//
//===----------------------------------------------------------------------===//
-#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"
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;
}
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 ||
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;
}
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;
}
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;
}
}
/// 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 ||
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 ||
}
/// 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:
/// 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;
}
}
/// 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;
}
}
/// 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;
}
public:
/// 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;
}
public:
/// 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;
}
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;
}
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
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