--- /dev/null
+//===- llvm/Analysis/ScalarEvolutionExpressions.h - SCEV Exprs --*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the classes used to represent and build scalar expressions.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ANALYSIS_SCALAREVOLUTION_EXPRESSIONS_H
+#define LLVM_ANALYSIS_SCALAREVOLUTION_EXPRESSIONS_H
+
+#include "llvm/Analysis/ScalarEvolution.h"
+
+namespace llvm {
+ class ConstantInt;
+ class ConstantRange;
+
+ enum SCEVTypes {
+ // These should be ordered in terms of increasing complexity to make the
+ // folders simpler.
+ scConstant, scTruncate, scZeroExtend, scAddExpr, scMulExpr, scUDivExpr,
+ scAddRecExpr, scUnknown, scCouldNotCompute
+ };
+
+ //===--------------------------------------------------------------------===//
+ /// SCEVConstant - This class represents a constant integer value.
+ ///
+ class SCEVConstant : public SCEV {
+ ConstantInt *V;
+ SCEVConstant(ConstantInt *v) : SCEV(scConstant), V(v) {}
+
+ virtual ~SCEVConstant();
+ public:
+ /// get method - This just gets and returns a new SCEVConstant object.
+ ///
+ static SCEVHandle get(ConstantInt *V);
+
+ ConstantInt *getValue() const { return V; }
+
+ /// getValueRange - Return the tightest constant bounds that this value is
+ /// known to have. This method is only valid on integer SCEV objects.
+ virtual ConstantRange getValueRange() const;
+
+ virtual bool isLoopInvariant(const Loop *L) const {
+ return true;
+ }
+
+ virtual bool hasComputableLoopEvolution(const Loop *L) const {
+ return false; // Not loop variant
+ }
+
+ virtual const Type *getType() const;
+
+ Value *expandCodeFor(ScalarEvolutionRewriter &SER,
+ Instruction *InsertPt) {
+ return (Value*)getValue();
+ }
+
+ virtual void print(std::ostream &OS) const;
+
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEVConstant *S) { return true; }
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scConstant;
+ }
+ };
+
+ //===--------------------------------------------------------------------===//
+ /// SCEVTruncateExpr - This class represents a truncation of an integer value
+ /// to a smaller integer value.
+ ///
+ class SCEVTruncateExpr : public SCEV {
+ SCEVHandle Op;
+ const Type *Ty;
+ SCEVTruncateExpr(const SCEVHandle &op, const Type *ty);
+ virtual ~SCEVTruncateExpr();
+ public:
+ /// get method - This just gets and returns a new SCEVTruncate object
+ ///
+ static SCEVHandle get(const SCEVHandle &Op, const Type *Ty);
+
+ const SCEVHandle &getOperand() const { return Op; }
+ virtual const Type *getType() const { return Ty; }
+
+ virtual bool isLoopInvariant(const Loop *L) const {
+ return Op->isLoopInvariant(L);
+ }
+
+ virtual bool hasComputableLoopEvolution(const Loop *L) const {
+ return Op->hasComputableLoopEvolution(L);
+ }
+
+ /// getValueRange - Return the tightest constant bounds that this value is
+ /// known to have. This method is only valid on integer SCEV objects.
+ virtual ConstantRange getValueRange() const;
+
+ Value *expandCodeFor(ScalarEvolutionRewriter &SER,
+ Instruction *InsertPt);
+
+ virtual void print(std::ostream &OS) const;
+
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEVTruncateExpr *S) { return true; }
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scTruncate;
+ }
+ };
+
+ //===--------------------------------------------------------------------===//
+ /// SCEVZeroExtendExpr - This class represents a zero extension of a small
+ /// integer value to a larger integer value.
+ ///
+ class SCEVZeroExtendExpr : public SCEV {
+ SCEVHandle Op;
+ const Type *Ty;
+ SCEVZeroExtendExpr(const SCEVHandle &op, const Type *ty);
+ virtual ~SCEVZeroExtendExpr();
+ public:
+ /// get method - This just gets and returns a new SCEVZeroExtend object
+ ///
+ static SCEVHandle get(const SCEVHandle &Op, const Type *Ty);
+
+ const SCEVHandle &getOperand() const { return Op; }
+ virtual const Type *getType() const { return Ty; }
+
+ virtual bool isLoopInvariant(const Loop *L) const {
+ return Op->isLoopInvariant(L);
+ }
+
+ virtual bool hasComputableLoopEvolution(const Loop *L) const {
+ return Op->hasComputableLoopEvolution(L);
+ }
+
+ /// getValueRange - Return the tightest constant bounds that this value is
+ /// known to have. This method is only valid on integer SCEV objects.
+ virtual ConstantRange getValueRange() const;
+
+ Value *expandCodeFor(ScalarEvolutionRewriter &SER,
+ Instruction *InsertPt);
+
+ virtual void print(std::ostream &OS) const;
+
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEVZeroExtendExpr *S) { return true; }
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scZeroExtend;
+ }
+ };
+
+
+ //===--------------------------------------------------------------------===//
+ /// SCEVCommutativeExpr - This node is the base class for n'ary commutative
+ /// operators.
+ ///
+ class SCEVCommutativeExpr : public SCEV {
+ std::vector<SCEVHandle> Operands;
+
+ protected:
+ SCEVCommutativeExpr(enum SCEVTypes T, const std::vector<SCEVHandle> &ops)
+ : SCEV(T) {
+ Operands.reserve(ops.size());
+ Operands.insert(Operands.end(), ops.begin(), ops.end());
+ }
+ ~SCEVCommutativeExpr();
+
+ public:
+ unsigned getNumOperands() const { return Operands.size(); }
+ const SCEVHandle &getOperand(unsigned i) const {
+ assert(i < Operands.size() && "Operand index out of range!");
+ return Operands[i];
+ }
+
+ const std::vector<SCEVHandle> &getOperands() const { return Operands; }
+ typedef std::vector<SCEVHandle>::const_iterator op_iterator;
+ op_iterator op_begin() const { return Operands.begin(); }
+ op_iterator op_end() const { return Operands.end(); }
+
+
+ virtual bool isLoopInvariant(const Loop *L) const {
+ for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
+ if (!getOperand(i)->isLoopInvariant(L)) return false;
+ return true;
+ }
+
+ virtual bool hasComputableLoopEvolution(const Loop *L) const {
+ for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
+ if (getOperand(i)->hasComputableLoopEvolution(L)) return true;
+ return false;
+ }
+
+ virtual const char *getOperationStr() const = 0;
+
+ virtual const Type *getType() const { return getOperand(0)->getType(); }
+ virtual void print(std::ostream &OS) const;
+
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEVCommutativeExpr *S) { return true; }
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scAddExpr ||
+ S->getSCEVType() == scMulExpr;
+ }
+ };
+
+
+ //===--------------------------------------------------------------------===//
+ /// SCEVAddExpr - This node represents an addition of some number of SCEVs.
+ ///
+ class SCEVAddExpr : public SCEVCommutativeExpr {
+ SCEVAddExpr(const std::vector<SCEVHandle> &ops)
+ : SCEVCommutativeExpr(scAddExpr, ops) {
+ }
+
+ public:
+ static SCEVHandle get(std::vector<SCEVHandle> &Ops);
+
+ static SCEVHandle get(const SCEVHandle &LHS, const SCEVHandle &RHS) {
+ std::vector<SCEVHandle> Ops;
+ Ops.push_back(LHS);
+ Ops.push_back(RHS);
+ return get(Ops);
+ }
+
+ static SCEVHandle get(const SCEVHandle &Op0, const SCEVHandle &Op1,
+ const SCEVHandle &Op2) {
+ std::vector<SCEVHandle> Ops;
+ Ops.push_back(Op0);
+ Ops.push_back(Op1);
+ Ops.push_back(Op2);
+ return get(Ops);
+ }
+
+ virtual const char *getOperationStr() const { return " + "; }
+
+ Value *expandCodeFor(ScalarEvolutionRewriter &SER,
+ Instruction *InsertPt);
+
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEVAddExpr *S) { return true; }
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scAddExpr;
+ }
+ };
+
+ //===--------------------------------------------------------------------===//
+ /// SCEVMulExpr - This node represents multiplication of some number of SCEVs.
+ ///
+ class SCEVMulExpr : public SCEVCommutativeExpr {
+ SCEVMulExpr(const std::vector<SCEVHandle> &ops)
+ : SCEVCommutativeExpr(scMulExpr, ops) {
+ }
+
+ public:
+ static SCEVHandle get(std::vector<SCEVHandle> &Ops);
+
+ static SCEVHandle get(const SCEVHandle &LHS, const SCEVHandle &RHS) {
+ std::vector<SCEVHandle> Ops;
+ Ops.push_back(LHS);
+ Ops.push_back(RHS);
+ return get(Ops);
+ }
+
+ virtual const char *getOperationStr() const { return " * "; }
+
+ Value *expandCodeFor(ScalarEvolutionRewriter &SER,
+ Instruction *InsertPt);
+
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEVMulExpr *S) { return true; }
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scMulExpr;
+ }
+ };
+
+
+ //===--------------------------------------------------------------------===//
+ /// SCEVUDivExpr - This class represents a binary unsigned division operation.
+ ///
+ class SCEVUDivExpr : public SCEV {
+ SCEVHandle LHS, RHS;
+ SCEVUDivExpr(const SCEVHandle &lhs, const SCEVHandle &rhs)
+ : SCEV(scUDivExpr), LHS(lhs), RHS(rhs) {}
+
+ virtual ~SCEVUDivExpr();
+ public:
+ /// get method - This just gets and returns a new SCEVUDiv object.
+ ///
+ static SCEVHandle get(const SCEVHandle &LHS, const SCEVHandle &RHS);
+
+ const SCEVHandle &getLHS() const { return LHS; }
+ const SCEVHandle &getRHS() const { return RHS; }
+
+ virtual bool isLoopInvariant(const Loop *L) const {
+ return LHS->isLoopInvariant(L) && RHS->isLoopInvariant(L);
+ }
+
+ virtual bool hasComputableLoopEvolution(const Loop *L) const {
+ return LHS->hasComputableLoopEvolution(L) &&
+ RHS->hasComputableLoopEvolution(L);
+ }
+
+ virtual const Type *getType() const;
+
+ Value *expandCodeFor(ScalarEvolutionRewriter &SER,
+ Instruction *InsertPt);
+
+ void print(std::ostream &OS) const;
+
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEVUDivExpr *S) { return true; }
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scUDivExpr;
+ }
+ };
+
+
+ //===--------------------------------------------------------------------===//
+ /// SCEVAddRecExpr - This node represents a polynomial recurrence on the trip
+ /// count of the specified loop.
+ ///
+ /// All operands of an AddRec are required to be loop invariant.
+ ///
+ class SCEVAddRecExpr : public SCEV {
+ std::vector<SCEVHandle> Operands;
+ const Loop *L;
+
+ SCEVAddRecExpr(const std::vector<SCEVHandle> &ops, const Loop *l)
+ : SCEV(scAddRecExpr), Operands(ops), L(l) {
+ for (unsigned i = 0, e = Operands.size(); i != e; ++i)
+ assert(Operands[i]->isLoopInvariant(l) &&
+ "Operands of AddRec must be loop-invariant!");
+ }
+ ~SCEVAddRecExpr();
+ public:
+ static SCEVHandle get(const SCEVHandle &Start, const SCEVHandle &Step,
+ const Loop *);
+ static SCEVHandle get(std::vector<SCEVHandle> &Operands,
+ const Loop *);
+ static SCEVHandle get(const std::vector<SCEVHandle> &Operands,
+ const Loop *L) {
+ std::vector<SCEVHandle> NewOp(Operands);
+ return get(NewOp, L);
+ }
+
+ typedef std::vector<SCEVHandle>::const_iterator op_iterator;
+ op_iterator op_begin() const { return Operands.begin(); }
+ op_iterator op_end() const { return Operands.end(); }
+
+ unsigned getNumOperands() const { return Operands.size(); }
+ const SCEVHandle &getOperand(unsigned i) const { return Operands[i]; }
+ const SCEVHandle &getStart() const { return Operands[0]; }
+ const Loop *getLoop() const { return L; }
+
+
+ /// getStepRecurrence - This method constructs and returns the recurrence
+ /// indicating how much this expression steps by. If this is a polynomial
+ /// of degree N, it returns a chrec of degree N-1.
+ SCEVHandle getStepRecurrence() const {
+ if (getNumOperands() == 2) return getOperand(1);
+ return SCEVAddRecExpr::get(std::vector<SCEVHandle>(op_begin()+1,op_end()),
+ getLoop());
+ }
+
+ virtual bool hasComputableLoopEvolution(const Loop *QL) const {
+ if (L == QL) return true;
+ /// FIXME: What if the start or step value a recurrence for the specified
+ /// loop?
+ return false;
+ }
+
+ virtual bool isLoopInvariant(const Loop *QueryLoop) const;
+
+ virtual const Type *getType() const { return Operands[0]->getType(); }
+
+ Value *expandCodeFor(ScalarEvolutionRewriter &SER,
+ Instruction *InsertPt);
+
+
+ /// isAffine - Return true if this is an affine AddRec (i.e., it represents
+ /// an expressions A+B*x where A and B are loop invariant values.
+ bool isAffine() const {
+ // We know that the start value is invariant. This expression is thus
+ // affine iff the step is also invariant.
+ return getNumOperands() == 2;
+ }
+
+ /// isQuadratic - Return true if this is an quadratic AddRec (i.e., it
+ /// represents an expressions A+B*x+C*x^2 where A, B and C are loop
+ /// invariant values. This corresponds to an addrec of the form {L,+,M,+,N}
+ bool isQuadratic() const {
+ return getNumOperands() == 3;
+ }
+
+ /// evaluateAtIteration - Return the value of this chain of recurrences at
+ /// the specified iteration number.
+ SCEVHandle evaluateAtIteration(SCEVHandle It) const;
+
+ /// getNumIterationsInRange - Return the number of iterations of this loop
+ /// that produce values in the specified constant range. Another way of
+ /// looking at this is that it returns the first iteration number where the
+ /// value is not in the condition, thus computing the exit count. If the
+ /// iteration count can't be computed, an instance of SCEVCouldNotCompute is
+ /// returned.
+ SCEVHandle getNumIterationsInRange(ConstantRange Range) const;
+
+
+ virtual void print(std::ostream &OS) const;
+
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEVAddRecExpr *S) { return true; }
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scAddRecExpr;
+ }
+ };
+
+ //===--------------------------------------------------------------------===//
+ /// SCEVUnknown - This means that we are dealing with an entirely unknown SCEV
+ /// value, and only represent it as it's LLVM Value. This is the "bottom"
+ /// value for the analysis.
+ ///
+ class SCEVUnknown : public SCEV {
+ Value *V;
+ SCEVUnknown(Value *v) : SCEV(scUnknown), V(v) {}
+
+ protected:
+ ~SCEVUnknown();
+ public:
+ /// get method - For SCEVUnknown, this just gets and returns a new
+ /// SCEVUnknown.
+ static SCEVHandle get(Value *V);
+
+ Value *getValue() const { return V; }
+
+ Value *expandCodeFor(ScalarEvolutionRewriter &SER,
+ Instruction *InsertPt) {
+ return V;
+ }
+
+ virtual bool isLoopInvariant(const Loop *L) const;
+ virtual bool hasComputableLoopEvolution(const Loop *QL) const {
+ return false; // not computable
+ }
+
+ virtual const Type *getType() const;
+
+ virtual void print(std::ostream &OS) const;
+
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEVUnknown *S) { return true; }
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scUnknown;
+ }
+ };
+}
+
+#endif
+
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