| //===- llvm/Analysis/ScalarEvolutionExpressions.h - SCEV Exprs --*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file 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_SCALAREVOLUTIONEXPRESSIONS_H |
| #define LLVM_ANALYSIS_SCALAREVOLUTIONEXPRESSIONS_H |
| |
| #include "llvm/ADT/iterator_range.h" |
| #include "llvm/ADT/SmallPtrSet.h" |
| #include "llvm/Analysis/ScalarEvolution.h" |
| #include "llvm/Support/ErrorHandling.h" |
| |
| namespace llvm { |
| class ConstantInt; |
| class ConstantRange; |
| class DominatorTree; |
| |
| enum SCEVTypes { |
| // These should be ordered in terms of increasing complexity to make the |
| // folders simpler. |
| scConstant, scTruncate, scZeroExtend, scSignExtend, scAddExpr, scMulExpr, |
| scUDivExpr, scAddRecExpr, scUMaxExpr, scSMaxExpr, |
| scUnknown, scCouldNotCompute |
| }; |
| |
| //===--------------------------------------------------------------------===// |
| /// SCEVConstant - This class represents a constant integer value. |
| /// |
| class SCEVConstant : public SCEV { |
| friend class ScalarEvolution; |
| |
| ConstantInt *V; |
| SCEVConstant(const FoldingSetNodeIDRef ID, ConstantInt *v) : |
| SCEV(ID, scConstant), V(v) {} |
| public: |
| ConstantInt *getValue() const { return V; } |
| |
| Type *getType() const { return V->getType(); } |
| |
| /// Methods for support type inquiry through isa, cast, and dyn_cast: |
| static inline bool classof(const SCEV *S) { |
| return S->getSCEVType() == scConstant; |
| } |
| }; |
| |
| //===--------------------------------------------------------------------===// |
| /// SCEVCastExpr - This is the base class for unary cast operator classes. |
| /// |
| class SCEVCastExpr : public SCEV { |
| protected: |
| const SCEV *Op; |
| Type *Ty; |
| |
| SCEVCastExpr(const FoldingSetNodeIDRef ID, |
| unsigned SCEVTy, const SCEV *op, Type *ty); |
| |
| 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 SCEV *S) { |
| 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 SCEVCastExpr { |
| friend class ScalarEvolution; |
| |
| 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 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 SCEVCastExpr { |
| friend class ScalarEvolution; |
| |
| 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 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 SCEVCastExpr { |
| friend class ScalarEvolution; |
| |
| 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 SCEV *S) { |
| return S->getSCEVType() == scSignExtend; |
| } |
| }; |
| |
| |
| //===--------------------------------------------------------------------===// |
| /// SCEVNAryExpr - This node is a base class providing common |
| /// functionality for n'ary operators. |
| /// |
| class SCEVNAryExpr : public SCEV { |
| protected: |
| // 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: |
| size_t getNumOperands() const { return NumOperands; } |
| const SCEV *getOperand(unsigned i) const { |
| assert(i < NumOperands && "Operand index out of range!"); |
| return Operands[i]; |
| } |
| |
| typedef const SCEV *const *op_iterator; |
| typedef iterator_range<op_iterator> op_range; |
| op_iterator op_begin() const { return Operands; } |
| op_iterator op_end() const { return Operands + NumOperands; } |
| op_range operands() const { |
| return make_range(op_begin(), op_end()); |
| } |
| |
| Type *getType() const { return getOperand(0)->getType(); } |
| |
| NoWrapFlags getNoWrapFlags(NoWrapFlags Mask = NoWrapMask) const { |
| return (NoWrapFlags)(SubclassData & Mask); |
| } |
| |
| /// 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; |
| } |
| }; |
| |
| //===--------------------------------------------------------------------===// |
| /// 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 SCEV *S) { |
| return S->getSCEVType() == scAddExpr || |
| 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; |
| } |
| }; |
| |
| |
| //===--------------------------------------------------------------------===// |
| /// SCEVAddExpr - This node represents an addition of some number of SCEVs. |
| /// |
| class SCEVAddExpr : public SCEVCommutativeExpr { |
| friend class ScalarEvolution; |
| |
| SCEVAddExpr(const FoldingSetNodeIDRef ID, |
| const SCEV *const *O, size_t N) |
| : SCEVCommutativeExpr(ID, scAddExpr, O, N) { |
| } |
| |
| public: |
| 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 SCEV *S) { |
| return S->getSCEVType() == scAddExpr; |
| } |
| }; |
| |
| //===--------------------------------------------------------------------===// |
| /// SCEVMulExpr - This node represents multiplication of some number of SCEVs. |
| /// |
| class SCEVMulExpr : public SCEVCommutativeExpr { |
| friend class ScalarEvolution; |
| |
| SCEVMulExpr(const FoldingSetNodeIDRef ID, |
| const SCEV *const *O, size_t N) |
| : SCEVCommutativeExpr(ID, scMulExpr, O, N) { |
| } |
| |
| public: |
| /// Methods for support type inquiry through isa, cast, and dyn_cast: |
| static inline bool classof(const SCEV *S) { |
| return S->getSCEVType() == scMulExpr; |
| } |
| }; |
| |
| |
| //===--------------------------------------------------------------------===// |
| /// SCEVUDivExpr - This class represents a binary unsigned division operation. |
| /// |
| class SCEVUDivExpr : public SCEV { |
| friend class ScalarEvolution; |
| |
| const SCEV *LHS; |
| const SCEV *RHS; |
| SCEVUDivExpr(const FoldingSetNodeIDRef ID, const SCEV *lhs, const SCEV *rhs) |
| : SCEV(ID, scUDivExpr), LHS(lhs), RHS(rhs) {} |
| |
| public: |
| const SCEV *getLHS() const { return LHS; } |
| const SCEV *getRHS() const { return RHS; } |
| |
| 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(); |
| } |
| |
| /// Methods for support type inquiry through isa, cast, and dyn_cast: |
| 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. 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 SCEVNAryExpr { |
| friend class ScalarEvolution; |
| |
| const Loop *L; |
| |
| SCEVAddRecExpr(const FoldingSetNodeIDRef ID, |
| const SCEV *const *O, size_t N, const Loop *l) |
| : SCEVNAryExpr(ID, scAddRecExpr, O, N), L(l) {} |
| |
| 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. |
| /// 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); |
| } |
| |
| /// isAffine - Return true if this represents an expression |
| /// 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 represents an expression |
| /// 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; |
| } |
| |
| /// 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. |
| 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 |
| /// 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. |
| const SCEV *getNumIterationsInRange(ConstantRange Range, |
| ScalarEvolution &SE) const; |
| |
| /// 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 SCEV *S) { |
| return S->getSCEVType() == scAddRecExpr; |
| } |
| |
| /// Collect parametric terms occurring in step expressions. |
| void collectParametricTerms(ScalarEvolution &SE, |
| SmallVectorImpl<const SCEV *> &Terms) const; |
| |
| /// Return in Subscripts the access functions for each dimension in Sizes. |
| void computeAccessFunctions(ScalarEvolution &SE, |
| SmallVectorImpl<const SCEV *> &Subscripts, |
| SmallVectorImpl<const SCEV *> &Sizes) const; |
| |
| /// Split this SCEVAddRecExpr into two vectors of SCEVs representing the |
| /// subscripts and sizes of an array access. |
| /// |
| /// The delinearization is a 3 step process: the first two steps compute the |
| /// sizes of each subscript and the third step computes the access functions |
| /// for the delinearized array: |
| /// |
| /// 1. Find the terms in the step functions |
| /// 2. Compute the array size |
| /// 3. Compute the access function: divide the SCEV by the array size |
| /// starting with the innermost dimensions found in step 2. The Quotient |
| /// is the SCEV to be divided in the next step of the recursion. The |
| /// Remainder is the subscript of the innermost dimension. Loop over all |
| /// array dimensions computed in step 2. |
| /// |
| /// To compute a uniform array size for several memory accesses to the same |
| /// object, one can collect in step 1 all the step terms for all the memory |
| /// accesses, and compute in step 2 a unique array shape. This guarantees |
| /// that the array shape will be the same across all memory accesses. |
| /// |
| /// FIXME: We could derive the result of steps 1 and 2 from a description of |
| /// the array shape given in metadata. |
| /// |
| /// Example: |
| /// |
| /// A[][n][m] |
| /// |
| /// for i |
| /// for j |
| /// for k |
| /// A[j+k][2i][5i] = |
| /// |
| /// The initial SCEV: |
| /// |
| /// A[{{{0,+,2*m+5}_i, +, n*m}_j, +, n*m}_k] |
| /// |
| /// 1. Find the different terms in the step functions: |
| /// -> [2*m, 5, n*m, n*m] |
| /// |
| /// 2. Compute the array size: sort and unique them |
| /// -> [n*m, 2*m, 5] |
| /// find the GCD of all the terms = 1 |
| /// divide by the GCD and erase constant terms |
| /// -> [n*m, 2*m] |
| /// GCD = m |
| /// divide by GCD -> [n, 2] |
| /// remove constant terms |
| /// -> [n] |
| /// size of the array is A[unknown][n][m] |
| /// |
| /// 3. Compute the access function |
| /// a. Divide {{{0,+,2*m+5}_i, +, n*m}_j, +, n*m}_k by the innermost size m |
| /// Quotient: {{{0,+,2}_i, +, n}_j, +, n}_k |
| /// Remainder: {{{0,+,5}_i, +, 0}_j, +, 0}_k |
| /// The remainder is the subscript of the innermost array dimension: [5i]. |
| /// |
| /// b. Divide Quotient: {{{0,+,2}_i, +, n}_j, +, n}_k by next outer size n |
| /// Quotient: {{{0,+,0}_i, +, 1}_j, +, 1}_k |
| /// Remainder: {{{0,+,2}_i, +, 0}_j, +, 0}_k |
| /// The Remainder is the subscript of the next array dimension: [2i]. |
| /// |
| /// The subscript of the outermost dimension is the Quotient: [j+k]. |
| /// |
| /// Overall, we have: A[][n][m], and the access function: A[j+k][2i][5i]. |
| void delinearize(ScalarEvolution &SE, |
| SmallVectorImpl<const SCEV *> &Subscripts, |
| SmallVectorImpl<const SCEV *> &Sizes, |
| const SCEV *ElementSize) const; |
| }; |
| |
| //===--------------------------------------------------------------------===// |
| /// SCEVSMaxExpr - This class represents a signed maximum selection. |
| /// |
| class SCEVSMaxExpr : public SCEVCommutativeExpr { |
| friend class ScalarEvolution; |
| |
| SCEVSMaxExpr(const FoldingSetNodeIDRef ID, |
| const SCEV *const *O, size_t N) |
| : SCEVCommutativeExpr(ID, scSMaxExpr, O, N) { |
| // Max never overflows. |
| setNoWrapFlags((NoWrapFlags)(FlagNUW | FlagNSW)); |
| } |
| |
| public: |
| /// 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; |
| |
| SCEVUMaxExpr(const FoldingSetNodeIDRef ID, |
| const SCEV *const *O, size_t N) |
| : SCEVCommutativeExpr(ID, scUMaxExpr, O, N) { |
| // Max never overflows. |
| setNoWrapFlags((NoWrapFlags)(FlagNUW | FlagNSW)); |
| } |
| |
| 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. |
| void deleted() override; |
| void allUsesReplacedWith(Value *New) override; |
| |
| /// 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; |
| |
| /// 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 SCEV *S) { |
| return S->getSCEVType() == scUnknown; |
| } |
| }; |
| |
| /// SCEVVisitor - This class defines a simple visitor class that may be used |
| /// for various SCEV analysis purposes. |
| template<typename SC, typename RetVal=void> |
| struct SCEVVisitor { |
| RetVal visit(const SCEV *S) { |
| switch (S->getSCEVType()) { |
| case scConstant: |
| return ((SC*)this)->visitConstant((const SCEVConstant*)S); |
| case scTruncate: |
| return ((SC*)this)->visitTruncateExpr((const SCEVTruncateExpr*)S); |
| case scZeroExtend: |
| return ((SC*)this)->visitZeroExtendExpr((const SCEVZeroExtendExpr*)S); |
| case scSignExtend: |
| return ((SC*)this)->visitSignExtendExpr((const SCEVSignExtendExpr*)S); |
| case scAddExpr: |
| return ((SC*)this)->visitAddExpr((const SCEVAddExpr*)S); |
| case scMulExpr: |
| return ((SC*)this)->visitMulExpr((const SCEVMulExpr*)S); |
| case scUDivExpr: |
| return ((SC*)this)->visitUDivExpr((const SCEVUDivExpr*)S); |
| case scAddRecExpr: |
| 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((const SCEVUnknown*)S); |
| case scCouldNotCompute: |
| return ((SC*)this)->visitCouldNotCompute((const SCEVCouldNotCompute*)S); |
| default: |
| llvm_unreachable("Unknown SCEV type!"); |
| } |
| } |
| |
| 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); |
| } |
| |
| 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 SCEVVisitor<SCEVParameterRewriter, const SCEV*> { |
| public: |
| static const SCEV *rewrite(const SCEV *Scev, ScalarEvolution &SE, |
| ValueToValueMap &Map, |
| bool InterpretConsts = false) { |
| SCEVParameterRewriter Rewriter(SE, Map, InterpretConsts); |
| return Rewriter.visit(Scev); |
| } |
| |
| SCEVParameterRewriter(ScalarEvolution &S, ValueToValueMap &M, bool C) |
| : SE(S), Map(M), InterpretConsts(C) {} |
| |
| const SCEV *visitConstant(const SCEVConstant *Constant) { |
| return Constant; |
| } |
| |
| const SCEV *visitTruncateExpr(const SCEVTruncateExpr *Expr) { |
| const SCEV *Operand = visit(Expr->getOperand()); |
| return SE.getTruncateExpr(Operand, Expr->getType()); |
| } |
| |
| const SCEV *visitZeroExtendExpr(const SCEVZeroExtendExpr *Expr) { |
| const SCEV *Operand = visit(Expr->getOperand()); |
| return SE.getZeroExtendExpr(Operand, Expr->getType()); |
| } |
| |
| const SCEV *visitSignExtendExpr(const SCEVSignExtendExpr *Expr) { |
| const SCEV *Operand = visit(Expr->getOperand()); |
| return SE.getSignExtendExpr(Operand, Expr->getType()); |
| } |
| |
| 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); |
| } |
| |
| 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); |
| } |
| |
| const SCEV *visitUDivExpr(const SCEVUDivExpr *Expr) { |
| return SE.getUDivExpr(visit(Expr->getLHS()), visit(Expr->getRHS())); |
| } |
| |
| 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()); |
| } |
| |
| 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); |
| } |
| |
| 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); |
| } |
| |
| const SCEV *visitUnknown(const SCEVUnknown *Expr) { |
| Value *V = Expr->getValue(); |
| if (Map.count(V)) { |
| Value *NV = Map[V]; |
| if (InterpretConsts && isa<ConstantInt>(NV)) |
| return SE.getConstant(cast<ConstantInt>(NV)); |
| return SE.getUnknown(NV); |
| } |
| return Expr; |
| } |
| |
| const SCEV *visitCouldNotCompute(const SCEVCouldNotCompute *Expr) { |
| return Expr; |
| } |
| |
| private: |
| ScalarEvolution &SE; |
| ValueToValueMap ⤅ |
| bool InterpretConsts; |
| }; |
| |
| 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 SCEVVisitor<SCEVApplyRewriter, const SCEV*> { |
| 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) |
| : SE(S), Map(M) {} |
| |
| const SCEV *visitConstant(const SCEVConstant *Constant) { |
| return Constant; |
| } |
| |
| const SCEV *visitTruncateExpr(const SCEVTruncateExpr *Expr) { |
| const SCEV *Operand = visit(Expr->getOperand()); |
| return SE.getTruncateExpr(Operand, Expr->getType()); |
| } |
| |
| const SCEV *visitZeroExtendExpr(const SCEVZeroExtendExpr *Expr) { |
| const SCEV *Operand = visit(Expr->getOperand()); |
| return SE.getZeroExtendExpr(Operand, Expr->getType()); |
| } |
| |
| const SCEV *visitSignExtendExpr(const SCEVSignExtendExpr *Expr) { |
| const SCEV *Operand = visit(Expr->getOperand()); |
| return SE.getSignExtendExpr(Operand, Expr->getType()); |
| } |
| |
| 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); |
| } |
| |
| 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); |
| } |
| |
| const SCEV *visitUDivExpr(const SCEVUDivExpr *Expr) { |
| return SE.getUDivExpr(visit(Expr->getLHS()), visit(Expr->getRHS())); |
| } |
| |
| 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); |
| } |
| |
| 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); |
| } |
| |
| 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); |
| } |
| |
| const SCEV *visitUnknown(const SCEVUnknown *Expr) { |
| return Expr; |
| } |
| |
| const SCEV *visitCouldNotCompute(const SCEVCouldNotCompute *Expr) { |
| return Expr; |
| } |
| |
| private: |
| ScalarEvolution &SE; |
| 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 |