1 //===- llvm/Analysis/ScalarEvolutionExpressions.h - SCEV Exprs --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // 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 scUDivExpr, scAddRecExpr, scUMaxExpr, scSMaxExpr, scUnknown,
32 //===--------------------------------------------------------------------===//
33 /// SCEVConstant - This class represents a constant integer value.
35 class SCEVConstant : public SCEV {
36 friend class ScalarEvolution;
39 explicit SCEVConstant(ConstantInt *v, const ScalarEvolution* p) :
40 SCEV(scConstant, p), V(v) {}
42 ConstantInt *getValue() const { return V; }
44 virtual bool isLoopInvariant(const Loop *L) const {
48 virtual bool hasComputableLoopEvolution(const Loop *L) const {
49 return false; // Not loop variant
52 virtual const Type *getType() const;
54 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
55 const SCEVHandle &Conc,
56 ScalarEvolution &SE) const {
60 bool dominates(BasicBlock *BB, DominatorTree *DT) const {
64 virtual void print(raw_ostream &OS) const;
66 /// Methods for support type inquiry through isa, cast, and dyn_cast:
67 static inline bool classof(const SCEVConstant *S) { return true; }
68 static inline bool classof(const SCEV *S) {
69 return S->getSCEVType() == scConstant;
73 //===--------------------------------------------------------------------===//
74 /// SCEVCastExpr - This is the base class for unary cast operator classes.
76 class SCEVCastExpr : public SCEV {
81 SCEVCastExpr(unsigned SCEVTy, const SCEVHandle &op, const Type *ty,
82 const ScalarEvolution* p);
83 virtual ~SCEVCastExpr();
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 virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const;
99 /// Methods for support type inquiry through isa, cast, and dyn_cast:
100 static inline bool classof(const SCEVCastExpr *S) { return true; }
101 static inline bool classof(const SCEV *S) {
102 return S->getSCEVType() == scTruncate ||
103 S->getSCEVType() == scZeroExtend ||
104 S->getSCEVType() == scSignExtend;
108 //===--------------------------------------------------------------------===//
109 /// SCEVTruncateExpr - This class represents a truncation of an integer value
110 /// to a smaller integer value.
112 class SCEVTruncateExpr : public SCEVCastExpr {
113 friend class ScalarEvolution;
115 SCEVTruncateExpr(const SCEVHandle &op, const Type *ty,
116 const ScalarEvolution* p);
119 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
120 const SCEVHandle &Conc,
121 ScalarEvolution &SE) const {
122 SCEVHandle H = Op->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
125 return SE.getTruncateExpr(H, Ty);
128 virtual void print(raw_ostream &OS) const;
130 /// Methods for support type inquiry through isa, cast, and dyn_cast:
131 static inline bool classof(const SCEVTruncateExpr *S) { return true; }
132 static inline bool classof(const SCEV *S) {
133 return S->getSCEVType() == scTruncate;
137 //===--------------------------------------------------------------------===//
138 /// SCEVZeroExtendExpr - This class represents a zero extension of a small
139 /// integer value to a larger integer value.
141 class SCEVZeroExtendExpr : public SCEVCastExpr {
142 friend class ScalarEvolution;
144 SCEVZeroExtendExpr(const SCEVHandle &op, const Type *ty,
145 const ScalarEvolution* p);
148 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
149 const SCEVHandle &Conc,
150 ScalarEvolution &SE) const {
151 SCEVHandle H = Op->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
154 return SE.getZeroExtendExpr(H, Ty);
157 virtual void print(raw_ostream &OS) const;
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 SCEVCastExpr {
171 friend class ScalarEvolution;
173 SCEVSignExtendExpr(const SCEVHandle &op, const Type *ty,
174 const ScalarEvolution* p);
177 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
178 const SCEVHandle &Conc,
179 ScalarEvolution &SE) const {
180 SCEVHandle H = Op->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
183 return SE.getSignExtendExpr(H, Ty);
186 virtual void print(raw_ostream &OS) const;
188 /// Methods for support type inquiry through isa, cast, and dyn_cast:
189 static inline bool classof(const SCEVSignExtendExpr *S) { return true; }
190 static inline bool classof(const SCEV *S) {
191 return S->getSCEVType() == scSignExtend;
196 //===--------------------------------------------------------------------===//
197 /// SCEVNAryExpr - This node is a base class providing common
198 /// functionality for n'ary operators.
200 class SCEVNAryExpr : public SCEV {
202 SmallVector<SCEVHandle, 8> Operands;
204 SCEVNAryExpr(enum SCEVTypes T, const SmallVectorImpl<SCEVHandle> &ops,
205 const ScalarEvolution* p)
206 : SCEV(T, p), Operands(ops.begin(), ops.end()) {}
207 virtual ~SCEVNAryExpr() {}
210 unsigned getNumOperands() const { return (unsigned)Operands.size(); }
211 const SCEVHandle &getOperand(unsigned i) const {
212 assert(i < Operands.size() && "Operand index out of range!");
216 const SmallVectorImpl<SCEVHandle> &getOperands() const { return Operands; }
217 typedef SmallVectorImpl<SCEVHandle>::const_iterator op_iterator;
218 op_iterator op_begin() const { return Operands.begin(); }
219 op_iterator op_end() const { return Operands.end(); }
221 virtual bool isLoopInvariant(const Loop *L) const {
222 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
223 if (!getOperand(i)->isLoopInvariant(L)) return false;
227 // hasComputableLoopEvolution - N-ary expressions have computable loop
228 // evolutions iff they have at least one operand that varies with the loop,
229 // but that all varying operands are computable.
230 virtual bool hasComputableLoopEvolution(const Loop *L) const {
231 bool HasVarying = false;
232 for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
233 if (!getOperand(i)->isLoopInvariant(L)) {
234 if (getOperand(i)->hasComputableLoopEvolution(L))
242 bool dominates(BasicBlock *BB, DominatorTree *DT) const;
244 virtual const Type *getType() const { return getOperand(0)->getType(); }
246 /// Methods for support type inquiry through isa, cast, and dyn_cast:
247 static inline bool classof(const SCEVNAryExpr *S) { return true; }
248 static inline bool classof(const SCEV *S) {
249 return S->getSCEVType() == scAddExpr ||
250 S->getSCEVType() == scMulExpr ||
251 S->getSCEVType() == scSMaxExpr ||
252 S->getSCEVType() == scUMaxExpr ||
253 S->getSCEVType() == scAddRecExpr;
257 //===--------------------------------------------------------------------===//
258 /// SCEVCommutativeExpr - This node is the base class for n'ary commutative
261 class SCEVCommutativeExpr : public SCEVNAryExpr {
263 SCEVCommutativeExpr(enum SCEVTypes T,
264 const SmallVectorImpl<SCEVHandle> &ops,
265 const ScalarEvolution* p)
266 : SCEVNAryExpr(T, ops, p) {}
269 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
270 const SCEVHandle &Conc,
271 ScalarEvolution &SE) const;
273 virtual const char *getOperationStr() const = 0;
275 virtual void print(raw_ostream &OS) const;
277 /// Methods for support type inquiry through isa, cast, and dyn_cast:
278 static inline bool classof(const SCEVCommutativeExpr *S) { return true; }
279 static inline bool classof(const SCEV *S) {
280 return S->getSCEVType() == scAddExpr ||
281 S->getSCEVType() == scMulExpr ||
282 S->getSCEVType() == scSMaxExpr ||
283 S->getSCEVType() == scUMaxExpr;
288 //===--------------------------------------------------------------------===//
289 /// SCEVAddExpr - This node represents an addition of some number of SCEVs.
291 class SCEVAddExpr : public SCEVCommutativeExpr {
292 friend class ScalarEvolution;
294 explicit SCEVAddExpr(const SmallVectorImpl<SCEVHandle> &ops,
295 const ScalarEvolution* p)
296 : SCEVCommutativeExpr(scAddExpr, ops, p) {
300 virtual const char *getOperationStr() const { return " + "; }
302 /// Methods for support type inquiry through isa, cast, and dyn_cast:
303 static inline bool classof(const SCEVAddExpr *S) { return true; }
304 static inline bool classof(const SCEV *S) {
305 return S->getSCEVType() == scAddExpr;
309 //===--------------------------------------------------------------------===//
310 /// SCEVMulExpr - This node represents multiplication of some number of SCEVs.
312 class SCEVMulExpr : public SCEVCommutativeExpr {
313 friend class ScalarEvolution;
315 explicit SCEVMulExpr(const SmallVectorImpl<SCEVHandle> &ops,
316 const ScalarEvolution* p)
317 : SCEVCommutativeExpr(scMulExpr, ops, p) {
321 virtual const char *getOperationStr() const { return " * "; }
323 /// Methods for support type inquiry through isa, cast, and dyn_cast:
324 static inline bool classof(const SCEVMulExpr *S) { return true; }
325 static inline bool classof(const SCEV *S) {
326 return S->getSCEVType() == scMulExpr;
331 //===--------------------------------------------------------------------===//
332 /// SCEVUDivExpr - This class represents a binary unsigned division operation.
334 class SCEVUDivExpr : public SCEV {
335 friend class ScalarEvolution;
338 SCEVUDivExpr(const SCEVHandle &lhs, const SCEVHandle &rhs,
339 const ScalarEvolution* p)
340 : SCEV(scUDivExpr, p), LHS(lhs), RHS(rhs) {}
343 const SCEVHandle &getLHS() const { return LHS; }
344 const SCEVHandle &getRHS() const { return RHS; }
346 virtual bool isLoopInvariant(const Loop *L) const {
347 return LHS->isLoopInvariant(L) && RHS->isLoopInvariant(L);
350 virtual bool hasComputableLoopEvolution(const Loop *L) const {
351 return LHS->hasComputableLoopEvolution(L) &&
352 RHS->hasComputableLoopEvolution(L);
355 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
356 const SCEVHandle &Conc,
357 ScalarEvolution &SE) const {
358 SCEVHandle L = LHS->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
359 SCEVHandle R = RHS->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
360 if (L == LHS && R == RHS)
363 return SE.getUDivExpr(L, R);
366 bool dominates(BasicBlock *BB, DominatorTree *DT) const;
368 virtual const Type *getType() const;
370 void print(raw_ostream &OS) const;
372 /// Methods for support type inquiry through isa, cast, and dyn_cast:
373 static inline bool classof(const SCEVUDivExpr *S) { return true; }
374 static inline bool classof(const SCEV *S) {
375 return S->getSCEVType() == scUDivExpr;
380 //===--------------------------------------------------------------------===//
381 /// SCEVAddRecExpr - This node represents a polynomial recurrence on the trip
382 /// count of the specified loop. This is the primary focus of the
383 /// ScalarEvolution framework; all the other SCEV subclasses are mostly just
384 /// supporting infrastructure to allow SCEVAddRecExpr expressions to be
385 /// created and analyzed.
387 /// All operands of an AddRec are required to be loop invariant.
389 class SCEVAddRecExpr : public SCEVNAryExpr {
390 friend class ScalarEvolution;
394 SCEVAddRecExpr(const SmallVectorImpl<SCEVHandle> &ops, const Loop *l,
395 const ScalarEvolution* p)
396 : SCEVNAryExpr(scAddRecExpr, ops, p), L(l) {
397 for (size_t i = 0, e = Operands.size(); i != e; ++i)
398 assert(Operands[i]->isLoopInvariant(l) &&
399 "Operands of AddRec must be loop-invariant!");
403 const SCEVHandle &getStart() const { return Operands[0]; }
404 const Loop *getLoop() const { return L; }
406 /// getStepRecurrence - This method constructs and returns the recurrence
407 /// indicating how much this expression steps by. If this is a polynomial
408 /// of degree N, it returns a chrec of degree N-1.
409 SCEVHandle getStepRecurrence(ScalarEvolution &SE) const {
410 if (isAffine()) return getOperand(1);
411 return SE.getAddRecExpr(SmallVector<SCEVHandle, 3>(op_begin()+1,op_end()),
415 virtual bool hasComputableLoopEvolution(const Loop *QL) const {
416 if (L == QL) return true;
420 virtual bool isLoopInvariant(const Loop *QueryLoop) const;
422 /// isAffine - Return true if this is an affine AddRec (i.e., it represents
423 /// an expressions A+B*x where A and B are loop invariant values.
424 bool isAffine() const {
425 // We know that the start value is invariant. This expression is thus
426 // affine iff the step is also invariant.
427 return getNumOperands() == 2;
430 /// isQuadratic - Return true if this is an quadratic AddRec (i.e., it
431 /// represents an expressions A+B*x+C*x^2 where A, B and C are loop
432 /// invariant values. This corresponds to an addrec of the form {L,+,M,+,N}
433 bool isQuadratic() const {
434 return getNumOperands() == 3;
437 /// evaluateAtIteration - Return the value of this chain of recurrences at
438 /// the specified iteration number.
439 SCEVHandle evaluateAtIteration(SCEVHandle It, ScalarEvolution &SE) const;
441 /// getNumIterationsInRange - Return the number of iterations of this loop
442 /// that produce values in the specified constant range. Another way of
443 /// looking at this is that it returns the first iteration number where the
444 /// value is not in the condition, thus computing the exit count. If the
445 /// iteration count can't be computed, an instance of SCEVCouldNotCompute is
447 SCEVHandle getNumIterationsInRange(ConstantRange Range,
448 ScalarEvolution &SE) const;
450 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
451 const SCEVHandle &Conc,
452 ScalarEvolution &SE) const;
454 virtual void print(raw_ostream &OS) const;
456 /// Methods for support type inquiry through isa, cast, and dyn_cast:
457 static inline bool classof(const SCEVAddRecExpr *S) { return true; }
458 static inline bool classof(const SCEV *S) {
459 return S->getSCEVType() == scAddRecExpr;
464 //===--------------------------------------------------------------------===//
465 /// SCEVSMaxExpr - This class represents a signed maximum selection.
467 class SCEVSMaxExpr : public SCEVCommutativeExpr {
468 friend class ScalarEvolution;
470 explicit SCEVSMaxExpr(const SmallVectorImpl<SCEVHandle> &ops,
471 const ScalarEvolution* p)
472 : SCEVCommutativeExpr(scSMaxExpr, ops, p) {
476 virtual const char *getOperationStr() const { return " smax "; }
478 /// Methods for support type inquiry through isa, cast, and dyn_cast:
479 static inline bool classof(const SCEVSMaxExpr *S) { return true; }
480 static inline bool classof(const SCEV *S) {
481 return S->getSCEVType() == scSMaxExpr;
486 //===--------------------------------------------------------------------===//
487 /// SCEVUMaxExpr - This class represents an unsigned maximum selection.
489 class SCEVUMaxExpr : public SCEVCommutativeExpr {
490 friend class ScalarEvolution;
492 explicit SCEVUMaxExpr(const SmallVectorImpl<SCEVHandle> &ops,
493 const ScalarEvolution* p)
494 : SCEVCommutativeExpr(scUMaxExpr, ops, p) {
498 virtual const char *getOperationStr() const { return " umax "; }
500 /// Methods for support type inquiry through isa, cast, and dyn_cast:
501 static inline bool classof(const SCEVUMaxExpr *S) { return true; }
502 static inline bool classof(const SCEV *S) {
503 return S->getSCEVType() == scUMaxExpr;
508 //===--------------------------------------------------------------------===//
509 /// SCEVUnknown - This means that we are dealing with an entirely unknown SCEV
510 /// value, and only represent it as it's LLVM Value. This is the "bottom"
511 /// value for the analysis.
513 class SCEVUnknown : public SCEV {
514 friend class ScalarEvolution;
517 explicit SCEVUnknown(Value *v, const ScalarEvolution* p) :
518 SCEV(scUnknown, p), V(v) {}
521 Value *getValue() const { return V; }
523 virtual bool isLoopInvariant(const Loop *L) const;
524 virtual bool hasComputableLoopEvolution(const Loop *QL) const {
525 return false; // not computable
528 SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
529 const SCEVHandle &Conc,
530 ScalarEvolution &SE) const {
531 if (&*Sym == this) return Conc;
535 bool dominates(BasicBlock *BB, DominatorTree *DT) const;
537 virtual const Type *getType() const;
539 virtual void print(raw_ostream &OS) const;
541 /// Methods for support type inquiry through isa, cast, and dyn_cast:
542 static inline bool classof(const SCEVUnknown *S) { return true; }
543 static inline bool classof(const SCEV *S) {
544 return S->getSCEVType() == scUnknown;
548 /// SCEVVisitor - This class defines a simple visitor class that may be used
549 /// for various SCEV analysis purposes.
550 template<typename SC, typename RetVal=void>
552 RetVal visit(const SCEV *S) {
553 switch (S->getSCEVType()) {
555 return ((SC*)this)->visitConstant((const SCEVConstant*)S);
557 return ((SC*)this)->visitTruncateExpr((const SCEVTruncateExpr*)S);
559 return ((SC*)this)->visitZeroExtendExpr((const SCEVZeroExtendExpr*)S);
561 return ((SC*)this)->visitSignExtendExpr((const SCEVSignExtendExpr*)S);
563 return ((SC*)this)->visitAddExpr((const SCEVAddExpr*)S);
565 return ((SC*)this)->visitMulExpr((const SCEVMulExpr*)S);
567 return ((SC*)this)->visitUDivExpr((const SCEVUDivExpr*)S);
569 return ((SC*)this)->visitAddRecExpr((const SCEVAddRecExpr*)S);
571 return ((SC*)this)->visitSMaxExpr((const SCEVSMaxExpr*)S);
573 return ((SC*)this)->visitUMaxExpr((const SCEVUMaxExpr*)S);
575 return ((SC*)this)->visitUnknown((const SCEVUnknown*)S);
576 case scCouldNotCompute:
577 return ((SC*)this)->visitCouldNotCompute((const SCEVCouldNotCompute*)S);
579 assert(0 && "Unknown SCEV type!");
584 RetVal visitCouldNotCompute(const SCEVCouldNotCompute *S) {
585 assert(0 && "Invalid use of SCEVCouldNotCompute!");