#define LLVM_TRANSFORMS_UTILS_LOOPUTILS_H
#include "llvm/ADT/SmallVector.h"
+#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/IRBuilder.h"
namespace llvm {
-class AliasAnalysis;
class AliasSet;
class AliasSetTracker;
class AssumptionCache;
RecurrenceDescriptor()
: StartValue(nullptr), LoopExitInstr(nullptr), Kind(RK_NoRecurrence),
- MinMaxKind(MRK_Invalid) {}
+ MinMaxKind(MRK_Invalid), UnsafeAlgebraInst(nullptr),
+ RecurrenceType(nullptr), IsSigned(false) {}
RecurrenceDescriptor(Value *Start, Instruction *Exit, RecurrenceKind K,
- MinMaxRecurrenceKind MK)
- : StartValue(Start), LoopExitInstr(Exit), Kind(K), MinMaxKind(MK) {}
+ MinMaxRecurrenceKind MK, Instruction *UAI, Type *RT,
+ bool Signed, SmallPtrSetImpl<Instruction *> &CI)
+ : StartValue(Start), LoopExitInstr(Exit), Kind(K), MinMaxKind(MK),
+ UnsafeAlgebraInst(UAI), RecurrenceType(RT), IsSigned(Signed) {
+ CastInsts.insert(CI.begin(), CI.end());
+ }
/// This POD struct holds information about a potential recurrence operation.
class InstDesc {
public:
- InstDesc(bool IsRecur, Instruction *I)
- : IsRecurrence(IsRecur), PatternLastInst(I), MinMaxKind(MRK_Invalid) {}
+ InstDesc(bool IsRecur, Instruction *I, Instruction *UAI = nullptr)
+ : IsRecurrence(IsRecur), PatternLastInst(I), MinMaxKind(MRK_Invalid),
+ UnsafeAlgebraInst(UAI) {}
- InstDesc(Instruction *I, MinMaxRecurrenceKind K)
- : IsRecurrence(true), PatternLastInst(I), MinMaxKind(K) {}
+ InstDesc(Instruction *I, MinMaxRecurrenceKind K, Instruction *UAI = nullptr)
+ : IsRecurrence(true), PatternLastInst(I), MinMaxKind(K),
+ UnsafeAlgebraInst(UAI) {}
bool isRecurrence() { return IsRecurrence; }
+ bool hasUnsafeAlgebra() { return UnsafeAlgebraInst != nullptr; }
+
+ Instruction *getUnsafeAlgebraInst() { return UnsafeAlgebraInst; }
+
MinMaxRecurrenceKind getMinMaxKind() { return MinMaxKind; }
Instruction *getPatternInst() { return PatternLastInst; }
Instruction *PatternLastInst;
// If this is a min/max pattern the comparison predicate.
MinMaxRecurrenceKind MinMaxKind;
+ // Recurrence has unsafe algebra.
+ Instruction *UnsafeAlgebraInst;
};
/// Returns a struct describing if the instruction 'I' can be a recurrence
static InstDesc isRecurrenceInstr(Instruction *I, RecurrenceKind Kind,
InstDesc &Prev, bool HasFunNoNaNAttr);
- /// Returns true if instuction I has multiple uses in Insts
+ /// Returns true if instruction I has multiple uses in Insts
static bool hasMultipleUsesOf(Instruction *I,
SmallPtrSetImpl<Instruction *> &Insts);
Instruction *getLoopExitInstr() { return LoopExitInstr; }
+ /// Returns true if the recurrence has unsafe algebra which requires a relaxed
+ /// floating-point model.
+ bool hasUnsafeAlgebra() { return UnsafeAlgebraInst != nullptr; }
+
+ /// Returns first unsafe algebra instruction in the PHI node's use-chain.
+ Instruction *getUnsafeAlgebraInst() { return UnsafeAlgebraInst; }
+
+ /// Returns true if the recurrence kind is an integer kind.
+ static bool isIntegerRecurrenceKind(RecurrenceKind Kind);
+
+ /// Returns true if the recurrence kind is a floating point kind.
+ static bool isFloatingPointRecurrenceKind(RecurrenceKind Kind);
+
+ /// Returns true if the recurrence kind is an arithmetic kind.
+ static bool isArithmeticRecurrenceKind(RecurrenceKind Kind);
+
+ /// Determines if Phi may have been type-promoted. If Phi has a single user
+ /// that ANDs the Phi with a type mask, return the user. RT is updated to
+ /// account for the narrower bit width represented by the mask, and the AND
+ /// instruction is added to CI.
+ static Instruction *lookThroughAnd(PHINode *Phi, Type *&RT,
+ SmallPtrSetImpl<Instruction *> &Visited,
+ SmallPtrSetImpl<Instruction *> &CI);
+
+ /// Returns true if all the source operands of a recurrence are either
+ /// SExtInsts or ZExtInsts. This function is intended to be used with
+ /// lookThroughAnd to determine if the recurrence has been type-promoted. The
+ /// source operands are added to CI, and IsSigned is updated to indicate if
+ /// all source operands are SExtInsts.
+ static bool getSourceExtensionKind(Instruction *Start, Instruction *Exit,
+ Type *RT, bool &IsSigned,
+ SmallPtrSetImpl<Instruction *> &Visited,
+ SmallPtrSetImpl<Instruction *> &CI);
+
+ /// Returns the type of the recurrence. This type can be narrower than the
+ /// actual type of the Phi if the recurrence has been type-promoted.
+ Type *getRecurrenceType() { return RecurrenceType; }
+
+ /// Returns a reference to the instructions used for type-promoting the
+ /// recurrence.
+ SmallPtrSet<Instruction *, 8> &getCastInsts() { return CastInsts; }
+
+ /// Returns true if all source operands of the recurrence are SExtInsts.
+ bool isSigned() { return IsSigned; }
+
private:
// The starting value of the recurrence.
// It does not have to be zero!
RecurrenceKind Kind;
// If this a min/max recurrence the kind of recurrence.
MinMaxRecurrenceKind MinMaxKind;
+ // First occurance of unasfe algebra in the PHI's use-chain.
+ Instruction *UnsafeAlgebraInst;
+ // The type of the recurrence.
+ Type *RecurrenceType;
+ // True if all source operands of the recurrence are SExtInsts.
+ bool IsSigned;
+ // Instructions used for type-promoting the recurrence.
+ SmallPtrSet<Instruction *, 8> CastInsts;
+};
+
+/// A struct for saving information about induction variables.
+class InductionDescriptor {
+public:
+ /// This enum represents the kinds of inductions that we support.
+ enum InductionKind {
+ IK_NoInduction, ///< Not an induction variable.
+ IK_IntInduction, ///< Integer induction variable. Step = C.
+ IK_PtrInduction ///< Pointer induction var. Step = C / sizeof(elem).
+ };
+
+public:
+ /// Default constructor - creates an invalid induction.
+ InductionDescriptor()
+ : StartValue(nullptr), IK(IK_NoInduction), StepValue(nullptr) {}
+
+ /// Get the consecutive direction. Returns:
+ /// 0 - unknown or non-consecutive.
+ /// 1 - consecutive and increasing.
+ /// -1 - consecutive and decreasing.
+ int getConsecutiveDirection() const;
+
+ /// Compute the transformed value of Index at offset StartValue using step
+ /// StepValue.
+ /// For integer induction, returns StartValue + Index * StepValue.
+ /// For pointer induction, returns StartValue[Index * StepValue].
+ /// FIXME: The newly created binary instructions should contain nsw/nuw
+ /// flags, which can be found from the original scalar operations.
+ Value *transform(IRBuilder<> &B, Value *Index) const;
+
+ Value *getStartValue() const { return StartValue; }
+ InductionKind getKind() const { return IK; }
+ ConstantInt *getStepValue() const { return StepValue; }
+
+ static bool isInductionPHI(PHINode *Phi, ScalarEvolution *SE,
+ InductionDescriptor &D);
+
+private:
+ /// Private constructor - used by \c isInductionPHI.
+ InductionDescriptor(Value *Start, InductionKind K, ConstantInt *Step);
+
+ /// Start value.
+ TrackingVH<Value> StartValue;
+ /// Induction kind.
+ InductionKind IK;
+ /// Step value.
+ ConstantInt *StepValue;
};
BasicBlock *InsertPreheaderForLoop(Loop *L, Pass *P);
/// \brief Try to promote memory values to scalars by sinking stores out of
/// the loop and moving loads to before the loop. We do this by looping over
-/// the stores in the loop, looking for stores to Must pointers which are
+/// the stores in the loop, looking for stores to Must pointers which are
/// loop invariant. It takes AliasSet, Loop exit blocks vector, loop exit blocks
/// insertion point vector, PredIteratorCache, LoopInfo, DominatorTree, Loop,
-/// AliasSet information for all instructions of the loop and loop safety
+/// AliasSet information for all instructions of the loop and loop safety
/// information as arguments. It returns changed status.
bool promoteLoopAccessesToScalars(AliasSet &, SmallVectorImpl<BasicBlock*> &,
SmallVectorImpl<Instruction*> &,
LICMSafetyInfo *);
/// \brief Computes safety information for a loop
-/// checks loop body & header for the possiblity of may throw
+/// checks loop body & header for the possibility of may throw
/// exception, it takes LICMSafetyInfo and loop as argument.
/// Updates safety information in LICMSafetyInfo argument.
void computeLICMSafetyInfo(LICMSafetyInfo *, Loop *);
-/// \brief Checks if the given PHINode in a loop header is an induction
-/// variable. Returns true if this is an induction PHI along with the step
-/// value.
-bool isInductionPHI(PHINode *, ScalarEvolution *, ConstantInt *&);
+/// \brief Returns the instructions that use values defined in the loop.
+SmallVector<Instruction *, 8> findDefsUsedOutsideOfLoop(Loop *L);
}
#endif
projects / oota-llvm.git / blobdiff