DAG.getTargetConstant(ResOpType, 4322 TLI.getPointerTy())); 4323 AsmNodeOperands.push_back(OpInfo.CallOperand); 4324 break; 4325 } 4326 4327 // Otherwise, this is a register or register class output. 4328 4329 // Copy the output from the appropriate register. Find a register that 4330 // we can use. 4331 if (OpInfo.AssignedRegs.Regs.empty()) { 4332 cerr << "Couldn't allocate output reg for constraint '" 4333 << OpInfo.ConstraintCode << "'!\n"; 4334 exit(1); 4335 } 4336 4337 // If this is an indirect operand, store through the pointer after the 4338 // asm. 4339 if (OpInfo.isIndirect) { 4340 IndirectStoresToEmit.push_back(std::make_pair(OpInfo.AssignedRegs, 4341 OpInfo.CallOperandVal)); 4342 } else { 4343 // This is the result value of the call. 4344 assert(CS.getType() != Type::VoidTy && "Bad inline asm!"); 4345 // Concatenate this output onto the outputs list. 4346 RetValRegs.append(OpInfo.AssignedRegs); 4347 } 4348 4349 // Add information to the INLINEASM node to know that this register is 4350 // set. 4351 OpInfo.AssignedRegs.AddInlineAsmOperands(2 /*REGDEF*/, DAG, 4352 AsmNodeOperands); 4353 break; 4354 } 4355 case InlineAsm::isInput: { 4356 SDValue InOperandVal = OpInfo.CallOperand; 4357 4358 if (isdigit(OpInfo.ConstraintCode[0])) { // Matching constraint? 4359 // If this is required to match an output register we have already set, 4360 // just use its register. 4361 unsigned OperandNo = atoi(OpInfo.ConstraintCode.c_str()); 4362 4363 // Scan until we find the definition we already emitted of this operand. 4364 // When we find it, create a RegsForValue operand. 4365 unsigned CurOp = 2; // The first operand. 4366 for (; OperandNo; --OperandNo) { 4367 // Advance to the next operand. 4368 unsigned NumOps = 4369 cast<ConstantSDNode>(AsmNodeOperands[CurOp])->getValue(); 4370 assert(((NumOps & 7) == 2 /*REGDEF*/ || 4371 (NumOps & 7) == 4 /*MEM*/) && 4372 "Skipped past definitions?"); 4373 CurOp += (NumOps>>3)+1; 4374 } 4375 4376 unsigned NumOps = 4377 cast<ConstantSDNode>(AsmNodeOperands[CurOp])->getValue(); 4378 if ((NumOps & 7) == 2 /*REGDEF*/) { 4379 // Add NumOps>>3 registers to MatchedRegs. 4380 RegsForValue MatchedRegs; 4381 MatchedRegs.TLI = &TLI; 4382 MatchedRegs.ValueVTs.push_back(InOperandVal.getValueType()); 4383 MatchedRegs.RegVTs.push_back(AsmNodeOperands[CurOp+1].getValueType()); 4384 for (unsigned i = 0, e = NumOps>>3; i != e; ++i) { 4385 unsigned Reg = 4386 cast<RegisterSDNode>(AsmNodeOperands[++CurOp])->getReg(); 4387 MatchedRegs.Regs.push_back(Reg); 4388 } 4389 4390 // Use the produced MatchedRegs object to 4391 MatchedRegs.getCopyToRegs(InOperandVal, DAG, Chain, &Flag); 4392 MatchedRegs.AddInlineAsmOperands(1 /*REGUSE*/, DAG, AsmNodeOperands); 4393 break; 4394 } else { 4395 assert((NumOps & 7) == 4/*MEM*/ && "Unknown matching constraint!"); 4396 assert((NumOps >> 3) == 1 && "Unexpected number of operands"); 4397 // Add information to the INLINEASM node to know about this input. 4398 unsigned ResOpType = 4/*MEM*/ | (1 << 3); 4399 AsmNodeOperands.push_back(DAG.getTargetConstant(ResOpType, 4400 TLI.getPointerTy())); 4401 AsmNodeOperands.push_back(AsmNodeOperands[CurOp+1]); 4402 break; 4403 } 4404 } 4405 4406 if (OpInfo.ConstraintType == TargetLowering::C_Other) { 4407 assert(!OpInfo.isIndirect && 4408 "Don't know how to handle indirect other inputs yet!"); 4409 4410 std::vector<SDValue> Ops; 4411 TLI.LowerAsmOperandForConstraint(InOperandVal, OpInfo.ConstraintCode[0], 4412 Ops, DAG); 4413 if (Ops.empty()) { 4414 cerr << "Invalid operand for inline asm constraint '" 4415 << OpInfo.ConstraintCode << "'!\n"; 4416 exit(1); 4417 } 4418 4419 // Add information to the INLINEASM node to know about this input. 4420 unsigned ResOpType = 3 /*IMM*/ | (Ops.size() << 3); 4421 AsmNodeOperands.push_back(DAG.getTargetConstant(ResOpType, 4422 TLI.getPointerTy())); 4423 AsmNodeOperands.insert(AsmNodeOperands.end(), Ops.begin(), Ops.end()); 4424 break; 4425 } else if (OpInfo.ConstraintType == TargetLowering::C_Memory) { 4426 assert(OpInfo.isIndirect && "Operand must be indirect to be a mem!"); 4427 assert(InOperandVal.getValueType() == TLI.getPointerTy() && 4428 "Memory operands expect pointer values"); 4429 4430 // Add information to the INLINEASM node to know about this input. 4431 unsigned ResOpType = 4/*MEM*/ | (1 << 3); 4432 AsmNodeOperands.push_back(DAG.getTargetConstant(ResOpType, 4433 TLI.getPointerTy())); 4434 AsmNodeOperands.push_back(InOperandVal); 4435 break; 4436 } 4437 4438 assert((OpInfo.ConstraintType == TargetLowering::C_RegisterClass || 4439 OpInfo.ConstraintType == TargetLowering::C_Register) && 4440 "Unknown constraint type!"); 4441 assert(!OpInfo.isIndirect && 4442 "Don't know how to handle indirect register inputs yet!"); 4443 4444 // Copy the input into the appropriate registers. 4445 assert(!OpInfo.AssignedRegs.Regs.empty() && 4446 "Couldn't allocate input reg!"); 4447 4448 OpInfo.AssignedRegs.getCopyToRegs(InOperandVal, DAG, Chain, &Flag); 4449 4450 OpInfo.AssignedRegs.AddInlineAsmOperands(1/*REGUSE*/, DAG, 4451 AsmNodeOperands); 4452 break; 4453 } 4454 case InlineAsm::isClobber: { 4455 // Add the clobbered value to the operand list, so that the register 4456 // allocator is aware that the physreg got clobbered. 4457 if (!OpInfo.AssignedRegs.Regs.empty()) 4458 OpInfo.AssignedRegs.AddInlineAsmOperands(2/*REGDEF*/, DAG, 4459 AsmNodeOperands); 4460 break; 4461 } 4462 } 4463 } 4464 4465 // Finish up input operands. 4466 AsmNodeOperands[0] = Chain; 4467 if (Flag.Val) AsmNodeOperands.push_back(Flag); 4468 4469 Chain = DAG.getNode(ISD::INLINEASM, 4470 DAG.getNodeValueTypes(MVT::Other, MVT::Flag), 2, 4471 &AsmNodeOperands[0], AsmNodeOperands.size()); 4472 Flag = Chain.getValue(1); 4473 4474 // If this asm returns a register value, copy the result from that register 4475 // and set it as the value of the call. 4476 if (!RetValRegs.Regs.empty()) { 4477 SDValue Val = RetValRegs.getCopyFromRegs(DAG, Chain, &Flag); 4478 4479 // If any of the results of the inline asm is a vector, it may have the 4480 // wrong width/num elts. This can happen for register classes that can 4481 // contain multiple different value types. The preg or vreg allocated may 4482 // not have the same VT as was expected. Convert it to the right type with 4483 // bit_convert. 4484 if (const StructType *ResSTy = dyn_cast<StructType>(CS.getType())) { 4485 for (unsigned i = 0, e = ResSTy->getNumElements(); i != e; ++i) { 4486 if (Val.Val->getValueType(i).isVector()) 4487 Val = DAG.getNode(ISD::BIT_CONVERT, 4488 TLI.getValueType(ResSTy->getElementType(i)), Val); 4489 } 4490 } else { 4491 if (Val.getValueType().isVector()) 4492 Val = DAG.getNode(ISD::BIT_CONVERT, TLI.getValueType(CS.getType()), 4493 Val); 4494 } 4495 4496 setValue(CS.getInstruction(), Val); 4497 } 4498 4499 std::vector<std::pair<SDValue, Value*> > StoresToEmit; 4500 4501 // Process indirect outputs, first output all of the flagged copies out of 4502 // physregs. 4503 for (unsigned i = 0, e = IndirectStoresToEmit.size(); i != e; ++i) { 4504 RegsForValue &OutRegs = IndirectStoresToEmit[i].first; 4505 Value *Ptr = IndirectStoresToEmit[i].second; 4506 SDValue OutVal = OutRegs.getCopyFromRegs(DAG, Chain, &Flag); 4507 StoresToEmit.push_back(std::make_pair(OutVal, Ptr)); 4508 } 4509 4510 // Emit the non-flagged stores from the physregs. 4511 SmallVector<SDValue, 8> OutChains; 4512 for (unsigned i = 0, e = StoresToEmit.size(); i != e; ++i) 4513 OutChains.push_back(DAG.getStore(Chain, StoresToEmit[i].first, 4514 getValue(StoresToEmit[i].second), 4515 StoresToEmit[i].second, 0)); 4516 if (!OutChains.empty()) 4517 Chain = DAG.getNode(ISD::TokenFactor, MVT::Other, 4518 &OutChains[0], OutChains.size()); 4519 DAG.setRoot(Chain); 4520} 4521 4522 4523void SelectionDAGLowering::visitMalloc(MallocInst &I) { 4524 SDValue Src = getValue(I.getOperand(0)); 4525 4526 MVT IntPtr = TLI.getPointerTy(); 4527 4528 if (IntPtr.bitsLT(Src.getValueType())) 4529 Src = DAG.getNode(ISD::TRUNCATE, IntPtr, Src); 4530 else if (IntPtr.bitsGT(Src.getValueType())) 4531 Src = DAG.getNode(ISD::ZERO_EXTEND, IntPtr, Src); 4532 4533 // Scale the source by the type size. 4534 uint64_t ElementSize = TD->getABITypeSize(I.getType()->getElementType()); 4535 Src = DAG.getNode(ISD::MUL, Src.getValueType(), 4536 Src, DAG.getIntPtrConstant(ElementSize)); 4537 4538 TargetLowering::ArgListTy Args; 4539 TargetLowering::ArgListEntry Entry; 4540 Entry.Node = Src; 4541 Entry.Ty = TLI.getTargetData()->getIntPtrType(); 4542 Args.push_back(Entry); 4543 4544 std::pair<SDValue,SDValue> Result = 4545 TLI.LowerCallTo(getRoot(), I.getType(), false, false, false, CallingConv::C, 4546 true, DAG.getExternalSymbol("malloc", IntPtr), Args, DAG); 4547 setValue(&I, Result.first); // Pointers always fit in registers 4548 DAG.setRoot(Result.second); 4549} 4550 4551void SelectionDAGLowering::visitFree(FreeInst &I) { 4552 TargetLowering::ArgListTy Args; 4553 TargetLowering::ArgListEntry Entry; 4554 Entry.Node = getValue(I.getOperand(0)); 4555 Entry.Ty = TLI.getTargetData()->getIntPtrType(); 4556 Args.push_back(Entry); 4557 MVT IntPtr = TLI.getPointerTy(); 4558 std::pair<SDValue,SDValue> Result = 4559 TLI.LowerCallTo(getRoot(), Type::VoidTy, false, false, false, 4560 CallingConv::C, true, 4561 DAG.getExternalSymbol("free", IntPtr), Args, DAG); 4562 DAG.setRoot(Result.second); 4563} 4564 4565// EmitInstrWithCustomInserter - This method should be implemented by targets 4566// that mark instructions with the 'usesCustomDAGSchedInserter' flag. These 4567// instructions are special in various ways, which require special support to 4568// insert. The specified MachineInstr is created but not inserted into any 4569// basic blocks, and the scheduler passes ownership of it to this method. 4570MachineBasicBlock *TargetLowering::EmitInstrWithCustomInserter(MachineInstr *MI, 4571 MachineBasicBlock *MBB) { 4572 cerr << "If a target marks an instruction with " 4573 << "'usesCustomDAGSchedInserter', it must implement " 4574 << "TargetLowering::EmitInstrWithCustomInserter!\n"; 4575 abort(); 4576 return 0; 4577} 4578 4579void SelectionDAGLowering::visitVAStart(CallInst &I) { 4580 DAG.setRoot(DAG.getNode(ISD::VASTART, MVT::Other, getRoot(), 4581 getValue(I.getOperand(1)), 4582 DAG.getSrcValue(I.getOperand(1)))); 4583} 4584 4585void SelectionDAGLowering::visitVAArg(VAArgInst &I) { 4586 SDValue V = DAG.getVAArg(TLI.getValueType(I.getType()), getRoot(), 4587 getValue(I.getOperand(0)), 4588 DAG.getSrcValue(I.getOperand(0))); 4589 setValue(&I, V); 4590 DAG.setRoot(V.getValue(1)); 4591} 4592 4593void SelectionDAGLowering::visitVAEnd(CallInst &I) { 4594 DAG.setRoot(DAG.getNode(ISD::VAEND, MVT::Other, getRoot(), 4595 getValue(I.getOperand(1)), 4596 DAG.getSrcValue(I.getOperand(1)))); 4597} 4598 4599void SelectionDAGLowering::visitVACopy(CallInst &I) { 4600 DAG.setRoot(DAG.getNode(ISD::VACOPY, MVT::Other, getRoot(), 4601 getValue(I.getOperand(1)), 4602 getValue(I.getOperand(2)), 4603 DAG.getSrcValue(I.getOperand(1)), 4604 DAG.getSrcValue(I.getOperand(2)))); 4605} 4606 4607/// TargetLowering::LowerArguments - This is the default LowerArguments 4608/// implementation, which just inserts a FORMAL_ARGUMENTS node. FIXME: When all 4609/// targets are migrated to using FORMAL_ARGUMENTS, this hook should be 4610/// integrated into SDISel. 4611void TargetLowering::LowerArguments(Function &F, SelectionDAG &DAG, 4612 SmallVectorImpl<SDValue> &ArgValues) { 4613 // Add CC# and isVararg as operands to the FORMAL_ARGUMENTS node. 4614 SmallVector<SDValue, 3+16> Ops; 4615 Ops.push_back(DAG.getRoot()); 4616 Ops.push_back(DAG.getConstant(F.getCallingConv(), getPointerTy())); 4617 Ops.push_back(DAG.getConstant(F.isVarArg(), getPointerTy())); 4618 4619 // Add one result value for each formal argument. 4620 SmallVector<MVT, 16> RetVals; 4621 unsigned j = 1; 4622 for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); 4623 I != E; ++I, ++j) { 4624 SmallVector<MVT, 4> ValueVTs; 4625 ComputeValueVTs(*this, I->getType(), ValueVTs); 4626 for (unsigned Value = 0, NumValues = ValueVTs.size(); 4627 Value != NumValues; ++Value) { 4628 MVT VT = ValueVTs[Value]; 4629 const Type *ArgTy = VT.getTypeForMVT(); 4630 ISD::ArgFlagsTy Flags; 4631 unsigned OriginalAlignment = 4632 getTargetData()->getABITypeAlignment(ArgTy); 4633 4634 if (F.paramHasAttr(j, ParamAttr::ZExt)) 4635 Flags.setZExt(); 4636 if (F.paramHasAttr(j, ParamAttr::SExt)) 4637 Flags.setSExt(); 4638 if (F.paramHasAttr(j, ParamAttr::InReg)) 4639 Flags.setInReg(); 4640 if (F.paramHasAttr(j, ParamAttr::StructRet)) 4641 Flags.setSRet(); 4642 if (F.paramHasAttr(j, ParamAttr::ByVal)) { 4643 Flags.setByVal(); 4644 const PointerType *Ty = cast<PointerType>(I->getType()); 4645 const Type *ElementTy = Ty->getElementType(); 4646 unsigned FrameAlign = getByValTypeAlignment(ElementTy); 4647 unsigned FrameSize = getTargetData()->getABITypeSize(ElementTy); 4648 // For ByVal, alignment should be passed from FE. BE will guess if 4649 // this info is not there but there are cases it cannot get right. 4650 if (F.getParamAlignment(j)) 4651 FrameAlign = F.getParamAlignment(j); 4652 Flags.setByValAlign(FrameAlign); 4653 Flags.setByValSize(FrameSize); 4654 } 4655 if (F.paramHasAttr(j, ParamAttr::Nest)) 4656 Flags.setNest(); 4657 Flags.setOrigAlign(OriginalAlignment); 4658 4659 MVT RegisterVT = getRegisterType(VT); 4660 unsigned NumRegs = getNumRegisters(VT); 4661 for (unsigned i = 0; i != NumRegs; ++i) { 4662 RetVals.push_back(RegisterVT); 4663 ISD::ArgFlagsTy MyFlags = Flags; 4664 if (NumRegs > 1 && i == 0) 4665 MyFlags.setSplit(); 4666 // if it isn't first piece, alignment must be 1 4667 else if (i > 0) 4668 MyFlags.setOrigAlign(1); 4669 Ops.push_back(DAG.getArgFlags(MyFlags)); 4670 } 4671 } 4672 } 4673 4674 RetVals.push_back(MVT::Other); 4675 4676 // Create the node. 4677 SDNode *Result = DAG.getNode(ISD::FORMAL_ARGUMENTS, 4678 DAG.getVTList(&RetVals[0], RetVals.size()), 4679 &Ops[0], Ops.size()).Val; 4680 4681 // Prelower FORMAL_ARGUMENTS. This isn't required for functionality, but 4682 // allows exposing the loads that may be part of the argument access to the 4683 // first DAGCombiner pass. 4684 SDValue TmpRes = LowerOperation(SDValue(Result, 0), DAG); 4685 4686 // The number of results should match up, except that the lowered one may have 4687 // an extra flag result. 4688 assert((Result->getNumValues() == TmpRes.Val->getNumValues() || 4689 (Result->getNumValues()+1 == TmpRes.Val->getNumValues() && 4690 TmpRes.getValue(Result->getNumValues()).getValueType() == MVT::Flag)) 4691 && "Lowering produced unexpected number of results!"); 4692 4693 // The FORMAL_ARGUMENTS node itself is likely no longer needed. 4694 if (Result != TmpRes.Val && Result->use_empty()) { 4695 HandleSDNode Dummy(DAG.getRoot()); 4696 DAG.RemoveDeadNode(Result); 4697 } 4698 4699 Result = TmpRes.Val; 4700 4701 unsigned NumArgRegs = Result->getNumValues() - 1; 4702 DAG.setRoot(SDValue(Result, NumArgRegs)); 4703 4704 // Set up the return result vector. 4705 unsigned i = 0; 4706 unsigned Idx = 1; 4707 for (Function::arg_iterator I = F.arg_begin(), E = F.arg_end(); I != E; 4708 ++I, ++Idx) { 4709 SmallVector<MVT, 4> ValueVTs; 4710 ComputeValueVTs(*this, I->getType(), ValueVTs); 4711 for (unsigned Value = 0, NumValues = ValueVTs.size(); 4712 Value != NumValues; ++Value) { 4713 MVT VT = ValueVTs[Value]; 4714 MVT PartVT = getRegisterType(VT); 4715 4716 unsigned NumParts = getNumRegisters(VT); 4717 SmallVector<SDValue, 4> Parts(NumParts); 4718 for (unsigned j = 0; j != NumParts; ++j) 4719 Parts[j] = SDValue(Result, i++); 4720 4721 ISD::NodeType AssertOp = ISD::DELETED_NODE; 4722 if (F.paramHasAttr(Idx, ParamAttr::SExt)) 4723 AssertOp = ISD::AssertSext; 4724 else if (F.paramHasAttr(Idx, ParamAttr::ZExt)) 4725 AssertOp = ISD::AssertZext; 4726 4727 ArgValues.push_back(getCopyFromParts(DAG, &Parts[0], NumParts, PartVT, VT, 4728 AssertOp)); 4729 } 4730 } 4731 assert(i == NumArgRegs && "Argument register count mismatch!"); 4732} 4733 4734 4735/// TargetLowering::LowerCallTo - This is the default LowerCallTo 4736/// implementation, which just inserts an ISD::CALL node, which is later custom 4737/// lowered by the target to something concrete. FIXME: When all targets are 4738/// migrated to using ISD::CALL, this hook should be integrated into SDISel. 4739std::pair<SDValue, SDValue> 4740TargetLowering::LowerCallTo(SDValue Chain, const Type *RetTy, 4741 bool RetSExt, bool RetZExt, bool isVarArg, 4742 unsigned CallingConv, bool isTailCall, 4743 SDValue Callee, 4744 ArgListTy &Args, SelectionDAG &DAG) { 4745 SmallVector<SDValue, 32> Ops; 4746 Ops.push_back(Chain); // Op#0 - Chain 4747 Ops.push_back(DAG.getConstant(CallingConv, getPointerTy())); // Op#1 - CC 4748 Ops.push_back(DAG.getConstant(isVarArg, getPointerTy())); // Op#2 - VarArg 4749 Ops.push_back(DAG.getConstant(isTailCall, getPointerTy())); // Op#3 - Tail 4750 Ops.push_back(Callee); 4751 4752 // Handle all of the outgoing arguments. 4753 for (unsigned i = 0, e = Args.size(); i != e; ++i) { 4754 SmallVector<MVT, 4> ValueVTs; 4755 ComputeValueVTs(*this, Args[i].Ty, ValueVTs); 4756 for (unsigned Value = 0, NumValues = ValueVTs.size(); 4757 Value != NumValues; ++Value) { 4758 MVT VT = ValueVTs[Value]; 4759 const Type *ArgTy = VT.getTypeForMVT(); 4760 SDValue Op = SDValue(Args[i].Node.Val, Args[i].Node.ResNo + Value); 4761 ISD::ArgFlagsTy Flags; 4762 unsigned OriginalAlignment = 4763 getTargetData()->getABITypeAlignment(ArgTy); 4764 4765 if (Args[i].isZExt) 4766 Flags.setZExt(); 4767 if (Args[i].isSExt) 4768 Flags.setSExt(); 4769 if (Args[i].isInReg) 4770 Flags.setInReg(); 4771 if (Args[i].isSRet) 4772 Flags.setSRet(); 4773 if (Args[i].isByVal) { 4774 Flags.setByVal(); 4775 const PointerType *Ty = cast<PointerType>(Args[i].Ty); 4776 const Type *ElementTy = Ty->getElementType(); 4777 unsigned FrameAlign = getByValTypeAlignment(ElementTy); 4778 unsigned FrameSize = getTargetData()->getABITypeSize(ElementTy); 4779 // For ByVal, alignment should come from FE. BE will guess if this 4780 // info is not there but there are cases it cannot get right. 4781 if (Args[i].Alignment) 4782 FrameAlign = Args[i].Alignment; 4783 Flags.setByValAlign(FrameAlign); 4784 Flags.setByValSize(FrameSize); 4785 } 4786 if (Args[i].isNest) 4787 Flags.setNest(); 4788 Flags.setOrigAlign(OriginalAlignment); 4789 4790 MVT PartVT = getRegisterType(VT); 4791 unsigned NumParts = getNumRegisters(VT); 4792 SmallVector<SDValue, 4> Parts(NumParts); 4793 ISD::NodeType ExtendKind = ISD::ANY_EXTEND; 4794 4795 if (Args[i].isSExt) 4796 ExtendKind = ISD::SIGN_EXTEND; 4797 else if (Args[i].isZExt) 4798 ExtendKind = ISD::ZERO_EXTEND; 4799 4800 getCopyToParts(DAG, Op, &Parts[0], NumParts, PartVT, ExtendKind); 4801 4802 for (unsigned i = 0; i != NumParts; ++i) { 4803 // if it isn't first piece, alignment must be 1 4804 ISD::ArgFlagsTy MyFlags = Flags; 4805 if (NumParts > 1 && i == 0) 4806 MyFlags.setSplit(); 4807 else if (i != 0) 4808 MyFlags.setOrigAlign(1); 4809 4810 Ops.push_back(Parts[i]); 4811 Ops.push_back(DAG.getArgFlags(MyFlags)); 4812 } 4813 } 4814 } 4815 4816 // Figure out the result value types. We start by making a list of 4817 // the potentially illegal return value types. 4818 SmallVector<MVT, 4> LoweredRetTys; 4819 SmallVector<MVT, 4> RetTys; 4820 ComputeValueVTs(*this, RetTy, RetTys); 4821 4822 // Then we translate that to a list of legal types. 4823 for (unsigned I = 0, E = RetTys.size(); I != E; ++I) { 4824 MVT VT = RetTys[I]; 4825 MVT RegisterVT = getRegisterType(VT); 4826 unsigned NumRegs = getNumRegisters(VT); 4827 for (unsigned i = 0; i != NumRegs; ++i) 4828 LoweredRetTys.push_back(RegisterVT); 4829 } 4830 4831 LoweredRetTys.push_back(MVT::Other); // Always has a chain. 4832 4833 // Create the CALL node. 4834 SDValue Res = DAG.getNode(ISD::CALL, 4835 DAG.getVTList(&LoweredRetTys[0], 4836 LoweredRetTys.size()), 4837 &Ops[0], Ops.size()); 4838 Chain = Res.getValue(LoweredRetTys.size() - 1); 4839 4840 // Gather up the call result into a single value. 4841 if (RetTy != Type::VoidTy) { 4842 ISD::NodeType AssertOp = ISD::DELETED_NODE; 4843 4844 if (RetSExt) 4845 AssertOp = ISD::AssertSext; 4846 else if (RetZExt) 4847 AssertOp = ISD::AssertZext; 4848 4849 SmallVector<SDValue, 4> ReturnValues; 4850 unsigned RegNo = 0; 4851 for (unsigned I = 0, E = RetTys.size(); I != E; ++I) { 4852 MVT VT = RetTys[I]; 4853 MVT RegisterVT = getRegisterType(VT); 4854 unsigned NumRegs = getNumRegisters(VT); 4855 unsigned RegNoEnd = NumRegs + RegNo; 4856 SmallVector<SDValue, 4> Results; 4857 for (; RegNo != RegNoEnd; ++RegNo) 4858 Results.push_back(Res.getValue(RegNo)); 4859 SDValue ReturnValue = 4860 getCopyFromParts(DAG, &Results[0], NumRegs, RegisterVT, VT, 4861 AssertOp); 4862 ReturnValues.push_back(ReturnValue); 4863 } 4864 Res = DAG.getMergeValues(DAG.getVTList(&RetTys[0], RetTys.size()), 4865 &ReturnValues[0], ReturnValues.size()); 4866 } 4867 4868 return std::make_pair(Res, Chain); 4869} 4870 4871SDValue TargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) { 4872 assert(0 && "LowerOperation not implemented for this target!"); 4873 abort(); 4874 return SDValue(); 4875} 4876 4877 4878//===----------------------------------------------------------------------===// 4879// SelectionDAGISel code 4880//===----------------------------------------------------------------------===// 4881 4882unsigned SelectionDAGISel::MakeReg(MVT VT) { 4883 return RegInfo->createVirtualRegister(TLI.getRegClassFor(VT)); 4884} 4885 4886void SelectionDAGISel::getAnalysisUsage(AnalysisUsage &AU) const { 4887 AU.addRequired<AliasAnalysis>(); 4888 AU.addRequired<GCModuleInfo>(); 4889 AU.setPreservesAll(); 4890} 4891 4892bool SelectionDAGISel::runOnFunction(Function &Fn) { 4893 // Get alias analysis for load/store combining. 4894 AA = &getAnalysis<AliasAnalysis>(); 4895 4896 MachineFunction &MF = MachineFunction::construct(&Fn, TLI.getTargetMachine()); 4897 if (MF.getFunction()->hasGC()) 4898 GFI = &getAnalysis<GCModuleInfo>().getFunctionInfo(*MF.getFunction()); 4899 else 4900 GFI = 0; 4901 RegInfo = &MF.getRegInfo(); 4902 DOUT << "\n\n\n=== " << Fn.getName() << "\n"; 4903 4904 FunctionLoweringInfo FuncInfo(TLI, Fn, MF); 4905 4906 for (Function::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I) 4907 if (InvokeInst *Invoke = dyn_cast<InvokeInst>(I->getTerminator())) 4908 // Mark landing pad. 4909 FuncInfo.MBBMap[Invoke->getSuccessor(1)]->setIsLandingPad(); 4910 4911 SelectAllBasicBlocks(Fn, MF, FuncInfo); 4912 4913 // Add function live-ins to entry block live-in set. 4914 BasicBlock *EntryBB = &Fn.getEntryBlock(); 4915 BB = FuncInfo.MBBMap[EntryBB]; 4916 if (!RegInfo->livein_empty()) 4917 for (MachineRegisterInfo::livein_iterator I = RegInfo->livein_begin(), 4918 E = RegInfo->livein_end(); I != E; ++I) 4919 BB->addLiveIn(I->first); 4920 4921#ifndef NDEBUG 4922 assert(FuncInfo.CatchInfoFound.size() == FuncInfo.CatchInfoLost.size() && 4923 "Not all catch info was assigned to a landing pad!"); 4924#endif 4925 4926 return true; 4927} 4928 4929void SelectionDAGLowering::CopyValueToVirtualRegister(Value *V, unsigned Reg) { 4930 SDValue Op = getValue(V); 4931 assert((Op.getOpcode() != ISD::CopyFromReg || 4932 cast<RegisterSDNode>(Op.getOperand(1))->getReg() != Reg) && 4933 "Copy from a reg to the same reg!"); 4934 assert(!TargetRegisterInfo::isPhysicalRegister(Reg) && "Is a physreg"); 4935 4936 RegsForValue RFV(TLI, Reg, V->getType()); 4937 SDValue Chain = DAG.getEntryNode(); 4938 RFV.getCopyToRegs(Op, DAG, Chain, 0); 4939 PendingExports.push_back(Chain); 4940} 4941 4942void SelectionDAGISel:: 4943LowerArguments(BasicBlock *LLVMBB, SelectionDAGLowering &SDL) { 4944 // If this is the entry block, emit arguments. 4945 Function &F = *LLVMBB->getParent(); 4946 FunctionLoweringInfo &FuncInfo = SDL.FuncInfo; 4947 SDValue OldRoot = SDL.DAG.getRoot(); 4948 SmallVector<SDValue, 16> Args; 4949 TLI.LowerArguments(F, SDL.DAG, Args); 4950 4951 unsigned a = 0; 4952 for (Function::arg_iterator AI = F.arg_begin(), E = F.arg_end(); 4953 AI != E; ++AI) { 4954 SmallVector<MVT, 4> ValueVTs; 4955 ComputeValueVTs(TLI, AI->getType(), ValueVTs); 4956 unsigned NumValues = ValueVTs.size(); 4957 if (!AI->use_empty()) { 4958 SDL.setValue(AI, SDL.DAG.getMergeValues(&Args[a], NumValues)); 4959 // If this argument is live outside of the entry block, insert a copy from 4960 // whereever we got it to the vreg that other BB's will reference it as. 4961 DenseMap<const Value*, unsigned>::iterator VMI=FuncInfo.ValueMap.find(AI); 4962 if (VMI != FuncInfo.ValueMap.end()) { 4963 SDL.CopyValueToVirtualRegister(AI, VMI->second); 4964 } 4965 } 4966 a += NumValues; 4967 } 4968 4969 // Finally, if the target has anything special to do, allow it to do so. 4970 // FIXME: this should insert code into the DAG! 4971 EmitFunctionEntryCode(F, SDL.DAG.getMachineFunction()); 4972} 4973 4974static void copyCatchInfo(BasicBlock *SrcBB, BasicBlock *DestBB, 4975 MachineModuleInfo *MMI, FunctionLoweringInfo &FLI) { 4976 for (BasicBlock::iterator I = SrcBB->begin(), E = --SrcBB->end(); I != E; ++I) 4977 if (isSelector(I)) { 4978 // Apply the catch info to DestBB. 4979 addCatchInfo(cast<CallInst>(*I), MMI, FLI.MBBMap[DestBB]); 4980#ifndef NDEBUG 4981 if (!FLI.MBBMap[SrcBB]->isLandingPad()) 4982 FLI.CatchInfoFound.insert(I); 4983#endif 4984 } 4985} 4986 4987/// IsFixedFrameObjectWithPosOffset - Check if object is a fixed frame object and 4988/// whether object offset >= 0. 4989static bool 4990IsFixedFrameObjectWithPosOffset(MachineFrameInfo * MFI, SDValue Op) { 4991 if (!isa<FrameIndexSDNode>(Op)) return false; 4992 4993 FrameIndexSDNode * FrameIdxNode = dyn_cast<FrameIndexSDNode>(Op); 4994 int FrameIdx = FrameIdxNode->getIndex(); 4995 return MFI->isFixedObjectIndex(FrameIdx) && 4996 MFI->getObjectOffset(FrameIdx) >= 0; 4997} 4998 4999/// IsPossiblyOverwrittenArgumentOfTailCall - Check if the operand could 5000/// possibly be overwritten when lowering the outgoing arguments in a tail 5001/// call. Currently the implementation of this call is very conservative and 5002/// assumes all arguments sourcing from FORMAL_ARGUMENTS or a CopyFromReg with 5003/// virtual registers would be overwritten by direct lowering. 5004static bool IsPossiblyOverwrittenArgumentOfTailCall(SDValue Op, 5005 MachineFrameInfo * MFI) { 5006 RegisterSDNode * OpReg = NULL; 5007 if (Op.getOpcode() == ISD::FORMAL_ARGUMENTS || 5008 (Op.getOpcode()== ISD::CopyFromReg && 5009 (OpReg = dyn_cast<RegisterSDNode>(Op.getOperand(1))) && 5010 (OpReg->getReg() >= TargetRegisterInfo::FirstVirtualRegister)) || 5011 (Op.getOpcode() == ISD::LOAD && 5012 IsFixedFrameObjectWithPosOffset(MFI, Op.getOperand(1))) || 5013 (Op.getOpcode() == ISD::MERGE_VALUES && 5014 Op.getOperand(Op.ResNo).getOpcode() == ISD::LOAD && 5015 IsFixedFrameObjectWithPosOffset(MFI, Op.getOperand(Op.ResNo). 5016 getOperand(1)))) 5017 return true; 5018 return false; 5019} 5020 5021/// CheckDAGForTailCallsAndFixThem - This Function looks for CALL nodes in the 5022/// DAG and fixes their tailcall attribute operand. 5023static void CheckDAGForTailCallsAndFixThem(SelectionDAG &DAG, 5024 TargetLowering& TLI) { 5025 SDNode * Ret = NULL; 5026 SDValue Terminator = DAG.getRoot(); 5027 5028 // Find RET node. 5029 if (Terminator.getOpcode() == ISD::RET) { 5030 Ret = Terminator.Val; 5031 } 5032 5033 // Fix tail call attribute of CALL nodes. 5034 for (SelectionDAG::allnodes_iterator BE = DAG.allnodes_begin(), 5035 BI = DAG.allnodes_end(); BI != BE; ) { 5036 --BI; 5037 if (BI->getOpcode() == ISD::CALL) { 5038 SDValue OpRet(Ret, 0); 5039 SDValue OpCall(BI, 0); 5040 bool isMarkedTailCall = 5041 cast<ConstantSDNode>(OpCall.getOperand(3))->getValue() != 0; 5042 // If CALL node has tail call attribute set to true and the call is not 5043 // eligible (no RET or the target rejects) the attribute is fixed to 5044 // false. The TargetLowering::IsEligibleForTailCallOptimization function 5045 // must correctly identify tail call optimizable calls. 5046 if (!isMarkedTailCall) continue; 5047 if (Ret==NULL || 5048 !TLI.IsEligibleForTailCallOptimization(OpCall, OpRet, DAG)) { 5049 // Not eligible. Mark CALL node as non tail call. 5050 SmallVector<SDValue, 32> Ops; 5051 unsigned idx=0; 5052 for(SDNode::op_iterator I =OpCall.Val->op_begin(), 5053 E = OpCall.Val->op_end(); I != E; I++, idx++) { 5054 if (idx!=3) 5055 Ops.push_back(*I); 5056 else 5057 Ops.push_back(DAG.getConstant(false, TLI.getPointerTy())); 5058 } 5059 DAG.UpdateNodeOperands(OpCall, Ops.begin(), Ops.size()); 5060 } else { 5061 // Look for tail call clobbered arguments. Emit a series of 5062 // copyto/copyfrom virtual register nodes to protect them. 5063 SmallVector<SDValue, 32> Ops; 5064 SDValue Chain = OpCall.getOperand(0), InFlag; 5065 unsigned idx=0; 5066 for(SDNode::op_iterator I = OpCall.Val->op_begin(), 5067 E = OpCall.Val->op_end(); I != E; I++, idx++) { 5068 SDValue Arg = *I; 5069 if (idx > 4 && (idx % 2)) { 5070 bool isByVal = cast<ARG_FLAGSSDNode>(OpCall.getOperand(idx+1))-> 5071 getArgFlags().isByVal(); 5072 MachineFunction &MF = DAG.getMachineFunction(); 5073 MachineFrameInfo *MFI = MF.getFrameInfo(); 5074 if (!isByVal && 5075 IsPossiblyOverwrittenArgumentOfTailCall(Arg, MFI)) { 5076 MVT VT = Arg.getValueType(); 5077 unsigned VReg = MF.getRegInfo(). 5078 createVirtualRegister(TLI.getRegClassFor(VT)); 5079 Chain = DAG.getCopyToReg(Chain, VReg, Arg, InFlag); 5080 InFlag = Chain.getValue(1); 5081 Arg = DAG.getCopyFromReg(Chain, VReg, VT, InFlag); 5082 Chain = Arg.getValue(1); 5083 InFlag = Arg.getValue(2); 5084 } 5085 } 5086 Ops.push_back(Arg); 5087 } 5088 // Link in chain of CopyTo/CopyFromReg. 5089 Ops[0] = Chain; 5090 DAG.UpdateNodeOperands(OpCall, Ops.begin(), Ops.size()); 5091 } 5092 } 5093 } 5094} 5095 5096void SelectionDAGISel::BuildSelectionDAG(SelectionDAG &DAG, BasicBlock *LLVMBB, 5097 std::vector<std::pair<MachineInstr*, unsigned> > &PHINodesToUpdate, 5098 FunctionLoweringInfo &FuncInfo) { 5099 SelectionDAGLowering SDL(DAG, TLI, *AA, FuncInfo, GFI); 5100 BB = FuncInfo.MBBMap[LLVMBB]; 5101 5102 // Before doing SelectionDAG ISel, see if FastISel has been requested. 5103 // FastISel doesn't currently support entry blocks, because that 5104 // requires special handling for arguments. And it doesn't support EH 5105 // landing pads, which also require special handling. 5106 // For now, also exclude blocks with terminators that aren't 5107 // unconditional branches. 5108 BasicBlock::iterator Begin = LLVMBB->begin(); 5109 if (EnableFastISel && 5110 LLVMBB != &LLVMBB->getParent()->getEntryBlock() && 5111 !BB->isLandingPad() && 5112 isa<BranchInst>(LLVMBB->getTerminator()) && 5113 cast<BranchInst>(LLVMBB->getTerminator())->isUnconditional()) { 5114 if (FastISel *F = TLI.createFastISel(FuncInfo.MF)) { 5115 Begin = F->SelectInstructions(Begin, LLVMBB->end(), 5116 FuncInfo.ValueMap, BB); 5117 5118 // Clean up the FastISel object. TODO: Reorganize what data is 5119 // stored in the FastISel class itself and what is merely passed 5120 // to the SelectInstructions method, and then move the creation 5121 // and deletion of the FastISel object up so that it is only 5122 // done once per MachineFunction. 5123 delete F; 5124 5125 if (Begin == LLVMBB->end()) 5126 // The "fast" selector selected the entire block, so we're done. 5127 return; 5128 5129 if (!DisableFastISelAbort) { 5130 // The "fast" selector couldn't handle something and bailed. 5131 // For the purpose of debugging, just abort. 5132#ifndef NDEBUG 5133 Begin->dump(); 5134#endif 5135 assert(0 && "FastISel didn't select the entire block"); 5136 abort(); 5137 } 5138 } 5139 } 5140 5141 // Lower any arguments needed in this block if this is the entry block. 5142 if (LLVMBB == &LLVMBB->getParent()->getEntryBlock()) 5143 LowerArguments(LLVMBB, SDL); 5144 5145 SDL.setCurrentBasicBlock(BB); 5146 5147 MachineModuleInfo *MMI = DAG.getMachineModuleInfo(); 5148 5149 if (MMI && BB->isLandingPad()) { 5150 // Add a label to mark the beginning of the landing pad. Deletion of the 5151 // landing pad can thus be detected via the MachineModuleInfo. 5152 unsigned LabelID = MMI->addLandingPad(BB); 5153 DAG.setRoot(DAG.getLabel(ISD::EH_LABEL, DAG.getEntryNode(), LabelID)); 5154 5155 // Mark exception register as live in. 5156 unsigned Reg = TLI.getExceptionAddressRegister(); 5157 if (Reg) BB->addLiveIn(Reg); 5158 5159 // Mark exception selector register as live in. 5160 Reg = TLI.getExceptionSelectorRegister(); 5161 if (Reg) BB->addLiveIn(Reg); 5162 5163 // FIXME: Hack around an exception handling flaw (PR1508): the personality 5164 // function and list of typeids logically belong to the invoke (or, if you 5165 // like, the basic block containing the invoke), and need to be associated 5166 // with it in the dwarf exception handling tables. Currently however the 5167 // information is provided by an intrinsic (eh.selector) that can be moved 5168 // to unexpected places by the optimizers: if the unwind edge is critical, 5169 // then breaking it can result in the intrinsics being in the successor of 5170 // the landing pad, not the landing pad itself. This results in exceptions 5171 // not being caught because no typeids are associated with the invoke. 5172 // This may not be the only way things can go wrong, but it is the only way 5173 // we try to work around for the moment. 5174 BranchInst *Br = dyn_cast<BranchInst>(LLVMBB->getTerminator()); 5175 5176 if (Br && Br->isUnconditional()) { // Critical edge? 5177 BasicBlock::iterator I, E; 5178 for (I = LLVMBB->begin(), E = --LLVMBB->end(); I != E; ++I) 5179 if (isSelector(I)) 5180 break; 5181 5182 if (I == E) 5183 // No catch info found - try to extract some from the successor. 5184 copyCatchInfo(Br->getSuccessor(0), LLVMBB, MMI, FuncInfo); 5185 } 5186 } 5187 5188 // Lower all of the non-terminator instructions. 5189 for (BasicBlock::iterator I = Begin, E = --LLVMBB->end(); 5190 I != E; ++I) 5191 SDL.visit(*I); 5192 5193 // Ensure that all instructions which are used outside of their defining 5194 // blocks are available as virtual registers. Invoke is handled elsewhere. 5195 for (BasicBlock::iterator I = Begin, E = LLVMBB->end(); I != E;++I) 5196 if (!I->use_empty() && !isa<PHINode>(I) && !isa<InvokeInst>(I)) { 5197 DenseMap<const Value*, unsigned>::iterator VMI =FuncInfo.ValueMap.find(I); 5198 if (VMI != FuncInfo.ValueMap.end()) 5199 SDL.CopyValueToVirtualRegister(I, VMI->second); 5200 } 5201 5202 // Handle PHI nodes in successor blocks. Emit code into the SelectionDAG to 5203 // ensure constants are generated when needed. Remember the virtual registers 5204 // that need to be added to the Machine PHI nodes as input. We cannot just 5205 // directly add them, because expansion might result in multiple MBB's for one 5206 // BB. As such, the start of the BB might correspond to a different MBB than 5207 // the end. 5208 // 5209 TerminatorInst *TI = LLVMBB->getTerminator(); 5210 5211 // Emit constants only once even if used by multiple PHI nodes. 5212 std::map<Constant*, unsigned> ConstantsOut; 5213 5214 BitVector SuccsHandled; 5215 if (TI->getNumSuccessors()) 5216 SuccsHandled.resize(BB->getParent()->getNumBlockIDs()); 5217 5218 // Check successor nodes' PHI nodes that expect a constant to be available 5219 // from this block. 5220 for (unsigned succ = 0, e = TI->getNumSuccessors(); succ != e; ++succ) { 5221 BasicBlock *SuccBB = TI->getSuccessor(succ); 5222 if (!isa<PHINode>(SuccBB->begin())) continue; 5223 MachineBasicBlock *SuccMBB = FuncInfo.MBBMap[SuccBB]; 5224 5225 // If this terminator has multiple identical successors (common for 5226 // switches), only handle each succ once. 5227 unsigned SuccMBBNo = SuccMBB->getNumber(); 5228 if (SuccsHandled[SuccMBBNo]) continue; 5229 SuccsHandled[SuccMBBNo] = true; 5230 5231 MachineBasicBlock::iterator MBBI = SuccMBB->begin(); 5232 PHINode *PN; 5233 5234 // At this point we know that there is a 1-1 correspondence between LLVM PHI 5235 // nodes and Machine PHI nodes, but the incoming operands have not been 5236 // emitted yet. 5237 for (BasicBlock::iterator I = SuccBB->begin(); 5238 (PN = dyn_cast<PHINode>(I)); ++I) { 5239 // Ignore dead phi's. 5240 if (PN->use_empty()) continue; 5241 5242 unsigned Reg; 5243 Value *PHIOp = PN->getIncomingValueForBlock(LLVMBB); 5244 5245 if (Constant *C = dyn_cast<Constant>(PHIOp)) { 5246 unsigned &RegOut = ConstantsOut[C]; 5247 if (RegOut == 0) { 5248 RegOut = FuncInfo.CreateRegForValue(C); 5249 SDL.CopyValueToVirtualRegister(C, RegOut); 5250 } 5251 Reg = RegOut; 5252 } else { 5253 Reg = FuncInfo.ValueMap[PHIOp]; 5254 if (Reg == 0) { 5255 assert(isa<AllocaInst>(PHIOp) && 5256 FuncInfo.StaticAllocaMap.count(cast<AllocaInst>(PHIOp)) && 5257 "Didn't codegen value into a register!??"); 5258 Reg = FuncInfo.CreateRegForValue(PHIOp); 5259 SDL.CopyValueToVirtualRegister(PHIOp, Reg); 5260 } 5261 } 5262 5263 // Remember that this register needs to added to the machine PHI node as 5264 // the input for this MBB. 5265 SmallVector<MVT, 4> ValueVTs; 5266 ComputeValueVTs(TLI, PN->getType(), ValueVTs); 5267 for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) { 5268 MVT VT = ValueVTs[vti]; 5269 unsigned NumRegisters = TLI.getNumRegisters(VT); 5270 for (unsigned i = 0, e = NumRegisters; i != e; ++i) 5271 PHINodesToUpdate.push_back(std::make_pair(MBBI++, Reg+i)); 5272 Reg += NumRegisters; 5273 } 5274 } 5275 } 5276 ConstantsOut.clear(); 5277 5278 // Lower the terminator after the copies are emitted. 5279 SDL.visit(*LLVMBB->getTerminator()); 5280 5281 // Copy over any CaseBlock records that may now exist due to SwitchInst 5282 // lowering, as well as any jump table information. 5283 SwitchCases.clear(); 5284 SwitchCases = SDL.SwitchCases; 5285 JTCases.clear(); 5286 JTCases = SDL.JTCases; 5287 BitTestCases.clear(); 5288 BitTestCases = SDL.BitTestCases; 5289 5290 // Make sure the root of the DAG is up-to-date. 5291 DAG.setRoot(SDL.getControlRoot()); 5292 5293 // Check whether calls in this block are real tail calls. Fix up CALL nodes 5294 // with correct tailcall attribute so that the target can rely on the tailcall 5295 // attribute indicating whether the call is really eligible for tail call 5296 // optimization. 5297 CheckDAGForTailCallsAndFixThem(DAG, TLI); 5298} 5299 5300void SelectionDAGISel::ComputeLiveOutVRegInfo(SelectionDAG &DAG) { 5301 SmallPtrSet<SDNode*, 128> VisitedNodes; 5302 SmallVector<SDNode*, 128> Worklist; 5303 5304 Worklist.push_back(DAG.getRoot().Val); 5305 5306 APInt Mask; 5307 APInt KnownZero; 5308 APInt KnownOne; 5309 5310 while (!Worklist.empty()) { 5311 SDNode *N = Worklist.back(); 5312 Worklist.pop_back(); 5313 5314 // If we've already seen this node, ignore it. 5315 if (!VisitedNodes.insert(N)) 5316 continue; 5317 5318 // Otherwise, add all chain operands to the worklist. 5319 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) 5320 if (N->getOperand(i).getValueType() == MVT::Other) 5321 Worklist.push_back(N->getOperand(i).Val); 5322 5323 // If this is a CopyToReg with a vreg dest, process it. 5324 if (N->getOpcode() != ISD::CopyToReg) 5325 continue; 5326 5327 unsigned DestReg = cast<RegisterSDNode>(N->getOperand(1))->getReg(); 5328 if (!TargetRegisterInfo::isVirtualRegister(DestReg)) 5329 continue; 5330 5331 // Ignore non-scalar or non-integer values. 5332 SDValue Src = N->getOperand(2); 5333 MVT SrcVT = Src.getValueType(); 5334 if (!SrcVT.isInteger() || SrcVT.isVector()) 5335 continue; 5336 5337 unsigned NumSignBits = DAG.ComputeNumSignBits(Src); 5338 Mask = APInt::getAllOnesValue(SrcVT.getSizeInBits()); 5339 DAG.ComputeMaskedBits(Src, Mask, KnownZero, KnownOne); 5340 5341 // Only install this information if it tells us something. 5342 if (NumSignBits != 1 || KnownZero != 0 || KnownOne != 0) { 5343 DestReg -= TargetRegisterInfo::FirstVirtualRegister; 5344 FunctionLoweringInfo &FLI = DAG.getFunctionLoweringInfo(); 5345 if (DestReg >= FLI.LiveOutRegInfo.size()) 5346 FLI.LiveOutRegInfo.resize(DestReg+1); 5347 FunctionLoweringInfo::LiveOutInfo &LOI = FLI.LiveOutRegInfo[DestReg]; 5348 LOI.NumSignBits = NumSignBits; 5349 LOI.KnownOne = NumSignBits; 5350 LOI.KnownZero = NumSignBits; 5351 } 5352 } 5353} 5354 5355void SelectionDAGISel::CodeGenAndEmitDAG(SelectionDAG &DAG) { 5356 std::string GroupName; 5357 if (TimePassesIsEnabled) 5358 GroupName = "Instruction Selection and Scheduling"; 5359 std::string BlockName; 5360 if (ViewDAGCombine1 || ViewLegalizeTypesDAGs || ViewLegalizeDAGs || 5361 ViewDAGCombine2 || ViewISelDAGs || ViewSchedDAGs || ViewSUnitDAGs) 5362 BlockName = DAG.getMachineFunction().getFunction()->getName() + ':' + 5363 BB->getBasicBlock()->getName(); 5364 5365 DOUT << "Initial selection DAG:\n"; 5366 DEBUG(DAG.dump()); 5367 5368 if (ViewDAGCombine1) DAG.viewGraph("dag-combine1 input for " + BlockName); 5369 5370 // Run the DAG combiner in pre-legalize mode. 5371 if (TimePassesIsEnabled) { 5372 NamedRegionTimer T("DAG Combining 1", GroupName); 5373 DAG.Combine(false, *AA, Fast); 5374 } else { 5375 DAG.Combine(false, *AA, Fast); 5376 } 5377 5378 DOUT << "Optimized lowered selection DAG:\n"; 5379 DEBUG(DAG.dump()); 5380 5381 // Second step, hack on the DAG until it only uses operations and types that 5382 // the target supports. 5383 if (EnableLegalizeTypes) {// Enable this some day. 5384 if (ViewLegalizeTypesDAGs) DAG.viewGraph("legalize-types input for " + 5385 BlockName); 5386 5387 if (TimePassesIsEnabled) { 5388 NamedRegionTimer T("Type Legalization", GroupName); 5389 DAG.LegalizeTypes(); 5390 } else { 5391 DAG.LegalizeTypes(); 5392 } 5393 5394 DOUT << "Type-legalized selection DAG:\n"; 5395 DEBUG(DAG.dump()); 5396 5397 // TODO: enable a dag combine pass here. 5398 } 5399 5400 if (ViewLegalizeDAGs) DAG.viewGraph("legalize input for " + BlockName); 5401 5402 if (TimePassesIsEnabled) { 5403 NamedRegionTimer T("DAG Legalization", GroupName); 5404 DAG.Legalize(); 5405 } else { 5406 DAG.Legalize(); 5407 } 5408 5409 DOUT << "Legalized selection DAG:\n"; 5410 DEBUG(DAG.dump()); 5411 5412 if (ViewDAGCombine2) DAG.viewGraph("dag-combine2 input for " + BlockName); 5413 5414 // Run the DAG combiner in post-legalize mode. 5415 if (TimePassesIsEnabled) { 5416 NamedRegionTimer T("DAG Combining 2", GroupName); 5417 DAG.Combine(true, *AA, Fast); 5418 } else { 5419 DAG.Combine(true, *AA, Fast); 5420 } 5421 5422 DOUT << "Optimized legalized selection DAG:\n"; 5423 DEBUG(DAG.dump()); 5424 5425 if (ViewISelDAGs) DAG.viewGraph("isel input for " + BlockName); 5426 5427 if (!Fast && EnableValueProp) 5428 ComputeLiveOutVRegInfo(DAG); 5429 5430 // Third, instruction select all of the operations to machine code, adding the 5431 // code to the MachineBasicBlock. 5432 if (TimePassesIsEnabled) { 5433 NamedRegionTimer T("Instruction Selection", GroupName); 5434 InstructionSelect(DAG); 5435 } else { 5436 InstructionSelect(DAG); 5437 } 5438 5439 DOUT << "Selected selection DAG:\n"; 5440 DEBUG(DAG.dump()); 5441 5442 if (ViewSchedDAGs) DAG.viewGraph("scheduler input for " + BlockName); 5443 5444 // Schedule machine code. 5445 ScheduleDAG *Scheduler; 5446 if (TimePassesIsEnabled) { 5447 NamedRegionTimer T("Instruction Scheduling", GroupName); 5448 Scheduler = Schedule(DAG); 5449 } else { 5450 Scheduler = Schedule(DAG); 5451 } 5452 5453 if (ViewSUnitDAGs) Scheduler->viewGraph(); 5454 5455 // Emit machine code to BB. This can change 'BB' to the last block being 5456 // inserted into. 5457 if (TimePassesIsEnabled) { 5458 NamedRegionTimer T("Instruction Creation", GroupName); 5459 BB = Scheduler->EmitSchedule(); 5460 } else { 5461 BB = Scheduler->EmitSchedule(); 5462 } 5463 5464 // Free the scheduler state. 5465 if (TimePassesIsEnabled) { 5466 NamedRegionTimer T("Instruction Scheduling Cleanup", GroupName); 5467 delete Scheduler; 5468 } else { 5469 delete Scheduler; 5470 } 5471 5472 // Perform target specific isel post processing. 5473 if (TimePassesIsEnabled) { 5474 NamedRegionTimer T("Instruction Selection Post Processing", GroupName); 5475 InstructionSelectPostProcessing(); 5476 } else { 5477 InstructionSelectPostProcessing(); 5478 } 5479 5480 DOUT << "Selected machine code:\n"; 5481 DEBUG(BB->dump()); 5482} 5483 5484void SelectionDAGISel::SelectAllBasicBlocks(Function &Fn, MachineFunction &MF, 5485 FunctionLoweringInfo &FuncInfo) { 5486 // Define NodeAllocator here so that memory allocation is reused for 5487 // each basic block. 5488 NodeAllocatorType NodeAllocator; 5489 5490 std::vector<std::pair<MachineInstr*, unsigned> > PHINodesToUpdate; 5491 for (Function::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I) { 5492 BasicBlock *LLVMBB = &*I; 5493 PHINodesToUpdate.clear(); 5494 5495 SelectBasicBlock(LLVMBB, MF, FuncInfo, PHINodesToUpdate, NodeAllocator); 5496 FinishBasicBlock(LLVMBB, MF, FuncInfo, PHINodesToUpdate, NodeAllocator); 5497 } 5498} 5499 5500void 5501SelectionDAGISel::SelectBasicBlock(BasicBlock *LLVMBB, MachineFunction &MF, 5502 FunctionLoweringInfo &FuncInfo, 5503 std::vector<std::pair<MachineInstr*, unsigned> > &PHINodesToUpdate, 5504 NodeAllocatorType &NodeAllocator) { 5505 SelectionDAG DAG(TLI, MF, FuncInfo, 5506 getAnalysisToUpdate<MachineModuleInfo>(), 5507 NodeAllocator); 5508 CurDAG = &DAG; 5509 5510 // First step, lower LLVM code to some DAG. This DAG may use operations and 5511 // types that are not supported by the target. 5512 BuildSelectionDAG(DAG, LLVMBB, PHINodesToUpdate, FuncInfo); 5513 5514 // Second step, emit the lowered DAG as machine code. 5515 CodeGenAndEmitDAG(DAG); 5516} 5517 5518void 5519SelectionDAGISel::FinishBasicBlock(BasicBlock *LLVMBB, MachineFunction &MF, 5520 FunctionLoweringInfo &FuncInfo, 5521 std::vector<std::pair<MachineInstr*, unsigned> > &PHINodesToUpdate, 5522 NodeAllocatorType &NodeAllocator) { 5523 DOUT << "Total amount of phi nodes to update: " 5524 << PHINodesToUpdate.size() << "\n"; 5525 DEBUG(for (unsigned i = 0, e = PHINodesToUpdate.size(); i != e; ++i) 5526 DOUT << "Node " << i << " : (" << PHINodesToUpdate[i].first 5527 << ", " << PHINodesToUpdate[i].second << ")\n";); 5528 5529 // Next, now that we know what the last MBB the LLVM BB expanded is, update 5530 // PHI nodes in successors. 5531 if (SwitchCases.empty() && JTCases.empty() && BitTestCases.empty()) { 5532 for (unsigned i = 0, e = PHINodesToUpdate.size(); i != e; ++i) { 5533 MachineInstr *PHI = PHINodesToUpdate[i].first; 5534 assert(PHI->getOpcode() == TargetInstrInfo::PHI && 5535 "This is not a machine PHI node that we are updating!"); 5536 PHI->addOperand(MachineOperand::CreateReg(PHINodesToUpdate[i].second, 5537 false)); 5538 PHI->addOperand(MachineOperand::CreateMBB(BB)); 5539 } 5540 return; 5541 } 5542 5543 for (unsigned i = 0, e = BitTestCases.size(); i != e; ++i) { 5544 // Lower header first, if it wasn't already lowered 5545 if (!BitTestCases[i].Emitted) { 5546 SelectionDAG HSDAG(TLI, MF, FuncInfo, 5547 getAnalysisToUpdate<MachineModuleInfo>(), 5548 NodeAllocator); 5549 CurDAG = &HSDAG; 5550 SelectionDAGLowering HSDL(HSDAG, TLI, *AA, FuncInfo, GFI); 5551 // Set the current basic block to the mbb we wish to insert the code into 5552 BB = BitTestCases[i].Parent; 5553 HSDL.setCurrentBasicBlock(BB); 5554 // Emit the code 5555 HSDL.visitBitTestHeader(BitTestCases[i]); 5556 HSDAG.setRoot(HSDL.getRoot()); 5557 CodeGenAndEmitDAG(HSDAG); 5558 } 5559 5560 for (unsigned j = 0, ej = BitTestCases[i].Cases.size(); j != ej; ++j) { 5561 SelectionDAG BSDAG(TLI, MF, FuncInfo, 5562 getAnalysisToUpdate<MachineModuleInfo>(), 5563 NodeAllocator); 5564 CurDAG = &BSDAG; 5565 SelectionDAGLowering BSDL(BSDAG, TLI, *AA, FuncInfo, GFI); 5566 // Set the current basic block to the mbb we wish to insert the code into 5567 BB = BitTestCases[i].Cases[j].ThisBB; 5568 BSDL.setCurrentBasicBlock(BB); 5569 // Emit the code 5570 if (j+1 != ej) 5571 BSDL.visitBitTestCase(BitTestCases[i].Cases[j+1].ThisBB, 5572 BitTestCases[i].Reg, 5573 BitTestCases[i].Cases[j]); 5574 else 5575 BSDL.visitBitTestCase(BitTestCases[i].Default, 5576 BitTestCases[i].Reg, 5577 BitTestCases[i].Cases[j]); 5578 5579 5580 BSDAG.setRoot(BSDL.getRoot()); 5581 CodeGenAndEmitDAG(BSDAG); 5582 } 5583 5584 // Update PHI Nodes 5585 for (unsigned pi = 0, pe = PHINodesToUpdate.size(); pi != pe; ++pi) { 5586 MachineInstr *PHI = PHINodesToUpdate[pi].first; 5587 MachineBasicBlock *PHIBB = PHI->getParent(); 5588 assert(PHI->getOpcode() == TargetInstrInfo::PHI && 5589 "This is not a machine PHI node that we are updating!"); 5590 // This is "default" BB. We have two jumps to it. From "header" BB and 5591 // from last "case" BB. 5592 if (PHIBB == BitTestCases[i].Default) { 5593 PHI->addOperand(MachineOperand::CreateReg(PHINodesToUpdate[pi].second, 5594 false)); 5595 PHI->addOperand(MachineOperand::CreateMBB(BitTestCases[i].Parent)); 5596 PHI->addOperand(MachineOperand::CreateReg(PHINodesToUpdate[pi].second, 5597 false)); 5598 PHI->addOperand(MachineOperand::CreateMBB(BitTestCases[i].Cases. 5599 back().ThisBB)); 5600 } 5601 // One of "cases" BB. 5602 for (unsigned j = 0, ej = BitTestCases[i].Cases.size(); j != ej; ++j) { 5603 MachineBasicBlock* cBB = BitTestCases[i].Cases[j].ThisBB; 5604 if (cBB->succ_end() != 5605 std::find(cBB->succ_begin(),cBB->succ_end(), PHIBB)) { 5606 PHI->addOperand(MachineOperand::CreateReg(PHINodesToUpdate[pi].second, 5607 false)); 5608 PHI->addOperand(MachineOperand::CreateMBB(cBB)); 5609 } 5610 } 5611 } 5612 } 5613 5614 // If the JumpTable record is filled in, then we need to emit a jump table. 5615 // Updating the PHI nodes is tricky in this case, since we need to determine 5616 // whether the PHI is a successor of the range check MBB or the jump table MBB 5617 for (unsigned i = 0, e = JTCases.size(); i != e; ++i) { 5618 // Lower header first, if it wasn't already lowered 5619 if (!JTCases[i].first.Emitted) { 5620 SelectionDAG HSDAG(TLI, MF, FuncInfo, 5621 getAnalysisToUpdate<MachineModuleInfo>(), 5622 NodeAllocator); 5623 CurDAG = &HSDAG; 5624 SelectionDAGLowering HSDL(HSDAG, TLI, *AA, FuncInfo, GFI); 5625 // Set the current basic block to the mbb we wish to insert the code into 5626 BB = JTCases[i].first.HeaderBB; 5627 HSDL.setCurrentBasicBlock(BB); 5628 // Emit the code 5629 HSDL.visitJumpTableHeader(JTCases[i].second, JTCases[i].first); 5630 HSDAG.setRoot(HSDL.getRoot()); 5631 CodeGenAndEmitDAG(HSDAG); 5632 } 5633 5634 SelectionDAG JSDAG(TLI, MF, FuncInfo, 5635 getAnalysisToUpdate<MachineModuleInfo>(), 5636 NodeAllocator); 5637 CurDAG = &JSDAG; 5638 SelectionDAGLowering JSDL(JSDAG, TLI, *AA, FuncInfo, GFI); 5639 // Set the current basic block to the mbb we wish to insert the code into 5640 BB = JTCases[i].second.MBB; 5641 JSDL.setCurrentBasicBlock(BB); 5642 // Emit the code 5643 JSDL.visitJumpTable(JTCases[i].second); 5644 JSDAG.setRoot(JSDL.getRoot()); 5645 CodeGenAndEmitDAG(JSDAG); 5646 5647 // Update PHI Nodes 5648 for (unsigned pi = 0, pe = PHINodesToUpdate.size(); pi != pe; ++pi) { 5649 MachineInstr *PHI = PHINodesToUpdate[pi].first; 5650 MachineBasicBlock *PHIBB = PHI->getParent(); 5651 assert(PHI->getOpcode() == TargetInstrInfo::PHI && 5652 "This is not a machine PHI node that we are updating!"); 5653 // "default" BB. We can go there only from header BB. 5654 if (PHIBB == JTCases[i].second.Default) { 5655 PHI->addOperand(MachineOperand::CreateReg(PHINodesToUpdate[pi].second, 5656 false)); 5657 PHI->addOperand(MachineOperand::CreateMBB(JTCases[i].first.HeaderBB)); 5658 } 5659 // JT BB. Just iterate over successors here 5660 if (BB->succ_end() != std::find(BB->succ_begin(),BB->succ_end(), PHIBB)) { 5661 PHI->addOperand(MachineOperand::CreateReg(PHINodesToUpdate[pi].second, 5662 false)); 5663 PHI->addOperand(MachineOperand::CreateMBB(BB)); 5664 } 5665 } 5666 } 5667 5668 // If the switch block involved a branch to one of the actual successors, we 5669 // need to update PHI nodes in that block. 5670 for (unsigned i = 0, e = PHINodesToUpdate.size(); i != e; ++i) { 5671 MachineInstr *PHI = PHINodesToUpdate[i].first; 5672 assert(PHI->getOpcode() == TargetInstrInfo::PHI && 5673 "This is not a machine PHI node that we are updating!"); 5674 if (BB->isSuccessor(PHI->getParent())) { 5675 PHI->addOperand(MachineOperand::CreateReg(PHINodesToUpdate[i].second, 5676 false)); 5677 PHI->addOperand(MachineOperand::CreateMBB(BB)); 5678 } 5679 } 5680 5681 // If we generated any switch lowering information, build and codegen any 5682 // additional DAGs necessary. 5683 for (unsigned i = 0, e = SwitchCases.size(); i != e; ++i) { 5684 SelectionDAG SDAG(TLI, MF, FuncInfo, 5685 getAnalysisToUpdate<MachineModuleInfo>(), 5686 NodeAllocator); 5687 CurDAG = &SDAG; 5688 SelectionDAGLowering SDL(SDAG, TLI, *AA, FuncInfo, GFI); 5689 5690 // Set the current basic block to the mbb we wish to insert the code into 5691 BB = SwitchCases[i].ThisBB; 5692 SDL.setCurrentBasicBlock(BB); 5693 5694 // Emit the code 5695 SDL.visitSwitchCase(SwitchCases[i]); 5696 SDAG.setRoot(SDL.getRoot()); 5697 CodeGenAndEmitDAG(SDAG); 5698 5699 // Handle any PHI nodes in successors of this chunk, as if we were coming 5700 // from the original BB before switch expansion. Note that PHI nodes can 5701 // occur multiple times in PHINodesToUpdate. We have to be very careful to 5702 // handle them the right number of times. 5703 while ((BB = SwitchCases[i].TrueBB)) { // Handle LHS and RHS. 5704 for (MachineBasicBlock::iterator Phi = BB->begin(); 5705 Phi != BB->end() && Phi->getOpcode() == TargetInstrInfo::PHI; ++Phi){ 5706 // This value for this PHI node is recorded in PHINodesToUpdate, get it. 5707 for (unsigned pn = 0; ; ++pn) { 5708 assert(pn != PHINodesToUpdate.size() && "Didn't find PHI entry!"); 5709 if (PHINodesToUpdate[pn].first == Phi) { 5710 Phi->addOperand(MachineOperand::CreateReg(PHINodesToUpdate[pn]. 5711 second, false)); 5712 Phi->addOperand(MachineOperand::CreateMBB(SwitchCases[i].ThisBB)); 5713 break; 5714 } 5715 } 5716 } 5717 5718 // Don't process RHS if same block as LHS. 5719 if (BB == SwitchCases[i].FalseBB) 5720 SwitchCases[i].FalseBB = 0; 5721 5722 // If we haven't handled the RHS, do so now. Otherwise, we're done. 5723 SwitchCases[i].TrueBB = SwitchCases[i].FalseBB; 5724 SwitchCases[i].FalseBB = 0; 5725 } 5726 assert(SwitchCases[i].TrueBB == 0 && SwitchCases[i].FalseBB == 0); 5727 } 5728} 5729 5730 5731/// Schedule - Pick a safe ordering for instructions for each 5732/// target node in the graph. 5733/// 5734ScheduleDAG *SelectionDAGISel::Schedule(SelectionDAG &DAG) { 5735 RegisterScheduler::FunctionPassCtor Ctor = RegisterScheduler::getDefault(); 5736 5737 if (!Ctor) { 5738 Ctor = ISHeuristic; 5739 RegisterScheduler::setDefault(Ctor); 5740 } 5741 5742 ScheduleDAG *Scheduler = Ctor(this, &DAG, BB, Fast); 5743 Scheduler->Run(); 5744 5745 return Scheduler; 5746} 5747 5748 5749HazardRecognizer *SelectionDAGISel::CreateTargetHazardRecognizer() { 5750 return new HazardRecognizer(); 5751} 5752 5753//===----------------------------------------------------------------------===// 5754// Helper functions used by the generated instruction selector. 5755//===----------------------------------------------------------------------===// 5756// Calls to these methods are generated by tblgen. 5757 5758/// CheckAndMask - The isel is trying to match something like (and X, 255). If 5759/// the dag combiner simplified the 255, we still want to match. RHS is the 5760/// actual value in the DAG on the RHS of an AND, and DesiredMaskS is the value 5761/// specified in the .td file (e.g. 255). 5762bool SelectionDAGISel::CheckAndMask(SDValue LHS, ConstantSDNode *RHS, 5763 int64_t DesiredMaskS) const { 5764 const APInt &ActualMask = RHS->getAPIntValue(); 5765 const APInt &DesiredMask = APInt(LHS.getValueSizeInBits(), DesiredMaskS); 5766 5767 // If the actual mask exactly matches, success! 5768 if (ActualMask == DesiredMask) 5769 return true; 5770 5771 // If the actual AND mask is allowing unallowed bits, this doesn't match. 5772 if (ActualMask.intersects(~DesiredMask)) 5773 return false; 5774 5775 // Otherwise, the DAG Combiner may have proven that the value coming in is 5776 // either already zero or is not demanded. Check for known zero input bits. 5777 APInt NeededMask = DesiredMask & ~ActualMask; 5778 if (CurDAG->MaskedValueIsZero(LHS, NeededMask)) 5779 return true; 5780 5781 // TODO: check to see if missing bits are just not demanded. 5782 5783 // Otherwise, this pattern doesn't match. 5784 return false; 5785} 5786 5787/// CheckOrMask - The isel is trying to match something like (or X, 255). If 5788/// the dag combiner simplified the 255, we still want to match. RHS is the 5789/// actual value in the DAG on the RHS of an OR, and DesiredMaskS is the value 5790/// specified in the .td file (e.g. 255). 5791bool SelectionDAGISel::CheckOrMask(SDValue LHS, ConstantSDNode *RHS, 5792 int64_t DesiredMaskS) const { 5793 const APInt &ActualMask = RHS->getAPIntValue(); 5794 const APInt &DesiredMask = APInt(LHS.getValueSizeInBits(), DesiredMaskS); 5795 5796 // If the actual mask exactly matches, success! 5797 if (ActualMask == DesiredMask) 5798 return true; 5799 5800 // If the actual AND mask is allowing unallowed bits, this doesn't match. 5801 if (ActualMask.intersects(~DesiredMask)) 5802 return false; 5803 5804 // Otherwise, the DAG Combiner may have proven that the value coming in is 5805 // either already zero or is not demanded. Check for known zero input bits. 5806 APInt NeededMask = DesiredMask & ~ActualMask; 5807 5808 APInt KnownZero, KnownOne; 5809 CurDAG->ComputeMaskedBits(LHS, NeededMask, KnownZero, KnownOne); 5810 5811 // If all the missing bits in the or are already known to be set, match! 5812 if ((NeededMask & KnownOne) == NeededMask) 5813 return true; 5814 5815 // TODO: check to see if missing bits are just not demanded. 5816 5817 // Otherwise, this pattern doesn't match. 5818 return false; 5819} 5820 5821 5822/// SelectInlineAsmMemoryOperands - Calls to this are automatically generated 5823/// by tblgen. Others should not call it. 5824void SelectionDAGISel:: 5825SelectInlineAsmMemoryOperands(std::vector<SDValue> &Ops, SelectionDAG &DAG) { 5826 std::vector<SDValue> InOps; 5827 std::swap(InOps, Ops); 5828 5829 Ops.push_back(InOps[0]); // input chain. 5830 Ops.push_back(InOps[1]); // input asm string. 5831 5832 unsigned i = 2, e = InOps.size(); 5833 if (InOps[e-1].getValueType() == MVT::Flag) 5834 --e; // Don't process a flag operand if it is here. 5835 5836 while (i != e) { 5837 unsigned Flags = cast<ConstantSDNode>(InOps[i])->getValue(); 5838 if ((Flags & 7) != 4 /*MEM*/) { 5839 // Just skip over this operand, copying the operands verbatim. 5840 Ops.insert(Ops.end(), InOps.begin()+i, InOps.begin()+i+(Flags >> 3) + 1); 5841 i += (Flags >> 3) + 1; 5842 } else { 5843 assert((Flags >> 3) == 1 && "Memory operand with multiple values?"); 5844 // Otherwise, this is a memory operand. Ask the target to select it. 5845 std::vector<SDValue> SelOps; 5846 if (SelectInlineAsmMemoryOperand(InOps[i+1], 'm', SelOps, DAG)) { 5847 cerr << "Could not match memory address. Inline asm failure!\n"; 5848 exit(1); 5849 } 5850 5851 // Add this to the output node. 5852 MVT IntPtrTy = DAG.getTargetLoweringInfo().getPointerTy(); 5853 Ops.push_back(DAG.getTargetConstant(4/*MEM*/ | (SelOps.size() << 3), 5854 IntPtrTy)); 5855 Ops.insert(Ops.end(), SelOps.begin(), SelOps.end()); 5856 i += 2; 5857 } 5858 } 5859 5860 // Add the flag input back if present. 5861 if (e != InOps.size()) 5862 Ops.push_back(InOps.back()); 5863} 5864 5865char SelectionDAGISel::ID = 0; 5866