1 //===- llvm/Analysis/ScalarEvolutionExpressions.h - SCEV Exprs --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the classes used to represent and build scalar expressions.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_ANALYSIS_SCALAREVOLUTION_EXPRESSIONS_H
15 #define LLVM_ANALYSIS_SCALAREVOLUTION_EXPRESSIONS_H
17 #include "llvm/Analysis/ScalarEvolution.h"
25 // These should be ordered in terms of increasing complexity to make the
27 scConstant, scTruncate, scZeroExtend, scSignExtend, scAddExpr, scMulExpr,
28 scSDivExpr, scAddRecExpr, scUnknown, scCouldNotCompute
31 //===--------------------------------------------------------------------===//
32 /// SCEVConstant - This class represents a constant integer value.
34 class SCEVConstant : public SCEV {
35 friend class ScalarEvolution;
38 explicit SCEVConstant(ConstantInt *v) : SCEV(scConstant), V(v) {}
40 virtual ~SCEVConstant();
42 ConstantInt *getValue() const { return V; }
44 /// getValueRange - Return the tightest constant bounds that this value is
45 /// known to have. This method is only valid on integer SCEV objects.
46 virtual ConstantRange getValueRange() const;
48 virtual bool isLoopInvariant(const Loop *L) const {
52 virtual bool hasComputableLoopEvolution(const Loop *L) const {
53 return false; // Not loop variant
56 virtual const Type *getType() const;
58 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
59 const SCEVHandle &Conc,
60 ScalarEvolution &SE) const {
64 virtual void print(std::ostream &OS) const;
65 void print(std::ostream *OS) const { if (OS) print(*OS); }
67 /// Methods for support type inquiry through isa, cast, and dyn_cast:
68 static inline bool classof(const SCEVConstant *S) { return true; }
69 static inline bool classof(const SCEV *S) {
70 return S->getSCEVType() == scConstant;
74 //===--------------------------------------------------------------------===//
75 /// SCEVTruncateExpr - This class represents a truncation of an integer value
76 /// to a smaller integer value.
78 class SCEVTruncateExpr : public SCEV {
79 friend class ScalarEvolution;
83 SCEVTruncateExpr(const SCEVHandle &op, const Type *ty);
84 virtual ~SCEVTruncateExpr();
86 const SCEVHandle &getOperand() const { return Op; }
87 virtual const Type *getType() const { return Ty; }
89 virtual bool isLoopInvariant(const Loop *L) const {
90 return Op->isLoopInvariant(L);
93 virtual bool hasComputableLoopEvolution(const Loop *L) const {
94 return Op->hasComputableLoopEvolution(L);
97 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
98 const SCEVHandle &Conc,
99 ScalarEvolution &SE) const {
100 SCEVHandle H = Op->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
103 return SE.getTruncateExpr(H, Ty);
106 /// getValueRange - Return the tightest constant bounds that this value is
107 /// known to have. This method is only valid on integer SCEV objects.
108 virtual ConstantRange getValueRange() const;
110 virtual void print(std::ostream &OS) const;
111 void print(std::ostream *OS) const { if (OS) print(*OS); }
113 /// Methods for support type inquiry through isa, cast, and dyn_cast:
114 static inline bool classof(const SCEVTruncateExpr *S) { return true; }
115 static inline bool classof(const SCEV *S) {
116 return S->getSCEVType() == scTruncate;
120 //===--------------------------------------------------------------------===//
121 /// SCEVZeroExtendExpr - This class represents a zero extension of a small
122 /// integer value to a larger integer value.
124 class SCEVZeroExtendExpr : public SCEV {
125 friend class ScalarEvolution;
129 SCEVZeroExtendExpr(const SCEVHandle &op, const Type *ty);
130 virtual ~SCEVZeroExtendExpr();
132 const SCEVHandle &getOperand() const { return Op; }
133 virtual const Type *getType() const { return Ty; }
135 virtual bool isLoopInvariant(const Loop *L) const {
136 return Op->isLoopInvariant(L);
139 virtual bool hasComputableLoopEvolution(const Loop *L) const {
140 return Op->hasComputableLoopEvolution(L);
143 /// getValueRange - Return the tightest constant bounds that this value is
144 /// known to have. This method is only valid on integer SCEV objects.
145 virtual ConstantRange getValueRange() const;
147 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
148 const SCEVHandle &Conc,
149 ScalarEvolution &SE) const {
150 SCEVHandle H = Op->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
153 return SE.getZeroExtendExpr(H, Ty);
156 virtual void print(std::ostream &OS) const;
157 void print(std::ostream *OS) const { if (OS) print(*OS); }
159 /// Methods for support type inquiry through isa, cast, and dyn_cast:
160 static inline bool classof(const SCEVZeroExtendExpr *S) { return true; }
161 static inline bool classof(const SCEV *S) {
162 return S->getSCEVType() == scZeroExtend;
166 //===--------------------------------------------------------------------===//
167 /// SCEVSignExtendExpr - This class represents a sign extension of a small
168 /// integer value to a larger integer value.
170 class SCEVSignExtendExpr : public SCEV {
171 friend class ScalarEvolution;
175 SCEVSignExtendExpr(const SCEVHandle &op, const Type *ty);
176 virtual ~SCEVSignExtendExpr();
178 const SCEVHandle &getOperand() const { return Op; }
179 virtual const Type *getType() const { return Ty; }
181 virtual bool isLoopInvariant(const Loop *L) const {
182 return Op->isLoopInvariant(L);
185 virtual bool hasComputableLoopEvolution(const Loop *L) const {
186 return Op->hasComputableLoopEvolution(L);
189 /// getValueRange - Return the tightest constant bounds that this value is
190 /// known to have. This method is only valid on integer SCEV objects.
191 virtual ConstantRange getValueRange() const;
193 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
194 const SCEVHandle &Conc,
195 ScalarEvolution &SE) const {
196 SCEVHandle H = Op->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
199 return SE.getSignExtendExpr(H, Ty);
202 virtual void print(std::ostream &OS) const;
203 void print(std::ostream *OS) const { if (OS) print(*OS); }
205 /// Methods for support type inquiry through isa, cast, and dyn_cast:
206 static inline bool classof(const SCEVSignExtendExpr *S) { return true; }
207 static inline bool classof(const SCEV *S) {
208 return S->getSCEVType() == scSignExtend;
213 //===--------------------------------------------------------------------===//
214 /// SCEVCommutativeExpr - This node is the base class for n'ary commutative
217 class SCEVCommutativeExpr : public SCEV {
218 friend class ScalarEvolution;
220 std::vector<SCEVHandle> Operands;
223 SCEVCommutativeExpr(enum SCEVTypes T, const std::vector<SCEVHandle> &ops)
225 Operands.reserve(ops.size());
226 Operands.insert(Operands.end(), ops.begin(), ops.end());
228 ~SCEVCommutativeExpr();
231 unsigned getNumOperands() const { return Operands.size(); }
232 const SCEVHandle &getOperand(unsigned i) const {
233 assert(i < Operands.size() && "Operand index out of range!");
237 const std::vector<SCEVHandle> &getOperands() const { return Operands; }
238 typedef std::vector<SCEVHandle>::const_iterator op_iterator;
239 op_iterator op_begin() const { return Operands.begin(); }
240 op_iterator op_end() const { return Operands.end(); }
243 virtual bool isLoopInvariant(const Loop *L) const {
244 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
245 if (!getOperand(i)->isLoopInvariant(L)) return false;
249 // hasComputableLoopEvolution - Commutative expressions have computable loop
250 // evolutions iff they have at least one operand that varies with the loop,
251 // but that all varying operands are computable.
252 virtual bool hasComputableLoopEvolution(const Loop *L) const {
253 bool HasVarying = false;
254 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
255 if (!getOperand(i)->isLoopInvariant(L))
256 if (getOperand(i)->hasComputableLoopEvolution(L))
263 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
264 const SCEVHandle &Conc,
265 ScalarEvolution &SE) const;
267 virtual const char *getOperationStr() const = 0;
269 virtual const Type *getType() const { return getOperand(0)->getType(); }
270 virtual void print(std::ostream &OS) const;
271 void print(std::ostream *OS) const { if (OS) print(*OS); }
273 /// Methods for support type inquiry through isa, cast, and dyn_cast:
274 static inline bool classof(const SCEVCommutativeExpr *S) { return true; }
275 static inline bool classof(const SCEV *S) {
276 return S->getSCEVType() == scAddExpr ||
277 S->getSCEVType() == scMulExpr;
282 //===--------------------------------------------------------------------===//
283 /// SCEVAddExpr - This node represents an addition of some number of SCEVs.
285 class SCEVAddExpr : public SCEVCommutativeExpr {
286 friend class ScalarEvolution;
288 explicit SCEVAddExpr(const std::vector<SCEVHandle> &ops)
289 : SCEVCommutativeExpr(scAddExpr, ops) {
293 virtual const char *getOperationStr() const { return " + "; }
295 /// Methods for support type inquiry through isa, cast, and dyn_cast:
296 static inline bool classof(const SCEVAddExpr *S) { return true; }
297 static inline bool classof(const SCEV *S) {
298 return S->getSCEVType() == scAddExpr;
302 //===--------------------------------------------------------------------===//
303 /// SCEVMulExpr - This node represents multiplication of some number of SCEVs.
305 class SCEVMulExpr : public SCEVCommutativeExpr {
306 friend class ScalarEvolution;
308 explicit SCEVMulExpr(const std::vector<SCEVHandle> &ops)
309 : SCEVCommutativeExpr(scMulExpr, ops) {
313 virtual const char *getOperationStr() const { return " * "; }
315 /// Methods for support type inquiry through isa, cast, and dyn_cast:
316 static inline bool classof(const SCEVMulExpr *S) { return true; }
317 static inline bool classof(const SCEV *S) {
318 return S->getSCEVType() == scMulExpr;
323 //===--------------------------------------------------------------------===//
324 /// SCEVSDivExpr - This class represents a binary signed division operation.
326 class SCEVSDivExpr : public SCEV {
327 friend class ScalarEvolution;
330 SCEVSDivExpr(const SCEVHandle &lhs, const SCEVHandle &rhs)
331 : SCEV(scSDivExpr), LHS(lhs), RHS(rhs) {}
333 virtual ~SCEVSDivExpr();
335 const SCEVHandle &getLHS() const { return LHS; }
336 const SCEVHandle &getRHS() const { return RHS; }
338 virtual bool isLoopInvariant(const Loop *L) const {
339 return LHS->isLoopInvariant(L) && RHS->isLoopInvariant(L);
342 virtual bool hasComputableLoopEvolution(const Loop *L) const {
343 return LHS->hasComputableLoopEvolution(L) &&
344 RHS->hasComputableLoopEvolution(L);
347 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
348 const SCEVHandle &Conc,
349 ScalarEvolution &SE) const {
350 SCEVHandle L = LHS->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
351 SCEVHandle R = RHS->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
352 if (L == LHS && R == RHS)
355 return SE.getSDivExpr(L, R);
359 virtual const Type *getType() const;
361 void print(std::ostream &OS) const;
362 void print(std::ostream *OS) const { if (OS) print(*OS); }
364 /// Methods for support type inquiry through isa, cast, and dyn_cast:
365 static inline bool classof(const SCEVSDivExpr *S) { return true; }
366 static inline bool classof(const SCEV *S) {
367 return S->getSCEVType() == scSDivExpr;
372 //===--------------------------------------------------------------------===//
373 /// SCEVAddRecExpr - This node represents a polynomial recurrence on the trip
374 /// count of the specified loop.
376 /// All operands of an AddRec are required to be loop invariant.
378 class SCEVAddRecExpr : public SCEV {
379 friend class ScalarEvolution;
381 std::vector<SCEVHandle> Operands;
384 SCEVAddRecExpr(const std::vector<SCEVHandle> &ops, const Loop *l)
385 : SCEV(scAddRecExpr), Operands(ops), L(l) {
386 for (unsigned i = 0, e = Operands.size(); i != e; ++i)
387 assert(Operands[i]->isLoopInvariant(l) &&
388 "Operands of AddRec must be loop-invariant!");
392 typedef std::vector<SCEVHandle>::const_iterator op_iterator;
393 op_iterator op_begin() const { return Operands.begin(); }
394 op_iterator op_end() const { return Operands.end(); }
396 unsigned getNumOperands() const { return Operands.size(); }
397 const SCEVHandle &getOperand(unsigned i) const { return Operands[i]; }
398 const SCEVHandle &getStart() const { return Operands[0]; }
399 const Loop *getLoop() const { return L; }
402 /// getStepRecurrence - This method constructs and returns the recurrence
403 /// indicating how much this expression steps by. If this is a polynomial
404 /// of degree N, it returns a chrec of degree N-1.
405 SCEVHandle getStepRecurrence(ScalarEvolution &SE) const {
406 if (getNumOperands() == 2) return getOperand(1);
407 return SE.getAddRecExpr(std::vector<SCEVHandle>(op_begin()+1,op_end()),
411 virtual bool hasComputableLoopEvolution(const Loop *QL) const {
412 if (L == QL) return true;
416 virtual bool isLoopInvariant(const Loop *QueryLoop) const;
418 virtual const Type *getType() const { return Operands[0]->getType(); }
420 /// isAffine - Return true if this is an affine AddRec (i.e., it represents
421 /// an expressions A+B*x where A and B are loop invariant values.
422 bool isAffine() const {
423 // We know that the start value is invariant. This expression is thus
424 // affine iff the step is also invariant.
425 return getNumOperands() == 2;
428 /// isQuadratic - Return true if this is an quadratic AddRec (i.e., it
429 /// represents an expressions A+B*x+C*x^2 where A, B and C are loop
430 /// invariant values. This corresponds to an addrec of the form {L,+,M,+,N}
431 bool isQuadratic() const {
432 return getNumOperands() == 3;
435 /// evaluateAtIteration - Return the value of this chain of recurrences at
436 /// the specified iteration number.
437 SCEVHandle evaluateAtIteration(SCEVHandle It, ScalarEvolution &SE) const;
439 /// getNumIterationsInRange - Return the number of iterations of this loop
440 /// that produce values in the specified constant range. Another way of
441 /// looking at this is that it returns the first iteration number where the
442 /// value is not in the condition, thus computing the exit count. If the
443 /// iteration count can't be computed, an instance of SCEVCouldNotCompute is
445 SCEVHandle getNumIterationsInRange(ConstantRange Range,
446 ScalarEvolution &SE) const;
448 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
449 const SCEVHandle &Conc,
450 ScalarEvolution &SE) const;
452 virtual void print(std::ostream &OS) const;
453 void print(std::ostream *OS) const { if (OS) print(*OS); }
455 /// Methods for support type inquiry through isa, cast, and dyn_cast:
456 static inline bool classof(const SCEVAddRecExpr *S) { return true; }
457 static inline bool classof(const SCEV *S) {
458 return S->getSCEVType() == scAddRecExpr;
462 //===--------------------------------------------------------------------===//
463 /// SCEVUnknown - This means that we are dealing with an entirely unknown SCEV
464 /// value, and only represent it as it's LLVM Value. This is the "bottom"
465 /// value for the analysis.
467 class SCEVUnknown : public SCEV {
468 friend class ScalarEvolution;
471 explicit SCEVUnknown(Value *v) : SCEV(scUnknown), V(v) {}
476 Value *getValue() const { return V; }
478 virtual bool isLoopInvariant(const Loop *L) const;
479 virtual bool hasComputableLoopEvolution(const Loop *QL) const {
480 return false; // not computable
483 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
484 const SCEVHandle &Conc,
485 ScalarEvolution &SE) const {
486 if (&*Sym == this) return Conc;
490 virtual const Type *getType() const;
492 virtual void print(std::ostream &OS) const;
493 void print(std::ostream *OS) const { if (OS) print(*OS); }
495 /// Methods for support type inquiry through isa, cast, and dyn_cast:
496 static inline bool classof(const SCEVUnknown *S) { return true; }
497 static inline bool classof(const SCEV *S) {
498 return S->getSCEVType() == scUnknown;
502 /// SCEVVisitor - This class defines a simple visitor class that may be used
503 /// for various SCEV analysis purposes.
504 template<typename SC, typename RetVal=void>
506 RetVal visit(SCEV *S) {
507 switch (S->getSCEVType()) {
509 return ((SC*)this)->visitConstant((SCEVConstant*)S);
511 return ((SC*)this)->visitTruncateExpr((SCEVTruncateExpr*)S);
513 return ((SC*)this)->visitZeroExtendExpr((SCEVZeroExtendExpr*)S);
515 return ((SC*)this)->visitSignExtendExpr((SCEVSignExtendExpr*)S);
517 return ((SC*)this)->visitAddExpr((SCEVAddExpr*)S);
519 return ((SC*)this)->visitMulExpr((SCEVMulExpr*)S);
521 return ((SC*)this)->visitSDivExpr((SCEVSDivExpr*)S);
523 return ((SC*)this)->visitAddRecExpr((SCEVAddRecExpr*)S);
525 return ((SC*)this)->visitUnknown((SCEVUnknown*)S);
526 case scCouldNotCompute:
527 return ((SC*)this)->visitCouldNotCompute((SCEVCouldNotCompute*)S);
529 assert(0 && "Unknown SCEV type!");
534 RetVal visitCouldNotCompute(SCEVCouldNotCompute *S) {
535 assert(0 && "Invalid use of SCEVCouldNotCompute!");