//===----------------------------------------------------------------------===//
//
// The ScalarEvolution class is an LLVM pass which can be used to analyze and
-// catagorize scalar expressions in loops. It specializes in recognizing
+// categorize scalar expressions in loops. It specializes in recognizing
// general induction variables, representing them with the abstract and opaque
// SCEV class. Given this analysis, trip counts of loops and other important
// properties can be obtained.
#define LLVM_ANALYSIS_SCALAREVOLUTION_H
#include "llvm/Pass.h"
-#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Instructions.h"
+#include "llvm/Function.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/ValueHandle.h"
-#include <iosfwd>
+#include "llvm/Support/Allocator.h"
+#include "llvm/Support/ConstantRange.h"
+#include "llvm/ADT/FoldingSet.h"
+#include "llvm/ADT/DenseMap.h"
+#include <map>
namespace llvm {
class APInt;
+ class Constant;
class ConstantInt;
+ class DominatorTree;
class Type;
- class SCEVHandle;
class ScalarEvolution;
class TargetData;
+ class LLVMContext;
+ class Loop;
+ class LoopInfo;
+ class Operator;
+ class SCEVUnknown;
+ class SCEV;
+ template<> struct FoldingSetTrait<SCEV>;
/// SCEV - This class represents an analyzed expression in the program. These
- /// are reference-counted opaque objects that the client is not allowed to
- /// do much with directly.
+ /// are opaque objects that the client is not allowed to do much with
+ /// directly.
///
- class SCEV {
- const unsigned SCEVType; // The SCEV baseclass this node corresponds to
- mutable unsigned RefCount;
-
- friend class SCEVHandle;
- void addRef() const { ++RefCount; }
- void dropRef() const {
- if (--RefCount == 0)
- delete this;
- }
+ class SCEV : public FoldingSetNode {
+ friend struct FoldingSetTrait<SCEV>;
+
+ /// FastID - A reference to an Interned FoldingSetNodeID for this node.
+ /// The ScalarEvolution's BumpPtrAllocator holds the data.
+ FoldingSetNodeIDRef FastID;
+ // The SCEV baseclass this node corresponds to
+ const unsigned short SCEVType;
+
+ protected:
+ /// SubclassData - This field is initialized to zero and may be used in
+ /// subclasses to store miscellaneous information.
+ unsigned short SubclassData;
+
+ private:
SCEV(const SCEV &); // DO NOT IMPLEMENT
void operator=(const SCEV &); // DO NOT IMPLEMENT
- protected:
- virtual ~SCEV();
+
public:
- explicit SCEV(unsigned SCEVTy) : SCEVType(SCEVTy), RefCount(0) {}
+ explicit SCEV(const FoldingSetNodeIDRef ID, unsigned SCEVTy) :
+ FastID(ID), SCEVType(SCEVTy), SubclassData(0) {}
unsigned getSCEVType() const { return SCEVType; }
- /// isLoopInvariant - Return true if the value of this SCEV is unchanging in
- /// the specified loop.
- virtual bool isLoopInvariant(const Loop *L) const = 0;
-
- /// hasComputableLoopEvolution - Return true if this SCEV changes value in a
- /// known way in the specified loop. This property being true implies that
- /// the value is variant in the loop AND that we can emit an expression to
- /// compute the value of the expression at any particular loop iteration.
- virtual bool hasComputableLoopEvolution(const Loop *L) const = 0;
-
/// getType - Return the LLVM type of this SCEV expression.
///
- virtual const Type *getType() const = 0;
+ const Type *getType() const;
/// isZero - Return true if the expression is a constant zero.
///
///
bool isOne() const;
- /// replaceSymbolicValuesWithConcrete - If this SCEV internally references
- /// the symbolic value "Sym", construct and return a new SCEV that produces
- /// the same value, but which uses the concrete value Conc instead of the
- /// symbolic value. If this SCEV does not use the symbolic value, it
- /// returns itself.
- virtual SCEVHandle
- replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
- ScalarEvolution &SE) const = 0;
-
- /// dominates - Return true if elements that makes up this SCEV dominates
- /// the specified basic block.
- virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const = 0;
+ /// isAllOnesValue - Return true if the expression is a constant
+ /// all-ones value.
+ ///
+ bool isAllOnesValue() const;
/// print - Print out the internal representation of this scalar to the
/// specified stream. This should really only be used for debugging
/// purposes.
- virtual void print(raw_ostream &OS) const = 0;
- void print(std::ostream &OS) const;
- void print(std::ostream *OS) const { if (OS) print(*OS); }
+ void print(raw_ostream &OS) const;
/// dump - This method is used for debugging.
///
void dump() const;
};
- inline raw_ostream &operator<<(raw_ostream &OS, const SCEV &S) {
- S.print(OS);
- return OS;
- }
+ // Specialize FoldingSetTrait for SCEV to avoid needing to compute
+ // temporary FoldingSetNodeID values.
+ template<> struct FoldingSetTrait<SCEV> : DefaultFoldingSetTrait<SCEV> {
+ static void Profile(const SCEV &X, FoldingSetNodeID& ID) {
+ ID = X.FastID;
+ }
+ static bool Equals(const SCEV &X, const FoldingSetNodeID &ID,
+ FoldingSetNodeID &TempID) {
+ return ID == X.FastID;
+ }
+ static unsigned ComputeHash(const SCEV &X, FoldingSetNodeID &TempID) {
+ return X.FastID.ComputeHash();
+ }
+ };
- inline std::ostream &operator<<(std::ostream &OS, const SCEV &S) {
+ inline raw_ostream &operator<<(raw_ostream &OS, const SCEV &S) {
S.print(OS);
return OS;
}
/// marker.
struct SCEVCouldNotCompute : public SCEV {
SCEVCouldNotCompute();
- ~SCEVCouldNotCompute();
-
- // None of these methods are valid for this object.
- virtual bool isLoopInvariant(const Loop *L) const;
- virtual const Type *getType() const;
- virtual bool hasComputableLoopEvolution(const Loop *L) const;
- virtual void print(raw_ostream &OS) const;
- virtual SCEVHandle
- replaceSymbolicValuesWithConcrete(const SCEVHandle &Sym,
- const SCEVHandle &Conc,
- ScalarEvolution &SE) const;
-
- virtual bool dominates(BasicBlock *BB, DominatorTree *DT) const {
- return true;
- }
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const SCEVCouldNotCompute *S) { return true; }
static bool classof(const SCEV *S);
};
- /// SCEVHandle - This class is used to maintain the SCEV object's refcounts,
- /// freeing the objects when the last reference is dropped.
- class SCEVHandle {
- const SCEV *S;
- SCEVHandle(); // DO NOT IMPLEMENT
- public:
- SCEVHandle(const SCEV *s) : S(s) {
- assert(S && "Cannot create a handle to a null SCEV!");
- S->addRef();
- }
- SCEVHandle(const SCEVHandle &RHS) : S(RHS.S) {
- S->addRef();
- }
- ~SCEVHandle() { S->dropRef(); }
-
- operator const SCEV*() const { return S; }
-
- const SCEV &operator*() const { return *S; }
- const SCEV *operator->() const { return S; }
-
- bool operator==(const SCEV *RHS) const { return S == RHS; }
- bool operator!=(const SCEV *RHS) const { return S != RHS; }
-
- const SCEVHandle &operator=(SCEV *RHS) {
- if (S != RHS) {
- S->dropRef();
- S = RHS;
- S->addRef();
- }
- return *this;
- }
-
- const SCEVHandle &operator=(const SCEVHandle &RHS) {
- if (S != RHS.S) {
- S->dropRef();
- S = RHS.S;
- S->addRef();
- }
- return *this;
- }
- };
-
- template<typename From> struct simplify_type;
- template<> struct simplify_type<const SCEVHandle> {
- typedef const SCEV* SimpleType;
- static SimpleType getSimplifiedValue(const SCEVHandle &Node) {
- return Node;
- }
- };
- template<> struct simplify_type<SCEVHandle>
- : public simplify_type<const SCEVHandle> {};
-
/// ScalarEvolution - This class is the main scalar evolution driver. Because
/// client code (intentionally) can't do much with the SCEV objects directly,
/// they must ask this class for services.
///
class ScalarEvolution : public FunctionPass {
+ public:
+ /// LoopDisposition - An enum describing the relationship between a
+ /// SCEV and a loop.
+ enum LoopDisposition {
+ LoopVariant, ///< The SCEV is loop-variant (unknown).
+ LoopInvariant, ///< The SCEV is loop-invariant.
+ LoopComputable ///< The SCEV varies predictably with the loop.
+ };
+
+ /// BlockDisposition - An enum describing the relationship between a
+ /// SCEV and a basic block.
+ enum BlockDisposition {
+ DoesNotDominateBlock, ///< The SCEV does not dominate the block.
+ DominatesBlock, ///< The SCEV dominates the block.
+ ProperlyDominatesBlock ///< The SCEV properly dominates the block.
+ };
+
+ private:
/// SCEVCallbackVH - A CallbackVH to arrange for ScalarEvolution to be
/// notified whenever a Value is deleted.
class SCEVCallbackVH : public CallbackVH {
friend class SCEVCallbackVH;
friend class SCEVExpander;
+ friend class SCEVUnknown;
/// F - The function we are analyzing.
///
///
LoopInfo *LI;
- /// TD - The target data information for the target we are targetting.
+ /// TD - The target data information for the target we are targeting.
///
TargetData *TD;
+ /// DT - The dominator tree.
+ ///
+ DominatorTree *DT;
+
/// CouldNotCompute - This SCEV is used to represent unknown trip
/// counts and things.
- SCEVHandle CouldNotCompute;
+ SCEVCouldNotCompute CouldNotCompute;
+
+ /// ValueExprMapType - The typedef for ValueExprMap.
+ ///
+ typedef DenseMap<SCEVCallbackVH, const SCEV *, DenseMapInfo<Value *> >
+ ValueExprMapType;
- /// Scalars - This is a cache of the scalars we have analyzed so far.
+ /// ValueExprMap - This is a cache of the values we have analyzed so far.
///
- std::map<SCEVCallbackVH, SCEVHandle> Scalars;
+ ValueExprMapType ValueExprMap;
/// BackedgeTakenInfo - Information about the backedge-taken count
- /// of a loop. This currently inclues an exact count and a maximum count.
+ /// of a loop. This currently includes an exact count and a maximum count.
///
struct BackedgeTakenInfo {
/// Exact - An expression indicating the exact backedge-taken count of
/// the loop if it is known, or a SCEVCouldNotCompute otherwise.
- SCEVHandle Exact;
+ const SCEV *Exact;
- /// Exact - An expression indicating the least maximum backedge-taken
+ /// Max - An expression indicating the least maximum backedge-taken
/// count of the loop that is known, or a SCEVCouldNotCompute.
- SCEVHandle Max;
-
- /*implicit*/ BackedgeTakenInfo(SCEVHandle exact) :
- Exact(exact), Max(exact) {}
+ const SCEV *Max;
/*implicit*/ BackedgeTakenInfo(const SCEV *exact) :
Exact(exact), Max(exact) {}
- BackedgeTakenInfo(SCEVHandle exact, SCEVHandle max) :
+ BackedgeTakenInfo(const SCEV *exact, const SCEV *max) :
Exact(exact), Max(max) {}
/// hasAnyInfo - Test whether this BackedgeTakenInfo contains any
/// exit value.
std::map<PHINode*, Constant*> ConstantEvolutionLoopExitValue;
- /// ValuesAtScopes - This map contains entries for all the instructions
- /// that we attempt to compute getSCEVAtScope information for without
- /// using SCEV techniques, which can be expensive.
- std::map<Instruction *, std::map<const Loop *, Constant *> > ValuesAtScopes;
+ /// ValuesAtScopes - This map contains entries for all the expressions
+ /// that we attempt to compute getSCEVAtScope information for, which can
+ /// be expensive in extreme cases.
+ std::map<const SCEV *,
+ std::map<const Loop *, const SCEV *> > ValuesAtScopes;
+
+ /// LoopDispositions - Memoized computeLoopDisposition results.
+ std::map<const SCEV *,
+ std::map<const Loop *, LoopDisposition> > LoopDispositions;
+
+ /// computeLoopDisposition - Compute a LoopDisposition value.
+ LoopDisposition computeLoopDisposition(const SCEV *S, const Loop *L);
+
+ /// BlockDispositions - Memoized computeBlockDisposition results.
+ std::map<const SCEV *,
+ std::map<const BasicBlock *, BlockDisposition> > BlockDispositions;
+
+ /// computeBlockDisposition - Compute a BlockDisposition value.
+ BlockDisposition computeBlockDisposition(const SCEV *S, const BasicBlock *BB);
+
+ /// UnsignedRanges - Memoized results from getUnsignedRange
+ DenseMap<const SCEV *, ConstantRange> UnsignedRanges;
+
+ /// SignedRanges - Memoized results from getSignedRange
+ DenseMap<const SCEV *, ConstantRange> SignedRanges;
+
+ /// setUnsignedRange - Set the memoized unsigned range for the given SCEV.
+ const ConstantRange &setUnsignedRange(const SCEV *S,
+ const ConstantRange &CR) {
+ std::pair<DenseMap<const SCEV *, ConstantRange>::iterator, bool> Pair =
+ UnsignedRanges.insert(std::make_pair(S, CR));
+ if (!Pair.second)
+ Pair.first->second = CR;
+ return Pair.first->second;
+ }
+
+ /// setUnsignedRange - Set the memoized signed range for the given SCEV.
+ const ConstantRange &setSignedRange(const SCEV *S,
+ const ConstantRange &CR) {
+ std::pair<DenseMap<const SCEV *, ConstantRange>::iterator, bool> Pair =
+ SignedRanges.insert(std::make_pair(S, CR));
+ if (!Pair.second)
+ Pair.first->second = CR;
+ return Pair.first->second;
+ }
/// createSCEV - We know that there is no SCEV for the specified value.
/// Analyze the expression.
- SCEVHandle createSCEV(Value *V);
+ const SCEV *createSCEV(Value *V);
/// createNodeForPHI - Provide the special handling we need to analyze PHI
/// SCEVs.
- SCEVHandle createNodeForPHI(PHINode *PN);
+ const SCEV *createNodeForPHI(PHINode *PN);
/// createNodeForGEP - Provide the special handling we need to analyze GEP
/// SCEVs.
- SCEVHandle createNodeForGEP(User *GEP);
+ const SCEV *createNodeForGEP(GEPOperator *GEP);
- /// ReplaceSymbolicValueWithConcrete - This looks up the computed SCEV value
- /// for the specified instruction and replaces any references to the
- /// symbolic value SymName with the specified value. This is used during
- /// PHI resolution.
- void ReplaceSymbolicValueWithConcrete(Instruction *I,
- const SCEVHandle &SymName,
- const SCEVHandle &NewVal);
+ /// computeSCEVAtScope - Implementation code for getSCEVAtScope; called
+ /// at most once for each SCEV+Loop pair.
+ ///
+ const SCEV *computeSCEVAtScope(const SCEV *S, const Loop *L);
+
+ /// ForgetSymbolicValue - This looks up computed SCEV values for all
+ /// instructions that depend on the given instruction and removes them from
+ /// the ValueExprMap map if they reference SymName. This is used during PHI
+ /// resolution.
+ void ForgetSymbolicName(Instruction *I, const SCEV *SymName);
+
+ /// getBECount - Subtract the end and start values and divide by the step,
+ /// rounding up, to get the number of times the backedge is executed. Return
+ /// CouldNotCompute if an intermediate computation overflows.
+ const SCEV *getBECount(const SCEV *Start,
+ const SCEV *End,
+ const SCEV *Step,
+ bool NoWrap);
/// getBackedgeTakenInfo - Return the BackedgeTakenInfo for the given
/// loop, lazily computing new values if the loop hasn't been analyzed
/// loop will iterate.
BackedgeTakenInfo ComputeBackedgeTakenCount(const Loop *L);
+ /// ComputeBackedgeTakenCountFromExit - Compute the number of times the
+ /// backedge of the specified loop will execute if it exits via the
+ /// specified block.
+ BackedgeTakenInfo ComputeBackedgeTakenCountFromExit(const Loop *L,
+ BasicBlock *ExitingBlock);
+
+ /// ComputeBackedgeTakenCountFromExitCond - Compute the number of times the
+ /// backedge of the specified loop will execute if its exit condition
+ /// were a conditional branch of ExitCond, TBB, and FBB.
+ BackedgeTakenInfo
+ ComputeBackedgeTakenCountFromExitCond(const Loop *L,
+ Value *ExitCond,
+ BasicBlock *TBB,
+ BasicBlock *FBB);
+
+ /// ComputeBackedgeTakenCountFromExitCondICmp - Compute the number of
+ /// times the backedge of the specified loop will execute if its exit
+ /// condition were a conditional branch of the ICmpInst ExitCond, TBB,
+ /// and FBB.
+ BackedgeTakenInfo
+ ComputeBackedgeTakenCountFromExitCondICmp(const Loop *L,
+ ICmpInst *ExitCond,
+ BasicBlock *TBB,
+ BasicBlock *FBB);
+
/// ComputeLoadConstantCompareBackedgeTakenCount - Given an exit condition
- /// of 'icmp op load X, cst', try to see if we can compute the trip count.
- SCEVHandle
+ /// of 'icmp op load X, cst', try to see if we can compute the
+ /// backedge-taken count.
+ BackedgeTakenInfo
ComputeLoadConstantCompareBackedgeTakenCount(LoadInst *LI,
Constant *RHS,
const Loop *L,
ICmpInst::Predicate p);
- /// ComputeBackedgeTakenCountExhaustively - If the trip is known to execute
+ /// ComputeBackedgeTakenCountExhaustively - If the loop is known to execute
/// a constant number of times (the condition evolves only from constants),
/// try to evaluate a few iterations of the loop until we get the exit
/// condition gets a value of ExitWhen (true or false). If we cannot
- /// evaluate the trip count of the loop, return CouldNotCompute.
- SCEVHandle ComputeBackedgeTakenCountExhaustively(const Loop *L, Value *Cond,
- bool ExitWhen);
+ /// evaluate the backedge-taken count of the loop, return CouldNotCompute.
+ const SCEV *ComputeBackedgeTakenCountExhaustively(const Loop *L,
+ Value *Cond,
+ bool ExitWhen);
/// HowFarToZero - Return the number of times a backedge comparing the
/// specified value to zero will execute. If not computable, return
/// CouldNotCompute.
- SCEVHandle HowFarToZero(const SCEV *V, const Loop *L);
+ BackedgeTakenInfo HowFarToZero(const SCEV *V, const Loop *L);
/// HowFarToNonZero - Return the number of times a backedge checking the
/// specified value for nonzero will execute. If not computable, return
/// CouldNotCompute.
- SCEVHandle HowFarToNonZero(const SCEV *V, const Loop *L);
+ BackedgeTakenInfo HowFarToNonZero(const SCEV *V, const Loop *L);
/// HowManyLessThans - Return the number of times a backedge containing the
/// specified less-than comparison will execute. If not computable, return
BackedgeTakenInfo HowManyLessThans(const SCEV *LHS, const SCEV *RHS,
const Loop *L, bool isSigned);
- /// getLoopPredecessor - If the given loop's header has exactly one unique
- /// predecessor outside the loop, return it. Otherwise return null.
- BasicBlock *getLoopPredecessor(const Loop *L);
-
/// getPredecessorWithUniqueSuccessorForBB - Return a predecessor of BB
/// (which may not be an immediate predecessor) which has exactly one
/// successor from which BB is reachable, or null if no such block is
/// found.
- BasicBlock* getPredecessorWithUniqueSuccessorForBB(BasicBlock *BB);
+ std::pair<BasicBlock *, BasicBlock *>
+ getPredecessorWithUniqueSuccessorForBB(BasicBlock *BB);
+
+ /// isImpliedCond - Test whether the condition described by Pred, LHS, and
+ /// RHS is true whenever the given FoundCondValue value evaluates to true.
+ bool isImpliedCond(ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS,
+ Value *FoundCondValue,
+ bool Inverse);
+
+ /// isImpliedCondOperands - Test whether the condition described by Pred,
+ /// LHS, and RHS is true whenever the condition described by Pred, FoundLHS,
+ /// and FoundRHS is true.
+ bool isImpliedCondOperands(ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS,
+ const SCEV *FoundLHS, const SCEV *FoundRHS);
+
+ /// isImpliedCondOperandsHelper - Test whether the condition described by
+ /// Pred, LHS, and RHS is true whenever the condition described by Pred,
+ /// FoundLHS, and FoundRHS is true.
+ bool isImpliedCondOperandsHelper(ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS,
+ const SCEV *FoundLHS, const SCEV *FoundRHS);
/// getConstantEvolutionLoopExitValue - If we know that the specified Phi is
/// in the header of its containing loop, we know the loop executes a
Constant *getConstantEvolutionLoopExitValue(PHINode *PN, const APInt& BEs,
const Loop *L);
- /// forgetLoopPHIs - Delete the memoized SCEVs associated with the
- /// PHI nodes in the given loop. This is used when the trip count of
- /// the loop may have changed.
- void forgetLoopPHIs(const Loop *L);
+ /// isKnownPredicateWithRanges - Test if the given expression is known to
+ /// satisfy the condition described by Pred and the known constant ranges
+ /// of LHS and RHS.
+ ///
+ bool isKnownPredicateWithRanges(ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS);
+
+ /// forgetMemoizedResults - Drop memoized information computed for S.
+ void forgetMemoizedResults(const SCEV *S);
public:
static char ID; // Pass identification, replacement for typeid
ScalarEvolution();
+ LLVMContext &getContext() const { return F->getContext(); }
+
/// isSCEVable - Test if values of the given type are analyzable within
/// the SCEV framework. This primarily includes integer types, and it
/// can optionally include pointer types if the ScalarEvolution class
/// this is the pointer-sized integer type.
const Type *getEffectiveSCEVType(const Type *Ty) const;
- /// getSCEV - Return a SCEV expression handle for the full generality of the
+ /// getSCEV - Return a SCEV expression for the full generality of the
/// specified expression.
- SCEVHandle getSCEV(Value *V);
-
- SCEVHandle getConstant(ConstantInt *V);
- SCEVHandle getConstant(const APInt& Val);
- SCEVHandle getTruncateExpr(const SCEVHandle &Op, const Type *Ty);
- SCEVHandle getZeroExtendExpr(const SCEVHandle &Op, const Type *Ty);
- SCEVHandle getSignExtendExpr(const SCEVHandle &Op, const Type *Ty);
- SCEVHandle getAnyExtendExpr(const SCEVHandle &Op, const Type *Ty);
- SCEVHandle getAddExpr(SmallVectorImpl<SCEVHandle> &Ops);
- SCEVHandle getAddExpr(const SCEVHandle &LHS, const SCEVHandle &RHS) {
- SmallVector<SCEVHandle, 2> Ops;
+ const SCEV *getSCEV(Value *V);
+
+ const SCEV *getConstant(ConstantInt *V);
+ const SCEV *getConstant(const APInt& Val);
+ const SCEV *getConstant(const Type *Ty, uint64_t V, bool isSigned = false);
+ const SCEV *getTruncateExpr(const SCEV *Op, const Type *Ty);
+ const SCEV *getZeroExtendExpr(const SCEV *Op, const Type *Ty);
+ const SCEV *getSignExtendExpr(const SCEV *Op, const Type *Ty);
+ const SCEV *getAnyExtendExpr(const SCEV *Op, const Type *Ty);
+ const SCEV *getAddExpr(SmallVectorImpl<const SCEV *> &Ops,
+ bool HasNUW = false, bool HasNSW = false);
+ const SCEV *getAddExpr(const SCEV *LHS, const SCEV *RHS,
+ bool HasNUW = false, bool HasNSW = false) {
+ SmallVector<const SCEV *, 2> Ops;
Ops.push_back(LHS);
Ops.push_back(RHS);
- return getAddExpr(Ops);
+ return getAddExpr(Ops, HasNUW, HasNSW);
}
- SCEVHandle getAddExpr(const SCEVHandle &Op0, const SCEVHandle &Op1,
- const SCEVHandle &Op2) {
- SmallVector<SCEVHandle, 3> Ops;
+ const SCEV *getAddExpr(const SCEV *Op0, const SCEV *Op1,
+ const SCEV *Op2,
+ bool HasNUW = false, bool HasNSW = false) {
+ SmallVector<const SCEV *, 3> Ops;
Ops.push_back(Op0);
Ops.push_back(Op1);
Ops.push_back(Op2);
- return getAddExpr(Ops);
+ return getAddExpr(Ops, HasNUW, HasNSW);
}
- SCEVHandle getMulExpr(SmallVectorImpl<SCEVHandle> &Ops);
- SCEVHandle getMulExpr(const SCEVHandle &LHS, const SCEVHandle &RHS) {
- SmallVector<SCEVHandle, 2> Ops;
+ const SCEV *getMulExpr(SmallVectorImpl<const SCEV *> &Ops,
+ bool HasNUW = false, bool HasNSW = false);
+ const SCEV *getMulExpr(const SCEV *LHS, const SCEV *RHS,
+ bool HasNUW = false, bool HasNSW = false) {
+ SmallVector<const SCEV *, 2> Ops;
Ops.push_back(LHS);
Ops.push_back(RHS);
- return getMulExpr(Ops);
+ return getMulExpr(Ops, HasNUW, HasNSW);
}
- SCEVHandle getUDivExpr(const SCEVHandle &LHS, const SCEVHandle &RHS);
- SCEVHandle getAddRecExpr(const SCEVHandle &Start, const SCEVHandle &Step,
- const Loop *L);
- SCEVHandle getAddRecExpr(SmallVectorImpl<SCEVHandle> &Operands,
- const Loop *L);
- SCEVHandle getAddRecExpr(const SmallVectorImpl<SCEVHandle> &Operands,
- const Loop *L) {
- SmallVector<SCEVHandle, 4> NewOp(Operands.begin(), Operands.end());
- return getAddRecExpr(NewOp, L);
+ const SCEV *getUDivExpr(const SCEV *LHS, const SCEV *RHS);
+ const SCEV *getAddRecExpr(const SCEV *Start, const SCEV *Step,
+ const Loop *L,
+ bool HasNUW = false, bool HasNSW = false);
+ const SCEV *getAddRecExpr(SmallVectorImpl<const SCEV *> &Operands,
+ const Loop *L,
+ bool HasNUW = false, bool HasNSW = false);
+ const SCEV *getAddRecExpr(const SmallVectorImpl<const SCEV *> &Operands,
+ const Loop *L,
+ bool HasNUW = false, bool HasNSW = false) {
+ SmallVector<const SCEV *, 4> NewOp(Operands.begin(), Operands.end());
+ return getAddRecExpr(NewOp, L, HasNUW, HasNSW);
}
- SCEVHandle getSMaxExpr(const SCEVHandle &LHS, const SCEVHandle &RHS);
- SCEVHandle getSMaxExpr(SmallVectorImpl<SCEVHandle> &Operands);
- SCEVHandle getUMaxExpr(const SCEVHandle &LHS, const SCEVHandle &RHS);
- SCEVHandle getUMaxExpr(SmallVectorImpl<SCEVHandle> &Operands);
- SCEVHandle getUnknown(Value *V);
- SCEVHandle getCouldNotCompute();
+ const SCEV *getSMaxExpr(const SCEV *LHS, const SCEV *RHS);
+ const SCEV *getSMaxExpr(SmallVectorImpl<const SCEV *> &Operands);
+ const SCEV *getUMaxExpr(const SCEV *LHS, const SCEV *RHS);
+ const SCEV *getUMaxExpr(SmallVectorImpl<const SCEV *> &Operands);
+ const SCEV *getSMinExpr(const SCEV *LHS, const SCEV *RHS);
+ const SCEV *getUMinExpr(const SCEV *LHS, const SCEV *RHS);
+ const SCEV *getUnknown(Value *V);
+ const SCEV *getCouldNotCompute();
+
+ /// getSizeOfExpr - Return an expression for sizeof on the given type.
+ ///
+ const SCEV *getSizeOfExpr(const Type *AllocTy);
+
+ /// getAlignOfExpr - Return an expression for alignof on the given type.
+ ///
+ const SCEV *getAlignOfExpr(const Type *AllocTy);
+
+ /// getOffsetOfExpr - Return an expression for offsetof on the given field.
+ ///
+ const SCEV *getOffsetOfExpr(const StructType *STy, unsigned FieldNo);
+
+ /// getOffsetOfExpr - Return an expression for offsetof on the given field.
+ ///
+ const SCEV *getOffsetOfExpr(const Type *CTy, Constant *FieldNo);
/// getNegativeSCEV - Return the SCEV object corresponding to -V.
///
- SCEVHandle getNegativeSCEV(const SCEVHandle &V);
+ const SCEV *getNegativeSCEV(const SCEV *V);
/// getNotSCEV - Return the SCEV object corresponding to ~V.
///
- SCEVHandle getNotSCEV(const SCEVHandle &V);
+ const SCEV *getNotSCEV(const SCEV *V);
- /// getMinusSCEV - Return LHS-RHS.
- ///
- SCEVHandle getMinusSCEV(const SCEVHandle &LHS,
- const SCEVHandle &RHS);
+ /// getMinusSCEV - Return LHS-RHS. Minus is represented in SCEV as A+B*-1,
+ /// and thus the HasNUW and HasNSW bits apply to the resultant add, not
+ /// whether the sub would have overflowed.
+ const SCEV *getMinusSCEV(const SCEV *LHS, const SCEV *RHS,
+ bool HasNUW = false, bool HasNSW = false);
/// getTruncateOrZeroExtend - Return a SCEV corresponding to a conversion
/// of the input value to the specified type. If the type must be
/// extended, it is zero extended.
- SCEVHandle getTruncateOrZeroExtend(const SCEVHandle &V, const Type *Ty);
+ const SCEV *getTruncateOrZeroExtend(const SCEV *V, const Type *Ty);
/// getTruncateOrSignExtend - Return a SCEV corresponding to a conversion
/// of the input value to the specified type. If the type must be
/// extended, it is sign extended.
- SCEVHandle getTruncateOrSignExtend(const SCEVHandle &V, const Type *Ty);
+ const SCEV *getTruncateOrSignExtend(const SCEV *V, const Type *Ty);
/// getNoopOrZeroExtend - Return a SCEV corresponding to a conversion of
/// the input value to the specified type. If the type must be extended,
/// it is zero extended. The conversion must not be narrowing.
- SCEVHandle getNoopOrZeroExtend(const SCEVHandle &V, const Type *Ty);
+ const SCEV *getNoopOrZeroExtend(const SCEV *V, const Type *Ty);
/// getNoopOrSignExtend - Return a SCEV corresponding to a conversion of
/// the input value to the specified type. If the type must be extended,
/// it is sign extended. The conversion must not be narrowing.
- SCEVHandle getNoopOrSignExtend(const SCEVHandle &V, const Type *Ty);
+ const SCEV *getNoopOrSignExtend(const SCEV *V, const Type *Ty);
/// getNoopOrAnyExtend - Return a SCEV corresponding to a conversion of
/// the input value to the specified type. If the type must be extended,
/// it is extended with unspecified bits. The conversion must not be
/// narrowing.
- SCEVHandle getNoopOrAnyExtend(const SCEVHandle &V, const Type *Ty);
+ const SCEV *getNoopOrAnyExtend(const SCEV *V, const Type *Ty);
/// getTruncateOrNoop - Return a SCEV corresponding to a conversion of the
/// input value to the specified type. The conversion must not be
/// widening.
- SCEVHandle getTruncateOrNoop(const SCEVHandle &V, const Type *Ty);
+ const SCEV *getTruncateOrNoop(const SCEV *V, const Type *Ty);
- /// getIntegerSCEV - Given an integer or FP type, create a constant for the
- /// specified signed integer value and return a SCEV for the constant.
- SCEVHandle getIntegerSCEV(int Val, const Type *Ty);
+ /// getUMaxFromMismatchedTypes - Promote the operands to the wider of
+ /// the types using zero-extension, and then perform a umax operation
+ /// with them.
+ const SCEV *getUMaxFromMismatchedTypes(const SCEV *LHS,
+ const SCEV *RHS);
- /// hasSCEV - Return true if the SCEV for this value has already been
- /// computed.
- bool hasSCEV(Value *V) const;
+ /// getUMinFromMismatchedTypes - Promote the operands to the wider of
+ /// the types using zero-extension, and then perform a umin operation
+ /// with them.
+ const SCEV *getUMinFromMismatchedTypes(const SCEV *LHS,
+ const SCEV *RHS);
- /// setSCEV - Insert the specified SCEV into the map of current SCEVs for
- /// the specified value.
- void setSCEV(Value *V, const SCEVHandle &H);
-
- /// getSCEVAtScope - Return a SCEV expression handle for the specified value
+ /// getSCEVAtScope - Return a SCEV expression for the specified value
/// at the specified scope in the program. The L value specifies a loop
/// nest to evaluate the expression at, where null is the top-level or a
/// specified loop is immediately inside of the loop.
///
/// In the case that a relevant loop exit value cannot be computed, the
/// original value V is returned.
- SCEVHandle getSCEVAtScope(const SCEV *S, const Loop *L);
+ const SCEV *getSCEVAtScope(const SCEV *S, const Loop *L);
/// getSCEVAtScope - This is a convenience function which does
/// getSCEVAtScope(getSCEV(V), L).
- SCEVHandle getSCEVAtScope(Value *V, const Loop *L);
+ const SCEV *getSCEVAtScope(Value *V, const Loop *L);
+
+ /// isLoopEntryGuardedByCond - Test whether entry to the loop is protected
+ /// by a conditional between LHS and RHS. This is used to help avoid max
+ /// expressions in loop trip counts, and to eliminate casts.
+ bool isLoopEntryGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS);
- /// isLoopGuardedByCond - Test whether entry to the loop is protected by
- /// a conditional between LHS and RHS. This is used to help avoid max
- /// expressions in loop trip counts.
- bool isLoopGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
- const SCEV *LHS, const SCEV *RHS);
+ /// isLoopBackedgeGuardedByCond - Test whether the backedge of the loop is
+ /// protected by a conditional between LHS and RHS. This is used to
+ /// to eliminate casts.
+ bool isLoopBackedgeGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS);
/// getBackedgeTakenCount - If the specified loop has a predictable
/// backedge-taken count, return it, otherwise return a SCEVCouldNotCompute
/// loop-invariant backedge-taken count (see
/// hasLoopInvariantBackedgeTakenCount).
///
- SCEVHandle getBackedgeTakenCount(const Loop *L);
+ const SCEV *getBackedgeTakenCount(const Loop *L);
/// getMaxBackedgeTakenCount - Similar to getBackedgeTakenCount, except
/// return the least SCEV value that is known never to be less than the
/// actual backedge taken count.
- SCEVHandle getMaxBackedgeTakenCount(const Loop *L);
+ const SCEV *getMaxBackedgeTakenCount(const Loop *L);
/// hasLoopInvariantBackedgeTakenCount - Return true if the specified loop
/// has an analyzable loop-invariant backedge-taken count.
bool hasLoopInvariantBackedgeTakenCount(const Loop *L);
- /// forgetLoopBackedgeTakenCount - This method should be called by the
- /// client when it has changed a loop in a way that may effect
- /// ScalarEvolution's ability to compute a trip count, or if the loop
- /// is deleted.
- void forgetLoopBackedgeTakenCount(const Loop *L);
+ /// forgetLoop - This method should be called by the client when it has
+ /// changed a loop in a way that may effect ScalarEvolution's ability to
+ /// compute a trip count, or if the loop is deleted.
+ void forgetLoop(const Loop *L);
+
+ /// forgetValue - This method should be called by the client when it has
+ /// changed a value in a way that may effect its value, or which may
+ /// disconnect it from a def-use chain linking it to a loop.
+ void forgetValue(Value *V);
+
+ /// GetMinTrailingZeros - Determine the minimum number of zero bits that S
+ /// is guaranteed to end in (at every loop iteration). It is, at the same
+ /// time, the minimum number of times S is divisible by 2. For example,
+ /// given {4,+,8} it returns 2. If S is guaranteed to be 0, it returns the
+ /// bitwidth of S.
+ uint32_t GetMinTrailingZeros(const SCEV *S);
+
+ /// getUnsignedRange - Determine the unsigned range for a particular SCEV.
+ ///
+ ConstantRange getUnsignedRange(const SCEV *S);
+
+ /// getSignedRange - Determine the signed range for a particular SCEV.
+ ///
+ ConstantRange getSignedRange(const SCEV *S);
+
+ /// isKnownNegative - Test if the given expression is known to be negative.
+ ///
+ bool isKnownNegative(const SCEV *S);
+
+ /// isKnownPositive - Test if the given expression is known to be positive.
+ ///
+ bool isKnownPositive(const SCEV *S);
+
+ /// isKnownNonNegative - Test if the given expression is known to be
+ /// non-negative.
+ ///
+ bool isKnownNonNegative(const SCEV *S);
+
+ /// isKnownNonPositive - Test if the given expression is known to be
+ /// non-positive.
+ ///
+ bool isKnownNonPositive(const SCEV *S);
+
+ /// isKnownNonZero - Test if the given expression is known to be
+ /// non-zero.
+ ///
+ bool isKnownNonZero(const SCEV *S);
+
+ /// isKnownPredicate - Test if the given expression is known to satisfy
+ /// the condition described by Pred, LHS, and RHS.
+ ///
+ bool isKnownPredicate(ICmpInst::Predicate Pred,
+ const SCEV *LHS, const SCEV *RHS);
+
+ /// SimplifyICmpOperands - Simplify LHS and RHS in a comparison with
+ /// predicate Pred. Return true iff any changes were made. If the
+ /// operands are provably equal or inequal, LHS and RHS are set to
+ /// the same value and Pred is set to either ICMP_EQ or ICMP_NE.
+ ///
+ bool SimplifyICmpOperands(ICmpInst::Predicate &Pred,
+ const SCEV *&LHS,
+ const SCEV *&RHS);
+
+ /// getLoopDisposition - Return the "disposition" of the given SCEV with
+ /// respect to the given loop.
+ LoopDisposition getLoopDisposition(const SCEV *S, const Loop *L);
+
+ /// isLoopInvariant - Return true if the value of the given SCEV is
+ /// unchanging in the specified loop.
+ bool isLoopInvariant(const SCEV *S, const Loop *L);
+
+ /// hasComputableLoopEvolution - Return true if the given SCEV changes value
+ /// in a known way in the specified loop. This property being true implies
+ /// that the value is variant in the loop AND that we can emit an expression
+ /// to compute the value of the expression at any particular loop iteration.
+ bool hasComputableLoopEvolution(const SCEV *S, const Loop *L);
+
+ /// getLoopDisposition - Return the "disposition" of the given SCEV with
+ /// respect to the given block.
+ BlockDisposition getBlockDisposition(const SCEV *S, const BasicBlock *BB);
+
+ /// dominates - Return true if elements that makes up the given SCEV
+ /// dominate the specified basic block.
+ bool dominates(const SCEV *S, const BasicBlock *BB);
+
+ /// properlyDominates - Return true if elements that makes up the given SCEV
+ /// properly dominate the specified basic block.
+ bool properlyDominates(const SCEV *S, const BasicBlock *BB);
+
+ /// hasOperand - Test whether the given SCEV has Op as a direct or
+ /// indirect operand.
+ bool hasOperand(const SCEV *S, const SCEV *Op) const;
virtual bool runOnFunction(Function &F);
virtual void releaseMemory();
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
- void print(raw_ostream &OS, const Module* = 0) const;
- virtual void print(std::ostream &OS, const Module* = 0) const;
- void print(std::ostream *OS, const Module* M = 0) const {
- if (OS) print(*OS, M);
- }
+ virtual void print(raw_ostream &OS, const Module* = 0) const;
+
+ private:
+ FoldingSet<SCEV> UniqueSCEVs;
+ BumpPtrAllocator SCEVAllocator;
+
+ /// FirstUnknown - The head of a linked list of all SCEVUnknown
+ /// values that have been allocated. This is used by releaseMemory
+ /// to locate them all and call their destructors.
+ SCEVUnknown *FirstUnknown;
};
}
projects / oota-llvm.git / blobdiff