ScalarEvolution.h revision 753ad615f96c3d56d6f17983bdba88012e88677c
1//===- llvm/Analysis/ScalarEvolution.h - Scalar Evolution -------*- C++ -*-===// 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// The ScalarEvolution class is an LLVM pass which can be used to analyze and 11// catagorize scalar expressions in loops. It specializes in recognizing 12// general induction variables, representing them with the abstract and opaque 13// SCEV class. Given this analysis, trip counts of loops and other important 14// properties can be obtained. 15// 16// This analysis is primarily useful for induction variable substitution and 17// strength reduction. 18// 19//===----------------------------------------------------------------------===// 20 21#ifndef LLVM_ANALYSIS_SCALAREVOLUTION_H 22#define LLVM_ANALYSIS_SCALAREVOLUTION_H 23 24#include "llvm/Pass.h" 25#include "llvm/Analysis/LoopInfo.h" 26#include "llvm/Support/DataTypes.h" 27#include "llvm/Support/ValueHandle.h" 28#include "llvm/ADT/DenseMap.h" 29#include <iosfwd> 30 31namespace llvm { 32 class APInt; 33 class ConstantInt; 34 class Type; 35 class ScalarEvolution; 36 class TargetData; 37 class SCEVConstant; 38 class SCEVTruncateExpr; 39 class SCEVZeroExtendExpr; 40 class SCEVCommutativeExpr; 41 class SCEVUDivExpr; 42 class SCEVSignExtendExpr; 43 class SCEVAddRecExpr; 44 class SCEVUnknown; 45 46 /// SCEV - This class represents an analyzed expression in the program. These 47 /// are reference-counted opaque objects that the client is not allowed to 48 /// do much with directly. 49 /// 50 class SCEV { 51 const unsigned SCEVType; // The SCEV baseclass this node corresponds to 52 53 SCEV(const SCEV &); // DO NOT IMPLEMENT 54 void operator=(const SCEV &); // DO NOT IMPLEMENT 55 protected: 56 virtual ~SCEV(); 57 public: 58 explicit SCEV(unsigned SCEVTy) : 59 SCEVType(SCEVTy) {} 60 61 unsigned getSCEVType() const { return SCEVType; } 62 63 /// isLoopInvariant - Return true if the value of this SCEV is unchanging in 64 /// the specified loop. 65 virtual bool isLoopInvariant(const Loop *L) const = 0; 66 67 /// hasComputableLoopEvolution - Return true if this SCEV changes value in a 68 /// known way in the specified loop. This property being true implies that 69 /// the value is variant in the loop AND that we can emit an expression to 70 /// compute the value of the expression at any particular loop iteration. 71 virtual bool hasComputableLoopEvolution(const Loop *L) const = 0; 72 73 /// getType - Return the LLVM type of this SCEV expression. 74 /// 75 virtual const Type *getType() const = 0; 76 77 /// isZero - Return true if the expression is a constant zero. 78 /// 79 bool isZero() const; 80 81 /// isOne - Return true if the expression is a constant one. 82 /// 83 bool isOne() const; 84 85 /// replaceSymbolicValuesWithConcrete - If this SCEV internally references 86 /// the symbolic value "Sym", construct and return a new SCEV that produces 87 /// the same value, but which uses the concrete value Conc instead of the 88 /// symbolic value. If this SCEV does not use the symbolic value, it 89 /// returns itself. 90 virtual const SCEV* 91 replaceSymbolicValuesWithConcrete(const SCEV* Sym, 92 const SCEV* Conc, 93 ScalarEvolution &SE) const = 0; 94 95 /// dominates - Return true if elements that makes up this SCEV dominates 96 /// the specified basic block. 97 virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const = 0; 98 99 /// print - Print out the internal representation of this scalar to the 100 /// specified stream. This should really only be used for debugging 101 /// purposes. 102 virtual void print(raw_ostream &OS) const = 0; 103 void print(std::ostream &OS) const; 104 void print(std::ostream *OS) const { if (OS) print(*OS); } 105 106 /// dump - This method is used for debugging. 107 /// 108 void dump() const; 109 }; 110 111 inline raw_ostream &operator<<(raw_ostream &OS, const SCEV &S) { 112 S.print(OS); 113 return OS; 114 } 115 116 inline std::ostream &operator<<(std::ostream &OS, const SCEV &S) { 117 S.print(OS); 118 return OS; 119 } 120 121 /// SCEVCouldNotCompute - An object of this class is returned by queries that 122 /// could not be answered. For example, if you ask for the number of 123 /// iterations of a linked-list traversal loop, you will get one of these. 124 /// None of the standard SCEV operations are valid on this class, it is just a 125 /// marker. 126 struct SCEVCouldNotCompute : public SCEV { 127 SCEVCouldNotCompute(); 128 129 // None of these methods are valid for this object. 130 virtual bool isLoopInvariant(const Loop *L) const; 131 virtual const Type *getType() const; 132 virtual bool hasComputableLoopEvolution(const Loop *L) const; 133 virtual void print(raw_ostream &OS) const; 134 virtual const SCEV* 135 replaceSymbolicValuesWithConcrete(const SCEV* Sym, 136 const SCEV* Conc, 137 ScalarEvolution &SE) const; 138 139 virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const { 140 return true; 141 } 142 143 /// Methods for support type inquiry through isa, cast, and dyn_cast: 144 static inline bool classof(const SCEVCouldNotCompute *S) { return true; } 145 static bool classof(const SCEV *S); 146 }; 147 148 /// ScalarEvolution - This class is the main scalar evolution driver. Because 149 /// client code (intentionally) can't do much with the SCEV objects directly, 150 /// they must ask this class for services. 151 /// 152 class ScalarEvolution : public FunctionPass { 153 /// SCEVCallbackVH - A CallbackVH to arrange for ScalarEvolution to be 154 /// notified whenever a Value is deleted. 155 class SCEVCallbackVH : public CallbackVH { 156 ScalarEvolution *SE; 157 virtual void deleted(); 158 virtual void allUsesReplacedWith(Value *New); 159 public: 160 SCEVCallbackVH(Value *V, ScalarEvolution *SE = 0); 161 }; 162 163 friend class SCEVCallbackVH; 164 friend class SCEVExpander; 165 166 /// F - The function we are analyzing. 167 /// 168 Function *F; 169 170 /// LI - The loop information for the function we are currently analyzing. 171 /// 172 LoopInfo *LI; 173 174 /// TD - The target data information for the target we are targetting. 175 /// 176 TargetData *TD; 177 178 /// CouldNotCompute - This SCEV is used to represent unknown trip 179 /// counts and things. 180 const SCEV* CouldNotCompute; 181 182 /// Scalars - This is a cache of the scalars we have analyzed so far. 183 /// 184 std::map<SCEVCallbackVH, const SCEV*> Scalars; 185 186 /// BackedgeTakenInfo - Information about the backedge-taken count 187 /// of a loop. This currently inclues an exact count and a maximum count. 188 /// 189 struct BackedgeTakenInfo { 190 /// Exact - An expression indicating the exact backedge-taken count of 191 /// the loop if it is known, or a SCEVCouldNotCompute otherwise. 192 const SCEV* Exact; 193 194 /// Exact - An expression indicating the least maximum backedge-taken 195 /// count of the loop that is known, or a SCEVCouldNotCompute. 196 const SCEV* Max; 197 198 /*implicit*/ BackedgeTakenInfo(const SCEV* exact) : 199 Exact(exact), Max(exact) {} 200 201 BackedgeTakenInfo(const SCEV* exact, const SCEV* max) : 202 Exact(exact), Max(max) {} 203 204 /// hasAnyInfo - Test whether this BackedgeTakenInfo contains any 205 /// computed information, or whether it's all SCEVCouldNotCompute 206 /// values. 207 bool hasAnyInfo() const { 208 return !isa<SCEVCouldNotCompute>(Exact) || 209 !isa<SCEVCouldNotCompute>(Max); 210 } 211 }; 212 213 /// BackedgeTakenCounts - Cache the backedge-taken count of the loops for 214 /// this function as they are computed. 215 std::map<const Loop*, BackedgeTakenInfo> BackedgeTakenCounts; 216 217 /// ConstantEvolutionLoopExitValue - This map contains entries for all of 218 /// the PHI instructions that we attempt to compute constant evolutions for. 219 /// This allows us to avoid potentially expensive recomputation of these 220 /// properties. An instruction maps to null if we are unable to compute its 221 /// exit value. 222 std::map<PHINode*, Constant*> ConstantEvolutionLoopExitValue; 223 224 /// ValuesAtScopes - This map contains entries for all the instructions 225 /// that we attempt to compute getSCEVAtScope information for without 226 /// using SCEV techniques, which can be expensive. 227 std::map<Instruction *, std::map<const Loop *, Constant *> > ValuesAtScopes; 228 229 /// createSCEV - We know that there is no SCEV for the specified value. 230 /// Analyze the expression. 231 const SCEV* createSCEV(Value *V); 232 233 /// createNodeForPHI - Provide the special handling we need to analyze PHI 234 /// SCEVs. 235 const SCEV* createNodeForPHI(PHINode *PN); 236 237 /// createNodeForGEP - Provide the special handling we need to analyze GEP 238 /// SCEVs. 239 const SCEV* createNodeForGEP(User *GEP); 240 241 /// ReplaceSymbolicValueWithConcrete - This looks up the computed SCEV value 242 /// for the specified instruction and replaces any references to the 243 /// symbolic value SymName with the specified value. This is used during 244 /// PHI resolution. 245 void ReplaceSymbolicValueWithConcrete(Instruction *I, 246 const SCEV* SymName, 247 const SCEV* NewVal); 248 249 /// getBECount - Subtract the end and start values and divide by the step, 250 /// rounding up, to get the number of times the backedge is executed. Return 251 /// CouldNotCompute if an intermediate computation overflows. 252 const SCEV* getBECount(const SCEV* Start, 253 const SCEV* End, 254 const SCEV* Step); 255 256 /// getBackedgeTakenInfo - Return the BackedgeTakenInfo for the given 257 /// loop, lazily computing new values if the loop hasn't been analyzed 258 /// yet. 259 const BackedgeTakenInfo &getBackedgeTakenInfo(const Loop *L); 260 261 /// ComputeBackedgeTakenCount - Compute the number of times the specified 262 /// loop will iterate. 263 BackedgeTakenInfo ComputeBackedgeTakenCount(const Loop *L); 264 265 /// ComputeBackedgeTakenCountFromExit - Compute the number of times the 266 /// backedge of the specified loop will execute if it exits via the 267 /// specified block. 268 BackedgeTakenInfo ComputeBackedgeTakenCountFromExit(const Loop *L, 269 BasicBlock *ExitingBlock); 270 271 /// ComputeBackedgeTakenCountFromExitCond - Compute the number of times the 272 /// backedge of the specified loop will execute if its exit condition 273 /// were a conditional branch of ExitCond, TBB, and FBB. 274 BackedgeTakenInfo 275 ComputeBackedgeTakenCountFromExitCond(const Loop *L, 276 Value *ExitCond, 277 BasicBlock *TBB, 278 BasicBlock *FBB); 279 280 /// ComputeBackedgeTakenCountFromExitCondICmp - Compute the number of 281 /// times the backedge of the specified loop will execute if its exit 282 /// condition were a conditional branch of the ICmpInst ExitCond, TBB, 283 /// and FBB. 284 BackedgeTakenInfo 285 ComputeBackedgeTakenCountFromExitCondICmp(const Loop *L, 286 ICmpInst *ExitCond, 287 BasicBlock *TBB, 288 BasicBlock *FBB); 289 290 /// ComputeLoadConstantCompareBackedgeTakenCount - Given an exit condition 291 /// of 'icmp op load X, cst', try to see if we can compute the trip count. 292 const SCEV* 293 ComputeLoadConstantCompareBackedgeTakenCount(LoadInst *LI, 294 Constant *RHS, 295 const Loop *L, 296 ICmpInst::Predicate p); 297 298 /// ComputeBackedgeTakenCountExhaustively - If the trip is known to execute 299 /// a constant number of times (the condition evolves only from constants), 300 /// try to evaluate a few iterations of the loop until we get the exit 301 /// condition gets a value of ExitWhen (true or false). If we cannot 302 /// evaluate the trip count of the loop, return CouldNotCompute. 303 const SCEV* ComputeBackedgeTakenCountExhaustively(const Loop *L, Value *Cond, 304 bool ExitWhen); 305 306 /// HowFarToZero - Return the number of times a backedge comparing the 307 /// specified value to zero will execute. If not computable, return 308 /// CouldNotCompute. 309 const SCEV* HowFarToZero(const SCEV *V, const Loop *L); 310 311 /// HowFarToNonZero - Return the number of times a backedge checking the 312 /// specified value for nonzero will execute. If not computable, return 313 /// CouldNotCompute. 314 const SCEV* HowFarToNonZero(const SCEV *V, const Loop *L); 315 316 /// HowManyLessThans - Return the number of times a backedge containing the 317 /// specified less-than comparison will execute. If not computable, return 318 /// CouldNotCompute. isSigned specifies whether the less-than is signed. 319 BackedgeTakenInfo HowManyLessThans(const SCEV *LHS, const SCEV *RHS, 320 const Loop *L, bool isSigned); 321 322 /// getLoopPredecessor - If the given loop's header has exactly one unique 323 /// predecessor outside the loop, return it. Otherwise return null. 324 BasicBlock *getLoopPredecessor(const Loop *L); 325 326 /// getPredecessorWithUniqueSuccessorForBB - Return a predecessor of BB 327 /// (which may not be an immediate predecessor) which has exactly one 328 /// successor from which BB is reachable, or null if no such block is 329 /// found. 330 BasicBlock* getPredecessorWithUniqueSuccessorForBB(BasicBlock *BB); 331 332 /// getConstantEvolutionLoopExitValue - If we know that the specified Phi is 333 /// in the header of its containing loop, we know the loop executes a 334 /// constant number of times, and the PHI node is just a recurrence 335 /// involving constants, fold it. 336 Constant *getConstantEvolutionLoopExitValue(PHINode *PN, const APInt& BEs, 337 const Loop *L); 338 339 /// forgetLoopPHIs - Delete the memoized SCEVs associated with the 340 /// PHI nodes in the given loop. This is used when the trip count of 341 /// the loop may have changed. 342 void forgetLoopPHIs(const Loop *L); 343 344 public: 345 static char ID; // Pass identification, replacement for typeid 346 ScalarEvolution(); 347 348 /// isSCEVable - Test if values of the given type are analyzable within 349 /// the SCEV framework. This primarily includes integer types, and it 350 /// can optionally include pointer types if the ScalarEvolution class 351 /// has access to target-specific information. 352 bool isSCEVable(const Type *Ty) const; 353 354 /// getTypeSizeInBits - Return the size in bits of the specified type, 355 /// for which isSCEVable must return true. 356 uint64_t getTypeSizeInBits(const Type *Ty) const; 357 358 /// getEffectiveSCEVType - Return a type with the same bitwidth as 359 /// the given type and which represents how SCEV will treat the given 360 /// type, for which isSCEVable must return true. For pointer types, 361 /// this is the pointer-sized integer type. 362 const Type *getEffectiveSCEVType(const Type *Ty) const; 363 364 /// getSCEV - Return a SCEV expression handle for the full generality of the 365 /// specified expression. 366 const SCEV* getSCEV(Value *V); 367 368 const SCEV* getConstant(ConstantInt *V); 369 const SCEV* getConstant(const APInt& Val); 370 const SCEV* getConstant(const Type *Ty, uint64_t V, bool isSigned = false); 371 const SCEV* getTruncateExpr(const SCEV* Op, const Type *Ty); 372 const SCEV* getZeroExtendExpr(const SCEV* Op, const Type *Ty); 373 const SCEV* getSignExtendExpr(const SCEV* Op, const Type *Ty); 374 const SCEV* getAnyExtendExpr(const SCEV* Op, const Type *Ty); 375 const SCEV* getAddExpr(SmallVectorImpl<const SCEV*> &Ops); 376 const SCEV* getAddExpr(const SCEV* LHS, const SCEV* RHS) { 377 SmallVector<const SCEV*, 2> Ops; 378 Ops.push_back(LHS); 379 Ops.push_back(RHS); 380 return getAddExpr(Ops); 381 } 382 const SCEV* getAddExpr(const SCEV* Op0, const SCEV* Op1, 383 const SCEV* Op2) { 384 SmallVector<const SCEV*, 3> Ops; 385 Ops.push_back(Op0); 386 Ops.push_back(Op1); 387 Ops.push_back(Op2); 388 return getAddExpr(Ops); 389 } 390 const SCEV* getMulExpr(SmallVectorImpl<const SCEV*> &Ops); 391 const SCEV* getMulExpr(const SCEV* LHS, const SCEV* RHS) { 392 SmallVector<const SCEV*, 2> Ops; 393 Ops.push_back(LHS); 394 Ops.push_back(RHS); 395 return getMulExpr(Ops); 396 } 397 const SCEV* getUDivExpr(const SCEV* LHS, const SCEV* RHS); 398 const SCEV* getAddRecExpr(const SCEV* Start, const SCEV* Step, 399 const Loop *L); 400 const SCEV* getAddRecExpr(SmallVectorImpl<const SCEV*> &Operands, 401 const Loop *L); 402 const SCEV* getAddRecExpr(const SmallVectorImpl<const SCEV*> &Operands, 403 const Loop *L) { 404 SmallVector<const SCEV*, 4> NewOp(Operands.begin(), Operands.end()); 405 return getAddRecExpr(NewOp, L); 406 } 407 const SCEV* getSMaxExpr(const SCEV* LHS, const SCEV* RHS); 408 const SCEV* getSMaxExpr(SmallVectorImpl<const SCEV*> &Operands); 409 const SCEV* getUMaxExpr(const SCEV* LHS, const SCEV* RHS); 410 const SCEV* getUMaxExpr(SmallVectorImpl<const SCEV*> &Operands); 411 const SCEV* getSMinExpr(const SCEV* LHS, const SCEV* RHS); 412 const SCEV* getUMinExpr(const SCEV* LHS, const SCEV* RHS); 413 const SCEV* getUnknown(Value *V); 414 const SCEV* getCouldNotCompute(); 415 416 /// getNegativeSCEV - Return the SCEV object corresponding to -V. 417 /// 418 const SCEV* getNegativeSCEV(const SCEV* V); 419 420 /// getNotSCEV - Return the SCEV object corresponding to ~V. 421 /// 422 const SCEV* getNotSCEV(const SCEV* V); 423 424 /// getMinusSCEV - Return LHS-RHS. 425 /// 426 const SCEV* getMinusSCEV(const SCEV* LHS, 427 const SCEV* RHS); 428 429 /// getTruncateOrZeroExtend - Return a SCEV corresponding to a conversion 430 /// of the input value to the specified type. If the type must be 431 /// extended, it is zero extended. 432 const SCEV* getTruncateOrZeroExtend(const SCEV* V, const Type *Ty); 433 434 /// getTruncateOrSignExtend - Return a SCEV corresponding to a conversion 435 /// of the input value to the specified type. If the type must be 436 /// extended, it is sign extended. 437 const SCEV* getTruncateOrSignExtend(const SCEV* V, const Type *Ty); 438 439 /// getNoopOrZeroExtend - Return a SCEV corresponding to a conversion of 440 /// the input value to the specified type. If the type must be extended, 441 /// it is zero extended. The conversion must not be narrowing. 442 const SCEV* getNoopOrZeroExtend(const SCEV* V, const Type *Ty); 443 444 /// getNoopOrSignExtend - Return a SCEV corresponding to a conversion of 445 /// the input value to the specified type. If the type must be extended, 446 /// it is sign extended. The conversion must not be narrowing. 447 const SCEV* getNoopOrSignExtend(const SCEV* V, const Type *Ty); 448 449 /// getNoopOrAnyExtend - Return a SCEV corresponding to a conversion of 450 /// the input value to the specified type. If the type must be extended, 451 /// it is extended with unspecified bits. The conversion must not be 452 /// narrowing. 453 const SCEV* getNoopOrAnyExtend(const SCEV* V, const Type *Ty); 454 455 /// getTruncateOrNoop - Return a SCEV corresponding to a conversion of the 456 /// input value to the specified type. The conversion must not be 457 /// widening. 458 const SCEV* getTruncateOrNoop(const SCEV* V, const Type *Ty); 459 460 /// getIntegerSCEV - Given an integer or FP type, create a constant for the 461 /// specified signed integer value and return a SCEV for the constant. 462 const SCEV* getIntegerSCEV(int Val, const Type *Ty); 463 464 /// getUMaxFromMismatchedTypes - Promote the operands to the wider of 465 /// the types using zero-extension, and then perform a umax operation 466 /// with them. 467 const SCEV* getUMaxFromMismatchedTypes(const SCEV* LHS, 468 const SCEV* RHS); 469 470 /// getUMinFromMismatchedTypes - Promote the operands to the wider of 471 /// the types using zero-extension, and then perform a umin operation 472 /// with them. 473 const SCEV* getUMinFromMismatchedTypes(const SCEV* LHS, 474 const SCEV* RHS); 475 476 /// hasSCEV - Return true if the SCEV for this value has already been 477 /// computed. 478 bool hasSCEV(Value *V) const; 479 480 /// setSCEV - Insert the specified SCEV into the map of current SCEVs for 481 /// the specified value. 482 void setSCEV(Value *V, const SCEV* H); 483 484 /// getSCEVAtScope - Return a SCEV expression handle for the specified value 485 /// at the specified scope in the program. The L value specifies a loop 486 /// nest to evaluate the expression at, where null is the top-level or a 487 /// specified loop is immediately inside of the loop. 488 /// 489 /// This method can be used to compute the exit value for a variable defined 490 /// in a loop by querying what the value will hold in the parent loop. 491 /// 492 /// In the case that a relevant loop exit value cannot be computed, the 493 /// original value V is returned. 494 const SCEV* getSCEVAtScope(const SCEV *S, const Loop *L); 495 496 /// getSCEVAtScope - This is a convenience function which does 497 /// getSCEVAtScope(getSCEV(V), L). 498 const SCEV* getSCEVAtScope(Value *V, const Loop *L); 499 500 /// isLoopGuardedByCond - Test whether entry to the loop is protected by 501 /// a conditional between LHS and RHS. This is used to help avoid max 502 /// expressions in loop trip counts. 503 bool isLoopGuardedByCond(const Loop *L, ICmpInst::Predicate Pred, 504 const SCEV *LHS, const SCEV *RHS); 505 506 /// getBackedgeTakenCount - If the specified loop has a predictable 507 /// backedge-taken count, return it, otherwise return a SCEVCouldNotCompute 508 /// object. The backedge-taken count is the number of times the loop header 509 /// will be branched to from within the loop. This is one less than the 510 /// trip count of the loop, since it doesn't count the first iteration, 511 /// when the header is branched to from outside the loop. 512 /// 513 /// Note that it is not valid to call this method on a loop without a 514 /// loop-invariant backedge-taken count (see 515 /// hasLoopInvariantBackedgeTakenCount). 516 /// 517 const SCEV* getBackedgeTakenCount(const Loop *L); 518 519 /// getMaxBackedgeTakenCount - Similar to getBackedgeTakenCount, except 520 /// return the least SCEV value that is known never to be less than the 521 /// actual backedge taken count. 522 const SCEV* getMaxBackedgeTakenCount(const Loop *L); 523 524 /// hasLoopInvariantBackedgeTakenCount - Return true if the specified loop 525 /// has an analyzable loop-invariant backedge-taken count. 526 bool hasLoopInvariantBackedgeTakenCount(const Loop *L); 527 528 /// forgetLoopBackedgeTakenCount - This method should be called by the 529 /// client when it has changed a loop in a way that may effect 530 /// ScalarEvolution's ability to compute a trip count, or if the loop 531 /// is deleted. 532 void forgetLoopBackedgeTakenCount(const Loop *L); 533 534 /// GetMinTrailingZeros - Determine the minimum number of zero bits that S is 535 /// guaranteed to end in (at every loop iteration). It is, at the same time, 536 /// the minimum number of times S is divisible by 2. For example, given {4,+,8} 537 /// it returns 2. If S is guaranteed to be 0, it returns the bitwidth of S. 538 uint32_t GetMinTrailingZeros(const SCEV* S); 539 540 /// GetMinLeadingZeros - Determine the minimum number of zero bits that S is 541 /// guaranteed to begin with (at every loop iteration). 542 uint32_t GetMinLeadingZeros(const SCEV* S); 543 544 /// GetMinSignBits - Determine the minimum number of sign bits that S is 545 /// guaranteed to begin with. 546 uint32_t GetMinSignBits(const SCEV* S); 547 548 virtual bool runOnFunction(Function &F); 549 virtual void releaseMemory(); 550 virtual void getAnalysisUsage(AnalysisUsage &AU) const; 551 void print(raw_ostream &OS, const Module* = 0) const; 552 virtual void print(std::ostream &OS, const Module* = 0) const; 553 void print(std::ostream *OS, const Module* M = 0) const { 554 if (OS) print(*OS, M); 555 } 556 557 private: 558 // Uniquing tables. 559 std::map<ConstantInt*, SCEVConstant*> SCEVConstants; 560 std::map<std::pair<const SCEV*, const Type*>, 561 SCEVTruncateExpr*> SCEVTruncates; 562 std::map<std::pair<const SCEV*, const Type*>, 563 SCEVZeroExtendExpr*> SCEVZeroExtends; 564 std::map<std::pair<unsigned, std::vector<const SCEV*> >, 565 SCEVCommutativeExpr*> SCEVCommExprs; 566 std::map<std::pair<const SCEV*, const SCEV*>, 567 SCEVUDivExpr*> SCEVUDivs; 568 std::map<std::pair<const SCEV*, const Type*>, 569 SCEVSignExtendExpr*> SCEVSignExtends; 570 std::map<std::pair<const Loop *, std::vector<const SCEV*> >, 571 SCEVAddRecExpr*> SCEVAddRecExprs; 572 std::map<Value*, SCEVUnknown*> SCEVUnknowns; 573 }; 574} 575 576#endif 577