[llvm] [DA][NFC] clang-format DependenceAnalysis (PR #151505)
Michael Kruse via llvm-commits
llvm-commits at lists.llvm.org
Thu Jul 31 05:29:27 PDT 2025
https://github.com/Meinersbur updated https://github.com/llvm/llvm-project/pull/151505
>From 78c857a6e08c2d4d4bf3776672b2224b7bee6b67 Mon Sep 17 00:00:00 2001
From: Michael Kruse <llvm-project at meinersbur.de>
Date: Thu, 31 Jul 2025 14:20:36 +0200
Subject: [PATCH] clang-format DependenceAnalysis
---
.../llvm/Analysis/DependenceAnalysis.h | 1800 ++++++++---------
llvm/lib/Analysis/DependenceAnalysis.cpp | 484 ++---
2 files changed, 1047 insertions(+), 1237 deletions(-)
diff --git a/llvm/include/llvm/Analysis/DependenceAnalysis.h b/llvm/include/llvm/Analysis/DependenceAnalysis.h
index f98bd684149f9..84b9f0464966b 100644
--- a/llvm/include/llvm/Analysis/DependenceAnalysis.h
+++ b/llvm/include/llvm/Analysis/DependenceAnalysis.h
@@ -47,994 +47,910 @@
#include "llvm/Support/Compiler.h"
namespace llvm {
- class AAResults;
- template <typename T> class ArrayRef;
- class Loop;
- class LoopInfo;
- class SCEVConstant;
- class raw_ostream;
-
- /// Dependence - This class represents a dependence between two memory
- /// memory references in a function. It contains minimal information and
- /// is used in the very common situation where the compiler is unable to
- /// determine anything beyond the existence of a dependence; that is, it
- /// represents a confused dependence (see also FullDependence). In most
- /// 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 LLVM_ABI Dependence {
- protected:
- Dependence(Dependence &&) = default;
- Dependence &operator=(Dependence &&) = default;
-
- public:
- Dependence(Instruction *Source, Instruction *Destination,
- const SCEVUnionPredicate &A)
- : Src(Source), Dst(Destination), Assumptions(A) {}
- virtual ~Dependence() = default;
-
- /// Dependence::DVEntry - Each level in the distance/direction vector
- /// has a direction (or perhaps a union of several directions), and
- /// perhaps a distance.
- struct DVEntry {
- enum : unsigned char {
- NONE = 0,
- LT = 1,
- EQ = 2,
- LE = 3,
- GT = 4,
- NE = 5,
- GE = 6,
- ALL = 7
- };
- unsigned char Direction : 3; // Init to ALL, then refine.
- bool Scalar : 1; // Init to true.
- bool PeelFirst : 1; // Peeling the first iteration will break dependence.
- bool PeelLast : 1; // Peeling the last iteration will break the dependence.
- bool Splitable : 1; // Splitting the loop will break dependence.
- const SCEV *Distance = nullptr; // NULL implies no distance available.
- DVEntry()
- : Direction(ALL), Scalar(true), PeelFirst(false), PeelLast(false),
- Splitable(false) {}
+class AAResults;
+template <typename T> class ArrayRef;
+class Loop;
+class LoopInfo;
+class SCEVConstant;
+class raw_ostream;
+
+/// Dependence - This class represents a dependence between two memory
+/// memory references in a function. It contains minimal information and
+/// is used in the very common situation where the compiler is unable to
+/// determine anything beyond the existence of a dependence; that is, it
+/// represents a confused dependence (see also FullDependence). In most
+/// 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 LLVM_ABI Dependence {
+protected:
+ Dependence(Dependence &&) = default;
+ Dependence &operator=(Dependence &&) = default;
+
+public:
+ Dependence(Instruction *Source, Instruction *Destination,
+ const SCEVUnionPredicate &A)
+ : Src(Source), Dst(Destination), Assumptions(A) {}
+ virtual ~Dependence() = default;
+
+ /// Dependence::DVEntry - Each level in the distance/direction vector
+ /// has a direction (or perhaps a union of several directions), and
+ /// perhaps a distance.
+ struct DVEntry {
+ enum : unsigned char {
+ NONE = 0,
+ LT = 1,
+ EQ = 2,
+ LE = 3,
+ GT = 4,
+ NE = 5,
+ GE = 6,
+ ALL = 7
};
+ unsigned char Direction : 3; // Init to ALL, then refine.
+ bool Scalar : 1; // Init to true.
+ bool PeelFirst : 1; // Peeling the first iteration will break dependence.
+ bool PeelLast : 1; // Peeling the last iteration will break the dependence.
+ bool Splitable : 1; // Splitting the loop will break dependence.
+ const SCEV *Distance = nullptr; // NULL implies no distance available.
+ DVEntry()
+ : Direction(ALL), Scalar(true), PeelFirst(false), PeelLast(false),
+ Splitable(false) {}
+ };
- /// getSrc - Returns the source instruction for this dependence.
- ///
- Instruction *getSrc() const { return Src; }
-
- /// getDst - Returns the destination instruction for this dependence.
- ///
- Instruction *getDst() const { return Dst; }
-
- /// isInput - Returns true if this is an input dependence.
- ///
- bool isInput() const;
+ /// getSrc - Returns the source instruction for this dependence.
+ Instruction *getSrc() const { return Src; }
- /// isOutput - Returns true if this is an output dependence.
- ///
- bool isOutput() const;
+ /// getDst - Returns the destination instruction for this dependence.
+ Instruction *getDst() const { return Dst; }
- /// isFlow - Returns true if this is a flow (aka true) dependence.
- ///
- bool isFlow() const;
+ /// isInput - Returns true if this is an input dependence.
+ bool isInput() const;
- /// isAnti - Returns true if this is an anti dependence.
- ///
- bool isAnti() const;
+ /// isOutput - Returns true if this is an output dependence.
+ bool isOutput() const;
- /// isOrdered - Returns true if dependence is Output, Flow, or Anti
- ///
- bool isOrdered() const { return isOutput() || isFlow() || isAnti(); }
+ /// isFlow - Returns true if this is a flow (aka true) dependence.
+ bool isFlow() const;
- /// isUnordered - Returns true if dependence is Input
- ///
- bool isUnordered() const { return isInput(); }
+ /// isAnti - Returns true if this is an anti dependence.
+ bool isAnti() const;
- /// isLoopIndependent - Returns true if this is a loop-independent
- /// dependence.
- virtual bool isLoopIndependent() const { return true; }
+ /// isOrdered - Returns true if dependence is Output, Flow, or Anti
+ bool isOrdered() const { return isOutput() || isFlow() || isAnti(); }
- /// isConfused - Returns true if this dependence is confused
- /// (the compiler understands nothing and makes worst-case
- /// assumptions).
- virtual bool isConfused() const { return true; }
+ /// isUnordered - Returns true if dependence is Input
+ bool isUnordered() const { return isInput(); }
- /// isConsistent - Returns true if this dependence is consistent
- /// (occurs every time the source and destination are executed).
- virtual bool isConsistent() const { return false; }
+ /// isLoopIndependent - Returns true if this is a loop-independent
+ /// dependence.
+ virtual bool isLoopIndependent() const { return true; }
- /// getLevels - Returns the number of common loops surrounding the
- /// source and destination of the dependence.
- virtual unsigned getLevels() const { return 0; }
+ /// isConfused - Returns true if this dependence is confused
+ /// (the compiler understands nothing and makes worst-case assumptions).
+ virtual bool isConfused() const { return true; }
- /// getDirection - Returns the direction associated with a particular
- /// level.
- virtual unsigned getDirection(unsigned Level) const { return DVEntry::ALL; }
+ /// isConsistent - Returns true if this dependence is consistent
+ /// (occurs every time the source and destination are executed).
+ virtual bool isConsistent() const { return false; }
- /// getDistance - Returns the distance (or NULL) associated with a
- /// particular level.
- virtual const SCEV *getDistance(unsigned Level) const { return nullptr; }
+ /// getLevels - Returns the number of common loops surrounding the
+ /// source and destination of the dependence.
+ virtual unsigned getLevels() const { return 0; }
- /// Check if the direction vector is negative. A negative direction
- /// vector means Src and Dst are reversed in the actual program.
- virtual bool isDirectionNegative() const { return false; }
+ /// getDirection - Returns the direction associated with a particular level.
+ virtual unsigned getDirection(unsigned Level) const { return DVEntry::ALL; }
- /// If the direction vector is negative, normalize the direction
- /// vector to make it non-negative. Normalization is done by reversing
- /// Src and Dst, plus reversing the dependence directions and distances
- /// in the vector.
- virtual bool normalize(ScalarEvolution *SE) { return false; }
+ /// getDistance - Returns the distance (or NULL) associated with a particular
+ /// level.
+ virtual const SCEV *getDistance(unsigned Level) const { return nullptr; }
- /// isPeelFirst - Returns true if peeling the first iteration from
- /// this loop will break this dependence.
- virtual bool isPeelFirst(unsigned Level) const { return false; }
+ /// Check if the direction vector is negative. A negative direction
+ /// vector means Src and Dst are reversed in the actual program.
+ virtual bool isDirectionNegative() const { return false; }
+
+ /// If the direction vector is negative, normalize the direction
+ /// vector to make it non-negative. Normalization is done by reversing
+ /// Src and Dst, plus reversing the dependence directions and distances
+ /// in the vector.
+ virtual bool normalize(ScalarEvolution *SE) { return false; }
- /// isPeelLast - Returns true if peeling the last iteration from
- /// this loop will break this dependence.
- virtual bool isPeelLast(unsigned Level) const { return false; }
+ /// isPeelFirst - Returns true if peeling the first iteration from
+ /// this loop will break this dependence.
+ virtual bool isPeelFirst(unsigned Level) const { return false; }
- /// isSplitable - Returns true if splitting this loop will break
- /// the dependence.
- virtual bool isSplitable(unsigned Level) const { return false; }
+ /// isPeelLast - Returns true if peeling the last iteration from
+ /// this loop will break this dependence.
+ virtual bool isPeelLast(unsigned Level) const { return false; }
- /// 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.
- virtual bool isScalar(unsigned Level) const;
+ /// isSplitable - Returns true if splitting this loop will break the
+ /// dependence.
+ virtual bool isSplitable(unsigned Level) const { return false; }
- /// getNextPredecessor - Returns the value of the NextPredecessor
- /// field.
- const Dependence *getNextPredecessor() const { return NextPredecessor; }
+ /// 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.
+ 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; }
+
+ /// getRuntimeAssumptions - Returns the runtime assumptions under which this
+ /// Dependence relation is valid.
+ SCEVUnionPredicate getRuntimeAssumptions() const { return Assumptions; }
+
+ /// dump - For debugging purposes, dumps a dependence to OS.
+ void dump(raw_ostream &OS) const;
+
+protected:
+ Instruction *Src, *Dst;
+
+private:
+ SCEVUnionPredicate Assumptions;
+ const Dependence *NextPredecessor = nullptr, *NextSuccessor = nullptr;
+ friend class DependenceInfo;
+};
+
+/// 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
+/// able to accurately analyze the interaction of the references; that is,
+/// it is not a confused dependence (see Dependence). In most 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.
+class LLVM_ABI FullDependence final : public Dependence {
+public:
+ FullDependence(Instruction *Source, Instruction *Destination,
+ const SCEVUnionPredicate &Assumes,
+ bool PossiblyLoopIndependent, unsigned Levels);
+
+ /// isLoopIndependent - Returns true if this is a loop-independent
+ /// dependence.
+ 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 override { return false; }
+
+ /// isConsistent - Returns true if this dependence is consistent
+ /// (occurs every time the source and destination are executed).
+ bool isConsistent() const override { return Consistent; }
+
+ /// getLevels - Returns the number of common loops surrounding the
+ /// source and destination of the dependence.
+ unsigned getLevels() const override { return Levels; }
+
+ /// getDirection - Returns the direction associated with a particular
+ /// level.
+ unsigned getDirection(unsigned Level) const override;
+
+ /// getDistance - Returns the distance (or NULL) associated with a
+ /// particular level.
+ const SCEV *getDistance(unsigned Level) const override;
+
+ /// Check if the direction vector is negative. A negative direction
+ /// vector means Src and Dst are reversed in the actual program.
+ bool isDirectionNegative() const override;
+
+ /// If the direction vector is negative, normalize the direction
+ /// vector to make it non-negative. Normalization is done by reversing
+ /// Src and Dst, plus reversing the dependence directions and distances
+ /// in the vector.
+ bool normalize(ScalarEvolution *SE) override;
+
+ /// isPeelFirst - Returns true if peeling the first iteration from
+ /// this loop will break this dependence.
+ 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 override;
+
+ /// isSplitable - Returns true if splitting the loop will break
+ /// the dependence.
+ 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 override;
+
+private:
+ unsigned short Levels;
+ bool LoopIndependent;
+ bool Consistent; // Init to true, then refine.
+ std::unique_ptr<DVEntry[]> DV;
+ friend class DependenceInfo;
+};
+
+/// DependenceInfo - This class is the main dependence-analysis driver.
+class DependenceInfo {
+public:
+ DependenceInfo(Function *F, AAResults *AA, ScalarEvolution *SE, LoopInfo *LI)
+ : AA(AA), SE(SE), LI(LI), F(F) {}
+
+ /// Handle transitive invalidation when the cached analysis results go away.
+ LLVM_ABI bool invalidate(Function &F, const PreservedAnalyses &PA,
+ FunctionAnalysisManager::Invalidator &Inv);
+
+ /// depends - Tests for a dependence between the Src and Dst instructions.
+ /// Returns NULL if no dependence; otherwise, returns a Dependence (or a
+ /// FullDependence) with as much information as can be gleaned. By default,
+ /// the dependence test collects a set of runtime assumptions that cannot be
+ /// solved at compilation time. By default UnderRuntimeAssumptions is false
+ /// for a safe approximation of the dependence relation that does not
+ /// require runtime checks.
+ LLVM_ABI std::unique_ptr<Dependence>
+ depends(Instruction *Src, Instruction *Dst,
+ bool UnderRuntimeAssumptions = false);
+
+ /// getSplitIteration - Give a dependence that's splittable at some
+ /// particular level, return the iteration that should be used to split
+ /// the loop.
+ ///
+ /// Generally, the dependence analyzer will be used to build
+ /// a dependence graph for a function (basically a map from instructions
+ /// to dependences). Looking for cycles in the graph shows us loops
+ /// that cannot be trivially vectorized/parallelized.
+ ///
+ /// We can try to improve the situation by examining all the dependences
+ /// that make up the cycle, looking for ones we can break.
+ /// Sometimes, peeling the first or last iteration of a loop will break
+ /// dependences, and there are flags for those possibilities.
+ /// Sometimes, splitting a loop at some other iteration will do the trick,
+ /// and we've got a flag for that case. Rather than waste the space to
+ /// record the exact iteration (since we rarely know), we provide
+ /// a method that calculates the iteration. It's a drag that it must work
+ /// from scratch, but wonderful in that it's possible.
+ ///
+ /// Here's an example:
+ ///
+ /// for (i = 0; i < 10; i++)
+ /// A[i] = ...
+ /// ... = A[11 - i]
+ ///
+ /// There's a loop-carried flow dependence from the store to the load,
+ /// found by the weak-crossing SIV test. The dependence will have a flag,
+ /// indicating that the dependence can be broken by splitting the loop.
+ /// Calling getSplitIteration will return 5.
+ /// Splitting the loop breaks the dependence, like so:
+ ///
+ /// for (i = 0; i <= 5; i++)
+ /// A[i] = ...
+ /// ... = A[11 - i]
+ /// for (i = 6; i < 10; i++)
+ /// A[i] = ...
+ /// ... = A[11 - i]
+ ///
+ /// breaks the dependence and allows us to vectorize/parallelize
+ /// both loops.
+ LLVM_ABI const SCEV *getSplitIteration(const Dependence &Dep, unsigned Level);
+
+ Function *getFunction() const { return F; }
+
+ /// getRuntimeAssumptions - Returns all the runtime assumptions under which
+ /// the dependence test is valid.
+ LLVM_ABI SCEVUnionPredicate getRuntimeAssumptions() const;
+
+private:
+ AAResults *AA;
+ ScalarEvolution *SE;
+ LoopInfo *LI;
+ Function *F;
+ SmallVector<const SCEVPredicate *, 4> Assumptions;
+
+ /// Subscript - This private struct represents a pair of subscripts from
+ /// a pair of potentially multi-dimensional array references. We use a
+ /// vector of them to guide subscript partitioning.
+ struct Subscript {
+ const SCEV *Src;
+ const SCEV *Dst;
+ enum ClassificationKind { ZIV, SIV, RDIV, MIV, NonLinear } Classification;
+ SmallBitVector Loops;
+ SmallBitVector GroupLoops;
+ SmallBitVector Group;
+ };
- /// getNextSuccessor - Returns the value of the NextSuccessor
- /// field.
- const Dependence *getNextSuccessor() const { return NextSuccessor; }
+ struct CoefficientInfo {
+ const SCEV *Coeff;
+ const SCEV *PosPart;
+ const SCEV *NegPart;
+ const SCEV *Iterations;
+ };
- /// setNextPredecessor - Sets the value of the NextPredecessor
- /// field.
- void setNextPredecessor(const Dependence *pred) { NextPredecessor = pred; }
+ struct BoundInfo {
+ const SCEV *Iterations;
+ const SCEV *Upper[8];
+ const SCEV *Lower[8];
+ unsigned char Direction;
+ unsigned char DirSet;
+ };
- /// setNextSuccessor - Sets the value of the NextSuccessor
- /// field.
- void setNextSuccessor(const Dependence *succ) { NextSuccessor = succ; }
+ /// Constraint - This private class represents a constraint, as defined
+ /// in the paper
+ ///
+ /// Practical Dependence Testing
+ /// Goff, Kennedy, Tseng
+ /// PLDI 1991
+ ///
+ /// There are 5 kinds of constraint, in a hierarchy.
+ /// 1) Any - indicates no constraint, any dependence is possible.
+ /// 2) Line - A line ax + by = c, where a, b, and c are parameters,
+ /// representing the dependence equation.
+ /// 3) Distance - The value d of the dependence distance;
+ /// 4) Point - A point <x, y> representing the dependence from
+ /// iteration x to iteration y.
+ /// 5) Empty - No dependence is possible.
+ class Constraint {
+ private:
+ enum ConstraintKind { Empty, Point, Distance, Line, Any } Kind;
+ ScalarEvolution *SE;
+ const SCEV *A;
+ const SCEV *B;
+ const SCEV *C;
+ const Loop *AssociatedLoop;
- /// getRuntimeAssumptions - Returns the runtime assumptions under which this
- /// Dependence relation is valid.
- SCEVUnionPredicate getRuntimeAssumptions() const { return Assumptions; }
+ public:
+ /// isEmpty - Return true if the constraint is of kind Empty.
+ bool isEmpty() const { return Kind == Empty; }
- /// dump - For debugging purposes, dumps a dependence to OS.
- ///
- void dump(raw_ostream &OS) const;
+ /// isPoint - Return true if the constraint is of kind Point.
+ bool isPoint() const { return Kind == Point; }
- protected:
- Instruction *Src, *Dst;
+ /// isDistance - Return true if the constraint is of kind Distance.
+ bool isDistance() const { return Kind == Distance; }
- private:
- SCEVUnionPredicate Assumptions;
- const Dependence *NextPredecessor = nullptr, *NextSuccessor = nullptr;
- friend class DependenceInfo;
- };
+ /// isLine - Return true if the constraint is of kind Line.
+ /// Since Distance's can also be represented as Lines, we also return
+ /// true if the constraint is of kind Distance.
+ bool isLine() const { return Kind == Line || Kind == Distance; }
- /// 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
- /// able to accurately analyze the interaction of the references; that is,
- /// it is not a confused dependence (see Dependence). In most 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.
- class LLVM_ABI FullDependence final : public Dependence {
- public:
- FullDependence(Instruction *Source, Instruction *Destination,
- const SCEVUnionPredicate &Assumes,
- bool PossiblyLoopIndependent, unsigned Levels);
-
- /// isLoopIndependent - Returns true if this is a loop-independent
- /// dependence.
- 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 override { return false; }
-
- /// isConsistent - Returns true if this dependence is consistent
- /// (occurs every time the source and destination are executed).
- bool isConsistent() const override { return Consistent; }
-
- /// getLevels - Returns the number of common loops surrounding the
- /// source and destination of the dependence.
- unsigned getLevels() const override { return Levels; }
-
- /// getDirection - Returns the direction associated with a particular
- /// level.
- unsigned getDirection(unsigned Level) const override;
-
- /// getDistance - Returns the distance (or NULL) associated with a
- /// particular level.
- const SCEV *getDistance(unsigned Level) const override;
-
- /// Check if the direction vector is negative. A negative direction
- /// vector means Src and Dst are reversed in the actual program.
- bool isDirectionNegative() const override;
-
- /// If the direction vector is negative, normalize the direction
- /// vector to make it non-negative. Normalization is done by reversing
- /// Src and Dst, plus reversing the dependence directions and distances
- /// in the vector.
- bool normalize(ScalarEvolution *SE) override;
-
- /// isPeelFirst - Returns true if peeling the first iteration from
- /// this loop will break this dependence.
- 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 override;
-
- /// isSplitable - Returns true if splitting the loop will break
- /// the dependence.
- 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 override;
+ /// isAny - Return true if the constraint is of kind Any;
+ bool isAny() const { return Kind == Any; }
- private:
- unsigned short Levels;
- bool LoopIndependent;
- bool Consistent; // Init to true, then refine.
- std::unique_ptr<DVEntry[]> DV;
- friend class DependenceInfo;
- };
+ /// getX - If constraint is a point <X, Y>, returns X.
+ /// Otherwise assert.
+ LLVM_ABI const SCEV *getX() const;
- /// DependenceInfo - This class is the main dependence-analysis driver.
- ///
- class DependenceInfo {
- public:
- DependenceInfo(Function *F, AAResults *AA, ScalarEvolution *SE,
- LoopInfo *LI)
- : AA(AA), SE(SE), LI(LI), F(F) {}
-
- /// Handle transitive invalidation when the cached analysis results go away.
- LLVM_ABI bool invalidate(Function &F, const PreservedAnalyses &PA,
- FunctionAnalysisManager::Invalidator &Inv);
-
- /// depends - Tests for a dependence between the Src and Dst instructions.
- /// Returns NULL if no dependence; otherwise, returns a Dependence (or a
- /// FullDependence) with as much information as can be gleaned. By default,
- /// the dependence test collects a set of runtime assumptions that cannot be
- /// solved at compilation time. By default UnderRuntimeAssumptions is false
- /// for a safe approximation of the dependence relation that does not
- /// require runtime checks.
- LLVM_ABI std::unique_ptr<Dependence>
- depends(Instruction *Src, Instruction *Dst,
- bool UnderRuntimeAssumptions = false);
-
- /// getSplitIteration - Give a dependence that's splittable at some
- /// particular level, return the iteration that should be used to split
- /// the loop.
- ///
- /// Generally, the dependence analyzer will be used to build
- /// a dependence graph for a function (basically a map from instructions
- /// to dependences). Looking for cycles in the graph shows us loops
- /// that cannot be trivially vectorized/parallelized.
- ///
- /// We can try to improve the situation by examining all the dependences
- /// that make up the cycle, looking for ones we can break.
- /// Sometimes, peeling the first or last iteration of a loop will break
- /// dependences, and there are flags for those possibilities.
- /// Sometimes, splitting a loop at some other iteration will do the trick,
- /// and we've got a flag for that case. Rather than waste the space to
- /// record the exact iteration (since we rarely know), we provide
- /// a method that calculates the iteration. It's a drag that it must work
- /// from scratch, but wonderful in that it's possible.
- ///
- /// Here's an example:
- ///
- /// for (i = 0; i < 10; i++)
- /// A[i] = ...
- /// ... = A[11 - i]
- ///
- /// There's a loop-carried flow dependence from the store to the load,
- /// found by the weak-crossing SIV test. The dependence will have a flag,
- /// indicating that the dependence can be broken by splitting the loop.
- /// Calling getSplitIteration will return 5.
- /// Splitting the loop breaks the dependence, like so:
- ///
- /// for (i = 0; i <= 5; i++)
- /// A[i] = ...
- /// ... = A[11 - i]
- /// for (i = 6; i < 10; i++)
- /// A[i] = ...
- /// ... = A[11 - i]
- ///
- /// breaks the dependence and allows us to vectorize/parallelize
- /// both loops.
- LLVM_ABI const SCEV *getSplitIteration(const Dependence &Dep,
- unsigned Level);
-
- Function *getFunction() const { return F; }
-
- /// getRuntimeAssumptions - Returns all the runtime assumptions under which
- /// the dependence test is valid.
- LLVM_ABI SCEVUnionPredicate getRuntimeAssumptions() const;
+ /// getY - If constraint is a point <X, Y>, returns Y.
+ /// Otherwise assert.
+ LLVM_ABI const SCEV *getY() const;
- private:
- AAResults *AA;
- ScalarEvolution *SE;
- LoopInfo *LI;
- Function *F;
- SmallVector<const SCEVPredicate *, 4> Assumptions;
-
- /// Subscript - This private struct represents a pair of subscripts from
- /// a pair of potentially multi-dimensional array references. We use a
- /// vector of them to guide subscript partitioning.
- struct Subscript {
- const SCEV *Src;
- const SCEV *Dst;
- enum ClassificationKind { ZIV, SIV, RDIV, MIV, NonLinear } Classification;
- SmallBitVector Loops;
- SmallBitVector GroupLoops;
- SmallBitVector Group;
- };
+ /// getA - If constraint is a line AX + BY = C, returns A.
+ /// Otherwise assert.
+ LLVM_ABI const SCEV *getA() const;
- struct CoefficientInfo {
- const SCEV *Coeff;
- const SCEV *PosPart;
- const SCEV *NegPart;
- const SCEV *Iterations;
- };
+ /// getB - If constraint is a line AX + BY = C, returns B.
+ /// Otherwise assert.
+ LLVM_ABI const SCEV *getB() const;
- struct BoundInfo {
- const SCEV *Iterations;
- const SCEV *Upper[8];
- const SCEV *Lower[8];
- unsigned char Direction;
- unsigned char DirSet;
- };
+ /// getC - If constraint is a line AX + BY = C, returns C.
+ /// Otherwise assert.
+ LLVM_ABI const SCEV *getC() const;
- /// Constraint - This private class represents a constraint, as defined
- /// in the paper
- ///
- /// Practical Dependence Testing
- /// Goff, Kennedy, Tseng
- /// PLDI 1991
- ///
- /// There are 5 kinds of constraint, in a hierarchy.
- /// 1) Any - indicates no constraint, any dependence is possible.
- /// 2) Line - A line ax + by = c, where a, b, and c are parameters,
- /// representing the dependence equation.
- /// 3) Distance - The value d of the dependence distance;
- /// 4) Point - A point <x, y> representing the dependence from
- /// iteration x to iteration y.
- /// 5) Empty - No dependence is possible.
- class Constraint {
- private:
- enum ConstraintKind { Empty, Point, Distance, Line, Any } Kind;
- ScalarEvolution *SE;
- const SCEV *A;
- 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; }
-
- /// isPoint - Return true if the constraint is of kind Point.
- bool isPoint() const { return Kind == Point; }
-
- /// isDistance - Return true if the constraint is of kind Distance.
- bool isDistance() const { return Kind == Distance; }
-
- /// isLine - Return true if the constraint is of kind Line.
- /// Since Distance's can also be represented as Lines, we also return
- /// true if the constraint is of kind Distance.
- bool isLine() const { return Kind == Line || Kind == Distance; }
-
- /// isAny - Return true if the constraint is of kind Any;
- bool isAny() const { return Kind == Any; }
-
- /// getX - If constraint is a point <X, Y>, returns X.
- /// Otherwise assert.
- LLVM_ABI const SCEV *getX() const;
-
- /// getY - If constraint is a point <X, Y>, returns Y.
- /// Otherwise assert.
- LLVM_ABI const SCEV *getY() const;
-
- /// getA - If constraint is a line AX + BY = C, returns A.
- /// Otherwise assert.
- LLVM_ABI const SCEV *getA() const;
-
- /// getB - If constraint is a line AX + BY = C, returns B.
- /// Otherwise assert.
- LLVM_ABI const SCEV *getB() const;
-
- /// getC - If constraint is a line AX + BY = C, returns C.
- /// Otherwise assert.
- LLVM_ABI const SCEV *getC() const;
-
- /// getD - If constraint is a distance, returns D.
- /// Otherwise assert.
- LLVM_ABI const SCEV *getD() const;
-
- /// getAssociatedLoop - Returns the loop associated with this constraint.
- LLVM_ABI const Loop *getAssociatedLoop() const;
-
- /// setPoint - Change a constraint to Point.
- LLVM_ABI void setPoint(const SCEV *X, const SCEV *Y,
- const Loop *CurrentLoop);
-
- /// setLine - Change a constraint to Line.
- LLVM_ABI void setLine(const SCEV *A, const SCEV *B, const SCEV *C,
- const Loop *CurrentLoop);
-
- /// setDistance - Change a constraint to Distance.
- LLVM_ABI void setDistance(const SCEV *D, const Loop *CurrentLoop);
-
- /// setEmpty - Change a constraint to Empty.
- LLVM_ABI void setEmpty();
-
- /// setAny - Change a constraint to Any.
- LLVM_ABI void setAny(ScalarEvolution *SE);
-
- /// dump - For debugging purposes. Dumps the constraint
- /// out to OS.
- LLVM_ABI void dump(raw_ostream &OS) const;
- };
+ /// getD - If constraint is a distance, returns D.
+ /// Otherwise assert.
+ LLVM_ABI const SCEV *getD() const;
- /// establishNestingLevels - Examines the loop nesting of the Src and Dst
- /// instructions and establishes their shared loops. Sets the variables
- /// CommonLevels, SrcLevels, and MaxLevels.
- /// The source and destination instructions needn't be contained in the same
- /// loop. The routine establishNestingLevels finds the level of most deeply
- /// nested loop that contains them both, CommonLevels. An instruction that's
- /// not contained in a loop is at level = 0. MaxLevels is equal to the level
- /// of the source plus the level of the destination, minus CommonLevels.
- /// This lets us allocate vectors MaxLevels in length, with room for every
- /// distinct loop referenced in both the source and destination subscripts.
- /// The variable SrcLevels is the nesting depth of the source instruction.
- /// It's used to help calculate distinct loops referenced by the destination.
- /// Here's the map from loops to levels:
- /// 0 - unused
- /// 1 - outermost common loop
- /// ... - other common loops
- /// CommonLevels - innermost common loop
- /// ... - loops containing Src but not Dst
- /// SrcLevels - innermost loop containing Src but not Dst
- /// ... - loops containing Dst but not Src
- /// MaxLevels - innermost loop containing Dst but not Src
- /// Consider the follow code fragment:
- /// for (a = ...) {
- /// for (b = ...) {
- /// for (c = ...) {
- /// for (d = ...) {
- /// A[] = ...;
- /// }
- /// }
- /// for (e = ...) {
- /// for (f = ...) {
- /// for (g = ...) {
- /// ... = A[];
- /// }
- /// }
- /// }
- /// }
- /// }
- /// If we're looking at the possibility of a dependence between the store
- /// to A (the Src) and the load from A (the Dst), we'll note that they
- /// have 2 loops in common, so CommonLevels will equal 2 and the direction
- /// vector for Result will have 2 entries. SrcLevels = 4 and MaxLevels = 7.
- /// A map from loop names to level indices would look like
- /// a - 1
- /// b - 2 = CommonLevels
- /// c - 3
- /// d - 4 = SrcLevels
- /// e - 5
- /// f - 6
- /// g - 7 = MaxLevels
- void establishNestingLevels(const Instruction *Src,
- const Instruction *Dst);
-
- unsigned CommonLevels, SrcLevels, MaxLevels;
-
- /// mapSrcLoop - Given one of the loops containing the source, return
- /// its level index in our numbering scheme.
- unsigned mapSrcLoop(const Loop *SrcLoop) const;
-
- /// mapDstLoop - Given one of the loops containing the destination,
- /// return its level index in our numbering scheme.
- unsigned mapDstLoop(const Loop *DstLoop) const;
-
- /// isLoopInvariant - Returns true if Expression is loop invariant
- /// 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
- /// simplify the actual analysis.
- void removeMatchingExtensions(Subscript *Pair);
-
- /// collectCommonLoops - Finds the set of loops from the LoopNest that
- /// have a level <= CommonLevels and are referred to by the SCEV Expression.
- void collectCommonLoops(const SCEV *Expression,
- const Loop *LoopNest,
- SmallBitVector &Loops) const;
-
- /// checkSrcSubscript - Examines the SCEV Src, returning true iff it's
- /// linear. Collect the set of loops mentioned by Src.
- bool checkSrcSubscript(const SCEV *Src,
- const Loop *LoopNest,
- SmallBitVector &Loops);
-
- /// checkDstSubscript - Examines the SCEV Dst, returning true iff it's
- /// linear. Collect the set of loops mentioned by Dst.
- bool checkDstSubscript(const SCEV *Dst,
- const Loop *LoopNest,
- SmallBitVector &Loops);
-
- /// isKnownPredicate - Compare X and Y using the predicate Pred.
- /// Basically a wrapper for SCEV::isKnownPredicate,
- /// but tries harder, especially in the presence of sign and zero
- /// extensions and symbolics.
- bool isKnownPredicate(ICmpInst::Predicate Pred,
- const SCEV *X,
- const SCEV *Y) const;
-
- /// isKnownLessThan - Compare to see if S is less than Size
- /// Another wrapper for isKnownNegative(S - max(Size, 1)) with some extra
- /// checking if S is an AddRec and we can prove lessthan using the loop
- /// bounds.
- bool isKnownLessThan(const SCEV *S, const SCEV *Size) const;
-
- /// isKnownNonNegative - Compare to see if S is known not to be negative
- /// Uses the fact that S comes from Ptr, which may be an inbound GEP,
- /// Proving there is no wrapping going on.
- bool isKnownNonNegative(const SCEV *S, const Value *Ptr) const;
-
- /// collectUpperBound - All subscripts are the same type (on my machine,
- /// an i64). The loop bound may be a smaller type. collectUpperBound
- /// find the bound, if available, and zero extends it to the Type T.
- /// (I zero extend since the bound should always be >= 0.)
- /// If no upper bound is available, return NULL.
- const SCEV *collectUpperBound(const Loop *l, Type *T) const;
-
- /// collectConstantUpperBound - Calls collectUpperBound(), then
- /// attempts to cast it to SCEVConstant. If the cast fails,
- /// returns NULL.
- const SCEVConstant *collectConstantUpperBound(const Loop *l, Type *T) const;
-
- /// classifyPair - Examines the subscript pair (the Src and Dst SCEVs)
- /// and classifies it as either ZIV, SIV, RDIV, MIV, or Nonlinear.
- /// Collects the associated loops in a set.
- Subscript::ClassificationKind classifyPair(const SCEV *Src,
- const Loop *SrcLoopNest,
- const SCEV *Dst,
- const Loop *DstLoopNest,
- SmallBitVector &Loops);
-
- /// testZIV - Tests the ZIV subscript pair (Src and Dst) for dependence.
- /// Returns true if any possible dependence is disproved.
- /// If there might be a dependence, returns false.
- /// If the dependence isn't proven to exist,
- /// marks the Result as inconsistent.
- bool testZIV(const SCEV *Src,
- const SCEV *Dst,
- FullDependence &Result) const;
-
- /// testSIV - Tests the SIV subscript pair (Src and Dst) for dependence.
- /// Things of the form [c1 + a1*i] and [c2 + a2*j], where
- /// i and j are induction variables, c1 and c2 are loop invariant,
- /// and a1 and a2 are constant.
- /// Returns true if any possible dependence is disproved.
- /// If there might be a dependence, returns false.
- /// Sets appropriate direction vector entry and, when possible,
- /// the distance vector entry.
- /// If the dependence isn't proven to exist,
- /// marks the Result as inconsistent.
- bool testSIV(const SCEV *Src,
- const SCEV *Dst,
- unsigned &Level,
- FullDependence &Result,
- Constraint &NewConstraint,
- const SCEV *&SplitIter) const;
-
- /// testRDIV - Tests the RDIV subscript pair (Src and Dst) for dependence.
- /// Things of the form [c1 + a1*i] and [c2 + a2*j]
- /// where i and j are induction variables, c1 and c2 are loop invariant,
- /// and a1 and a2 are constant.
- /// With minor algebra, this test can also be used for things like
- /// [c1 + a1*i + a2*j][c2].
- /// Returns true if any possible dependence is disproved.
- /// If there might be a dependence, returns false.
- /// Marks the Result as inconsistent.
- bool testRDIV(const SCEV *Src,
- const SCEV *Dst,
- FullDependence &Result) const;
+ /// getAssociatedLoop - Returns the loop associated with this constraint.
+ LLVM_ABI const Loop *getAssociatedLoop() const;
- /// testMIV - Tests the MIV subscript pair (Src and Dst) for dependence.
- /// Returns true if dependence disproved.
- /// Can sometimes refine direction vectors.
- bool testMIV(const SCEV *Src,
- const SCEV *Dst,
- const SmallBitVector &Loops,
- FullDependence &Result) const;
-
- /// strongSIVtest - Tests the strong SIV subscript pair (Src and Dst)
- /// for dependence.
- /// Things of the form [c1 + a*i] and [c2 + a*i],
- /// where i is an induction variable, c1 and c2 are loop invariant,
- /// and a is a constant
- /// Returns true if any possible dependence is disproved.
- /// If there might be a dependence, returns false.
- /// Sets appropriate direction and distance.
- bool strongSIVtest(const SCEV *Coeff,
- const SCEV *SrcConst,
- const SCEV *DstConst,
- const Loop *CurrentLoop,
- unsigned Level,
- FullDependence &Result,
- Constraint &NewConstraint) const;
-
- /// weakCrossingSIVtest - Tests the weak-crossing SIV subscript pair
- /// (Src and Dst) for dependence.
- /// Things of the form [c1 + a*i] and [c2 - a*i],
- /// where i is an induction variable, c1 and c2 are loop invariant,
- /// and a is a constant.
- /// Returns true if any possible dependence is disproved.
- /// If there might be a dependence, returns false.
- /// Sets appropriate direction entry.
- /// Set consistent to false.
- /// Marks the dependence as splitable.
- bool weakCrossingSIVtest(const SCEV *SrcCoeff,
- const SCEV *SrcConst,
- const SCEV *DstConst,
- const Loop *CurrentLoop,
- unsigned Level,
- FullDependence &Result,
- Constraint &NewConstraint,
- const SCEV *&SplitIter) const;
-
- /// ExactSIVtest - Tests the SIV subscript pair
- /// (Src and Dst) for dependence.
- /// Things of the form [c1 + a1*i] and [c2 + a2*i],
- /// where i is an induction variable, c1 and c2 are loop invariant,
- /// and a1 and a2 are constant.
- /// Returns true if any possible dependence is disproved.
- /// If there might be a dependence, returns false.
- /// Sets appropriate direction entry.
- /// Set consistent to false.
- bool exactSIVtest(const SCEV *SrcCoeff,
- const SCEV *DstCoeff,
- const SCEV *SrcConst,
- const SCEV *DstConst,
- const Loop *CurrentLoop,
- unsigned Level,
- FullDependence &Result,
- Constraint &NewConstraint) const;
-
- /// weakZeroSrcSIVtest - Tests the weak-zero SIV subscript pair
- /// (Src and Dst) for dependence.
- /// Things of the form [c1] and [c2 + a*i],
- /// where i is an induction variable, c1 and c2 are loop invariant,
- /// and a is a constant. See also weakZeroDstSIVtest.
- /// Returns true if any possible dependence is disproved.
- /// If there might be a dependence, returns false.
- /// Sets appropriate direction entry.
- /// Set consistent to false.
- /// If loop peeling will break the dependence, mark appropriately.
- bool weakZeroSrcSIVtest(const SCEV *DstCoeff,
- const SCEV *SrcConst,
- const SCEV *DstConst,
- const Loop *CurrentLoop,
- unsigned Level,
- FullDependence &Result,
- Constraint &NewConstraint) const;
-
- /// weakZeroDstSIVtest - Tests the weak-zero SIV subscript pair
- /// (Src and Dst) for dependence.
- /// Things of the form [c1 + a*i] and [c2],
- /// where i is an induction variable, c1 and c2 are loop invariant,
- /// and a is a constant. See also weakZeroSrcSIVtest.
- /// Returns true if any possible dependence is disproved.
- /// If there might be a dependence, returns false.
- /// Sets appropriate direction entry.
- /// Set consistent to false.
- /// If loop peeling will break the dependence, mark appropriately.
- bool weakZeroDstSIVtest(const SCEV *SrcCoeff,
- const SCEV *SrcConst,
- const SCEV *DstConst,
- const Loop *CurrentLoop,
- unsigned Level,
- FullDependence &Result,
- Constraint &NewConstraint) const;
-
- /// exactRDIVtest - Tests the RDIV subscript pair for dependence.
- /// Things of the form [c1 + a*i] and [c2 + b*j],
- /// where i and j are induction variable, c1 and c2 are loop invariant,
- /// and a and b are constants.
- /// Returns true if any possible dependence is disproved.
- /// Marks the result as inconsistent.
- /// Works in some cases that symbolicRDIVtest doesn't,
- /// and vice versa.
- bool exactRDIVtest(const SCEV *SrcCoeff,
- const SCEV *DstCoeff,
- const SCEV *SrcConst,
- const SCEV *DstConst,
- const Loop *SrcLoop,
- const Loop *DstLoop,
- FullDependence &Result) const;
+ /// setPoint - Change a constraint to Point.
+ LLVM_ABI void setPoint(const SCEV *X, const SCEV *Y,
+ const Loop *CurrentLoop);
- /// symbolicRDIVtest - Tests the RDIV subscript pair for dependence.
- /// Things of the form [c1 + a*i] and [c2 + b*j],
- /// where i and j are induction variable, c1 and c2 are loop invariant,
- /// and a and b are constants.
- /// Returns true if any possible dependence is disproved.
- /// Marks the result as inconsistent.
- /// Works in some cases that exactRDIVtest doesn't,
- /// and vice versa. Can also be used as a backup for
- /// ordinary SIV tests.
- bool symbolicRDIVtest(const SCEV *SrcCoeff,
- const SCEV *DstCoeff,
- const SCEV *SrcConst,
- const SCEV *DstConst,
- const Loop *SrcLoop,
- const Loop *DstLoop) const;
-
- /// gcdMIVtest - Tests an MIV subscript pair for dependence.
- /// Returns true if any possible dependence is disproved.
- /// Marks the result as inconsistent.
- /// Can sometimes disprove the equal direction for 1 or more loops.
- // Can handle some symbolics that even the SIV tests don't get,
- /// so we use it as a backup for everything.
- bool gcdMIVtest(const SCEV *Src,
- const SCEV *Dst,
- FullDependence &Result) const;
-
- /// banerjeeMIVtest - Tests an MIV subscript pair for dependence.
- /// Returns true if any possible dependence is disproved.
- /// Marks the result as inconsistent.
- /// Computes directions.
- bool banerjeeMIVtest(const SCEV *Src,
- const SCEV *Dst,
- const SmallBitVector &Loops,
- FullDependence &Result) const;
-
- /// collectCoefficientInfo - Walks through the subscript,
- /// collecting each coefficient, the associated loop bounds,
- /// and recording its positive and negative parts for later use.
- CoefficientInfo *collectCoeffInfo(const SCEV *Subscript,
- bool SrcFlag,
- const SCEV *&Constant) const;
-
- /// getPositivePart - X^+ = max(X, 0).
- ///
- const SCEV *getPositivePart(const SCEV *X) const;
-
- /// getNegativePart - X^- = min(X, 0).
- ///
- const SCEV *getNegativePart(const SCEV *X) const;
-
- /// getLowerBound - Looks through all the bounds info and
- /// computes the lower bound given the current direction settings
- /// at each level.
- const SCEV *getLowerBound(BoundInfo *Bound) const;
-
- /// getUpperBound - Looks through all the bounds info and
- /// computes the upper bound given the current direction settings
- /// at each level.
- const SCEV *getUpperBound(BoundInfo *Bound) const;
-
- /// exploreDirections - Hierarchically expands the direction vector
- /// search space, combining the directions of discovered dependences
- /// in the DirSet field of Bound. Returns the number of distinct
- /// dependences discovered. If the dependence is disproved,
- /// it will return 0.
- unsigned exploreDirections(unsigned Level,
- CoefficientInfo *A,
- CoefficientInfo *B,
- BoundInfo *Bound,
- const SmallBitVector &Loops,
- unsigned &DepthExpanded,
- const SCEV *Delta) const;
-
- /// testBounds - Returns true iff the current bounds are plausible.
- bool testBounds(unsigned char DirKind,
- unsigned Level,
- BoundInfo *Bound,
- const SCEV *Delta) const;
-
- /// findBoundsALL - Computes the upper and lower bounds for level K
- /// using the * direction. Records them in Bound.
- void findBoundsALL(CoefficientInfo *A,
- CoefficientInfo *B,
- BoundInfo *Bound,
- unsigned K) const;
-
- /// findBoundsLT - Computes the upper and lower bounds for level K
- /// using the < direction. Records them in Bound.
- void findBoundsLT(CoefficientInfo *A,
- CoefficientInfo *B,
- BoundInfo *Bound,
- unsigned K) const;
-
- /// findBoundsGT - Computes the upper and lower bounds for level K
- /// using the > direction. Records them in Bound.
- void findBoundsGT(CoefficientInfo *A,
- CoefficientInfo *B,
- BoundInfo *Bound,
- unsigned K) const;
-
- /// findBoundsEQ - Computes the upper and lower bounds for level K
- /// using the = direction. Records them in Bound.
- void findBoundsEQ(CoefficientInfo *A,
- CoefficientInfo *B,
- BoundInfo *Bound,
- unsigned K) const;
-
- /// intersectConstraints - Updates X with the intersection
- /// of the Constraints X and Y. Returns true if X has changed.
- bool intersectConstraints(Constraint *X,
- const Constraint *Y);
-
- /// propagate - Review the constraints, looking for opportunities
- /// to simplify a subscript pair (Src and Dst).
- /// Return true if some simplification occurs.
- /// If the simplification isn't exact (that is, if it is conservative
- /// in terms of dependence), set consistent to false.
- bool propagate(const SCEV *&Src,
- const SCEV *&Dst,
- SmallBitVector &Loops,
- SmallVectorImpl<Constraint> &Constraints,
- bool &Consistent);
-
- /// propagateDistance - Attempt to propagate a distance
- /// constraint into a subscript pair (Src and Dst).
- /// Return true if some simplification occurs.
- /// If the simplification isn't exact (that is, if it is conservative
- /// in terms of dependence), set consistent to false.
- bool propagateDistance(const SCEV *&Src,
- const SCEV *&Dst,
- Constraint &CurConstraint,
- bool &Consistent);
-
- /// propagatePoint - Attempt to propagate a point
- /// constraint into a subscript pair (Src and Dst).
- /// Return true if some simplification occurs.
- bool propagatePoint(const SCEV *&Src,
- const SCEV *&Dst,
- Constraint &CurConstraint);
-
- /// propagateLine - Attempt to propagate a line
- /// constraint into a subscript pair (Src and Dst).
- /// Return true if some simplification occurs.
- /// If the simplification isn't exact (that is, if it is conservative
- /// in terms of dependence), set consistent to false.
- bool propagateLine(const SCEV *&Src,
- const SCEV *&Dst,
- Constraint &CurConstraint,
- bool &Consistent);
-
- /// findCoefficient - Given a linear SCEV,
- /// return the coefficient corresponding to specified loop.
- /// If there isn't one, return the SCEV constant 0.
- /// For example, given a*i + b*j + c*k, returning the coefficient
- /// corresponding to the j loop would yield b.
- const SCEV *findCoefficient(const SCEV *Expr,
- const Loop *TargetLoop) const;
-
- /// zeroCoefficient - Given a linear SCEV,
- /// return the SCEV given by zeroing out the coefficient
- /// corresponding to the specified loop.
- /// For example, given a*i + b*j + c*k, zeroing the coefficient
- /// corresponding to the j loop would yield a*i + c*k.
- const SCEV *zeroCoefficient(const SCEV *Expr,
- const Loop *TargetLoop) const;
-
- /// addToCoefficient - Given a linear SCEV Expr,
- /// return the SCEV given by adding some Value to the
- /// coefficient corresponding to the specified TargetLoop.
- /// For example, given a*i + b*j + c*k, adding 1 to the coefficient
- /// corresponding to the j loop would yield a*i + (b+1)*j + c*k.
- const SCEV *addToCoefficient(const SCEV *Expr,
- const Loop *TargetLoop,
- const SCEV *Value) const;
-
- /// updateDirection - Update direction vector entry
- /// based on the current constraint.
- void updateDirection(Dependence::DVEntry &Level,
- const Constraint &CurConstraint) const;
-
- /// Given a linear access function, tries to recover subscripts
- /// for each dimension of the array element access.
- bool tryDelinearize(Instruction *Src, Instruction *Dst,
- SmallVectorImpl<Subscript> &Pair);
-
- /// Tries to delinearize \p Src and \p Dst access functions for a fixed size
- /// multi-dimensional array. Calls tryDelinearizeFixedSizeImpl() to
- /// delinearize \p Src and \p Dst separately,
- bool tryDelinearizeFixedSize(Instruction *Src, Instruction *Dst,
- const SCEV *SrcAccessFn,
- const SCEV *DstAccessFn,
- SmallVectorImpl<const SCEV *> &SrcSubscripts,
- SmallVectorImpl<const SCEV *> &DstSubscripts);
-
- /// Tries to delinearize access function for a multi-dimensional array with
- /// symbolic runtime sizes.
- /// Returns true upon success and false otherwise.
- bool tryDelinearizeParametricSize(
- Instruction *Src, Instruction *Dst, const SCEV *SrcAccessFn,
- const SCEV *DstAccessFn, SmallVectorImpl<const SCEV *> &SrcSubscripts,
- SmallVectorImpl<const SCEV *> &DstSubscripts);
-
- /// checkSubscript - Helper function for checkSrcSubscript and
- /// checkDstSubscript to avoid duplicate code
- bool checkSubscript(const SCEV *Expr, const Loop *LoopNest,
- SmallBitVector &Loops, bool IsSrc);
- }; // class DependenceInfo
-
- /// AnalysisPass to compute dependence information in a function
- class DependenceAnalysis : public AnalysisInfoMixin<DependenceAnalysis> {
- public:
- typedef DependenceInfo Result;
- LLVM_ABI Result run(Function &F, FunctionAnalysisManager &FAM);
+ /// setLine - Change a constraint to Line.
+ LLVM_ABI void setLine(const SCEV *A, const SCEV *B, const SCEV *C,
+ const Loop *CurrentLoop);
- private:
- LLVM_ABI static AnalysisKey Key;
- friend struct AnalysisInfoMixin<DependenceAnalysis>;
- }; // class DependenceAnalysis
+ /// setDistance - Change a constraint to Distance.
+ LLVM_ABI void setDistance(const SCEV *D, const Loop *CurrentLoop);
- /// Printer pass to dump DA results.
- struct DependenceAnalysisPrinterPass
- : public PassInfoMixin<DependenceAnalysisPrinterPass> {
- DependenceAnalysisPrinterPass(raw_ostream &OS,
- bool NormalizeResults = false)
- : OS(OS), NormalizeResults(NormalizeResults) {}
+ /// setEmpty - Change a constraint to Empty.
+ LLVM_ABI void setEmpty();
- LLVM_ABI PreservedAnalyses run(Function &F, FunctionAnalysisManager &FAM);
+ /// setAny - Change a constraint to Any.
+ LLVM_ABI void setAny(ScalarEvolution *SE);
- static bool isRequired() { return true; }
+ /// dump - For debugging purposes. Dumps the constraint
+ /// out to OS.
+ LLVM_ABI void dump(raw_ostream &OS) const;
+ };
- private:
- raw_ostream &OS;
- bool NormalizeResults;
- }; // class DependenceAnalysisPrinterPass
+ /// establishNestingLevels - Examines the loop nesting of the Src and Dst
+ /// instructions and establishes their shared loops. Sets the variables
+ /// CommonLevels, SrcLevels, and MaxLevels.
+ /// The source and destination instructions needn't be contained in the same
+ /// loop. The routine establishNestingLevels finds the level of most deeply
+ /// nested loop that contains them both, CommonLevels. An instruction that's
+ /// not contained in a loop is at level = 0. MaxLevels is equal to the level
+ /// of the source plus the level of the destination, minus CommonLevels.
+ /// This lets us allocate vectors MaxLevels in length, with room for every
+ /// distinct loop referenced in both the source and destination subscripts.
+ /// The variable SrcLevels is the nesting depth of the source instruction.
+ /// It's used to help calculate distinct loops referenced by the destination.
+ /// Here's the map from loops to levels:
+ /// 0 - unused
+ /// 1 - outermost common loop
+ /// ... - other common loops
+ /// CommonLevels - innermost common loop
+ /// ... - loops containing Src but not Dst
+ /// SrcLevels - innermost loop containing Src but not Dst
+ /// ... - loops containing Dst but not Src
+ /// MaxLevels - innermost loop containing Dst but not Src
+ /// Consider the follow code fragment:
+ /// for (a = ...) {
+ /// for (b = ...) {
+ /// for (c = ...) {
+ /// for (d = ...) {
+ /// A[] = ...;
+ /// }
+ /// }
+ /// for (e = ...) {
+ /// for (f = ...) {
+ /// for (g = ...) {
+ /// ... = A[];
+ /// }
+ /// }
+ /// }
+ /// }
+ /// }
+ /// If we're looking at the possibility of a dependence between the store
+ /// to A (the Src) and the load from A (the Dst), we'll note that they
+ /// have 2 loops in common, so CommonLevels will equal 2 and the direction
+ /// vector for Result will have 2 entries. SrcLevels = 4 and MaxLevels = 7.
+ /// A map from loop names to level indices would look like
+ /// a - 1
+ /// b - 2 = CommonLevels
+ /// c - 3
+ /// d - 4 = SrcLevels
+ /// e - 5
+ /// f - 6
+ /// g - 7 = MaxLevels
+ void establishNestingLevels(const Instruction *Src, const Instruction *Dst);
+
+ unsigned CommonLevels, SrcLevels, MaxLevels;
+
+ /// mapSrcLoop - Given one of the loops containing the source, return
+ /// its level index in our numbering scheme.
+ unsigned mapSrcLoop(const Loop *SrcLoop) const;
+
+ /// mapDstLoop - Given one of the loops containing the destination,
+ /// return its level index in our numbering scheme.
+ unsigned mapDstLoop(const Loop *DstLoop) const;
+
+ /// isLoopInvariant - Returns true if Expression is loop invariant
+ /// 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
+ /// simplify the actual analysis.
+ void removeMatchingExtensions(Subscript *Pair);
+
+ /// collectCommonLoops - Finds the set of loops from the LoopNest that
+ /// have a level <= CommonLevels and are referred to by the SCEV Expression.
+ void collectCommonLoops(const SCEV *Expression, const Loop *LoopNest,
+ SmallBitVector &Loops) const;
+
+ /// checkSrcSubscript - Examines the SCEV Src, returning true iff it's
+ /// linear. Collect the set of loops mentioned by Src.
+ bool checkSrcSubscript(const SCEV *Src, const Loop *LoopNest,
+ SmallBitVector &Loops);
+
+ /// checkDstSubscript - Examines the SCEV Dst, returning true iff it's
+ /// linear. Collect the set of loops mentioned by Dst.
+ bool checkDstSubscript(const SCEV *Dst, const Loop *LoopNest,
+ SmallBitVector &Loops);
+
+ /// isKnownPredicate - Compare X and Y using the predicate Pred.
+ /// Basically a wrapper for SCEV::isKnownPredicate,
+ /// but tries harder, especially in the presence of sign and zero
+ /// extensions and symbolics.
+ bool isKnownPredicate(ICmpInst::Predicate Pred, const SCEV *X,
+ const SCEV *Y) const;
+
+ /// isKnownLessThan - Compare to see if S is less than Size
+ /// Another wrapper for isKnownNegative(S - max(Size, 1)) with some extra
+ /// checking if S is an AddRec and we can prove lessthan using the loop
+ /// bounds.
+ bool isKnownLessThan(const SCEV *S, const SCEV *Size) const;
+
+ /// isKnownNonNegative - Compare to see if S is known not to be negative
+ /// Uses the fact that S comes from Ptr, which may be an inbound GEP,
+ /// Proving there is no wrapping going on.
+ bool isKnownNonNegative(const SCEV *S, const Value *Ptr) const;
+
+ /// collectUpperBound - All subscripts are the same type (on my machine,
+ /// an i64). The loop bound may be a smaller type. collectUpperBound
+ /// find the bound, if available, and zero extends it to the Type T.
+ /// (I zero extend since the bound should always be >= 0.)
+ /// If no upper bound is available, return NULL.
+ const SCEV *collectUpperBound(const Loop *l, Type *T) const;
+
+ /// collectConstantUpperBound - Calls collectUpperBound(), then
+ /// attempts to cast it to SCEVConstant. If the cast fails,
+ /// returns NULL.
+ const SCEVConstant *collectConstantUpperBound(const Loop *l, Type *T) const;
+
+ /// classifyPair - Examines the subscript pair (the Src and Dst SCEVs)
+ /// and classifies it as either ZIV, SIV, RDIV, MIV, or Nonlinear.
+ /// Collects the associated loops in a set.
+ Subscript::ClassificationKind
+ classifyPair(const SCEV *Src, const Loop *SrcLoopNest, const SCEV *Dst,
+ const Loop *DstLoopNest, SmallBitVector &Loops);
+
+ /// testZIV - Tests the ZIV subscript pair (Src and Dst) for dependence.
+ /// Returns true if any possible dependence is disproved.
+ /// If there might be a dependence, returns false.
+ /// If the dependence isn't proven to exist,
+ /// marks the Result as inconsistent.
+ bool testZIV(const SCEV *Src, const SCEV *Dst, FullDependence &Result) const;
+
+ /// testSIV - Tests the SIV subscript pair (Src and Dst) for dependence.
+ /// Things of the form [c1 + a1*i] and [c2 + a2*j], where
+ /// i and j are induction variables, c1 and c2 are loop invariant,
+ /// and a1 and a2 are constant.
+ /// Returns true if any possible dependence is disproved.
+ /// If there might be a dependence, returns false.
+ /// Sets appropriate direction vector entry and, when possible,
+ /// the distance vector entry.
+ /// If the dependence isn't proven to exist,
+ /// marks the Result as inconsistent.
+ bool testSIV(const SCEV *Src, const SCEV *Dst, unsigned &Level,
+ FullDependence &Result, Constraint &NewConstraint,
+ const SCEV *&SplitIter) const;
+
+ /// testRDIV - Tests the RDIV subscript pair (Src and Dst) for dependence.
+ /// Things of the form [c1 + a1*i] and [c2 + a2*j]
+ /// where i and j are induction variables, c1 and c2 are loop invariant,
+ /// and a1 and a2 are constant.
+ /// With minor algebra, this test can also be used for things like
+ /// [c1 + a1*i + a2*j][c2].
+ /// Returns true if any possible dependence is disproved.
+ /// If there might be a dependence, returns false.
+ /// Marks the Result as inconsistent.
+ bool testRDIV(const SCEV *Src, const SCEV *Dst, FullDependence &Result) const;
+
+ /// testMIV - Tests the MIV subscript pair (Src and Dst) for dependence.
+ /// Returns true if dependence disproved.
+ /// Can sometimes refine direction vectors.
+ bool testMIV(const SCEV *Src, const SCEV *Dst, const SmallBitVector &Loops,
+ FullDependence &Result) const;
+
+ /// strongSIVtest - Tests the strong SIV subscript pair (Src and Dst)
+ /// for dependence.
+ /// Things of the form [c1 + a*i] and [c2 + a*i],
+ /// where i is an induction variable, c1 and c2 are loop invariant,
+ /// and a is a constant
+ /// Returns true if any possible dependence is disproved.
+ /// If there might be a dependence, returns false.
+ /// Sets appropriate direction and distance.
+ bool strongSIVtest(const SCEV *Coeff, const SCEV *SrcConst,
+ const SCEV *DstConst, const Loop *CurrentLoop,
+ unsigned Level, FullDependence &Result,
+ Constraint &NewConstraint) const;
+
+ /// weakCrossingSIVtest - Tests the weak-crossing SIV subscript pair
+ /// (Src and Dst) for dependence.
+ /// Things of the form [c1 + a*i] and [c2 - a*i],
+ /// where i is an induction variable, c1 and c2 are loop invariant,
+ /// and a is a constant.
+ /// Returns true if any possible dependence is disproved.
+ /// If there might be a dependence, returns false.
+ /// Sets appropriate direction entry.
+ /// Set consistent to false.
+ /// Marks the dependence as splitable.
+ bool weakCrossingSIVtest(const SCEV *SrcCoeff, const SCEV *SrcConst,
+ const SCEV *DstConst, const Loop *CurrentLoop,
+ unsigned Level, FullDependence &Result,
+ Constraint &NewConstraint,
+ const SCEV *&SplitIter) const;
+
+ /// ExactSIVtest - Tests the SIV subscript pair
+ /// (Src and Dst) for dependence.
+ /// Things of the form [c1 + a1*i] and [c2 + a2*i],
+ /// where i is an induction variable, c1 and c2 are loop invariant,
+ /// and a1 and a2 are constant.
+ /// Returns true if any possible dependence is disproved.
+ /// If there might be a dependence, returns false.
+ /// Sets appropriate direction entry.
+ /// Set consistent to false.
+ bool exactSIVtest(const SCEV *SrcCoeff, const SCEV *DstCoeff,
+ const SCEV *SrcConst, const SCEV *DstConst,
+ const Loop *CurrentLoop, unsigned Level,
+ FullDependence &Result, Constraint &NewConstraint) const;
+
+ /// weakZeroSrcSIVtest - Tests the weak-zero SIV subscript pair
+ /// (Src and Dst) for dependence.
+ /// Things of the form [c1] and [c2 + a*i],
+ /// where i is an induction variable, c1 and c2 are loop invariant,
+ /// and a is a constant. See also weakZeroDstSIVtest.
+ /// Returns true if any possible dependence is disproved.
+ /// If there might be a dependence, returns false.
+ /// Sets appropriate direction entry.
+ /// Set consistent to false.
+ /// If loop peeling will break the dependence, mark appropriately.
+ bool weakZeroSrcSIVtest(const SCEV *DstCoeff, const SCEV *SrcConst,
+ const SCEV *DstConst, const Loop *CurrentLoop,
+ unsigned Level, FullDependence &Result,
+ Constraint &NewConstraint) const;
+
+ /// weakZeroDstSIVtest - Tests the weak-zero SIV subscript pair
+ /// (Src and Dst) for dependence.
+ /// Things of the form [c1 + a*i] and [c2],
+ /// where i is an induction variable, c1 and c2 are loop invariant,
+ /// and a is a constant. See also weakZeroSrcSIVtest.
+ /// Returns true if any possible dependence is disproved.
+ /// If there might be a dependence, returns false.
+ /// Sets appropriate direction entry.
+ /// Set consistent to false.
+ /// If loop peeling will break the dependence, mark appropriately.
+ bool weakZeroDstSIVtest(const SCEV *SrcCoeff, const SCEV *SrcConst,
+ const SCEV *DstConst, const Loop *CurrentLoop,
+ unsigned Level, FullDependence &Result,
+ Constraint &NewConstraint) const;
+
+ /// exactRDIVtest - Tests the RDIV subscript pair for dependence.
+ /// Things of the form [c1 + a*i] and [c2 + b*j],
+ /// where i and j are induction variable, c1 and c2 are loop invariant,
+ /// and a and b are constants.
+ /// Returns true if any possible dependence is disproved.
+ /// Marks the result as inconsistent.
+ /// Works in some cases that symbolicRDIVtest doesn't,
+ /// and vice versa.
+ bool exactRDIVtest(const SCEV *SrcCoeff, const SCEV *DstCoeff,
+ const SCEV *SrcConst, const SCEV *DstConst,
+ const Loop *SrcLoop, const Loop *DstLoop,
+ FullDependence &Result) const;
+
+ /// symbolicRDIVtest - Tests the RDIV subscript pair for dependence.
+ /// Things of the form [c1 + a*i] and [c2 + b*j],
+ /// where i and j are induction variable, c1 and c2 are loop invariant,
+ /// and a and b are constants.
+ /// Returns true if any possible dependence is disproved.
+ /// Marks the result as inconsistent.
+ /// Works in some cases that exactRDIVtest doesn't,
+ /// and vice versa. Can also be used as a backup for
+ /// ordinary SIV tests.
+ bool symbolicRDIVtest(const SCEV *SrcCoeff, const SCEV *DstCoeff,
+ const SCEV *SrcConst, const SCEV *DstConst,
+ const Loop *SrcLoop, const Loop *DstLoop) const;
+
+ /// gcdMIVtest - Tests an MIV subscript pair for dependence.
+ /// Returns true if any possible dependence is disproved.
+ /// Marks the result as inconsistent.
+ /// Can sometimes disprove the equal direction for 1 or more loops.
+ // Can handle some symbolics that even the SIV tests don't get,
+ /// so we use it as a backup for everything.
+ bool gcdMIVtest(const SCEV *Src, const SCEV *Dst,
+ FullDependence &Result) const;
- /// Legacy pass manager pass to access dependence information
- class LLVM_ABI DependenceAnalysisWrapperPass : public FunctionPass {
- public:
- static char ID; // Class identification, replacement for typeinfo
- DependenceAnalysisWrapperPass();
+ /// banerjeeMIVtest - Tests an MIV subscript pair for dependence.
+ /// Returns true if any possible dependence is disproved.
+ /// Marks the result as inconsistent.
+ /// Computes directions.
+ bool banerjeeMIVtest(const SCEV *Src, const SCEV *Dst,
+ const SmallBitVector &Loops,
+ FullDependence &Result) const;
- bool runOnFunction(Function &F) override;
- void releaseMemory() override;
- void getAnalysisUsage(AnalysisUsage &) const override;
- void print(raw_ostream &, const Module * = nullptr) const override;
- DependenceInfo &getDI() const;
+ /// collectCoefficientInfo - Walks through the subscript,
+ /// collecting each coefficient, the associated loop bounds,
+ /// and recording its positive and negative parts for later use.
+ CoefficientInfo *collectCoeffInfo(const SCEV *Subscript, bool SrcFlag,
+ const SCEV *&Constant) const;
- private:
- std::unique_ptr<DependenceInfo> info;
- }; // class DependenceAnalysisWrapperPass
+ /// getPositivePart - X^+ = max(X, 0).
+ ///
+ const SCEV *getPositivePart(const SCEV *X) const;
- /// createDependenceAnalysisPass - This creates an instance of the
- /// DependenceAnalysis wrapper pass.
- LLVM_ABI FunctionPass *createDependenceAnalysisWrapperPass();
+ /// getNegativePart - X^- = min(X, 0).
+ ///
+ const SCEV *getNegativePart(const SCEV *X) const;
+
+ /// getLowerBound - Looks through all the bounds info and
+ /// computes the lower bound given the current direction settings
+ /// at each level.
+ const SCEV *getLowerBound(BoundInfo *Bound) const;
+
+ /// getUpperBound - Looks through all the bounds info and
+ /// computes the upper bound given the current direction settings
+ /// at each level.
+ const SCEV *getUpperBound(BoundInfo *Bound) const;
+
+ /// exploreDirections - Hierarchically expands the direction vector
+ /// search space, combining the directions of discovered dependences
+ /// in the DirSet field of Bound. Returns the number of distinct
+ /// dependences discovered. If the dependence is disproved,
+ /// it will return 0.
+ unsigned exploreDirections(unsigned Level, CoefficientInfo *A,
+ CoefficientInfo *B, BoundInfo *Bound,
+ const SmallBitVector &Loops,
+ unsigned &DepthExpanded, const SCEV *Delta) const;
+
+ /// testBounds - Returns true iff the current bounds are plausible.
+ bool testBounds(unsigned char DirKind, unsigned Level, BoundInfo *Bound,
+ const SCEV *Delta) const;
+
+ /// findBoundsALL - Computes the upper and lower bounds for level K
+ /// using the * direction. Records them in Bound.
+ void findBoundsALL(CoefficientInfo *A, CoefficientInfo *B, BoundInfo *Bound,
+ unsigned K) const;
+
+ /// findBoundsLT - Computes the upper and lower bounds for level K
+ /// using the < direction. Records them in Bound.
+ void findBoundsLT(CoefficientInfo *A, CoefficientInfo *B, BoundInfo *Bound,
+ unsigned K) const;
+
+ /// findBoundsGT - Computes the upper and lower bounds for level K
+ /// using the > direction. Records them in Bound.
+ void findBoundsGT(CoefficientInfo *A, CoefficientInfo *B, BoundInfo *Bound,
+ unsigned K) const;
+
+ /// findBoundsEQ - Computes the upper and lower bounds for level K
+ /// using the = direction. Records them in Bound.
+ void findBoundsEQ(CoefficientInfo *A, CoefficientInfo *B, BoundInfo *Bound,
+ unsigned K) const;
+
+ /// intersectConstraints - Updates X with the intersection
+ /// of the Constraints X and Y. Returns true if X has changed.
+ bool intersectConstraints(Constraint *X, const Constraint *Y);
+
+ /// propagate - Review the constraints, looking for opportunities
+ /// to simplify a subscript pair (Src and Dst).
+ /// Return true if some simplification occurs.
+ /// If the simplification isn't exact (that is, if it is conservative
+ /// in terms of dependence), set consistent to false.
+ bool propagate(const SCEV *&Src, const SCEV *&Dst, SmallBitVector &Loops,
+ SmallVectorImpl<Constraint> &Constraints, bool &Consistent);
+
+ /// propagateDistance - Attempt to propagate a distance
+ /// constraint into a subscript pair (Src and Dst).
+ /// Return true if some simplification occurs.
+ /// If the simplification isn't exact (that is, if it is conservative
+ /// in terms of dependence), set consistent to false.
+ bool propagateDistance(const SCEV *&Src, const SCEV *&Dst,
+ Constraint &CurConstraint, bool &Consistent);
+
+ /// propagatePoint - Attempt to propagate a point
+ /// constraint into a subscript pair (Src and Dst).
+ /// Return true if some simplification occurs.
+ bool propagatePoint(const SCEV *&Src, const SCEV *&Dst,
+ Constraint &CurConstraint);
+
+ /// propagateLine - Attempt to propagate a line
+ /// constraint into a subscript pair (Src and Dst).
+ /// Return true if some simplification occurs.
+ /// If the simplification isn't exact (that is, if it is conservative
+ /// in terms of dependence), set consistent to false.
+ bool propagateLine(const SCEV *&Src, const SCEV *&Dst,
+ Constraint &CurConstraint, bool &Consistent);
+
+ /// findCoefficient - Given a linear SCEV,
+ /// return the coefficient corresponding to specified loop.
+ /// If there isn't one, return the SCEV constant 0.
+ /// For example, given a*i + b*j + c*k, returning the coefficient
+ /// corresponding to the j loop would yield b.
+ const SCEV *findCoefficient(const SCEV *Expr, const Loop *TargetLoop) const;
+
+ /// zeroCoefficient - Given a linear SCEV,
+ /// return the SCEV given by zeroing out the coefficient
+ /// corresponding to the specified loop.
+ /// For example, given a*i + b*j + c*k, zeroing the coefficient
+ /// corresponding to the j loop would yield a*i + c*k.
+ const SCEV *zeroCoefficient(const SCEV *Expr, const Loop *TargetLoop) const;
+
+ /// addToCoefficient - Given a linear SCEV Expr,
+ /// return the SCEV given by adding some Value to the
+ /// coefficient corresponding to the specified TargetLoop.
+ /// For example, given a*i + b*j + c*k, adding 1 to the coefficient
+ /// corresponding to the j loop would yield a*i + (b+1)*j + c*k.
+ const SCEV *addToCoefficient(const SCEV *Expr, const Loop *TargetLoop,
+ const SCEV *Value) const;
+
+ /// updateDirection - Update direction vector entry
+ /// based on the current constraint.
+ void updateDirection(Dependence::DVEntry &Level,
+ const Constraint &CurConstraint) const;
+
+ /// Given a linear access function, tries to recover subscripts
+ /// for each dimension of the array element access.
+ bool tryDelinearize(Instruction *Src, Instruction *Dst,
+ SmallVectorImpl<Subscript> &Pair);
+
+ /// Tries to delinearize \p Src and \p Dst access functions for a fixed size
+ /// multi-dimensional array. Calls tryDelinearizeFixedSizeImpl() to
+ /// delinearize \p Src and \p Dst separately,
+ bool tryDelinearizeFixedSize(Instruction *Src, Instruction *Dst,
+ const SCEV *SrcAccessFn, const SCEV *DstAccessFn,
+ SmallVectorImpl<const SCEV *> &SrcSubscripts,
+ SmallVectorImpl<const SCEV *> &DstSubscripts);
+
+ /// Tries to delinearize access function for a multi-dimensional array with
+ /// symbolic runtime sizes.
+ /// Returns true upon success and false otherwise.
+ bool
+ tryDelinearizeParametricSize(Instruction *Src, Instruction *Dst,
+ const SCEV *SrcAccessFn, const SCEV *DstAccessFn,
+ SmallVectorImpl<const SCEV *> &SrcSubscripts,
+ SmallVectorImpl<const SCEV *> &DstSubscripts);
+
+ /// checkSubscript - Helper function for checkSrcSubscript and
+ /// checkDstSubscript to avoid duplicate code
+ bool checkSubscript(const SCEV *Expr, const Loop *LoopNest,
+ SmallBitVector &Loops, bool IsSrc);
+}; // class DependenceInfo
+
+/// AnalysisPass to compute dependence information in a function
+class DependenceAnalysis : public AnalysisInfoMixin<DependenceAnalysis> {
+public:
+ typedef DependenceInfo Result;
+ LLVM_ABI Result run(Function &F, FunctionAnalysisManager &FAM);
+
+private:
+ LLVM_ABI static AnalysisKey Key;
+ friend struct AnalysisInfoMixin<DependenceAnalysis>;
+}; // class DependenceAnalysis
+
+/// Printer pass to dump DA results.
+struct DependenceAnalysisPrinterPass
+ : public PassInfoMixin<DependenceAnalysisPrinterPass> {
+ DependenceAnalysisPrinterPass(raw_ostream &OS, bool NormalizeResults = false)
+ : OS(OS), NormalizeResults(NormalizeResults) {}
+
+ LLVM_ABI PreservedAnalyses run(Function &F, FunctionAnalysisManager &FAM);
+
+ static bool isRequired() { return true; }
+
+private:
+ raw_ostream &OS;
+ bool NormalizeResults;
+}; // class DependenceAnalysisPrinterPass
+
+/// Legacy pass manager pass to access dependence information
+class LLVM_ABI DependenceAnalysisWrapperPass : public FunctionPass {
+public:
+ static char ID; // Class identification, replacement for typeinfo
+ DependenceAnalysisWrapperPass();
+
+ bool runOnFunction(Function &F) override;
+ void releaseMemory() override;
+ void getAnalysisUsage(AnalysisUsage &) const override;
+ void print(raw_ostream &, const Module * = nullptr) const override;
+ DependenceInfo &getDI() const;
+
+private:
+ std::unique_ptr<DependenceInfo> info;
+}; // class DependenceAnalysisWrapperPass
+
+/// createDependenceAnalysisPass - This creates an instance of the
+/// DependenceAnalysis wrapper pass.
+LLVM_ABI FunctionPass *createDependenceAnalysisWrapperPass();
} // namespace llvm
diff --git a/llvm/lib/Analysis/DependenceAnalysis.cpp b/llvm/lib/Analysis/DependenceAnalysis.cpp
index f1473b2694ca4..e96cb93f8fb15 100644
--- a/llvm/lib/Analysis/DependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/DependenceAnalysis.cpp
@@ -180,8 +180,8 @@ static void dumpExampleDependence(raw_ostream &OS, DependenceInfo *DA,
for (inst_iterator SrcI = inst_begin(F), SrcE = inst_end(F); SrcI != SrcE;
++SrcI) {
if (SrcI->mayReadOrWriteMemory()) {
- for (inst_iterator DstI = SrcI, DstE = inst_end(F);
- DstI != DstE; ++DstI) {
+ for (inst_iterator DstI = SrcI, DstE = inst_end(F); DstI != DstE;
+ ++DstI) {
if (DstI->mayReadOrWriteMemory()) {
OS << "Src:" << *SrcI << " --> Dst:" << *DstI << "\n";
OS << " da analyze - ";
@@ -203,7 +203,7 @@ static void dumpExampleDependence(raw_ostream &OS, DependenceInfo *DA,
// Normalize negative direction vectors if required by clients.
if (NormalizeResults && D->normalize(&SE))
- OS << "normalized - ";
+ OS << "normalized - ";
D->dump(OS);
for (unsigned Level = 1; Level <= D->getLevels(); Level++) {
if (D->isSplitable(Level)) {
@@ -227,8 +227,8 @@ static void dumpExampleDependence(raw_ostream &OS, DependenceInfo *DA,
void DependenceAnalysisWrapperPass::print(raw_ostream &OS,
const Module *) const {
- dumpExampleDependence(OS, info.get(),
- getAnalysis<ScalarEvolutionWrapperPass>().getSE(), false);
+ dumpExampleDependence(
+ OS, info.get(), getAnalysis<ScalarEvolutionWrapperPass>().getSE(), false);
}
PreservedAnalyses
@@ -249,33 +249,26 @@ bool Dependence::isInput() const {
return Src->mayReadFromMemory() && Dst->mayReadFromMemory();
}
-
// Returns true if this is an output dependence.
bool Dependence::isOutput() const {
return Src->mayWriteToMemory() && Dst->mayWriteToMemory();
}
-
// Returns true if this is an flow (aka true) dependence.
bool Dependence::isFlow() const {
return Src->mayWriteToMemory() && Dst->mayReadFromMemory();
}
-
// Returns true if this is an anti dependence.
bool Dependence::isAnti() const {
return Src->mayReadFromMemory() && Dst->mayWriteToMemory();
}
-
// 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.
// Leave this out of line, so it will serve as a virtual method anchor
-bool Dependence::isScalar(unsigned level) const {
- return false;
-}
-
+bool Dependence::isScalar(unsigned level) const { return false; }
//===----------------------------------------------------------------------===//
// FullDependence methods
@@ -338,8 +331,7 @@ bool FullDependence::normalize(ScalarEvolution *SE) {
DV[Level - 1].Direction = RevDirection;
// Reverse the dependence distance as well.
if (DV[Level - 1].Distance != nullptr)
- DV[Level - 1].Distance =
- SE->getNegativeSCEV(DV[Level - 1].Distance);
+ DV[Level - 1].Distance = SE->getNegativeSCEV(DV[Level - 1].Distance);
}
LLVM_DEBUG(dbgs() << "After normalizing negative direction vectors:\n";
@@ -355,14 +347,12 @@ unsigned FullDependence::getDirection(unsigned Level) const {
return DV[Level - 1].Direction;
}
-
// Returns the distance (or NULL) associated with a particular level.
const SCEV *FullDependence::getDistance(unsigned Level) const {
assert(0 < Level && Level <= Levels && "Level out of range");
return DV[Level - 1].Distance;
}
-
// 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.
@@ -371,7 +361,6 @@ bool FullDependence::isScalar(unsigned Level) const {
return DV[Level - 1].Scalar;
}
-
// Returns true if peeling the first iteration from this loop
// will break this dependence.
bool FullDependence::isPeelFirst(unsigned Level) const {
@@ -379,7 +368,6 @@ bool FullDependence::isPeelFirst(unsigned Level) const {
return DV[Level - 1].PeelFirst;
}
-
// Returns true if peeling the last iteration from this loop
// will break this dependence.
bool FullDependence::isPeelLast(unsigned Level) const {
@@ -387,14 +375,12 @@ bool FullDependence::isPeelLast(unsigned Level) const {
return DV[Level - 1].PeelLast;
}
-
// Returns true if splitting this loop will break the dependence.
bool FullDependence::isSplitable(unsigned Level) const {
assert(0 < Level && Level <= Levels && "Level out of range");
return DV[Level - 1].Splitable;
}
-
//===----------------------------------------------------------------------===//
// DependenceInfo::Constraint methods
@@ -405,7 +391,6 @@ const SCEV *DependenceInfo::Constraint::getX() const {
return A;
}
-
// If constraint is a point <X, Y>, returns Y.
// Otherwise assert.
const SCEV *DependenceInfo::Constraint::getY() const {
@@ -413,7 +398,6 @@ const SCEV *DependenceInfo::Constraint::getY() const {
return B;
}
-
// If constraint is a line AX + BY = C, returns A.
// Otherwise assert.
const SCEV *DependenceInfo::Constraint::getA() const {
@@ -422,7 +406,6 @@ const SCEV *DependenceInfo::Constraint::getA() const {
return A;
}
-
// If constraint is a line AX + BY = C, returns B.
// Otherwise assert.
const SCEV *DependenceInfo::Constraint::getB() const {
@@ -431,7 +414,6 @@ const SCEV *DependenceInfo::Constraint::getB() const {
return B;
}
-
// If constraint is a line AX + BY = C, returns C.
// Otherwise assert.
const SCEV *DependenceInfo::Constraint::getC() const {
@@ -440,7 +422,6 @@ const SCEV *DependenceInfo::Constraint::getC() const {
return C;
}
-
// If constraint is a distance, returns D.
// Otherwise assert.
const SCEV *DependenceInfo::Constraint::getD() const {
@@ -448,7 +429,6 @@ const SCEV *DependenceInfo::Constraint::getD() const {
return SE->getNegativeSCEV(C);
}
-
// Returns the loop associated with this constraint.
const Loop *DependenceInfo::Constraint::getAssociatedLoop() const {
assert((Kind == Distance || Kind == Line || Kind == Point) &&
@@ -499,17 +479,16 @@ LLVM_DUMP_METHOD void DependenceInfo::Constraint::dump(raw_ostream &OS) const {
else if (isPoint())
OS << " Point is <" << *getX() << ", " << *getY() << ">\n";
else if (isDistance())
- OS << " Distance is " << *getD() <<
- " (" << *getA() << "*X + " << *getB() << "*Y = " << *getC() << ")\n";
+ OS << " Distance is " << *getD() << " (" << *getA() << "*X + " << *getB()
+ << "*Y = " << *getC() << ")\n";
else if (isLine())
- OS << " Line is " << *getA() << "*X + " <<
- *getB() << "*Y = " << *getC() << "\n";
+ OS << " Line is " << *getA() << "*X + " << *getB() << "*Y = " << *getC()
+ << "\n";
else
llvm_unreachable("unknown constraint type in Constraint::dump");
}
#endif
-
// Updates X with the intersection
// of the Constraints X and Y. Returns true if X has changed.
// Corresponds to Figure 4 from the paper
@@ -591,15 +570,14 @@ bool DependenceInfo::intersectConstraints(Constraint *X, const Constraint *Y) {
const SCEV *A1B2 = SE->getMulExpr(X->getA(), Y->getB());
const SCEV *A2B1 = SE->getMulExpr(Y->getA(), X->getB());
const SCEVConstant *C1A2_C2A1 =
- dyn_cast<SCEVConstant>(SE->getMinusSCEV(C1A2, C2A1));
+ dyn_cast<SCEVConstant>(SE->getMinusSCEV(C1A2, C2A1));
const SCEVConstant *C1B2_C2B1 =
- dyn_cast<SCEVConstant>(SE->getMinusSCEV(C1B2, C2B1));
+ dyn_cast<SCEVConstant>(SE->getMinusSCEV(C1B2, C2B1));
const SCEVConstant *A1B2_A2B1 =
- dyn_cast<SCEVConstant>(SE->getMinusSCEV(A1B2, A2B1));
+ dyn_cast<SCEVConstant>(SE->getMinusSCEV(A1B2, A2B1));
const SCEVConstant *A2B1_A1B2 =
- dyn_cast<SCEVConstant>(SE->getMinusSCEV(A2B1, A1B2));
- if (!C1B2_C2B1 || !C1A2_C2A1 ||
- !A1B2_A2B1 || !A2B1_A1B2)
+ dyn_cast<SCEVConstant>(SE->getMinusSCEV(A2B1, A1B2));
+ if (!C1B2_C2B1 || !C1A2_C2A1 || !A1B2_A2B1 || !A2B1_A1B2)
return false;
APInt Xtop = C1B2_C2B1->getAPInt();
APInt Xbot = A1B2_A2B1->getAPInt();
@@ -626,8 +604,8 @@ bool DependenceInfo::intersectConstraints(Constraint *X, const Constraint *Y) {
++DeltaSuccesses;
return true;
}
- if (const SCEVConstant *CUB =
- collectConstantUpperBound(X->getAssociatedLoop(), Prod1->getType())) {
+ if (const SCEVConstant *CUB = collectConstantUpperBound(
+ X->getAssociatedLoop(), Prod1->getType())) {
const APInt &UpperBound = CUB->getAPInt();
LLVM_DEBUG(dbgs() << "\t\tupper bound = " << UpperBound << "\n");
if (Xq.sgt(UpperBound) || Yq.sgt(UpperBound)) {
@@ -636,8 +614,7 @@ bool DependenceInfo::intersectConstraints(Constraint *X, const Constraint *Y) {
return true;
}
}
- X->setPoint(SE->getConstant(Xq),
- SE->getConstant(Yq),
+ X->setPoint(SE->getConstant(Xq), SE->getConstant(Yq),
X->getAssociatedLoop());
++DeltaSuccesses;
return true;
@@ -667,7 +644,6 @@ bool DependenceInfo::intersectConstraints(Constraint *X, const Constraint *Y) {
return false;
}
-
//===----------------------------------------------------------------------===//
// DependenceInfo methods
@@ -737,8 +713,7 @@ void Dependence::dump(raw_ostream &OS) const {
// tbaa, non-overlapping regions etc), then it is known there is no dependecy.
// Otherwise the underlying objects are checked to see if they point to
// different identifiable objects.
-static AliasResult underlyingObjectsAlias(AAResults *AA,
- const DataLayout &DL,
+static AliasResult underlyingObjectsAlias(AAResults *AA, const DataLayout &DL,
const MemoryLocation &LocA,
const MemoryLocation &LocB) {
// Check the original locations (minus size) for noalias, which can happen for
@@ -773,8 +748,7 @@ static AliasResult underlyingObjectsAlias(AAResults *AA,
// Returns true if the load or store can be analyzed. Atomic and volatile
// operations have properties which this analysis does not understand.
-static
-bool isLoadOrStore(const Instruction *I) {
+static bool isLoadOrStore(const Instruction *I) {
if (const LoadInst *LI = dyn_cast<LoadInst>(I))
return LI->isUnordered();
else if (const StoreInst *SI = dyn_cast<StoreInst>(I))
@@ -782,7 +756,6 @@ bool isLoadOrStore(const Instruction *I) {
return false;
}
-
// Examines the loop nesting of the Src and Dst
// instructions and establishes their shared loops. Sets the variables
// CommonLevels, SrcLevels, and MaxLevels.
@@ -860,14 +833,12 @@ void DependenceInfo::establishNestingLevels(const Instruction *Src,
MaxLevels -= CommonLevels;
}
-
// Given one of the loops containing the source, return
// its level index in our numbering scheme.
unsigned DependenceInfo::mapSrcLoop(const Loop *SrcLoop) const {
return SrcLoop->getLoopDepth();
}
-
// Given one of the loops containing the destination,
// return its level index in our numbering scheme.
unsigned DependenceInfo::mapDstLoop(const Loop *DstLoop) const {
@@ -880,7 +851,6 @@ unsigned DependenceInfo::mapDstLoop(const Loop *DstLoop) const {
return D;
}
-
// Returns true if Expression is loop invariant in LoopNest.
bool DependenceInfo::isLoopInvariant(const SCEV *Expression,
const Loop *LoopNest) const {
@@ -896,8 +866,6 @@ bool DependenceInfo::isLoopInvariant(const SCEV *Expression,
return SE->isLoopInvariant(Expression, LoopNest->getOutermostLoop());
}
-
-
// Finds the set of loops from the LoopNest that
// have a level <= CommonLevels and are referred to by the SCEV Expression.
void DependenceInfo::collectCommonLoops(const SCEV *Expression,
@@ -924,9 +892,9 @@ void DependenceInfo::unifySubscriptType(ArrayRef<Subscript *> Pairs) {
IntegerType *SrcTy = dyn_cast<IntegerType>(Src->getType());
IntegerType *DstTy = dyn_cast<IntegerType>(Dst->getType());
if (SrcTy == nullptr || DstTy == nullptr) {
- assert(SrcTy == DstTy && "This function only unify integer types and "
- "expect Src and Dst share the same type "
- "otherwise.");
+ assert(SrcTy == DstTy &&
+ "This function only unify integer types and "
+ "expect Src and Dst share the same type otherwise.");
continue;
}
if (SrcTy->getBitWidth() > widestWidthSeen) {
@@ -939,7 +907,6 @@ void DependenceInfo::unifySubscriptType(ArrayRef<Subscript *> Pairs) {
}
}
-
assert(widestWidthSeen > 0);
// Now extend each pair to the widest seen.
@@ -949,9 +916,9 @@ void DependenceInfo::unifySubscriptType(ArrayRef<Subscript *> Pairs) {
IntegerType *SrcTy = dyn_cast<IntegerType>(Src->getType());
IntegerType *DstTy = dyn_cast<IntegerType>(Dst->getType());
if (SrcTy == nullptr || DstTy == nullptr) {
- assert(SrcTy == DstTy && "This function only unify integer types and "
- "expect Src and Dst share the same type "
- "otherwise.");
+ assert(SrcTy == DstTy &&
+ "This function only unify integer types and "
+ "expect Src and Dst share the same type otherwise.");
continue;
}
if (SrcTy->getBitWidth() < widestWidthSeen)
@@ -1028,7 +995,6 @@ bool DependenceInfo::checkDstSubscript(const SCEV *Dst, const Loop *LoopNest,
return checkSubscript(Dst, LoopNest, Loops, false);
}
-
// Examines the subscript pair (the Src and Dst SCEVs)
// and classifies it as either ZIV, SIV, RDIV, MIV, or Nonlinear.
// Collects the associated loops in a set.
@@ -1049,14 +1015,12 @@ DependenceInfo::classifyPair(const SCEV *Src, const Loop *SrcLoopNest,
return Subscript::ZIV;
if (N == 1)
return Subscript::SIV;
- if (N == 2 && (SrcLoops.count() == 0 ||
- DstLoops.count() == 0 ||
+ if (N == 2 && (SrcLoops.count() == 0 || DstLoops.count() == 0 ||
(SrcLoops.count() == 1 && DstLoops.count() == 1)))
return Subscript::RDIV;
return Subscript::MIV;
}
-
// A wrapper around SCEV::isKnownPredicate.
// Looks for cases where we're interested in comparing for equality.
// If both X and Y have been identically sign or zero extended,
@@ -1069,12 +1033,9 @@ DependenceInfo::classifyPair(const SCEV *Src, const Loop *SrcLoopNest,
// involving symbolics.
bool DependenceInfo::isKnownPredicate(ICmpInst::Predicate Pred, const SCEV *X,
const SCEV *Y) const {
- if (Pred == CmpInst::ICMP_EQ ||
- Pred == CmpInst::ICMP_NE) {
- if ((isa<SCEVSignExtendExpr>(X) &&
- isa<SCEVSignExtendExpr>(Y)) ||
- (isa<SCEVZeroExtendExpr>(X) &&
- isa<SCEVZeroExtendExpr>(Y))) {
+ if (Pred == CmpInst::ICMP_EQ || Pred == CmpInst::ICMP_NE) {
+ if ((isa<SCEVSignExtendExpr>(X) && isa<SCEVSignExtendExpr>(Y)) ||
+ (isa<SCEVZeroExtendExpr>(X) && isa<SCEVZeroExtendExpr>(Y))) {
const SCEVIntegralCastExpr *CX = cast<SCEVIntegralCastExpr>(X);
const SCEVIntegralCastExpr *CY = cast<SCEVIntegralCastExpr>(Y);
const SCEV *Xop = CX->getOperand();
@@ -1111,7 +1072,10 @@ bool DependenceInfo::isKnownPredicate(ICmpInst::Predicate Pred, const SCEV *X,
}
}
-/// Compare to see if S is less than Size, using isKnownNegative(S - max(Size, 1))
+/// Compare to see if S is less than Size, using
+///
+/// isKnownNegative(S - max(Size, 1))
+///
/// with some extra checking if S is an AddRec and we can prove less-than using
/// the loop bounds.
bool DependenceInfo::isKnownLessThan(const SCEV *S, const SCEV *Size) const {
@@ -1178,7 +1142,6 @@ const SCEV *DependenceInfo::collectUpperBound(const Loop *L, Type *T) const {
return nullptr;
}
-
// Calls collectUpperBound(), then attempts to cast it to SCEVConstant.
// If the cast fails, returns NULL.
const SCEVConstant *DependenceInfo::collectConstantUpperBound(const Loop *L,
@@ -1188,7 +1151,6 @@ const SCEVConstant *DependenceInfo::collectConstantUpperBound(const Loop *L,
return nullptr;
}
-
// testZIV -
// When we have a pair of subscripts of the form [c1] and [c2],
// where c1 and c2 are both loop invariant, we attack it using
@@ -1218,7 +1180,6 @@ bool DependenceInfo::testZIV(const SCEV *Src, const SCEV *Dst,
return false; // possibly dependent
}
-
// strongSIVtest -
// From the paper, Practical Dependence Testing, Section 4.2.1
//
@@ -1270,9 +1231,9 @@ bool DependenceInfo::strongSIVtest(const SCEV *Coeff, const SCEV *SrcConst,
LLVM_DEBUG(dbgs() << "\t UpperBound = " << *UpperBound);
LLVM_DEBUG(dbgs() << ", " << *UpperBound->getType() << "\n");
const SCEV *AbsDelta =
- SE->isKnownNonNegative(Delta) ? Delta : SE->getNegativeSCEV(Delta);
+ SE->isKnownNonNegative(Delta) ? Delta : SE->getNegativeSCEV(Delta);
const SCEV *AbsCoeff =
- SE->isKnownNonNegative(Coeff) ? Coeff : SE->getNegativeSCEV(Coeff);
+ SE->isKnownNonNegative(Coeff) ? Coeff : SE->getNegativeSCEV(Coeff);
const SCEV *Product = SE->getMulExpr(UpperBound, AbsCoeff);
if (isKnownPredicate(CmpInst::ICMP_SGT, AbsDelta, Product)) {
// Distance greater than trip count - no dependence
@@ -1286,7 +1247,7 @@ bool DependenceInfo::strongSIVtest(const SCEV *Coeff, const SCEV *SrcConst,
if (isa<SCEVConstant>(Delta) && isa<SCEVConstant>(Coeff)) {
APInt ConstDelta = cast<SCEVConstant>(Delta)->getAPInt();
APInt ConstCoeff = cast<SCEVConstant>(Coeff)->getAPInt();
- APInt Distance = ConstDelta; // these need to be initialized
+ APInt Distance = ConstDelta; // these need to be initialized
APInt Remainder = ConstDelta;
APInt::sdivrem(ConstDelta, ConstCoeff, Distance, Remainder);
LLVM_DEBUG(dbgs() << "\t Distance = " << Distance << "\n");
@@ -1307,29 +1268,25 @@ bool DependenceInfo::strongSIVtest(const SCEV *Coeff, const SCEV *SrcConst,
else
Result.DV[Level].Direction &= Dependence::DVEntry::EQ;
++StrongSIVsuccesses;
- }
- else if (Delta->isZero()) {
+ } else if (Delta->isZero()) {
// since 0/X == 0
Result.DV[Level].Distance = Delta;
NewConstraint.setDistance(Delta, CurLoop);
Result.DV[Level].Direction &= Dependence::DVEntry::EQ;
++StrongSIVsuccesses;
- }
- else {
+ } else {
if (Coeff->isOne()) {
LLVM_DEBUG(dbgs() << "\t Distance = " << *Delta << "\n");
Result.DV[Level].Distance = Delta; // since X/1 == X
NewConstraint.setDistance(Delta, CurLoop);
- }
- else {
+ } else {
Result.Consistent = false;
- NewConstraint.setLine(Coeff,
- SE->getNegativeSCEV(Coeff),
+ NewConstraint.setLine(Coeff, SE->getNegativeSCEV(Coeff),
SE->getNegativeSCEV(Delta), CurLoop);
}
// maybe we can get a useful direction
- bool DeltaMaybeZero = !SE->isKnownNonZero(Delta);
+ bool DeltaMaybeZero = !SE->isKnownNonZero(Delta);
bool DeltaMaybePositive = !SE->isKnownNonPositive(Delta);
bool DeltaMaybeNegative = !SE->isKnownNonNegative(Delta);
bool CoeffMaybePositive = !SE->isKnownNonPositive(Coeff);
@@ -1353,7 +1310,6 @@ bool DependenceInfo::strongSIVtest(const SCEV *Coeff, const SCEV *SrcConst,
return false;
}
-
// weakCrossingSIVtest -
// From the paper, Practical Dependence Testing, Section 4.2.2
//
@@ -1447,8 +1403,8 @@ bool DependenceInfo::weakCrossingSIVtest(
if (const SCEV *UpperBound = collectUpperBound(CurLoop, Delta->getType())) {
LLVM_DEBUG(dbgs() << "\t UpperBound = " << *UpperBound << "\n");
const SCEV *ConstantTwo = SE->getConstant(UpperBound->getType(), 2);
- const SCEV *ML = SE->getMulExpr(SE->getMulExpr(ConstCoeff, UpperBound),
- ConstantTwo);
+ const SCEV *ML =
+ SE->getMulExpr(SE->getMulExpr(ConstCoeff, UpperBound), ConstantTwo);
LLVM_DEBUG(dbgs() << "\t ML = " << *ML << "\n");
if (isKnownPredicate(CmpInst::ICMP_SGT, Delta, ML)) {
// Delta too big, no dependence
@@ -1498,7 +1454,6 @@ bool DependenceInfo::weakCrossingSIVtest(
return false;
}
-
// Kirch's algorithm, from
//
// Optimizing Supercompilers for Supercomputers
@@ -1519,9 +1474,14 @@ static bool findGCD(unsigned Bits, const APInt &AM, const APInt &BM,
APInt R = G0;
APInt::sdivrem(G0, G1, Q, R);
while (R != 0) {
- APInt A2 = A0 - Q*A1; A0 = A1; A1 = A2;
- APInt B2 = B0 - Q*B1; B0 = B1; B1 = B2;
- G0 = G1; G1 = R;
+ APInt A2 = A0 - Q * A1;
+ A0 = A1;
+ A1 = A2;
+ APInt B2 = B0 - Q * B1;
+ B0 = B1;
+ B1 = B2;
+ G0 = G1;
+ G1 = R;
APInt::sdivrem(G0, G1, Q, R);
}
G = G1;
@@ -1543,8 +1503,7 @@ static APInt floorOfQuotient(const APInt &A, const APInt &B) {
APInt::sdivrem(A, B, Q, R);
if (R == 0)
return Q;
- if ((A.sgt(0) && B.sgt(0)) ||
- (A.slt(0) && B.slt(0)))
+ if ((A.sgt(0) && B.sgt(0)) || (A.slt(0) && B.slt(0)))
return Q;
else
return Q - 1;
@@ -1556,8 +1515,7 @@ static APInt ceilingOfQuotient(const APInt &A, const APInt &B) {
APInt::sdivrem(A, B, Q, R);
if (R == 0)
return Q;
- if ((A.sgt(0) && B.sgt(0)) ||
- (A.slt(0) && B.slt(0)))
+ if ((A.sgt(0) && B.sgt(0)) || (A.slt(0) && B.slt(0)))
return Q + 1;
else
return Q;
@@ -1733,17 +1691,14 @@ bool DependenceInfo::exactSIVtest(const SCEV *SrcCoeff, const SCEV *DstCoeff,
return Result.DV[Level].Direction == Dependence::DVEntry::NONE;
}
-
// Return true if the divisor evenly divides the dividend.
-static
-bool isRemainderZero(const SCEVConstant *Dividend,
- const SCEVConstant *Divisor) {
+static bool isRemainderZero(const SCEVConstant *Dividend,
+ const SCEVConstant *Divisor) {
const APInt &ConstDividend = Dividend->getAPInt();
const APInt &ConstDivisor = Divisor->getAPInt();
return ConstDividend.srem(ConstDivisor) == 0;
}
-
// weakZeroSrcSIVtest -
// From the paper, Practical Dependence Testing, Section 4.2.2
//
@@ -1807,11 +1762,11 @@ bool DependenceInfo::weakZeroSrcSIVtest(const SCEV *DstCoeff,
const SCEVConstant *ConstCoeff = dyn_cast<SCEVConstant>(DstCoeff);
if (!ConstCoeff)
return false;
- const SCEV *AbsCoeff =
- SE->isKnownNegative(ConstCoeff) ?
- SE->getNegativeSCEV(ConstCoeff) : ConstCoeff;
+ const SCEV *AbsCoeff = SE->isKnownNegative(ConstCoeff)
+ ? SE->getNegativeSCEV(ConstCoeff)
+ : ConstCoeff;
const SCEV *NewDelta =
- SE->isKnownNegative(ConstCoeff) ? SE->getNegativeSCEV(Delta) : Delta;
+ SE->isKnownNegative(ConstCoeff) ? SE->getNegativeSCEV(Delta) : Delta;
// check that Delta/SrcCoeff < iteration count
// really check NewDelta < count*AbsCoeff
@@ -1853,7 +1808,6 @@ bool DependenceInfo::weakZeroSrcSIVtest(const SCEV *DstCoeff,
return false;
}
-
// weakZeroDstSIVtest -
// From the paper, Practical Dependence Testing, Section 4.2.2
//
@@ -1916,11 +1870,11 @@ bool DependenceInfo::weakZeroDstSIVtest(const SCEV *SrcCoeff,
const SCEVConstant *ConstCoeff = dyn_cast<SCEVConstant>(SrcCoeff);
if (!ConstCoeff)
return false;
- const SCEV *AbsCoeff =
- SE->isKnownNegative(ConstCoeff) ?
- SE->getNegativeSCEV(ConstCoeff) : ConstCoeff;
+ const SCEV *AbsCoeff = SE->isKnownNegative(ConstCoeff)
+ ? SE->getNegativeSCEV(ConstCoeff)
+ : ConstCoeff;
const SCEV *NewDelta =
- SE->isKnownNegative(ConstCoeff) ? SE->getNegativeSCEV(Delta) : Delta;
+ SE->isKnownNegative(ConstCoeff) ? SE->getNegativeSCEV(Delta) : Delta;
// check that Delta/SrcCoeff < iteration count
// really check NewDelta < count*AbsCoeff
@@ -1962,7 +1916,6 @@ bool DependenceInfo::weakZeroDstSIVtest(const SCEV *SrcCoeff,
return false;
}
-
// exactRDIVtest - Tests the RDIV subscript pair for dependence.
// Things of the form [c1 + a*i] and [c2 + b*j],
// where i and j are induction variable, c1 and c2 are loop invariant,
@@ -2084,7 +2037,6 @@ bool DependenceInfo::exactRDIVtest(const SCEV *SrcCoeff, const SCEV *DstCoeff,
return TL.sgt(TU);
}
-
// symbolicRDIVtest -
// In Section 4.5 of the Practical Dependence Testing paper,the authors
// introduce a special case of Banerjee's Inequalities (also called the
@@ -2167,8 +2119,7 @@ bool DependenceInfo::symbolicRDIVtest(const SCEV *A1, const SCEV *A2,
return true;
}
}
- }
- else if (SE->isKnownNonPositive(A2)) {
+ } else if (SE->isKnownNonPositive(A2)) {
// a1 >= 0 && a2 <= 0
if (N1 && N2) {
// make sure that c2 - c1 <= a1*N1 - a2*N2
@@ -2187,8 +2138,7 @@ bool DependenceInfo::symbolicRDIVtest(const SCEV *A1, const SCEV *A2,
return true;
}
}
- }
- else if (SE->isKnownNonPositive(A1)) {
+ } else if (SE->isKnownNonPositive(A1)) {
if (SE->isKnownNonNegative(A2)) {
// a1 <= 0 && a2 >= 0
if (N1 && N2) {
@@ -2207,8 +2157,7 @@ bool DependenceInfo::symbolicRDIVtest(const SCEV *A1, const SCEV *A2,
++SymbolicRDIVindependence;
return true;
}
- }
- else if (SE->isKnownNonPositive(A2)) {
+ } else if (SE->isKnownNonPositive(A2)) {
// a1 <= 0 && a2 <= 0
if (N1) {
// make sure that a1*N1 <= c2 - c1
@@ -2233,7 +2182,6 @@ bool DependenceInfo::symbolicRDIVtest(const SCEV *A1, const SCEV *A2,
return false;
}
-
// testSIV -
// When we have a pair of subscripts of the form [c1 + a1*i] and [c2 - a2*i]
// where i is an induction variable, c1 and c2 are loop invariant, and a1 and
@@ -2260,17 +2208,17 @@ bool DependenceInfo::testSIV(const SCEV *Src, const SCEV *Dst, unsigned &Level,
Level = mapSrcLoop(CurLoop);
bool disproven;
if (SrcCoeff == DstCoeff)
- disproven = strongSIVtest(SrcCoeff, SrcConst, DstConst, CurLoop,
- Level, Result, NewConstraint);
+ disproven = strongSIVtest(SrcCoeff, SrcConst, DstConst, CurLoop, Level,
+ Result, NewConstraint);
else if (SrcCoeff == SE->getNegativeSCEV(DstCoeff))
disproven = weakCrossingSIVtest(SrcCoeff, SrcConst, DstConst, CurLoop,
Level, Result, NewConstraint, SplitIter);
else
disproven = exactSIVtest(SrcCoeff, DstCoeff, SrcConst, DstConst, CurLoop,
Level, Result, NewConstraint);
- return disproven ||
- gcdMIVtest(Src, Dst, Result) ||
- symbolicRDIVtest(SrcCoeff, DstCoeff, SrcConst, DstConst, CurLoop, CurLoop);
+ return disproven || gcdMIVtest(Src, Dst, Result) ||
+ symbolicRDIVtest(SrcCoeff, DstCoeff, SrcConst, DstConst, CurLoop,
+ CurLoop);
}
if (SrcAddRec) {
const SCEV *SrcConst = SrcAddRec->getStart();
@@ -2278,9 +2226,9 @@ bool DependenceInfo::testSIV(const SCEV *Src, const SCEV *Dst, unsigned &Level,
const SCEV *DstConst = Dst;
const Loop *CurLoop = SrcAddRec->getLoop();
Level = mapSrcLoop(CurLoop);
- return weakZeroDstSIVtest(SrcCoeff, SrcConst, DstConst, CurLoop,
- Level, Result, NewConstraint) ||
- gcdMIVtest(Src, Dst, Result);
+ return weakZeroDstSIVtest(SrcCoeff, SrcConst, DstConst, CurLoop, Level,
+ Result, NewConstraint) ||
+ gcdMIVtest(Src, Dst, Result);
}
if (DstAddRec) {
const SCEV *DstConst = DstAddRec->getStart();
@@ -2288,15 +2236,14 @@ bool DependenceInfo::testSIV(const SCEV *Src, const SCEV *Dst, unsigned &Level,
const SCEV *SrcConst = Src;
const Loop *CurLoop = DstAddRec->getLoop();
Level = mapDstLoop(CurLoop);
- return weakZeroSrcSIVtest(DstCoeff, SrcConst, DstConst,
- CurLoop, Level, Result, NewConstraint) ||
- gcdMIVtest(Src, Dst, Result);
+ return weakZeroSrcSIVtest(DstCoeff, SrcConst, DstConst, CurLoop, Level,
+ Result, NewConstraint) ||
+ gcdMIVtest(Src, Dst, Result);
}
llvm_unreachable("SIV test expected at least one AddRec");
return false;
}
-
// testRDIV -
// When we have a pair of subscripts of the form [c1 + a1*i] and [c2 + a2*j]
// where i and j are induction variables, c1 and c2 are loop invariant,
@@ -2333,46 +2280,37 @@ bool DependenceInfo::testRDIV(const SCEV *Src, const SCEV *Dst,
DstConst = DstAddRec->getStart();
DstCoeff = DstAddRec->getStepRecurrence(*SE);
DstLoop = DstAddRec->getLoop();
- }
- else if (SrcAddRec) {
+ } else if (SrcAddRec) {
if (const SCEVAddRecExpr *tmpAddRec =
- dyn_cast<SCEVAddRecExpr>(SrcAddRec->getStart())) {
+ dyn_cast<SCEVAddRecExpr>(SrcAddRec->getStart())) {
SrcConst = tmpAddRec->getStart();
SrcCoeff = tmpAddRec->getStepRecurrence(*SE);
SrcLoop = tmpAddRec->getLoop();
DstConst = Dst;
DstCoeff = SE->getNegativeSCEV(SrcAddRec->getStepRecurrence(*SE));
DstLoop = SrcAddRec->getLoop();
- }
- else
+ } else
llvm_unreachable("RDIV reached by surprising SCEVs");
- }
- else if (DstAddRec) {
+ } else if (DstAddRec) {
if (const SCEVAddRecExpr *tmpAddRec =
- dyn_cast<SCEVAddRecExpr>(DstAddRec->getStart())) {
+ dyn_cast<SCEVAddRecExpr>(DstAddRec->getStart())) {
DstConst = tmpAddRec->getStart();
DstCoeff = tmpAddRec->getStepRecurrence(*SE);
DstLoop = tmpAddRec->getLoop();
SrcConst = Src;
SrcCoeff = SE->getNegativeSCEV(DstAddRec->getStepRecurrence(*SE));
SrcLoop = DstAddRec->getLoop();
- }
- else
+ } else
llvm_unreachable("RDIV reached by surprising SCEVs");
- }
- else
+ } else
llvm_unreachable("RDIV expected at least one AddRec");
- return exactRDIVtest(SrcCoeff, DstCoeff,
- SrcConst, DstConst,
- SrcLoop, DstLoop,
+ return exactRDIVtest(SrcCoeff, DstCoeff, SrcConst, DstConst, SrcLoop, DstLoop,
Result) ||
- gcdMIVtest(Src, Dst, Result) ||
- symbolicRDIVtest(SrcCoeff, DstCoeff,
- SrcConst, DstConst,
- SrcLoop, DstLoop);
+ gcdMIVtest(Src, Dst, Result) ||
+ symbolicRDIVtest(SrcCoeff, DstCoeff, SrcConst, DstConst, SrcLoop,
+ DstLoop);
}
-
// Tests the single-subscript MIV pair (Src and Dst) for dependence.
// Return true if dependence disproved.
// Can sometimes refine direction vectors.
@@ -2383,7 +2321,7 @@ bool DependenceInfo::testMIV(const SCEV *Src, const SCEV *Dst,
LLVM_DEBUG(dbgs() << " dst = " << *Dst << "\n");
Result.Consistent = false;
return gcdMIVtest(Src, Dst, Result) ||
- banerjeeMIVtest(Src, Dst, Loops, Result);
+ banerjeeMIVtest(Src, Dst, Loops, Result);
}
// Given a product, e.g., 10*X*Y, returns the first constant operand,
@@ -2428,7 +2366,7 @@ bool DependenceInfo::gcdMIVtest(const SCEV *Src, const SCEV *Dst,
// we can't quit the loop just because the GCD == 1.
const SCEV *Coefficients = Src;
while (const SCEVAddRecExpr *AddRec =
- dyn_cast<SCEVAddRecExpr>(Coefficients)) {
+ dyn_cast<SCEVAddRecExpr>(Coefficients)) {
const SCEV *Coeff = AddRec->getStepRecurrence(*SE);
// If the coefficient is the product of a constant and other stuff,
// we can use the constant in the GCD computation.
@@ -2446,7 +2384,7 @@ bool DependenceInfo::gcdMIVtest(const SCEV *Src, const SCEV *Dst,
// we can't quit the loop just because the GCD == 1.
Coefficients = Dst;
while (const SCEVAddRecExpr *AddRec =
- dyn_cast<SCEVAddRecExpr>(Coefficients)) {
+ dyn_cast<SCEVAddRecExpr>(Coefficients)) {
const SCEV *Coeff = AddRec->getStepRecurrence(*SE);
// If the coefficient is the product of a constant and other stuff,
// we can use the constant in the GCD computation.
@@ -2468,16 +2406,14 @@ bool DependenceInfo::gcdMIVtest(const SCEV *Src, const SCEV *Dst,
if (isa<SCEVConstant>(Operand)) {
assert(!Constant && "Surprised to find multiple constants");
Constant = cast<SCEVConstant>(Operand);
- }
- else if (const SCEVMulExpr *Product = dyn_cast<SCEVMulExpr>(Operand)) {
+ } else if (const SCEVMulExpr *Product = dyn_cast<SCEVMulExpr>(Operand)) {
// Search for constant operand to participate in GCD;
// If none found; return false.
std::optional<APInt> ConstOp = getConstantPart(Product);
if (!ConstOp)
return false;
ExtraGCD = APIntOps::GreatestCommonDivisor(ExtraGCD, ConstOp->abs());
- }
- else
+ } else
return false;
}
}
@@ -2512,7 +2448,7 @@ bool DependenceInfo::gcdMIVtest(const SCEV *Src, const SCEV *Dst,
bool Improved = false;
Coefficients = Src;
while (const SCEVAddRecExpr *AddRec =
- dyn_cast<SCEVAddRecExpr>(Coefficients)) {
+ dyn_cast<SCEVAddRecExpr>(Coefficients)) {
Coefficients = AddRec->getStart();
const Loop *CurLoop = AddRec->getLoop();
RunningGCD = ExtraGCD;
@@ -2578,7 +2514,6 @@ bool DependenceInfo::gcdMIVtest(const SCEV *Src, const SCEV *Dst,
return false;
}
-
//===----------------------------------------------------------------------===//
// banerjeeMIVtest -
// Use Banerjee's Inequalities to test an MIV subscript pair.
@@ -2652,8 +2587,8 @@ bool DependenceInfo::banerjeeMIVtest(const SCEV *Src, const SCEV *Dst,
if (testBounds(Dependence::DVEntry::ALL, 0, Bound, Delta)) {
// Explore the direction vector hierarchy.
unsigned DepthExpanded = 0;
- unsigned NewDeps = exploreDirections(1, A, B, Bound,
- Loops, DepthExpanded, Delta);
+ unsigned NewDeps =
+ exploreDirections(1, A, B, Bound, Loops, DepthExpanded, Delta);
if (NewDeps > 0) {
bool Improved = false;
for (unsigned K = 1; K <= CommonLevels; ++K) {
@@ -2670,23 +2605,20 @@ bool DependenceInfo::banerjeeMIVtest(const SCEV *Src, const SCEV *Dst,
}
if (Improved)
++BanerjeeSuccesses;
- }
- else {
+ } else {
++BanerjeeIndependence;
Disproved = true;
}
- }
- else {
+ } else {
++BanerjeeIndependence;
Disproved = true;
}
- delete [] Bound;
- delete [] A;
- delete [] B;
+ delete[] Bound;
+ delete[] A;
+ delete[] B;
return Disproved;
}
-
// Hierarchically expands the direction vector
// search space, combining the directions of discovered dependences
// in the DirSet field of Bound. Returns the number of distinct
@@ -2788,27 +2720,26 @@ unsigned DependenceInfo::exploreDirections(unsigned Level, CoefficientInfo *A,
// test bounds for <, *, *, ...
if (testBounds(Dependence::DVEntry::LT, Level, Bound, Delta))
- NewDeps += exploreDirections(Level + 1, A, B, Bound,
- Loops, DepthExpanded, Delta);
+ NewDeps += exploreDirections(Level + 1, A, B, Bound, Loops, DepthExpanded,
+ Delta);
// Test bounds for =, *, *, ...
if (testBounds(Dependence::DVEntry::EQ, Level, Bound, Delta))
- NewDeps += exploreDirections(Level + 1, A, B, Bound,
- Loops, DepthExpanded, Delta);
+ NewDeps += exploreDirections(Level + 1, A, B, Bound, Loops, DepthExpanded,
+ Delta);
// test bounds for >, *, *, ...
if (testBounds(Dependence::DVEntry::GT, Level, Bound, Delta))
- NewDeps += exploreDirections(Level + 1, A, B, Bound,
- Loops, DepthExpanded, Delta);
+ NewDeps += exploreDirections(Level + 1, A, B, Bound, Loops, DepthExpanded,
+ Delta);
Bound[Level].Direction = Dependence::DVEntry::ALL;
return NewDeps;
- }
- else
- return exploreDirections(Level + 1, A, B, Bound, Loops, DepthExpanded, Delta);
+ } else
+ return exploreDirections(Level + 1, A, B, Bound, Loops, DepthExpanded,
+ Delta);
}
-
// Returns true iff the current bounds are plausible.
bool DependenceInfo::testBounds(unsigned char DirKind, unsigned Level,
BoundInfo *Bound, const SCEV *Delta) const {
@@ -2822,7 +2753,6 @@ bool DependenceInfo::testBounds(unsigned char DirKind, unsigned Level,
return true;
}
-
// Computes the upper and lower bounds for level K
// using the * direction. Records them in Bound.
// Wolfe gives the equations
@@ -2840,17 +2770,14 @@ bool DependenceInfo::testBounds(unsigned char DirKind, unsigned Level,
// and the upper bound is always >= 0.
void DependenceInfo::findBoundsALL(CoefficientInfo *A, CoefficientInfo *B,
BoundInfo *Bound, unsigned K) const {
- Bound[K].Lower[Dependence::DVEntry::ALL] = nullptr; // Default value = -infinity.
- Bound[K].Upper[Dependence::DVEntry::ALL] = nullptr; // Default value = +infinity.
+ Bound[K].Lower[Dependence::DVEntry::ALL] = nullptr; // Represents -infinity
+ Bound[K].Upper[Dependence::DVEntry::ALL] = nullptr; // Represents +infinity
if (Bound[K].Iterations) {
- Bound[K].Lower[Dependence::DVEntry::ALL] =
- SE->getMulExpr(SE->getMinusSCEV(A[K].NegPart, B[K].PosPart),
- Bound[K].Iterations);
- Bound[K].Upper[Dependence::DVEntry::ALL] =
- SE->getMulExpr(SE->getMinusSCEV(A[K].PosPart, B[K].NegPart),
- Bound[K].Iterations);
- }
- else {
+ Bound[K].Lower[Dependence::DVEntry::ALL] = SE->getMulExpr(
+ SE->getMinusSCEV(A[K].NegPart, B[K].PosPart), Bound[K].Iterations);
+ Bound[K].Upper[Dependence::DVEntry::ALL] = SE->getMulExpr(
+ SE->getMinusSCEV(A[K].PosPart, B[K].NegPart), Bound[K].Iterations);
+ } else {
// If the difference is 0, we won't need to know the number of iterations.
if (isKnownPredicate(CmpInst::ICMP_EQ, A[K].NegPart, B[K].PosPart))
Bound[K].Lower[Dependence::DVEntry::ALL] =
@@ -2861,7 +2788,6 @@ void DependenceInfo::findBoundsALL(CoefficientInfo *A, CoefficientInfo *B,
}
}
-
// Computes the upper and lower bounds for level K
// using the = direction. Records them in Bound.
// Wolfe gives the equations
@@ -2879,18 +2805,19 @@ void DependenceInfo::findBoundsALL(CoefficientInfo *A, CoefficientInfo *B,
// and the upper bound is always >= 0.
void DependenceInfo::findBoundsEQ(CoefficientInfo *A, CoefficientInfo *B,
BoundInfo *Bound, unsigned K) const {
- Bound[K].Lower[Dependence::DVEntry::EQ] = nullptr; // Default value = -infinity.
- Bound[K].Upper[Dependence::DVEntry::EQ] = nullptr; // Default value = +infinity.
+ Bound[K].Lower[Dependence::DVEntry::EQ] =
+ nullptr; // Default value = -infinity.
+ Bound[K].Upper[Dependence::DVEntry::EQ] =
+ nullptr; // Default value = +infinity.
if (Bound[K].Iterations) {
const SCEV *Delta = SE->getMinusSCEV(A[K].Coeff, B[K].Coeff);
const SCEV *NegativePart = getNegativePart(Delta);
Bound[K].Lower[Dependence::DVEntry::EQ] =
- SE->getMulExpr(NegativePart, Bound[K].Iterations);
+ SE->getMulExpr(NegativePart, Bound[K].Iterations);
const SCEV *PositivePart = getPositivePart(Delta);
Bound[K].Upper[Dependence::DVEntry::EQ] =
- SE->getMulExpr(PositivePart, Bound[K].Iterations);
- }
- else {
+ SE->getMulExpr(PositivePart, Bound[K].Iterations);
+ } else {
// If the positive/negative part of the difference is 0,
// we won't need to know the number of iterations.
const SCEV *Delta = SE->getMinusSCEV(A[K].Coeff, B[K].Coeff);
@@ -2903,7 +2830,6 @@ void DependenceInfo::findBoundsEQ(CoefficientInfo *A, CoefficientInfo *B,
}
}
-
// Computes the upper and lower bounds for level K
// using the < direction. Records them in Bound.
// Wolfe gives the equations
@@ -2919,35 +2845,35 @@ void DependenceInfo::findBoundsEQ(CoefficientInfo *A, CoefficientInfo *B,
// We must be careful to handle the case where the upper bound is unknown.
void DependenceInfo::findBoundsLT(CoefficientInfo *A, CoefficientInfo *B,
BoundInfo *Bound, unsigned K) const {
- Bound[K].Lower[Dependence::DVEntry::LT] = nullptr; // Default value = -infinity.
- Bound[K].Upper[Dependence::DVEntry::LT] = nullptr; // Default value = +infinity.
+ Bound[K].Lower[Dependence::DVEntry::LT] =
+ nullptr; // Default value = -infinity.
+ Bound[K].Upper[Dependence::DVEntry::LT] =
+ nullptr; // Default value = +infinity.
if (Bound[K].Iterations) {
const SCEV *Iter_1 = SE->getMinusSCEV(
Bound[K].Iterations, SE->getOne(Bound[K].Iterations->getType()));
const SCEV *NegPart =
- getNegativePart(SE->getMinusSCEV(A[K].NegPart, B[K].Coeff));
+ getNegativePart(SE->getMinusSCEV(A[K].NegPart, B[K].Coeff));
Bound[K].Lower[Dependence::DVEntry::LT] =
- SE->getMinusSCEV(SE->getMulExpr(NegPart, Iter_1), B[K].Coeff);
+ SE->getMinusSCEV(SE->getMulExpr(NegPart, Iter_1), B[K].Coeff);
const SCEV *PosPart =
- getPositivePart(SE->getMinusSCEV(A[K].PosPart, B[K].Coeff));
+ getPositivePart(SE->getMinusSCEV(A[K].PosPart, B[K].Coeff));
Bound[K].Upper[Dependence::DVEntry::LT] =
- SE->getMinusSCEV(SE->getMulExpr(PosPart, Iter_1), B[K].Coeff);
- }
- else {
+ SE->getMinusSCEV(SE->getMulExpr(PosPart, Iter_1), B[K].Coeff);
+ } else {
// If the positive/negative part of the difference is 0,
// we won't need to know the number of iterations.
const SCEV *NegPart =
- getNegativePart(SE->getMinusSCEV(A[K].NegPart, B[K].Coeff));
+ getNegativePart(SE->getMinusSCEV(A[K].NegPart, B[K].Coeff));
if (NegPart->isZero())
Bound[K].Lower[Dependence::DVEntry::LT] = SE->getNegativeSCEV(B[K].Coeff);
const SCEV *PosPart =
- getPositivePart(SE->getMinusSCEV(A[K].PosPart, B[K].Coeff));
+ getPositivePart(SE->getMinusSCEV(A[K].PosPart, B[K].Coeff));
if (PosPart->isZero())
Bound[K].Upper[Dependence::DVEntry::LT] = SE->getNegativeSCEV(B[K].Coeff);
}
}
-
// Computes the upper and lower bounds for level K
// using the > direction. Records them in Bound.
// Wolfe gives the equations
@@ -2963,45 +2889,45 @@ void DependenceInfo::findBoundsLT(CoefficientInfo *A, CoefficientInfo *B,
// We must be careful to handle the case where the upper bound is unknown.
void DependenceInfo::findBoundsGT(CoefficientInfo *A, CoefficientInfo *B,
BoundInfo *Bound, unsigned K) const {
- Bound[K].Lower[Dependence::DVEntry::GT] = nullptr; // Default value = -infinity.
- Bound[K].Upper[Dependence::DVEntry::GT] = nullptr; // Default value = +infinity.
+ Bound[K].Lower[Dependence::DVEntry::GT] =
+ nullptr; // Default value = -infinity.
+ Bound[K].Upper[Dependence::DVEntry::GT] =
+ nullptr; // Default value = +infinity.
if (Bound[K].Iterations) {
const SCEV *Iter_1 = SE->getMinusSCEV(
Bound[K].Iterations, SE->getOne(Bound[K].Iterations->getType()));
const SCEV *NegPart =
- getNegativePart(SE->getMinusSCEV(A[K].Coeff, B[K].PosPart));
+ getNegativePart(SE->getMinusSCEV(A[K].Coeff, B[K].PosPart));
Bound[K].Lower[Dependence::DVEntry::GT] =
- SE->getAddExpr(SE->getMulExpr(NegPart, Iter_1), A[K].Coeff);
+ SE->getAddExpr(SE->getMulExpr(NegPart, Iter_1), A[K].Coeff);
const SCEV *PosPart =
- getPositivePart(SE->getMinusSCEV(A[K].Coeff, B[K].NegPart));
+ getPositivePart(SE->getMinusSCEV(A[K].Coeff, B[K].NegPart));
Bound[K].Upper[Dependence::DVEntry::GT] =
- SE->getAddExpr(SE->getMulExpr(PosPart, Iter_1), A[K].Coeff);
- }
- else {
+ SE->getAddExpr(SE->getMulExpr(PosPart, Iter_1), A[K].Coeff);
+ } else {
// If the positive/negative part of the difference is 0,
// we won't need to know the number of iterations.
- const SCEV *NegPart = getNegativePart(SE->getMinusSCEV(A[K].Coeff, B[K].PosPart));
+ const SCEV *NegPart =
+ getNegativePart(SE->getMinusSCEV(A[K].Coeff, B[K].PosPart));
if (NegPart->isZero())
Bound[K].Lower[Dependence::DVEntry::GT] = A[K].Coeff;
- const SCEV *PosPart = getPositivePart(SE->getMinusSCEV(A[K].Coeff, B[K].NegPart));
+ const SCEV *PosPart =
+ getPositivePart(SE->getMinusSCEV(A[K].Coeff, B[K].NegPart));
if (PosPart->isZero())
Bound[K].Upper[Dependence::DVEntry::GT] = A[K].Coeff;
}
}
-
// X^+ = max(X, 0)
const SCEV *DependenceInfo::getPositivePart(const SCEV *X) const {
return SE->getSMaxExpr(X, SE->getZero(X->getType()));
}
-
// X^- = min(X, 0)
const SCEV *DependenceInfo::getNegativePart(const SCEV *X) const {
return SE->getSMinExpr(X, SE->getZero(X->getType()));
}
-
// Walks through the subscript,
// collecting each coefficient, the associated loop bounds,
// and recording its positive and negative parts for later use.
@@ -3046,7 +2972,6 @@ DependenceInfo::collectCoeffInfo(const SCEV *Subscript, bool SrcFlag,
return CI;
}
-
// Looks through all the bounds info and
// computes the lower bound given the current direction settings
// at each level. If the lower bound for any level is -inf,
@@ -3062,7 +2987,6 @@ const SCEV *DependenceInfo::getLowerBound(BoundInfo *Bound) const {
return Sum;
}
-
// Looks through all the bounds info and
// computes the upper bound given the current direction settings
// at each level. If the upper bound at any level is +inf,
@@ -3078,7 +3002,6 @@ const SCEV *DependenceInfo::getUpperBound(BoundInfo *Bound) const {
return Sum;
}
-
//===----------------------------------------------------------------------===//
// Constraint manipulation for Delta test.
@@ -3098,7 +3021,6 @@ const SCEV *DependenceInfo::findCoefficient(const SCEV *Expr,
return findCoefficient(AddRec->getStart(), TargetLoop);
}
-
// Given a linear SCEV,
// return the SCEV given by zeroing out the coefficient
// corresponding to the specified loop.
@@ -3112,12 +3034,10 @@ const SCEV *DependenceInfo::zeroCoefficient(const SCEV *Expr,
if (AddRec->getLoop() == TargetLoop)
return AddRec->getStart();
return SE->getAddRecExpr(zeroCoefficient(AddRec->getStart(), TargetLoop),
- AddRec->getStepRecurrence(*SE),
- AddRec->getLoop(),
+ AddRec->getStepRecurrence(*SE), AddRec->getLoop(),
AddRec->getNoWrapFlags());
}
-
// Given a linear SCEV Expr,
// return the SCEV given by adding some Value to the
// coefficient corresponding to the specified TargetLoop.
@@ -3128,17 +3048,13 @@ const SCEV *DependenceInfo::addToCoefficient(const SCEV *Expr,
const SCEV *Value) const {
const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(Expr);
if (!AddRec) // create a new addRec
- return SE->getAddRecExpr(Expr,
- Value,
- TargetLoop,
+ return SE->getAddRecExpr(Expr, Value, TargetLoop,
SCEV::FlagAnyWrap); // Worst case, with no info.
if (AddRec->getLoop() == TargetLoop) {
const SCEV *Sum = SE->getAddExpr(AddRec->getStepRecurrence(*SE), Value);
if (Sum->isZero())
return AddRec->getStart();
- return SE->getAddRecExpr(AddRec->getStart(),
- Sum,
- AddRec->getLoop(),
+ return SE->getAddRecExpr(AddRec->getStart(), Sum, AddRec->getLoop(),
AddRec->getNoWrapFlags());
}
if (SE->isLoopInvariant(AddRec, TargetLoop))
@@ -3149,7 +3065,6 @@ const SCEV *DependenceInfo::addToCoefficient(const SCEV *Expr,
AddRec->getNoWrapFlags());
}
-
// Review the constraints, looking for opportunities
// to simplify a subscript pair (Src and Dst).
// Return true if some simplification occurs.
@@ -3178,7 +3093,6 @@ bool DependenceInfo::propagate(const SCEV *&Src, const SCEV *&Dst,
return Result;
}
-
// Attempt to propagate a distance
// constraint into a subscript pair (Src and Dst).
// Return true if some simplification occurs.
@@ -3204,7 +3118,6 @@ bool DependenceInfo::propagateDistance(const SCEV *&Src, const SCEV *&Dst,
return true;
}
-
// Attempt to propagate a line
// constraint into a subscript pair (Src and Dst).
// Return true if some simplification occurs.
@@ -3224,22 +3137,24 @@ bool DependenceInfo::propagateLine(const SCEV *&Src, const SCEV *&Dst,
if (A->isZero()) {
const SCEVConstant *Bconst = dyn_cast<SCEVConstant>(B);
const SCEVConstant *Cconst = dyn_cast<SCEVConstant>(C);
- if (!Bconst || !Cconst) return false;
+ if (!Bconst || !Cconst)
+ return false;
APInt Beta = Bconst->getAPInt();
APInt Charlie = Cconst->getAPInt();
APInt CdivB = Charlie.sdiv(Beta);
assert(Charlie.srem(Beta) == 0 && "C should be evenly divisible by B");
const SCEV *AP_K = findCoefficient(Dst, CurLoop);
- // Src = SE->getAddExpr(Src, SE->getMulExpr(AP_K, SE->getConstant(CdivB)));
+ // Src = SE->getAddExpr(Src, SE->getMulExpr(AP_K,
+ // SE->getConstant(CdivB)));
Src = SE->getMinusSCEV(Src, SE->getMulExpr(AP_K, SE->getConstant(CdivB)));
Dst = zeroCoefficient(Dst, CurLoop);
if (!findCoefficient(Src, CurLoop)->isZero())
Consistent = false;
- }
- else if (B->isZero()) {
+ } else if (B->isZero()) {
const SCEVConstant *Aconst = dyn_cast<SCEVConstant>(A);
const SCEVConstant *Cconst = dyn_cast<SCEVConstant>(C);
- if (!Aconst || !Cconst) return false;
+ if (!Aconst || !Cconst)
+ return false;
APInt Alpha = Aconst->getAPInt();
APInt Charlie = Cconst->getAPInt();
APInt CdivA = Charlie.sdiv(Alpha);
@@ -3249,11 +3164,11 @@ bool DependenceInfo::propagateLine(const SCEV *&Src, const SCEV *&Dst,
Src = zeroCoefficient(Src, CurLoop);
if (!findCoefficient(Dst, CurLoop)->isZero())
Consistent = false;
- }
- else if (isKnownPredicate(CmpInst::ICMP_EQ, A, B)) {
+ } else if (isKnownPredicate(CmpInst::ICMP_EQ, A, B)) {
const SCEVConstant *Aconst = dyn_cast<SCEVConstant>(A);
const SCEVConstant *Cconst = dyn_cast<SCEVConstant>(C);
- if (!Aconst || !Cconst) return false;
+ if (!Aconst || !Cconst)
+ return false;
APInt Alpha = Aconst->getAPInt();
APInt Charlie = Cconst->getAPInt();
APInt CdivA = Charlie.sdiv(Alpha);
@@ -3264,8 +3179,7 @@ bool DependenceInfo::propagateLine(const SCEV *&Src, const SCEV *&Dst,
Dst = addToCoefficient(Dst, CurLoop, A_K);
if (!findCoefficient(Dst, CurLoop)->isZero())
Consistent = false;
- }
- else {
+ } else {
// paper is incorrect here, or perhaps just misleading
const SCEV *A_K = findCoefficient(Src, CurLoop);
Src = SE->getMulExpr(Src, A);
@@ -3281,7 +3195,6 @@ bool DependenceInfo::propagateLine(const SCEV *&Src, const SCEV *&Dst,
return true;
}
-
// Attempt to propagate a point
// constraint into a subscript pair (Src and Dst).
// Return true if some simplification occurs.
@@ -3302,7 +3215,6 @@ bool DependenceInfo::propagatePoint(const SCEV *&Src, const SCEV *&Dst,
return true;
}
-
// Update direction vector entry based on the current constraint.
void DependenceInfo::updateDirection(Dependence::DVEntry &Level,
const Constraint &CurConstraint) const {
@@ -3322,34 +3234,28 @@ void DependenceInfo::updateDirection(Dependence::DVEntry &Level,
if (!SE->isKnownNonNegative(Level.Distance)) // if may be negative
NewDirection |= Dependence::DVEntry::GT;
Level.Direction &= NewDirection;
- }
- else if (CurConstraint.isLine()) {
+ } else if (CurConstraint.isLine()) {
Level.Scalar = false;
Level.Distance = nullptr;
// direction should be accurate
- }
- else if (CurConstraint.isPoint()) {
+ } else if (CurConstraint.isPoint()) {
Level.Scalar = false;
Level.Distance = nullptr;
unsigned NewDirection = Dependence::DVEntry::NONE;
- if (!isKnownPredicate(CmpInst::ICMP_NE,
- CurConstraint.getY(),
+ if (!isKnownPredicate(CmpInst::ICMP_NE, CurConstraint.getY(),
CurConstraint.getX()))
// if X may be = Y
NewDirection |= Dependence::DVEntry::EQ;
- if (!isKnownPredicate(CmpInst::ICMP_SLE,
- CurConstraint.getY(),
+ if (!isKnownPredicate(CmpInst::ICMP_SLE, CurConstraint.getY(),
CurConstraint.getX()))
// if Y may be > X
NewDirection |= Dependence::DVEntry::LT;
- if (!isKnownPredicate(CmpInst::ICMP_SGE,
- CurConstraint.getY(),
+ if (!isKnownPredicate(CmpInst::ICMP_SGE, CurConstraint.getY(),
CurConstraint.getX()))
// if Y may be < X
NewDirection |= Dependence::DVEntry::GT;
Level.Direction &= NewDirection;
- }
- else
+ } else
llvm_unreachable("constraint has unexpected kind");
}
@@ -3425,7 +3331,7 @@ bool DependenceInfo::tryDelinearizeFixedSize(
dyn_cast<SCEVUnknown>(SE->getPointerBase(DstAccessFn));
assert(SrcBase && DstBase && SrcBase == DstBase &&
"expected src and dst scev unknowns to be equal");
- });
+ });
SmallVector<int, 4> SrcSizes;
SmallVector<int, 4> DstSizes;
@@ -3737,9 +3643,8 @@ DependenceInfo::depends(Instruction *Src, Instruction *Dst,
Pair[P].Group.resize(Pairs);
removeMatchingExtensions(&Pair[P]);
Pair[P].Classification =
- classifyPair(Pair[P].Src, LI->getLoopFor(Src->getParent()),
- Pair[P].Dst, LI->getLoopFor(Dst->getParent()),
- Pair[P].Loops);
+ classifyPair(Pair[P].Src, LI->getLoopFor(Src->getParent()), Pair[P].Dst,
+ LI->getLoopFor(Dst->getParent()), Pair[P].Loops);
Pair[P].GroupLoops = Pair[P].Loops;
Pair[P].Group.set(P);
LLVM_DEBUG(dbgs() << " subscript " << P << "\n");
@@ -3814,18 +3719,15 @@ DependenceInfo::depends(Instruction *Src, Instruction *Dst,
if (Pair[SI].Classification == Subscript::NonLinear) {
// ignore these, but collect loops for later
++NonlinearSubscriptPairs;
- collectCommonLoops(Pair[SI].Src,
- LI->getLoopFor(Src->getParent()),
+ collectCommonLoops(Pair[SI].Src, LI->getLoopFor(Src->getParent()),
Pair[SI].Loops);
- collectCommonLoops(Pair[SI].Dst,
- LI->getLoopFor(Dst->getParent()),
+ collectCommonLoops(Pair[SI].Dst, LI->getLoopFor(Dst->getParent()),
Pair[SI].Loops);
Result.Consistent = false;
} else if (Pair[SI].Classification == Subscript::ZIV) {
// always separable
Separable.set(SI);
- }
- else {
+ } else {
// SIV, RDIV, or MIV, so check for coupled group
bool Done = true;
for (unsigned SJ = SI + 1; SJ < Pairs; ++SJ) {
@@ -3843,8 +3745,7 @@ DependenceInfo::depends(Instruction *Src, Instruction *Dst,
if (Pair[SI].Group.count() == 1) {
Separable.set(SI);
++SeparableSubscriptPairs;
- }
- else {
+ } else {
Coupled.set(SI);
++CoupledSubscriptPairs;
}
@@ -3950,10 +3851,9 @@ DependenceInfo::depends(Instruction *Src, Instruction *Dst,
Constraints, Result.Consistent)) {
LLVM_DEBUG(dbgs() << "\t Changed\n");
++DeltaPropagations;
- Pair[SJ].Classification =
- classifyPair(Pair[SJ].Src, LI->getLoopFor(Src->getParent()),
- Pair[SJ].Dst, LI->getLoopFor(Dst->getParent()),
- Pair[SJ].Loops);
+ Pair[SJ].Classification = classifyPair(
+ Pair[SJ].Src, LI->getLoopFor(Src->getParent()), Pair[SJ].Dst,
+ LI->getLoopFor(Dst->getParent()), Pair[SJ].Loops);
switch (Pair[SJ].Classification) {
case Subscript::ZIV:
LLVM_DEBUG(dbgs() << "ZIV\n");
@@ -3995,8 +3895,7 @@ DependenceInfo::depends(Instruction *Src, Instruction *Dst,
LLVM_DEBUG(dbgs() << "MIV test\n");
if (testMIV(Pair[SJ].Src, Pair[SJ].Dst, Pair[SJ].Loops, Result))
return nullptr;
- }
- else
+ } else
llvm_unreachable("expected only MIV subscripts at this point");
}
@@ -4052,8 +3951,7 @@ DependenceInfo::depends(Instruction *Src, Instruction *Dst,
break;
}
}
- }
- else {
+ } else {
// On the other hand, if all directions are equal and there's no
// loop-independent dependence possible, then no dependence exists.
bool AllEqual = true;
@@ -4158,9 +4056,8 @@ const SCEV *DependenceInfo::getSplitIteration(const Dependence &Dep,
Pair[P].Group.resize(Pairs);
removeMatchingExtensions(&Pair[P]);
Pair[P].Classification =
- classifyPair(Pair[P].Src, LI->getLoopFor(Src->getParent()),
- Pair[P].Dst, LI->getLoopFor(Dst->getParent()),
- Pair[P].Loops);
+ classifyPair(Pair[P].Src, LI->getLoopFor(Src->getParent()), Pair[P].Dst,
+ LI->getLoopFor(Dst->getParent()), Pair[P].Loops);
Pair[P].GroupLoops = Pair[P].Loops;
Pair[P].Group.set(P);
}
@@ -4172,15 +4069,12 @@ const SCEV *DependenceInfo::getSplitIteration(const Dependence &Dep,
for (unsigned SI = 0; SI < Pairs; ++SI) {
if (Pair[SI].Classification == Subscript::NonLinear) {
// ignore these, but collect loops for later
- collectCommonLoops(Pair[SI].Src,
- LI->getLoopFor(Src->getParent()),
+ collectCommonLoops(Pair[SI].Src, LI->getLoopFor(Src->getParent()),
Pair[SI].Loops);
- collectCommonLoops(Pair[SI].Dst,
- LI->getLoopFor(Dst->getParent()),
+ collectCommonLoops(Pair[SI].Dst, LI->getLoopFor(Dst->getParent()),
Pair[SI].Loops);
Result.Consistent = false;
- }
- else if (Pair[SI].Classification == Subscript::ZIV)
+ } else if (Pair[SI].Classification == Subscript::ZIV)
Separable.set(SI);
else {
// SIV, RDIV, or MIV, so check for coupled group
@@ -4214,8 +4108,8 @@ const SCEV *DependenceInfo::getSplitIteration(const Dependence &Dep,
case Subscript::SIV: {
unsigned Level;
const SCEV *SplitIter = nullptr;
- (void) testSIV(Pair[SI].Src, Pair[SI].Dst, Level,
- Result, NewConstraint, SplitIter);
+ (void)testSIV(Pair[SI].Src, Pair[SI].Dst, Level, Result, NewConstraint,
+ SplitIter);
if (Level == SplitLevel) {
assert(SplitIter != nullptr);
return SplitIter;
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