//
//===----------------------------------------------------------------------===//
-#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/ADT/iterator_range.h"
#include "llvm/Analysis/ScalarEvolution.h"
#include "llvm/Support/ErrorHandling.h"
SCEV(ID, scConstant), V(v) {}
public:
ConstantInt *getValue() const { return V; }
+ const APInt &getAPInt() const { return getValue()->getValue(); }
- 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;
-
- virtual bool hasOperand(const SCEV *) const {
- return false;
- }
-
- bool dominates(BasicBlock *BB, DominatorTree *DT) const {
- return true;
- }
-
- bool properlyDominates(BasicBlock *BB, DominatorTree *DT) const {
- return true;
- }
-
- virtual void print(raw_ostream &OS) const;
+ Type *getType() const { return V->getType(); }
/// 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;
}
class SCEVCastExpr : public SCEV {
protected:
const SCEV *Op;
- const Type *Ty;
+ Type *Ty;
SCEVCastExpr(const FoldingSetNodeIDRef ID,
- unsigned SCEVTy, const SCEV *op, const Type *ty);
+ unsigned SCEVTy, const SCEV *op, Type *ty);
public:
const SCEV *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);
- }
-
- virtual bool hasOperand(const SCEV *O) const {
- return Op == O || Op->hasOperand(O);
- }
-
- virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const;
-
- virtual bool properlyDominates(BasicBlock *BB, DominatorTree *DT) const;
+ Type *getType() const { return Ty; }
/// Methods for support type inquiry through isa, cast, and dyn_cast:
- static inline bool classof(const SCEVCastExpr *S) { return true; }
static inline bool classof(const SCEV *S) {
return S->getSCEVType() == scTruncate ||
S->getSCEVType() == scZeroExtend ||
friend class ScalarEvolution;
SCEVTruncateExpr(const FoldingSetNodeIDRef ID,
- const SCEV *op, const Type *ty);
+ const SCEV *op, Type *ty);
public:
- virtual void print(raw_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;
}
friend class ScalarEvolution;
SCEVZeroExtendExpr(const FoldingSetNodeIDRef ID,
- const SCEV *op, const Type *ty);
+ const SCEV *op, Type *ty);
public:
- virtual void print(raw_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;
}
friend class ScalarEvolution;
SCEVSignExtendExpr(const FoldingSetNodeIDRef ID,
- const SCEV *op, const Type *ty);
+ const SCEV *op, Type *ty);
public:
- virtual void print(raw_ostream &OS) const;
-
/// 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;
}
}
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());
+ }
- virtual bool isLoopInvariant(const Loop *L) const;
-
- // hasComputableLoopEvolution - N-ary 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;
-
- virtual bool hasOperand(const SCEV *O) const;
-
- bool dominates(BasicBlock *BB, DominatorTree *DT) const;
-
- bool properlyDominates(BasicBlock *BB, DominatorTree *DT) const;
-
- virtual const Type *getType() const { return getOperand(0)->getType(); }
+ Type *getType() const { return getOperand(0)->getType(); }
- bool hasNoUnsignedWrap() const { return SubclassData & (1 << 0); }
- void setHasNoUnsignedWrap(bool B) {
- SubclassData = (SubclassData & ~(1 << 0)) | (B << 0);
- }
- bool hasNoSignedWrap() const { return SubclassData & (1 << 1); }
- void setHasNoSignedWrap(bool B) {
- SubclassData = (SubclassData & ~(1 << 1)) | (B << 1);
+ 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 SCEVNAryExpr *S) { return true; }
static inline bool classof(const SCEV *S) {
return S->getSCEVType() == scAddExpr ||
S->getSCEVType() == scMulExpr ||
: SCEVNAryExpr(ID, T, O, N) {}
public:
- virtual const char *getOperationStr() const = 0;
-
- virtual void print(raw_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 ||
S->getSCEVType() == scSMaxExpr ||
S->getSCEVType() == scUMaxExpr;
}
+
+ /// Set flags for a non-recurrence without clearing previously set flags.
+ void setNoWrapFlags(NoWrapFlags Flags) {
+ SubclassData |= Flags;
+ }
};
}
public:
- virtual const char *getOperationStr() const { return " + "; }
-
- virtual const Type *getType() const {
+ 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.
}
/// 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;
}
}
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;
}
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);
- }
-
- virtual bool hasComputableLoopEvolution(const Loop *L) const {
- return LHS->hasComputableLoopEvolution(L) &&
- RHS->hasComputableLoopEvolution(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 hasOperand(const SCEV *O) const {
- return O == LHS || O == RHS || LHS->hasOperand(O) || RHS->hasOperand(O);
- }
-
- bool dominates(BasicBlock *BB, DominatorTree *DT) const;
-
- bool properlyDominates(BasicBlock *BB, DominatorTree *DT) const;
-
- virtual const Type *getType() const;
-
- void print(raw_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;
}
/// 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());
- }
-
- virtual bool hasComputableLoopEvolution(const Loop *QL) const {
- return L == QL;
+ getLoop(), FlagAnyWrap);
}
- virtual bool isLoopInvariant(const Loop *QueryLoop) const;
-
- bool dominates(BasicBlock *BB, DominatorTree *DT) const;
-
- bool properlyDominates(BasicBlock *BB, DominatorTree *DT) const;
-
- /// 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.
+ /// 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 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}
+ /// 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;
return cast<SCEVAddRecExpr>(SE.getAddExpr(this, getStepRecurrence(SE)));
}
- virtual void print(raw_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;
}
};
-
//===--------------------------------------------------------------------===//
/// SCEVSMaxExpr - This class represents a signed maximum selection.
///
const SCEV *const *O, size_t N)
: SCEVCommutativeExpr(ID, scSMaxExpr, O, N) {
// Max never overflows.
- setHasNoUnsignedWrap(true);
- setHasNoSignedWrap(true);
+ setNoWrapFlags((NoWrapFlags)(FlagNUW | FlagNSW));
}
public:
- virtual const char *getOperationStr() const { return " smax "; }
-
/// Methods for support type inquiry through isa, cast, and dyn_cast:
- static inline bool classof(const SCEVSMaxExpr *S) { return true; }
static inline bool classof(const SCEV *S) {
return S->getSCEVType() == scSMaxExpr;
}
const SCEV *const *O, size_t N)
: SCEVCommutativeExpr(ID, scUMaxExpr, O, N) {
// Max never overflows.
- setHasNoUnsignedWrap(true);
- setHasNoSignedWrap(true);
+ setNoWrapFlags((NoWrapFlags)(FlagNUW | FlagNSW));
}
public:
- virtual const char *getOperationStr() const { return " umax "; }
-
/// Methods for support type inquiry through isa, cast, and dyn_cast:
- static inline bool classof(const SCEVUMaxExpr *S) { return true; }
static inline bool classof(const SCEV *S) {
return S->getSCEVType() == scUMaxExpr;
}
/// value, and only represent it as its LLVM Value. This is the "bottom"
/// value for the analysis.
///
- class SCEVUnknown : public SCEV, private CallbackVH {
+ class SCEVUnknown final : public SCEV, private CallbackVH {
friend class ScalarEvolution;
// Implement CallbackVH.
- virtual void deleted();
- virtual void allUsesReplacedWith(Value *New);
+ 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
/// 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(const Type *&AllocTy) const;
- bool isAlignOf(const Type *&AllocTy) const;
- bool isOffsetOf(const Type *&STy, Constant *&FieldNo) const;
-
- virtual bool isLoopInvariant(const Loop *L) const;
- virtual bool hasComputableLoopEvolution(const Loop *QL) const {
- return false; // not computable
- }
-
- virtual bool hasOperand(const SCEV *) const {
- return false;
- }
-
- bool dominates(BasicBlock *BB, DominatorTree *DT) const;
-
- bool properlyDominates(BasicBlock *BB, DominatorTree *DT) const;
+ bool isSizeOf(Type *&AllocTy) const;
+ bool isAlignOf(Type *&AllocTy) const;
+ bool isOffsetOf(Type *&STy, Constant *&FieldNo) const;
- virtual const Type *getType() const;
-
- virtual void print(raw_ostream &OS) 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;
}
RetVal visitCouldNotCompute(const SCEVCouldNotCompute *S) {
llvm_unreachable("Invalid use of SCEVCouldNotCompute!");
- return RetVal();
}
};
+
+ /// 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).second && 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 given expression tree.
+ template<typename SV>
+ void visitAll(const SCEV *Root, SV& Visitor) {
+ SCEVTraversal<SV> T(Visitor);
+ T.visitAll(Root);
+ }
+
+ /// Recursively visits a SCEV expression and re-writes it.
+ template<typename SC>
+ class SCEVRewriteVisitor : public SCEVVisitor<SC, const SCEV *> {
+ protected:
+ ScalarEvolution &SE;
+ public:
+ SCEVRewriteVisitor(ScalarEvolution &SE) : SE(SE) {}
+
+ const SCEV *visitConstant(const SCEVConstant *Constant) {
+ return Constant;
+ }
+
+ const SCEV *visitTruncateExpr(const SCEVTruncateExpr *Expr) {
+ const SCEV *Operand = ((SC*)this)->visit(Expr->getOperand());
+ return SE.getTruncateExpr(Operand, Expr->getType());
+ }
+
+ const SCEV *visitZeroExtendExpr(const SCEVZeroExtendExpr *Expr) {
+ const SCEV *Operand = ((SC*)this)->visit(Expr->getOperand());
+ return SE.getZeroExtendExpr(Operand, Expr->getType());
+ }
+
+ const SCEV *visitSignExtendExpr(const SCEVSignExtendExpr *Expr) {
+ const SCEV *Operand = ((SC*)this)->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(((SC*)this)->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(((SC*)this)->visit(Expr->getOperand(i)));
+ return SE.getMulExpr(Operands);
+ }
+
+ const SCEV *visitUDivExpr(const SCEVUDivExpr *Expr) {
+ return SE.getUDivExpr(((SC*)this)->visit(Expr->getLHS()),
+ ((SC*)this)->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(((SC*)this)->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(((SC*)this)->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(((SC*)this)->visit(Expr->getOperand(i)));
+ return SE.getUMaxExpr(Operands);
+ }
+
+ const SCEV *visitUnknown(const SCEVUnknown *Expr) {
+ return Expr;
+ }
+
+ const SCEV *visitCouldNotCompute(const SCEVCouldNotCompute *Expr) {
+ return Expr;
+ }
+ };
+
+ typedef DenseMap<const Value*, Value*> ValueToValueMap;
+
+ /// The SCEVParameterRewriter takes a scalar evolution expression and updates
+ /// the SCEVUnknown components following the Map (Value -> Value).
+ class SCEVParameterRewriter : public SCEVRewriteVisitor<SCEVParameterRewriter> {
+ 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 &SE, ValueToValueMap &M, bool C)
+ : SCEVRewriteVisitor(SE), Map(M), InterpretConsts(C) {}
+
+ 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;
+ }
+
+ private:
+ ValueToValueMap ⤅
+ bool InterpretConsts;
+ };
+
+ typedef DenseMap<const Loop*, const SCEV*> LoopToScevMapT;
+
+ /// The SCEVLoopAddRecRewriter takes a scalar evolution expression and applies
+ /// the Map (Loop -> SCEV) to all AddRecExprs.
+ class SCEVLoopAddRecRewriter
+ : public SCEVRewriteVisitor<SCEVLoopAddRecRewriter> {
+ public:
+ static const SCEV *rewrite(const SCEV *Scev, LoopToScevMapT &Map,
+ ScalarEvolution &SE) {
+ SCEVLoopAddRecRewriter Rewriter(SE, Map);
+ return Rewriter.visit(Scev);
+ }
+
+ SCEVLoopAddRecRewriter(ScalarEvolution &SE, LoopToScevMapT &M)
+ : SCEVRewriteVisitor(SE), Map(M) {}
+
+ 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 = cast<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 SCEVLoopAddRecRewriter::rewrite(Scev, Map, SE);
+}
+
}
#endif
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