#define LLVM_ANALYSIS_DEPENDENCEANALYSIS_H
#include "llvm/ADT/SmallBitVector.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/IR/Instructions.h"
#include "llvm/Pass.h"
namespace llvm {
- class AliasAnalysis;
class Loop;
class LoopInfo;
class ScalarEvolution;
/// cases (for output, flow, and anti dependences), the dependence implies
/// an ordering, where the source must precede the destination; in contrast,
/// input dependences are unordered.
+ ///
+ /// When a dependence graph is built, each Dependence will be a member of
+ /// the set of predecessor edges for its destination instruction and a set
+ /// if successor edges for its source instruction. These sets are represented
+ /// as singly-linked lists, with the "next" fields stored in the dependence
+ /// itelf.
class Dependence {
+ protected:
+ Dependence(const Dependence &) = default;
+
+ // FIXME: When we move to MSVC 2015 as the base compiler for Visual Studio
+ // support, uncomment this line to allow a defaulted move constructor for
+ // Dependence. Currently, FullDependence relies on the copy constructor, but
+ // that is acceptable given the triviality of the class.
+ // Dependence(Dependence &&) = default;
+
public:
Dependence(Instruction *Source,
Instruction *Destination) :
- Src(Source), Dst(Destination) {}
+ Src(Source),
+ Dst(Destination),
+ NextPredecessor(nullptr),
+ NextSuccessor(nullptr) {}
virtual ~Dependence() {}
/// Dependence::DVEntry - Each level in the distance/direction vector
bool Splitable : 1; // Splitting the loop will break dependence.
const SCEV *Distance; // NULL implies no distance available.
DVEntry() : Direction(ALL), Scalar(true), PeelFirst(false),
- PeelLast(false), Splitable(false), Distance(NULL) { }
+ PeelLast(false), Splitable(false), Distance(nullptr) { }
};
/// getSrc - Returns the source instruction for this dependence.
/// getDistance - Returns the distance (or NULL) associated with a
/// particular level.
- virtual const SCEV *getDistance(unsigned Level) const { return NULL; }
+ virtual const SCEV *getDistance(unsigned Level) const { return nullptr; }
/// isPeelFirst - Returns true if peeling the first iteration from
/// this loop will break this dependence.
/// variable associated with the loop at this level.
virtual bool isScalar(unsigned Level) const;
+ /// getNextPredecessor - Returns the value of the NextPredecessor
+ /// field.
+ const Dependence *getNextPredecessor() const { return NextPredecessor; }
+
+ /// getNextSuccessor - Returns the value of the NextSuccessor
+ /// field.
+ const Dependence *getNextSuccessor() const { return NextSuccessor; }
+
+ /// setNextPredecessor - Sets the value of the NextPredecessor
+ /// field.
+ void setNextPredecessor(const Dependence *pred) { NextPredecessor = pred; }
+
+ /// setNextSuccessor - Sets the value of the NextSuccessor
+ /// field.
+ void setNextSuccessor(const Dependence *succ) { NextSuccessor = succ; }
+
/// dump - For debugging purposes, dumps a dependence to OS.
///
void dump(raw_ostream &OS) const;
+
private:
Instruction *Src, *Dst;
+ const Dependence *NextPredecessor, *NextSuccessor;
friend class DependenceAnalysis;
};
-
/// FullDependence - This class represents a dependence between two memory
/// references in a function. It contains detailed information about the
/// dependence (direction vectors, etc.) and is used when the compiler is
/// (for output, flow, and anti dependences), the dependence implies an
/// ordering, where the source must precede the destination; in contrast,
/// input dependences are unordered.
- class FullDependence : public Dependence {
+ class FullDependence final : public Dependence {
public:
- FullDependence(Instruction *Src,
- Instruction *Dst,
- bool LoopIndependent,
+ FullDependence(Instruction *Src, Instruction *Dst, bool LoopIndependent,
unsigned Levels);
- ~FullDependence() {
- delete[] DV;
- }
+
+ FullDependence(FullDependence &&RHS)
+ : Dependence(std::move(RHS)), Levels(RHS.Levels),
+ LoopIndependent(RHS.LoopIndependent), Consistent(RHS.Consistent),
+ DV(std::move(RHS.DV)) {}
/// isLoopIndependent - Returns true if this is a loop-independent
/// dependence.
- bool isLoopIndependent() const { return LoopIndependent; }
+ bool isLoopIndependent() const override { return LoopIndependent; }
/// isConfused - Returns true if this dependence is confused
/// (the compiler understands nothing and makes worst-case
/// assumptions).
- bool isConfused() const { return false; }
+ bool isConfused() const override { return false; }
/// isConsistent - Returns true if this dependence is consistent
/// (occurs every time the source and destination are executed).
- bool isConsistent() const { return Consistent; }
+ bool isConsistent() const override { return Consistent; }
/// getLevels - Returns the number of common loops surrounding the
/// source and destination of the dependence.
- unsigned getLevels() const { return Levels; }
+ unsigned getLevels() const override { return Levels; }
/// getDirection - Returns the direction associated with a particular
/// level.
- unsigned getDirection(unsigned Level) const;
+ unsigned getDirection(unsigned Level) const override;
/// getDistance - Returns the distance (or NULL) associated with a
/// particular level.
- const SCEV *getDistance(unsigned Level) const;
+ const SCEV *getDistance(unsigned Level) const override;
/// isPeelFirst - Returns true if peeling the first iteration from
/// this loop will break this dependence.
- bool isPeelFirst(unsigned Level) const;
+ bool isPeelFirst(unsigned Level) const override;
/// isPeelLast - Returns true if peeling the last iteration from
/// this loop will break this dependence.
- bool isPeelLast(unsigned Level) const;
+ bool isPeelLast(unsigned Level) const override;
/// isSplitable - Returns true if splitting the loop will break
/// the dependence.
- bool isSplitable(unsigned Level) const;
+ bool isSplitable(unsigned Level) const override;
/// isScalar - Returns true if a particular level is scalar; that is,
/// if no subscript in the source or destination mention the induction
/// variable associated with the loop at this level.
- bool isScalar(unsigned Level) const;
+ bool isScalar(unsigned Level) const override;
+
private:
unsigned short Levels;
bool LoopIndependent;
bool Consistent; // Init to true, then refine.
- DVEntry *DV;
+ std::unique_ptr<DVEntry[]> DV;
friend class DependenceAnalysis;
};
-
/// DependenceAnalysis - This class is the main dependence-analysis driver.
///
class DependenceAnalysis : public FunctionPass {
- void operator=(const DependenceAnalysis &) LLVM_DELETED_FUNCTION;
- DependenceAnalysis(const DependenceAnalysis &) LLVM_DELETED_FUNCTION;
+ void operator=(const DependenceAnalysis &) = delete;
+ DependenceAnalysis(const DependenceAnalysis &) = delete;
+
public:
/// depends - Tests for a dependence between the Src and Dst instructions.
/// Returns NULL if no dependence; otherwise, returns a Dependence (or a
/// The flag PossiblyLoopIndependent should be set by the caller
/// if it appears that control flow can reach from Src to Dst
/// without traversing a loop back edge.
- Dependence *depends(Instruction *Src,
- Instruction *Dst,
- bool PossiblyLoopIndependent);
+ std::unique_ptr<Dependence> depends(Instruction *Src,
+ Instruction *Dst,
+ bool PossiblyLoopIndependent);
/// getSplitIteration - Give a dependence that's splittable at some
/// particular level, return the iteration that should be used to split
///
/// breaks the dependence and allows us to vectorize/parallelize
/// both loops.
- const SCEV *getSplitIteration(const Dependence *Dep, unsigned Level);
+ const SCEV *getSplitIteration(const Dependence &Dep, unsigned Level);
private:
AliasAnalysis *AA;
const SCEV *B;
const SCEV *C;
const Loop *AssociatedLoop;
+
public:
/// isEmpty - Return true if the constraint is of kind Empty.
bool isEmpty() const { return Kind == Empty; }
void dump(raw_ostream &OS) const;
};
-
/// establishNestingLevels - Examines the loop nesting of the Src and Dst
/// instructions and establishes their shared loops. Sets the variables
/// CommonLevels, SrcLevels, and MaxLevels.
/// in LoopNest.
bool isLoopInvariant(const SCEV *Expression, const Loop *LoopNest) const;
+ /// Makes sure all subscript pairs share the same integer type by
+ /// sign-extending as necessary.
+ /// Sign-extending a subscript is safe because getelementptr assumes the
+ /// array subscripts are signed.
+ void unifySubscriptType(ArrayRef<Subscript *> Pairs);
+
/// removeMatchingExtensions - Examines a subscript pair.
/// If the source and destination are identically sign (or zero)
/// extended, it strips off the extension in an effort to
const SCEV *Delta) const;
/// testBounds - Returns true iff the current bounds are plausible.
- ///
bool testBounds(unsigned char DirKind,
unsigned Level,
BoundInfo *Bound,
bool propagate(const SCEV *&Src,
const SCEV *&Dst,
SmallBitVector &Loops,
- SmallVector<Constraint, 4> &Constraints,
+ SmallVectorImpl<Constraint> &Constraints,
bool &Consistent);
/// propagateDistance - Attempt to propagate a distance
/// based on the current constraint.
void updateDirection(Dependence::DVEntry &Level,
const Constraint &CurConstraint) const;
+
+ bool tryDelinearize(Instruction *Src, Instruction *Dst,
+ SmallVectorImpl<Subscript> &Pair);
+
public:
static char ID; // Class identification, replacement for typeinfo
DependenceAnalysis() : FunctionPass(ID) {
initializeDependenceAnalysisPass(*PassRegistry::getPassRegistry());
}
- bool runOnFunction(Function &F);
- void releaseMemory();
- void getAnalysisUsage(AnalysisUsage &) const;
- void print(raw_ostream &, const Module * = 0) const;
+ bool runOnFunction(Function &F) override;
+ void releaseMemory() override;
+ void getAnalysisUsage(AnalysisUsage &) const override;
+ void print(raw_ostream &, const Module * = nullptr) const override;
}; // class DependenceAnalysis
/// createDependenceAnalysisPass - This creates an instance of the
projects / oota-llvm.git / blobdiff