//
// 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 is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//
//===----------------------------------------------------------------------===//
-#ifndef LLVM_ANALYSIS_SCALAREVOLUTION_EXPRESSIONS_H
-#define LLVM_ANALYSIS_SCALAREVOLUTION_EXPRESSIONS_H
+#ifndef LLVM_ANALYSIS_SCALAREVOLUTIONEXPRESSIONS_H
+#define LLVM_ANALYSIS_SCALAREVOLUTIONEXPRESSIONS_H
+#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Analysis/ScalarEvolution.h"
+#include "llvm/Support/ErrorHandling.h"
namespace llvm {
class ConstantInt;
class ConstantRange;
- class APInt;
+ class DominatorTree;
enum SCEVTypes {
// These should be ordered in terms of increasing complexity to make the
// folders simpler.
scConstant, scTruncate, scZeroExtend, scSignExtend, scAddExpr, scMulExpr,
- scSDivExpr, scAddRecExpr, scUnknown, scCouldNotCompute
+ scUDivExpr, scAddRecExpr, scUMaxExpr, scSMaxExpr,
+ scUnknown, scCouldNotCompute
};
//===--------------------------------------------------------------------===//
friend class ScalarEvolution;
ConstantInt *V;
- explicit SCEVConstant(ConstantInt *v) : SCEV(scConstant), V(v) {}
-
- virtual ~SCEVConstant();
+ SCEVConstant(const FoldingSetNodeIDRef ID, ConstantInt *v) :
+ SCEV(ID, scConstant), V(v) {}
public:
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;
- }
+ Type *getType() const { return V->getType(); }
- virtual bool hasComputableLoopEvolution(const Loop *L) const {
- return false; // Not loop variant
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scConstant;
}
+ };
- virtual const Type *getType() const;
+ //===--------------------------------------------------------------------===//
+ /// SCEVCastExpr - This is the base class for unary cast operator classes.
+ ///
+ class SCEVCastExpr : public SCEV {
+ protected:
+ const SCEV *Op;
+ Type *Ty;
- SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
- ScalarEvolution &SE) const {
- return this;
- }
+ SCEVCastExpr(const FoldingSetNodeIDRef ID,
+ unsigned SCEVTy, const SCEV *op, Type *ty);
- virtual void print(std::ostream &OS) const;
- void print(std::ostream *OS) const { if (OS) print(*OS); }
+ public:
+ const SCEV *getOperand() const { return Op; }
+ Type *getType() const { return Ty; }
/// 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;
+ return S->getSCEVType() == scTruncate ||
+ S->getSCEVType() == scZeroExtend ||
+ S->getSCEVType() == scSignExtend;
}
};
/// SCEVTruncateExpr - This class represents a truncation of an integer value
/// to a smaller integer value.
///
- class SCEVTruncateExpr : public SCEV {
+ class SCEVTruncateExpr : public SCEVCastExpr {
friend class ScalarEvolution;
- SCEVHandle Op;
- const Type *Ty;
- SCEVTruncateExpr(const SCEVHandle &op, const Type *ty);
- virtual ~SCEVTruncateExpr();
- public:
- 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);
- }
-
- SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
- ScalarEvolution &SE) const {
- SCEVHandle H = Op->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
- if (H == Op)
- return this;
- return SE.getTruncateExpr(H, Ty);
- }
-
- /// 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 void print(std::ostream &OS) const;
- void print(std::ostream *OS) const { if (OS) print(*OS); }
+ SCEVTruncateExpr(const FoldingSetNodeIDRef ID,
+ const SCEV *op, Type *ty);
+ public:
/// 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 {
+ class SCEVZeroExtendExpr : public SCEVCastExpr {
friend class ScalarEvolution;
- SCEVHandle Op;
- const Type *Ty;
- SCEVZeroExtendExpr(const SCEVHandle &op, const Type *ty);
- virtual ~SCEVZeroExtendExpr();
- public:
- 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;
-
- SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
- ScalarEvolution &SE) const {
- SCEVHandle H = Op->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
- if (H == Op)
- return this;
- return SE.getZeroExtendExpr(H, Ty);
- }
-
- virtual void print(std::ostream &OS) const;
- void print(std::ostream *OS) const { if (OS) print(*OS); }
+ SCEVZeroExtendExpr(const FoldingSetNodeIDRef ID,
+ const SCEV *op, Type *ty);
+ public:
/// 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;
}
/// SCEVSignExtendExpr - This class represents a sign extension of a small
/// integer value to a larger integer value.
///
- class SCEVSignExtendExpr : public SCEV {
+ class SCEVSignExtendExpr : public SCEVCastExpr {
friend class ScalarEvolution;
- SCEVHandle Op;
- const Type *Ty;
- SCEVSignExtendExpr(const SCEVHandle &op, const Type *ty);
- virtual ~SCEVSignExtendExpr();
- public:
- 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;
-
- SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
- ScalarEvolution &SE) const {
- SCEVHandle H = Op->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
- if (H == Op)
- return this;
- return SE.getSignExtendExpr(H, Ty);
- }
-
- virtual void print(std::ostream &OS) const;
- void print(std::ostream *OS) const { if (OS) print(*OS); }
+ SCEVSignExtendExpr(const FoldingSetNodeIDRef ID,
+ const SCEV *op, Type *ty);
+ public:
/// Methods for support type inquiry through isa, cast, and dyn_cast:
- static inline bool classof(const SCEVSignExtendExpr *S) { return true; }
static inline bool classof(const SCEV *S) {
return S->getSCEVType() == scSignExtend;
}
//===--------------------------------------------------------------------===//
- /// SCEVCommutativeExpr - This node is the base class for n'ary commutative
- /// operators.
+ /// SCEVNAryExpr - This node is a base class providing common
+ /// functionality for n'ary operators.
///
- class SCEVCommutativeExpr : public SCEV {
- friend class ScalarEvolution;
-
- std::vector<SCEVHandle> Operands;
-
+ class SCEVNAryExpr : public SCEV {
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();
+ // Since SCEVs are immutable, ScalarEvolution allocates operand
+ // arrays with its SCEVAllocator, so this class just needs a simple
+ // pointer rather than a more elaborate vector-like data structure.
+ // This also avoids the need for a non-trivial destructor.
+ const SCEV *const *Operands;
+ size_t NumOperands;
+
+ SCEVNAryExpr(const FoldingSetNodeIDRef ID,
+ enum SCEVTypes T, const SCEV *const *O, size_t N)
+ : SCEV(ID, T), Operands(O), NumOperands(N) {}
public:
- unsigned getNumOperands() const { return Operands.size(); }
- const SCEVHandle &getOperand(unsigned i) const {
- assert(i < Operands.size() && "Operand index out of range!");
+ size_t getNumOperands() const { return NumOperands; }
+ const SCEV *getOperand(unsigned i) const {
+ assert(i < NumOperands && "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(); }
+ typedef const SCEV *const *op_iterator;
+ op_iterator op_begin() const { return Operands; }
+ op_iterator op_end() const { return Operands + NumOperands; }
+ Type *getType() const { return getOperand(0)->getType(); }
- 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;
+ NoWrapFlags getNoWrapFlags(NoWrapFlags Mask = NoWrapMask) const {
+ return (NoWrapFlags)(SubclassData & Mask);
}
- // hasComputableLoopEvolution - Commutative expressions have computable loop
- // evolutions iff they have at least one operand that varies with the loop,
- // but that all varying operands are computable.
- virtual bool hasComputableLoopEvolution(const Loop *L) const {
- bool HasVarying = false;
- for (unsigned i = 0, e = getNumOperands(); i != e; ++i)
- if (!getOperand(i)->isLoopInvariant(L))
- if (getOperand(i)->hasComputableLoopEvolution(L))
- HasVarying = true;
- else
- return false;
- return HasVarying;
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scAddExpr ||
+ S->getSCEVType() == scMulExpr ||
+ S->getSCEVType() == scSMaxExpr ||
+ S->getSCEVType() == scUMaxExpr ||
+ S->getSCEVType() == scAddRecExpr;
}
+ };
- SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
- ScalarEvolution &SE) const;
-
- virtual const char *getOperationStr() const = 0;
-
- virtual const Type *getType() const { return getOperand(0)->getType(); }
- virtual void print(std::ostream &OS) const;
- void print(std::ostream *OS) const { if (OS) print(*OS); }
+ //===--------------------------------------------------------------------===//
+ /// SCEVCommutativeExpr - This node is the base class for n'ary commutative
+ /// operators.
+ ///
+ class SCEVCommutativeExpr : public SCEVNAryExpr {
+ protected:
+ SCEVCommutativeExpr(const FoldingSetNodeIDRef ID,
+ enum SCEVTypes T, const SCEV *const *O, size_t N)
+ : SCEVNAryExpr(ID, T, O, N) {}
+ public:
/// 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;
+ S->getSCEVType() == scMulExpr ||
+ S->getSCEVType() == scSMaxExpr ||
+ S->getSCEVType() == scUMaxExpr;
+ }
+
+ /// Set flags for a non-recurrence without clearing previously set flags.
+ void setNoWrapFlags(NoWrapFlags Flags) {
+ SubclassData |= Flags;
}
};
class SCEVAddExpr : public SCEVCommutativeExpr {
friend class ScalarEvolution;
- SCEVAddExpr(const std::vector<SCEVHandle> &ops)
- : SCEVCommutativeExpr(scAddExpr, ops) {
+ SCEVAddExpr(const FoldingSetNodeIDRef ID,
+ const SCEV *const *O, size_t N)
+ : SCEVCommutativeExpr(ID, scAddExpr, O, N) {
}
public:
- virtual const char *getOperationStr() const { return " + "; }
+ Type *getType() const {
+ // Use the type of the last operand, which is likely to be a pointer
+ // type, if there is one. This doesn't usually matter, but it can help
+ // reduce casts when the expressions are expanded.
+ return getOperand(getNumOperands() - 1)->getType();
+ }
/// 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;
}
class SCEVMulExpr : public SCEVCommutativeExpr {
friend class ScalarEvolution;
- SCEVMulExpr(const std::vector<SCEVHandle> &ops)
- : SCEVCommutativeExpr(scMulExpr, ops) {
+ SCEVMulExpr(const FoldingSetNodeIDRef ID,
+ const SCEV *const *O, size_t N)
+ : SCEVCommutativeExpr(ID, scMulExpr, O, N) {
}
public:
- virtual const char *getOperationStr() const { return " * "; }
-
/// 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;
}
//===--------------------------------------------------------------------===//
- /// SCEVSDivExpr - This class represents a binary signed division operation.
+ /// SCEVUDivExpr - This class represents a binary unsigned division operation.
///
- class SCEVSDivExpr : public SCEV {
+ class SCEVUDivExpr : public SCEV {
friend class ScalarEvolution;
- SCEVHandle LHS, RHS;
- SCEVSDivExpr(const SCEVHandle &lhs, const SCEVHandle &rhs)
- : SCEV(scSDivExpr), LHS(lhs), RHS(rhs) {}
+ const SCEV *LHS;
+ const SCEV *RHS;
+ SCEVUDivExpr(const FoldingSetNodeIDRef ID, const SCEV *lhs, const SCEV *rhs)
+ : SCEV(ID, scUDivExpr), LHS(lhs), RHS(rhs) {}
- virtual ~SCEVSDivExpr();
public:
- const SCEVHandle &getLHS() const { return LHS; }
- const SCEVHandle &getRHS() const { return RHS; }
+ const SCEV *getLHS() const { return LHS; }
+ const SCEV *getRHS() const { return RHS; }
- virtual bool isLoopInvariant(const Loop *L) const {
- return LHS->isLoopInvariant(L) && RHS->isLoopInvariant(L);
+ Type *getType() const {
+ // In most cases the types of LHS and RHS will be the same, but in some
+ // crazy cases one or the other may be a pointer. ScalarEvolution doesn't
+ // depend on the type for correctness, but handling types carefully can
+ // avoid extra casts in the SCEVExpander. The LHS is more likely to be
+ // a pointer type than the RHS, so use the RHS' type here.
+ return getRHS()->getType();
}
- virtual bool hasComputableLoopEvolution(const Loop *L) const {
- return LHS->hasComputableLoopEvolution(L) &&
- RHS->hasComputableLoopEvolution(L);
- }
-
- SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
- ScalarEvolution &SE) const {
- SCEVHandle L = LHS->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
- SCEVHandle R = RHS->replaceSymbolicValuesWithConcrete(Sym, Conc, SE);
- if (L == LHS && R == RHS)
- return this;
- else
- return SE.getSDivExpr(L, R);
- }
-
-
- virtual const Type *getType() const;
-
- void print(std::ostream &OS) const;
- void print(std::ostream *OS) const { if (OS) print(*OS); }
-
/// Methods for support type inquiry through isa, cast, and dyn_cast:
- static inline bool classof(const SCEVSDivExpr *S) { return true; }
static inline bool classof(const SCEV *S) {
- return S->getSCEVType() == scSDivExpr;
+ return S->getSCEVType() == scUDivExpr;
}
};
//===--------------------------------------------------------------------===//
/// SCEVAddRecExpr - This node represents a polynomial recurrence on the trip
- /// count of the specified loop.
+ /// count of the specified loop. This is the primary focus of the
+ /// ScalarEvolution framework; all the other SCEV subclasses are mostly just
+ /// supporting infrastructure to allow SCEVAddRecExpr expressions to be
+ /// created and analyzed.
///
/// All operands of an AddRec are required to be loop invariant.
///
- class SCEVAddRecExpr : public SCEV {
+ class SCEVAddRecExpr : public SCEVNAryExpr {
friend class ScalarEvolution;
- 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:
- typedef std::vector<SCEVHandle>::const_iterator op_iterator;
- op_iterator op_begin() const { return Operands.begin(); }
- op_iterator op_end() const { return Operands.end(); }
+ SCEVAddRecExpr(const FoldingSetNodeIDRef ID,
+ const SCEV *const *O, size_t N, const Loop *l)
+ : SCEVNAryExpr(ID, scAddRecExpr, O, N), L(l) {}
- unsigned getNumOperands() const { return Operands.size(); }
- const SCEVHandle &getOperand(unsigned i) const { return Operands[i]; }
- const SCEVHandle &getStart() const { return Operands[0]; }
+ public:
+ const SCEV *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(ScalarEvolution &SE) const {
- if (getNumOperands() == 2) return getOperand(1);
- return SE.getAddRecExpr(std::vector<SCEVHandle>(op_begin()+1,op_end()),
- getLoop());
+ /// We cannot determine whether the step recurrence has self-wraparound.
+ const SCEV *getStepRecurrence(ScalarEvolution &SE) const {
+ if (isAffine()) return getOperand(1);
+ return SE.getAddRecExpr(SmallVector<const SCEV *, 3>(op_begin()+1,
+ op_end()),
+ getLoop(), FlagAnyWrap);
}
- virtual bool hasComputableLoopEvolution(const Loop *QL) const {
- if (L == QL) return true;
- return false;
- }
-
- virtual bool isLoopInvariant(const Loop *QueryLoop) const;
-
- virtual const Type *getType() const { return Operands[0]->getType(); }
-
/// 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 {
return getNumOperands() == 3;
}
+ /// Set flags for a recurrence without clearing any previously set flags.
+ /// For AddRec, either NUW or NSW implies NW. Keep track of this fact here
+ /// to make it easier to propagate flags.
+ void setNoWrapFlags(NoWrapFlags Flags) {
+ if (Flags & (FlagNUW | FlagNSW))
+ Flags = ScalarEvolution::setFlags(Flags, FlagNW);
+ SubclassData |= Flags;
+ }
+
/// evaluateAtIteration - Return the value of this chain of recurrences at
/// the specified iteration number.
- SCEVHandle evaluateAtIteration(SCEVHandle It, ScalarEvolution &SE) const;
+ const SCEV *evaluateAtIteration(const SCEV *It, ScalarEvolution &SE) const;
/// getNumIterationsInRange - Return the number of iterations of this loop
/// that produce values in the specified constant range. Another way of
/// 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 SCEV *getNumIterationsInRange(ConstantRange Range,
ScalarEvolution &SE) const;
- SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
- ScalarEvolution &SE) const;
-
- virtual void print(std::ostream &OS) const;
- void print(std::ostream *OS) const { if (OS) print(*OS); }
+ /// getPostIncExpr - Return an expression representing the value of
+ /// this expression one iteration of the loop ahead.
+ const SCEVAddRecExpr *getPostIncExpr(ScalarEvolution &SE) const {
+ return cast<SCEVAddRecExpr>(SE.getAddExpr(this, getStepRecurrence(SE)));
+ }
/// 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.
+ /// SCEVSMaxExpr - This class represents a signed maximum selection.
///
- class SCEVUnknown : public SCEV {
+ class SCEVSMaxExpr : public SCEVCommutativeExpr {
friend class ScalarEvolution;
- Value *V;
- SCEVUnknown(Value *v) : SCEV(scUnknown), V(v) {}
+ SCEVSMaxExpr(const FoldingSetNodeIDRef ID,
+ const SCEV *const *O, size_t N)
+ : SCEVCommutativeExpr(ID, scSMaxExpr, O, N) {
+ // Max never overflows.
+ setNoWrapFlags((NoWrapFlags)(FlagNUW | FlagNSW));
+ }
- protected:
- ~SCEVUnknown();
public:
- Value *getValue() const { return V; }
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scSMaxExpr;
+ }
+ };
+
+
+ //===--------------------------------------------------------------------===//
+ /// SCEVUMaxExpr - This class represents an unsigned maximum selection.
+ ///
+ class SCEVUMaxExpr : public SCEVCommutativeExpr {
+ friend class ScalarEvolution;
- virtual bool isLoopInvariant(const Loop *L) const;
- virtual bool hasComputableLoopEvolution(const Loop *QL) const {
- return false; // not computable
+ SCEVUMaxExpr(const FoldingSetNodeIDRef ID,
+ const SCEV *const *O, size_t N)
+ : SCEVCommutativeExpr(ID, scUMaxExpr, O, N) {
+ // Max never overflows.
+ setNoWrapFlags((NoWrapFlags)(FlagNUW | FlagNSW));
}
- SCEVHandle replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
- ScalarEvolution &SE) const {
- if (&*Sym == this) return Conc;
- return this;
+ public:
+ /// Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const SCEV *S) {
+ return S->getSCEVType() == scUMaxExpr;
}
+ };
+
+ //===--------------------------------------------------------------------===//
+ /// SCEVUnknown - This means that we are dealing with an entirely unknown SCEV
+ /// value, and only represent it as its LLVM Value. This is the "bottom"
+ /// value for the analysis.
+ ///
+ class SCEVUnknown : public SCEV, private CallbackVH {
+ friend class ScalarEvolution;
+
+ // Implement CallbackVH.
+ virtual void deleted();
+ virtual void allUsesReplacedWith(Value *New);
- virtual const Type *getType() const;
+ /// SE - The parent ScalarEvolution value. This is used to update
+ /// the parent's maps when the value associated with a SCEVUnknown
+ /// is deleted or RAUW'd.
+ ScalarEvolution *SE;
- virtual void print(std::ostream &OS) const;
- void print(std::ostream *OS) const { if (OS) print(*OS); }
+ /// Next - The next pointer in the linked list of all
+ /// SCEVUnknown instances owned by a ScalarEvolution.
+ SCEVUnknown *Next;
+
+ SCEVUnknown(const FoldingSetNodeIDRef ID, Value *V,
+ ScalarEvolution *se, SCEVUnknown *next) :
+ SCEV(ID, scUnknown), CallbackVH(V), SE(se), Next(next) {}
+
+ public:
+ Value *getValue() const { return getValPtr(); }
+
+ /// isSizeOf, isAlignOf, isOffsetOf - Test whether this is a special
+ /// constant representing a type size, alignment, or field offset in
+ /// a target-independent manner, and hasn't happened to have been
+ /// folded with other operations into something unrecognizable. This
+ /// is mainly only useful for pretty-printing and other situations
+ /// where it isn't absolutely required for these to succeed.
+ bool isSizeOf(Type *&AllocTy) const;
+ bool isAlignOf(Type *&AllocTy) const;
+ bool isOffsetOf(Type *&STy, Constant *&FieldNo) const;
+
+ Type *getType() const { return getValPtr()->getType(); }
/// 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;
}
/// for various SCEV analysis purposes.
template<typename SC, typename RetVal=void>
struct SCEVVisitor {
- RetVal visit(SCEV *S) {
+ RetVal visit(const SCEV *S) {
switch (S->getSCEVType()) {
case scConstant:
- return ((SC*)this)->visitConstant((SCEVConstant*)S);
+ return ((SC*)this)->visitConstant((const SCEVConstant*)S);
case scTruncate:
- return ((SC*)this)->visitTruncateExpr((SCEVTruncateExpr*)S);
+ return ((SC*)this)->visitTruncateExpr((const SCEVTruncateExpr*)S);
case scZeroExtend:
- return ((SC*)this)->visitZeroExtendExpr((SCEVZeroExtendExpr*)S);
+ return ((SC*)this)->visitZeroExtendExpr((const SCEVZeroExtendExpr*)S);
case scSignExtend:
- return ((SC*)this)->visitSignExtendExpr((SCEVSignExtendExpr*)S);
+ return ((SC*)this)->visitSignExtendExpr((const SCEVSignExtendExpr*)S);
case scAddExpr:
- return ((SC*)this)->visitAddExpr((SCEVAddExpr*)S);
+ return ((SC*)this)->visitAddExpr((const SCEVAddExpr*)S);
case scMulExpr:
- return ((SC*)this)->visitMulExpr((SCEVMulExpr*)S);
- case scSDivExpr:
- return ((SC*)this)->visitSDivExpr((SCEVSDivExpr*)S);
+ return ((SC*)this)->visitMulExpr((const SCEVMulExpr*)S);
+ case scUDivExpr:
+ return ((SC*)this)->visitUDivExpr((const SCEVUDivExpr*)S);
case scAddRecExpr:
- return ((SC*)this)->visitAddRecExpr((SCEVAddRecExpr*)S);
+ return ((SC*)this)->visitAddRecExpr((const SCEVAddRecExpr*)S);
+ case scSMaxExpr:
+ return ((SC*)this)->visitSMaxExpr((const SCEVSMaxExpr*)S);
+ case scUMaxExpr:
+ return ((SC*)this)->visitUMaxExpr((const SCEVUMaxExpr*)S);
case scUnknown:
- return ((SC*)this)->visitUnknown((SCEVUnknown*)S);
+ return ((SC*)this)->visitUnknown((const SCEVUnknown*)S);
case scCouldNotCompute:
- return ((SC*)this)->visitCouldNotCompute((SCEVCouldNotCompute*)S);
+ return ((SC*)this)->visitCouldNotCompute((const SCEVCouldNotCompute*)S);
default:
- assert(0 && "Unknown SCEV type!");
- abort();
+ llvm_unreachable("Unknown SCEV type!");
}
}
- RetVal visitCouldNotCompute(SCEVCouldNotCompute *S) {
- assert(0 && "Invalid use of SCEVCouldNotCompute!");
- abort();
- return RetVal();
+ RetVal visitCouldNotCompute(const SCEVCouldNotCompute *S) {
+ llvm_unreachable("Invalid use of SCEVCouldNotCompute!");
+ }
+ };
+
+ /// Visit all nodes in the expression tree using worklist traversal.
+ ///
+ /// Visitor implements:
+ /// // return true to follow this node.
+ /// bool follow(const SCEV *S);
+ /// // return true to terminate the search.
+ /// bool isDone();
+ template<typename SV>
+ class SCEVTraversal {
+ SV &Visitor;
+ SmallVector<const SCEV *, 8> Worklist;
+ SmallPtrSet<const SCEV *, 8> Visited;
+
+ void push(const SCEV *S) {
+ if (Visited.insert(S) && Visitor.follow(S))
+ Worklist.push_back(S);
+ }
+ public:
+ SCEVTraversal(SV& V): Visitor(V) {}
+
+ void visitAll(const SCEV *Root) {
+ push(Root);
+ while (!Worklist.empty() && !Visitor.isDone()) {
+ const SCEV *S = Worklist.pop_back_val();
+
+ switch (S->getSCEVType()) {
+ case scConstant:
+ case scUnknown:
+ break;
+ case scTruncate:
+ case scZeroExtend:
+ case scSignExtend:
+ push(cast<SCEVCastExpr>(S)->getOperand());
+ break;
+ case scAddExpr:
+ case scMulExpr:
+ case scSMaxExpr:
+ case scUMaxExpr:
+ case scAddRecExpr: {
+ const SCEVNAryExpr *NAry = cast<SCEVNAryExpr>(S);
+ for (SCEVNAryExpr::op_iterator I = NAry->op_begin(),
+ E = NAry->op_end(); I != E; ++I) {
+ push(*I);
+ }
+ break;
+ }
+ case scUDivExpr: {
+ const SCEVUDivExpr *UDiv = cast<SCEVUDivExpr>(S);
+ push(UDiv->getLHS());
+ push(UDiv->getRHS());
+ break;
+ }
+ case scCouldNotCompute:
+ llvm_unreachable("Attempt to use a SCEVCouldNotCompute object!");
+ default:
+ llvm_unreachable("Unknown SCEV kind!");
+ }
+ }
}
};
+
+ /// Use SCEVTraversal to visit all nodes in the givien expression tree.
+ template<typename SV>
+ void visitAll(const SCEV *Root, SV& Visitor) {
+ SCEVTraversal<SV> T(Visitor);
+ T.visitAll(Root);
+ }
+
+ /// The SCEVRewriter takes a scalar evolution expression and copies all its
+ /// components. The result after a rewrite is an identical SCEV.
+ struct SCEVRewriter
+ : public SCEVVisitor<SCEVRewriter, const SCEV*> {
+ public:
+ SCEVRewriter(ScalarEvolution &S) : SE(S) {}
+
+ virtual ~SCEVRewriter() {}
+
+ virtual const SCEV *visitConstant(const SCEVConstant *Constant) {
+ return Constant;
+ }
+
+ virtual const SCEV *visitTruncateExpr(const SCEVTruncateExpr *Expr) {
+ const SCEV *Operand = visit(Expr->getOperand());
+ return SE.getTruncateExpr(Operand, Expr->getType());
+ }
+
+ virtual const SCEV *visitZeroExtendExpr(const SCEVZeroExtendExpr *Expr) {
+ const SCEV *Operand = visit(Expr->getOperand());
+ return SE.getZeroExtendExpr(Operand, Expr->getType());
+ }
+
+ virtual const SCEV *visitSignExtendExpr(const SCEVSignExtendExpr *Expr) {
+ const SCEV *Operand = visit(Expr->getOperand());
+ return SE.getSignExtendExpr(Operand, Expr->getType());
+ }
+
+ virtual const SCEV *visitAddExpr(const SCEVAddExpr *Expr) {
+ SmallVector<const SCEV *, 2> Operands;
+ for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
+ Operands.push_back(visit(Expr->getOperand(i)));
+ return SE.getAddExpr(Operands);
+ }
+
+ virtual const SCEV *visitMulExpr(const SCEVMulExpr *Expr) {
+ SmallVector<const SCEV *, 2> Operands;
+ for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
+ Operands.push_back(visit(Expr->getOperand(i)));
+ return SE.getMulExpr(Operands);
+ }
+
+ virtual const SCEV *visitUDivExpr(const SCEVUDivExpr *Expr) {
+ return SE.getUDivExpr(visit(Expr->getLHS()), visit(Expr->getRHS()));
+ }
+
+ virtual const SCEV *visitAddRecExpr(const SCEVAddRecExpr *Expr) {
+ SmallVector<const SCEV *, 2> Operands;
+ for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
+ Operands.push_back(visit(Expr->getOperand(i)));
+ return SE.getAddRecExpr(Operands, Expr->getLoop(),
+ Expr->getNoWrapFlags());
+ }
+
+ virtual const SCEV *visitSMaxExpr(const SCEVSMaxExpr *Expr) {
+ SmallVector<const SCEV *, 2> Operands;
+ for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
+ Operands.push_back(visit(Expr->getOperand(i)));
+ return SE.getSMaxExpr(Operands);
+ }
+
+ virtual const SCEV *visitUMaxExpr(const SCEVUMaxExpr *Expr) {
+ SmallVector<const SCEV *, 2> Operands;
+ for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
+ Operands.push_back(visit(Expr->getOperand(i)));
+ return SE.getUMaxExpr(Operands);
+ }
+
+ virtual const SCEV *visitUnknown(const SCEVUnknown *Expr) {
+ return Expr;
+ }
+
+ virtual const SCEV *visitCouldNotCompute(const SCEVCouldNotCompute *Expr) {
+ return Expr;
+ }
+
+ protected:
+ ScalarEvolution &SE;
+ };
+
+ typedef DenseMap<const Value*, Value*> ValueToValueMap;
+
+ /// The SCEVParameterRewriter takes a scalar evolution expression and updates
+ /// the SCEVUnknown components following the Map (Value -> Value).
+ struct SCEVParameterRewriter: public SCEVRewriter {
+ public:
+ static const SCEV *rewrite(const SCEV *Scev, ScalarEvolution &SE,
+ ValueToValueMap &Map) {
+ SCEVParameterRewriter Rewriter(SE, Map);
+ return Rewriter.visit(Scev);
+ }
+ SCEVParameterRewriter(ScalarEvolution &S, ValueToValueMap &M)
+ : SCEVRewriter(S), Map(M) {}
+
+ virtual const SCEV *visitUnknown(const SCEVUnknown *Expr) {
+ Value *V = Expr->getValue();
+ if (Map.count(V))
+ return SE.getUnknown(Map[V]);
+ return Expr;
+ }
+
+ private:
+ ValueToValueMap ⤅
+ };
+
+ typedef DenseMap<const Loop*, const SCEV*> LoopToScevMapT;
+
+ /// The SCEVApplyRewriter takes a scalar evolution expression and applies
+ /// the Map (Loop -> SCEV) to all AddRecExprs.
+ struct SCEVApplyRewriter: public SCEVRewriter {
+ public:
+ static const SCEV *rewrite(const SCEV *Scev, LoopToScevMapT &Map,
+ ScalarEvolution &SE) {
+ SCEVApplyRewriter Rewriter(SE, Map);
+ return Rewriter.visit(Scev);
+ }
+ SCEVApplyRewriter(ScalarEvolution &S, LoopToScevMapT &M)
+ : SCEVRewriter(S), Map(M) {}
+
+ virtual const SCEV *visitAddRecExpr(const SCEVAddRecExpr *Expr) {
+ SmallVector<const SCEV *, 2> Operands;
+ for (int i = 0, e = Expr->getNumOperands(); i < e; ++i)
+ Operands.push_back(visit(Expr->getOperand(i)));
+
+ const Loop *L = Expr->getLoop();
+ const SCEV *Res = SE.getAddRecExpr(Operands, L, Expr->getNoWrapFlags());
+
+ if (0 == Map.count(L))
+ return Res;
+
+ const SCEVAddRecExpr *Rec = (const SCEVAddRecExpr *) Res;
+ return Rec->evaluateAtIteration(Map[L], SE);
+ }
+
+ private:
+ LoopToScevMapT ⤅
+ };
+
+/// Applies the Map (Loop -> SCEV) to the given Scev.
+static inline const SCEV *apply(const SCEV *Scev, LoopToScevMapT &Map,
+ ScalarEvolution &SE) {
+ return SCEVApplyRewriter::rewrite(Scev, Map, SE);
}
-#endif
+}
+#endif