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[SCEV] Don't repeat method/field names in comment in header; NFC.

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llvm-svn: 247918
This commit is contained in:
Sanjoy Das 2015-09-17 19:04:03 +00:00
parent 5ec9755415
commit a2013dbe4c
1 changed files with 249 additions and 288 deletions
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537
include/llvm/Analysis/ScalarEvolution.h
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@ -53,23 +53,22 @@ namespace llvm {
class SCEV;
template<> struct FoldingSetTrait<SCEV>;
/// SCEV - This class represents an analyzed expression in the program. These
/// are opaque objects that the client is not allowed to do much with
/// directly.
/// This class represents an analyzed expression in the program. These are
/// opaque objects that the client is not allowed to do much with directly.
///
class SCEV : public FoldingSetNode {
friend struct FoldingSetTrait<SCEV>;
/// FastID - A reference to an Interned FoldingSetNodeID for this node.
/// The ScalarEvolution's BumpPtrAllocator holds the data.
/// A reference to an Interned FoldingSetNodeID for this node. The
/// ScalarEvolution's BumpPtrAllocator holds the data.
FoldingSetNodeIDRef FastID;
// The SCEV baseclass this node corresponds to
const unsigned short SCEVType;
protected:
/// SubclassData - This field is initialized to zero and may be used in
/// subclasses to store miscellaneous information.
/// This field is initialized to zero and may be used in subclasses to store
/// miscellaneous information.
unsigned short SubclassData;
private:
@ -106,34 +105,31 @@ namespace llvm {
unsigned getSCEVType() const { return SCEVType; }
/// getType - Return the LLVM type of this SCEV expression.
/// Return the LLVM type of this SCEV expression.
///
Type *getType() const;
/// isZero - Return true if the expression is a constant zero.
/// Return true if the expression is a constant zero.
///
bool isZero() const;
/// isOne - Return true if the expression is a constant one.
/// Return true if the expression is a constant one.
///
bool isOne() const;
/// isAllOnesValue - Return true if the expression is a constant
/// all-ones value.
/// Return true if the expression is a constant all-ones value.
///
bool isAllOnesValue() const;
/// isNonConstantNegative - Return true if the specified scev is negated,
/// but not a constant.
/// Return true if the specified scev is negated, but not a constant.
bool isNonConstantNegative() const;
/// print - Print out the internal representation of this scalar to the
/// specified stream. This should really only be used for debugging
/// purposes.
/// Print out the internal representation of this scalar to the specified
/// stream. This should really only be used for debugging purposes.
void print(raw_ostream &OS) const;
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
/// dump - This method is used for debugging.
/// This method is used for debugging.
///
void dump() const;
#endif
@ -159,11 +155,10 @@ namespace llvm {
return OS;
}
/// SCEVCouldNotCompute - An object of this class is returned by queries that
/// could not be answered. For example, if you ask for the number of
/// iterations of a linked-list traversal loop, you will get one of these.
/// None of the standard SCEV operations are valid on this class, it is just a
/// marker.
/// An object of this class is returned by queries that could not be answered.
/// For example, if you ask for the number of iterations of a linked-list
/// traversal loop, you will get one of these. None of the standard SCEV
/// operations are valid on this class, it is just a marker.
struct SCEVCouldNotCompute : public SCEV {
SCEVCouldNotCompute();
@ -176,16 +171,14 @@ namespace llvm {
/// for services.
class ScalarEvolution {
public:
/// LoopDisposition - An enum describing the relationship between a
/// SCEV and a loop.
/// An enum describing the relationship between a SCEV and a loop.
enum LoopDisposition {
LoopVariant, ///< The SCEV is loop-variant (unknown).
LoopInvariant, ///< The SCEV is loop-invariant.
LoopComputable ///< The SCEV varies predictably with the loop.
};
/// BlockDisposition - An enum describing the relationship between a
/// SCEV and a basic block.
/// An enum describing the relationship between a SCEV and a basic block.
enum BlockDisposition {
DoesNotDominateBlock, ///< The SCEV does not dominate the block.
DominatesBlock, ///< The SCEV dominates the block.
@ -208,8 +201,8 @@ namespace llvm {
}
private:
/// SCEVCallbackVH - A CallbackVH to arrange for ScalarEvolution to be
/// notified whenever a Value is deleted.
/// A CallbackVH to arrange for ScalarEvolution to be notified whenever a
/// Value is deleted.
class SCEVCallbackVH final : public CallbackVH {
ScalarEvolution *SE;
void deleted() override;
@ -222,35 +215,34 @@ namespace llvm {
friend class SCEVExpander;
friend class SCEVUnknown;
/// F - The function we are analyzing.
/// The function we are analyzing.
///
Function &F;
/// TLI - The target library information for the target we are targeting.
/// The target library information for the target we are targeting.
///
TargetLibraryInfo &TLI;
/// The tracker for @llvm.assume intrinsics in this function.
AssumptionCache &AC;
/// DT - The dominator tree.
/// The dominator tree.
///
DominatorTree &DT;
/// LI - The loop information for the function we are currently analyzing.
/// The loop information for the function we are currently analyzing.
///
LoopInfo &LI;
/// CouldNotCompute - This SCEV is used to represent unknown trip
/// counts and things.
/// This SCEV is used to represent unknown trip counts and things.
std::unique_ptr<SCEVCouldNotCompute> CouldNotCompute;
/// ValueExprMapType - The typedef for ValueExprMap.
/// The typedef for ValueExprMap.
///
typedef DenseMap<SCEVCallbackVH, const SCEV *, DenseMapInfo<Value *> >
ValueExprMapType;
/// ValueExprMap - This is a cache of the values we have analyzed so far.
/// This is a cache of the values we have analyzed so far.
///
ValueExprMapType ValueExprMap;
@ -261,10 +253,10 @@ namespace llvm {
/// conditions dominating the backedge of a loop.
bool WalkingBEDominatingConds;
/// ExitLimit - Information about the number of loop iterations for which a
/// loop exit's branch condition evaluates to the not-taken path. This is a
/// temporary pair of exact and max expressions that are eventually
/// summarized in ExitNotTakenInfo and BackedgeTakenInfo.
/// Information about the number of loop iterations for which a loop exit's
/// branch condition evaluates to the not-taken path. This is a temporary
/// pair of exact and max expressions that are eventually summarized in
/// ExitNotTakenInfo and BackedgeTakenInfo.
struct ExitLimit {
const SCEV *Exact;
const SCEV *Max;
@ -273,16 +265,16 @@ namespace llvm {
ExitLimit(const SCEV *E, const SCEV *M) : Exact(E), Max(M) {}
/// hasAnyInfo - Test whether this ExitLimit contains any computed
/// information, or whether it's all SCEVCouldNotCompute values.
/// Test whether this ExitLimit contains any computed information, or
/// whether it's all SCEVCouldNotCompute values.
bool hasAnyInfo() const {
return !isa<SCEVCouldNotCompute>(Exact) ||
!isa<SCEVCouldNotCompute>(Max);
}
};
/// ExitNotTakenInfo - Information about the number of times a particular
/// loop exit may be reached before exiting the loop.
/// Information about the number of times a particular loop exit may be
/// reached before exiting the loop.
struct ExitNotTakenInfo {
AssertingVH<BasicBlock> ExitingBlock;
const SCEV *ExactNotTaken;
@ -290,14 +282,14 @@ namespace llvm {
ExitNotTakenInfo() : ExitingBlock(nullptr), ExactNotTaken(nullptr) {}
/// isCompleteList - Return true if all loop exits are computable.
/// Return true if all loop exits are computable.
bool isCompleteList() const {
return NextExit.getInt() == 0;
}
void setIncomplete() { NextExit.setInt(1); }
/// getNextExit - Return a pointer to the next exit's not-taken info.
/// Return a pointer to the next exit's not-taken info.
ExitNotTakenInfo *getNextExit() const {
return NextExit.getPointer();
}
@ -305,16 +297,16 @@ namespace llvm {
void setNextExit(ExitNotTakenInfo *ENT) { NextExit.setPointer(ENT); }
};
/// BackedgeTakenInfo - Information about the backedge-taken count
/// of a loop. This currently includes an exact count and a maximum count.
/// Information about the backedge-taken count of a loop. This currently
/// includes an exact count and a maximum count.
///
class BackedgeTakenInfo {
/// ExitNotTaken - A list of computable exits and their not-taken counts.
/// Loops almost never have more than one computable exit.
/// A list of computable exits and their not-taken counts. Loops almost
/// never have more than one computable exit.
ExitNotTakenInfo ExitNotTaken;
/// Max - An expression indicating the least maximum backedge-taken
/// count of the loop that is known, or a SCEVCouldNotCompute.
/// An expression indicating the least maximum backedge-taken count of the
/// loop that is known, or a SCEVCouldNotCompute.
const SCEV *Max;
public:
@ -325,80 +317,78 @@ namespace llvm {
SmallVectorImpl< std::pair<BasicBlock *, const SCEV *> > &ExitCounts,
bool Complete, const SCEV *MaxCount);
/// hasAnyInfo - Test whether this BackedgeTakenInfo contains any
/// computed information, or whether it's all SCEVCouldNotCompute
/// values.
/// Test whether this BackedgeTakenInfo contains any computed information,
/// or whether it's all SCEVCouldNotCompute values.
bool hasAnyInfo() const {
return ExitNotTaken.ExitingBlock || !isa<SCEVCouldNotCompute>(Max);
}
/// getExact - Return an expression indicating the exact backedge-taken
/// count of the loop if it is known, or SCEVCouldNotCompute
/// otherwise. This is the number of times the loop header can be
/// guaranteed to execute, minus one.
/// Return an expression indicating the exact backedge-taken count of the
/// loop if it is known, or SCEVCouldNotCompute otherwise. This is the
/// number of times the loop header can be guaranteed to execute, minus
/// one.
const SCEV *getExact(ScalarEvolution *SE) const;
/// getExact - Return the number of times this loop exit may fall through
/// to the back edge, or SCEVCouldNotCompute. The loop is guaranteed not
/// to exit via this block before this number of iterations, but may exit
/// via another block.
/// Return the number of times this loop exit may fall through to the back
/// edge, or SCEVCouldNotCompute. The loop is guaranteed not to exit via
/// this block before this number of iterations, but may exit via another
/// block.
const SCEV *getExact(BasicBlock *ExitingBlock, ScalarEvolution *SE) const;
/// getMax - Get the max backedge taken count for the loop.
/// Get the max backedge taken count for the loop.
const SCEV *getMax(ScalarEvolution *SE) const;
/// Return true if any backedge taken count expressions refer to the given
/// subexpression.
bool hasOperand(const SCEV *S, ScalarEvolution *SE) const;
/// clear - Invalidate this result and free associated memory.
/// Invalidate this result and free associated memory.
void clear();
};
/// BackedgeTakenCounts - Cache the backedge-taken count of the loops for
/// this function as they are computed.
/// Cache the backedge-taken count of the loops for this function as they
/// are computed.
DenseMap<const Loop*, BackedgeTakenInfo> BackedgeTakenCounts;
/// ConstantEvolutionLoopExitValue - This map contains entries for all of
/// the PHI instructions that we attempt to compute constant evolutions for.
/// This allows us to avoid potentially expensive recomputation of these
/// properties. An instruction maps to null if we are unable to compute its
/// exit value.
/// This map contains entries for all of the PHI instructions that we
/// attempt to compute constant evolutions for. This allows us to avoid
/// potentially expensive recomputation of these properties. An instruction
/// maps to null if we are unable to compute its exit value.
DenseMap<PHINode*, Constant*> ConstantEvolutionLoopExitValue;
/// ValuesAtScopes - This map contains entries for all the expressions
/// that we attempt to compute getSCEVAtScope information for, which can
/// be expensive in extreme cases.
/// This map contains entries for all the expressions that we attempt to
/// compute getSCEVAtScope information for, which can be expensive in
/// extreme cases.
DenseMap<const SCEV *,
SmallVector<std::pair<const Loop *, const SCEV *>, 2> > ValuesAtScopes;
/// LoopDispositions - Memoized computeLoopDisposition results.
/// Memoized computeLoopDisposition results.
DenseMap<const SCEV *,
SmallVector<PointerIntPair<const Loop *, 2, LoopDisposition>, 2>>
LoopDispositions;
/// computeLoopDisposition - Compute a LoopDisposition value.
/// Compute a LoopDisposition value.
LoopDisposition computeLoopDisposition(const SCEV *S, const Loop *L);
/// BlockDispositions - Memoized computeBlockDisposition results.
/// Memoized computeBlockDisposition results.
DenseMap<
const SCEV *,
SmallVector<PointerIntPair<const BasicBlock *, 2, BlockDisposition>, 2>>
BlockDispositions;
/// computeBlockDisposition - Compute a BlockDisposition value.
/// Compute a BlockDisposition value.
BlockDisposition computeBlockDisposition(const SCEV *S, const BasicBlock *BB);
/// UnsignedRanges - Memoized results from getRange
/// Memoized results from getRange
DenseMap<const SCEV *, ConstantRange> UnsignedRanges;
/// SignedRanges - Memoized results from getRange
/// Memoized results from getRange
DenseMap<const SCEV *, ConstantRange> SignedRanges;
/// RangeSignHint - Used to parameterize getRange
/// Used to parameterize getRange
enum RangeSignHint { HINT_RANGE_UNSIGNED, HINT_RANGE_SIGNED };
/// setRange - Set the memoized range for the given SCEV.
/// Set the memoized range for the given SCEV.
const ConstantRange &setRange(const SCEV *S, RangeSignHint Hint,
const ConstantRange &CR) {
DenseMap<const SCEV *, ConstantRange> &Cache =
@ -411,159 +401,147 @@ namespace llvm {
return Pair.first->second;
}
/// getRange - Determine the range for a particular SCEV.
/// Determine the range for a particular SCEV.
ConstantRange getRange(const SCEV *S, RangeSignHint Hint);
/// createSCEV - We know that there is no SCEV for the specified value.
/// Analyze the expression.
/// We know that there is no SCEV for the specified value. Analyze the
/// expression.
const SCEV *createSCEV(Value *V);
/// createNodeForPHI - Provide the special handling we need to analyze PHI
/// SCEVs.
/// Provide the special handling we need to analyze PHI SCEVs.
const SCEV *createNodeForPHI(PHINode *PN);
/// createNodeForGEP - Provide the special handling we need to analyze GEP
/// SCEVs.
/// Provide the special handling we need to analyze GEP SCEVs.
const SCEV *createNodeForGEP(GEPOperator *GEP);
/// computeSCEVAtScope - Implementation code for getSCEVAtScope; called
/// at most once for each SCEV+Loop pair.
/// Implementation code for getSCEVAtScope; called at most once for each
/// SCEV+Loop pair.
///
const SCEV *computeSCEVAtScope(const SCEV *S, const Loop *L);
/// ForgetSymbolicValue - This looks up computed SCEV values for all
/// instructions that depend on the given instruction and removes them from
/// the ValueExprMap map if they reference SymName. This is used during PHI
/// resolution.
/// This looks up computed SCEV values for all instructions that depend on
/// the given instruction and removes them from the ValueExprMap map if they
/// reference SymName. This is used during PHI resolution.
void ForgetSymbolicName(Instruction *I, const SCEV *SymName);
/// getBackedgeTakenInfo - Return the BackedgeTakenInfo for the given
/// loop, lazily computing new values if the loop hasn't been analyzed
/// yet.
/// Return the BackedgeTakenInfo for the given loop, lazily computing new
/// values if the loop hasn't been analyzed yet.
const BackedgeTakenInfo &getBackedgeTakenInfo(const Loop *L);
/// ComputeBackedgeTakenCount - Compute the number of times the specified
/// loop will iterate.
/// Compute the number of times the specified loop will iterate.
BackedgeTakenInfo ComputeBackedgeTakenCount(const Loop *L);
/// ComputeExitLimit - Compute the number of times the backedge of the
/// specified loop will execute if it exits via the specified block.
/// Compute the number of times the backedge of the specified loop will
/// execute if it exits via the specified block.
ExitLimit ComputeExitLimit(const Loop *L, BasicBlock *ExitingBlock);
/// ComputeExitLimitFromCond - Compute the number of times the backedge of
/// the specified loop will execute if its exit condition were a conditional
/// branch of ExitCond, TBB, and FBB.
/// Compute the number of times the backedge of the specified loop will
/// execute if its exit condition were a conditional branch of ExitCond,
/// TBB, and FBB.
ExitLimit ComputeExitLimitFromCond(const Loop *L,
Value *ExitCond,
BasicBlock *TBB,
BasicBlock *FBB,
bool IsSubExpr);
/// ComputeExitLimitFromICmp - Compute the number of times the backedge of
/// the specified loop will execute if its exit condition were a conditional
/// branch of the ICmpInst ExitCond, TBB, and FBB.
/// Compute the number of times the backedge of the specified loop will
/// execute if its exit condition were a conditional branch of the ICmpInst
/// ExitCond, TBB, and FBB.
ExitLimit ComputeExitLimitFromICmp(const Loop *L,
ICmpInst *ExitCond,
BasicBlock *TBB,
BasicBlock *FBB,
bool IsSubExpr);
/// ComputeExitLimitFromSingleExitSwitch - Compute the number of times the
/// backedge of the specified loop will execute if its exit condition were a
/// switch with a single exiting case to ExitingBB.
/// Compute the number of times the backedge of the specified loop will
/// execute if its exit condition were a switch with a single exiting case
/// to ExitingBB.
ExitLimit
ComputeExitLimitFromSingleExitSwitch(const Loop *L, SwitchInst *Switch,
BasicBlock *ExitingBB, bool IsSubExpr);
/// ComputeLoadConstantCompareExitLimit - Given an exit condition
/// of 'icmp op load X, cst', try to see if we can compute the
/// backedge-taken count.
/// Given an exit condition of 'icmp op load X, cst', try to see if we can
/// compute the backedge-taken count.
ExitLimit ComputeLoadConstantCompareExitLimit(LoadInst *LI,
Constant *RHS,
const Loop *L,
ICmpInst::Predicate p);
/// ComputeExitCountExhaustively - If the loop is known to execute a
/// constant number of times (the condition evolves only from constants),
/// try to evaluate a few iterations of the loop until we get the exit
/// condition gets a value of ExitWhen (true or false). If we cannot
/// evaluate the exit count of the loop, return CouldNotCompute.
/// If the loop is known to execute a constant number of times (the
/// condition evolves only from constants), try to evaluate a few iterations
/// of the loop until we get the exit condition gets a value of ExitWhen
/// (true or false). If we cannot evaluate the exit count of the loop,
/// return CouldNotCompute.
const SCEV *ComputeExitCountExhaustively(const Loop *L,
Value *Cond,
bool ExitWhen);
/// HowFarToZero - Return the number of times an exit condition comparing
/// the specified value to zero will execute. If not computable, return
/// CouldNotCompute.
/// Return the number of times an exit condition comparing the specified
/// value to zero will execute. If not computable, return CouldNotCompute.
ExitLimit HowFarToZero(const SCEV *V, const Loop *L, bool IsSubExpr);
/// HowFarToNonZero - Return the number of times an exit condition checking
/// the specified value for nonzero will execute. If not computable, return
/// Return the number of times an exit condition checking the specified
/// value for nonzero will execute. If not computable, return
/// CouldNotCompute.
ExitLimit HowFarToNonZero(const SCEV *V, const Loop *L);
/// HowManyLessThans - Return the number of times an exit condition
/// containing the specified less-than comparison will execute. If not
/// computable, return CouldNotCompute. isSigned specifies whether the
/// less-than is signed.
/// Return the number of times an exit condition containing the specified
/// less-than comparison will execute. If not computable, return
/// CouldNotCompute. isSigned specifies whether the less-than is signed.
ExitLimit HowManyLessThans(const SCEV *LHS, const SCEV *RHS,
const Loop *L, bool isSigned, bool IsSubExpr);
ExitLimit HowManyGreaterThans(const SCEV *LHS, const SCEV *RHS,
const Loop *L, bool isSigned, bool IsSubExpr);
/// getPredecessorWithUniqueSuccessorForBB - Return a predecessor of BB
/// (which may not be an immediate predecessor) which has exactly one
/// successor from which BB is reachable, or null if no such block is
/// found.
/// Return a predecessor of BB (which may not be an immediate predecessor)
/// which has exactly one successor from which BB is reachable, or null if
/// no such block is found.
std::pair<BasicBlock *, BasicBlock *>
getPredecessorWithUniqueSuccessorForBB(BasicBlock *BB);
/// isImpliedCond - Test whether the condition described by Pred, LHS, and
/// RHS is true whenever the given FoundCondValue value evaluates to true.
/// Test whether the condition described by Pred, LHS, and RHS is true
/// whenever the given FoundCondValue value evaluates to true.
bool isImpliedCond(ICmpInst::Predicate Pred,
const SCEV *LHS, const SCEV *RHS,
Value *FoundCondValue,
bool Inverse);
/// isImpliedCondOperands - Test whether the condition described by Pred,
/// LHS, and RHS is true whenever the condition described by Pred, FoundLHS,
/// and FoundRHS is true.
/// Test whether the condition described by Pred, LHS, and RHS is true
/// whenever the condition described by Pred, FoundLHS, and FoundRHS is
/// true.
bool isImpliedCondOperands(ICmpInst::Predicate Pred,
const SCEV *LHS, const SCEV *RHS,
const SCEV *FoundLHS, const SCEV *FoundRHS);
/// isImpliedCondOperandsHelper - Test whether the condition described by
/// Pred, LHS, and RHS is true whenever the condition described by Pred,
/// FoundLHS, and FoundRHS is true.
/// Test whether the condition described by Pred, LHS, and RHS is true
/// whenever the condition described by Pred, FoundLHS, and FoundRHS is
/// true.
bool isImpliedCondOperandsHelper(ICmpInst::Predicate Pred,
const SCEV *LHS, const SCEV *RHS,
const SCEV *FoundLHS,
const SCEV *FoundRHS);
/// isImpliedCondOperandsViaRanges - Test whether the condition described by
/// Pred, LHS, and RHS is true whenever the condition described by Pred,
/// FoundLHS, and FoundRHS is true. Utility function used by
/// isImpliedCondOperands.
/// Test whether the condition described by Pred, LHS, and RHS is true
/// whenever the condition described by Pred, FoundLHS, and FoundRHS is
/// true. Utility function used by isImpliedCondOperands.
bool isImpliedCondOperandsViaRanges(ICmpInst::Predicate Pred,
const SCEV *LHS, const SCEV *RHS,
const SCEV *FoundLHS,
const SCEV *FoundRHS);
/// getConstantEvolutionLoopExitValue - If we know that the specified Phi is
/// in the header of its containing loop, we know the loop executes a
/// constant number of times, and the PHI node is just a recurrence
/// involving constants, fold it.
/// If we know that the specified Phi is in the header of its containing
/// loop, we know the loop executes a constant number of times, and the PHI
/// node is just a recurrence involving constants, fold it.
Constant *getConstantEvolutionLoopExitValue(PHINode *PN, const APInt& BEs,
const Loop *L);
/// isKnownPredicateWithRanges - Test if the given expression is known to
/// satisfy the condition described by Pred and the known constant ranges
/// of LHS and RHS.
/// Test if the given expression is known to satisfy the condition described
/// by Pred and the known constant ranges of LHS and RHS.
///
bool isKnownPredicateWithRanges(ICmpInst::Predicate Pred,
const SCEV *LHS, const SCEV *RHS);
/// forgetMemoizedResults - Drop memoized information computed for S.
/// Drop memoized information computed for S.
void forgetMemoizedResults(const SCEV *S);
/// Return an existing SCEV for V if there is one, otherwise return nullptr.
@ -611,24 +589,23 @@ namespace llvm {
LLVMContext &getContext() const { return F.getContext(); }
/// isSCEVable - Test if values of the given type are analyzable within
/// the SCEV framework. This primarily includes integer types, and it
/// can optionally include pointer types if the ScalarEvolution class
/// has access to target-specific information.
/// Test if values of the given type are analyzable within the SCEV
/// framework. This primarily includes integer types, and it can optionally
/// include pointer types if the ScalarEvolution class has access to
/// target-specific information.
bool isSCEVable(Type *Ty) const;
/// getTypeSizeInBits - Return the size in bits of the specified type,
/// for which isSCEVable must return true.
/// Return the size in bits of the specified type, for which isSCEVable must
/// return true.
uint64_t getTypeSizeInBits(Type *Ty) const;
/// getEffectiveSCEVType - Return a type with the same bitwidth as
/// the given type and which represents how SCEV will treat the given
/// type, for which isSCEVable must return true. For pointer types,
/// this is the pointer-sized integer type.
/// Return a type with the same bitwidth as the given type and which
/// represents how SCEV will treat the given type, for which isSCEVable must
/// return true. For pointer types, this is the pointer-sized integer type.
Type *getEffectiveSCEVType(Type *Ty) const;
/// getSCEV - Return a SCEV expression for the full generality of the
/// specified expression.
/// Return a SCEV expression for the full generality of the specified
/// expression.
const SCEV *getSCEV(Value *V);
const SCEV *getConstant(ConstantInt *V);
@ -702,82 +679,74 @@ namespace llvm {
const SCEV *getUnknown(Value *V);
const SCEV *getCouldNotCompute();
/// getSizeOfExpr - Return an expression for sizeof AllocTy that is type
/// IntTy
/// Return an expression for sizeof AllocTy that is type IntTy
///
const SCEV *getSizeOfExpr(Type *IntTy, Type *AllocTy);
/// getOffsetOfExpr - Return an expression for offsetof on the given field
/// with type IntTy
/// Return an expression for offsetof on the given field with type IntTy
///
const SCEV *getOffsetOfExpr(Type *IntTy, StructType *STy, unsigned FieldNo);
/// getNegativeSCEV - Return the SCEV object corresponding to -V.
/// Return the SCEV object corresponding to -V.
///
const SCEV *getNegativeSCEV(const SCEV *V,
SCEV::NoWrapFlags Flags = SCEV::FlagAnyWrap);
/// getNotSCEV - Return the SCEV object corresponding to ~V.
/// Return the SCEV object corresponding to ~V.
///
const SCEV *getNotSCEV(const SCEV *V);
/// getMinusSCEV - Return LHS-RHS. Minus is represented in SCEV as A+B*-1.
/// Return LHS-RHS. Minus is represented in SCEV as A+B*-1.
const SCEV *getMinusSCEV(const SCEV *LHS, const SCEV *RHS,
SCEV::NoWrapFlags Flags = SCEV::FlagAnyWrap);
/// getTruncateOrZeroExtend - Return a SCEV corresponding to a conversion
/// of the input value to the specified type. If the type must be
/// extended, it is zero extended.
/// Return a SCEV corresponding to a conversion of the input value to the
/// specified type. If the type must be extended, it is zero extended.
const SCEV *getTruncateOrZeroExtend(const SCEV *V, Type *Ty);
/// getTruncateOrSignExtend - Return a SCEV corresponding to a conversion
/// of the input value to the specified type. If the type must be
/// extended, it is sign extended.
/// Return a SCEV corresponding to a conversion of the input value to the
/// specified type. If the type must be extended, it is sign extended.
const SCEV *getTruncateOrSignExtend(const SCEV *V, Type *Ty);
/// getNoopOrZeroExtend - Return a SCEV corresponding to a conversion of
/// the input value to the specified type. If the type must be extended,
/// it is zero extended. The conversion must not be narrowing.
/// Return a SCEV corresponding to a conversion of the input value to the
/// specified type. If the type must be extended, it is zero extended. The
/// conversion must not be narrowing.
const SCEV *getNoopOrZeroExtend(const SCEV *V, Type *Ty);
/// getNoopOrSignExtend - Return a SCEV corresponding to a conversion of
/// the input value to the specified type. If the type must be extended,
/// it is sign extended. The conversion must not be narrowing.
/// Return a SCEV corresponding to a conversion of the input value to the
/// specified type. If the type must be extended, it is sign extended. The
/// conversion must not be narrowing.
const SCEV *getNoopOrSignExtend(const SCEV *V, Type *Ty);
/// getNoopOrAnyExtend - Return a SCEV corresponding to a conversion of
/// the input value to the specified type. If the type must be extended,
/// it is extended with unspecified bits. The conversion must not be
/// narrowing.
/// Return a SCEV corresponding to a conversion of the input value to the
/// specified type. If the type must be extended, it is extended with
/// unspecified bits. The conversion must not be narrowing.
const SCEV *getNoopOrAnyExtend(const SCEV *V, Type *Ty);
/// getTruncateOrNoop - Return a SCEV corresponding to a conversion of the
/// input value to the specified type. The conversion must not be
/// widening.
/// Return a SCEV corresponding to a conversion of the input value to the
/// specified type. The conversion must not be widening.
const SCEV *getTruncateOrNoop(const SCEV *V, Type *Ty);
/// getUMaxFromMismatchedTypes - Promote the operands to the wider of
/// the types using zero-extension, and then perform a umax operation
/// with them.
/// Promote the operands to the wider of the types using zero-extension, and
/// then perform a umax operation with them.
const SCEV *getUMaxFromMismatchedTypes(const SCEV *LHS,
const SCEV *RHS);
/// getUMinFromMismatchedTypes - Promote the operands to the wider of
/// the types using zero-extension, and then perform a umin operation
/// with them.
/// Promote the operands to the wider of the types using zero-extension, and
/// then perform a umin operation with them.
const SCEV *getUMinFromMismatchedTypes(const SCEV *LHS,
const SCEV *RHS);
/// getPointerBase - Transitively follow the chain of pointer-type operands
/// until reaching a SCEV that does not have a single pointer operand. This
/// returns a SCEVUnknown pointer for well-formed pointer-type expressions,
/// but corner cases do exist.
/// Transitively follow the chain of pointer-type operands until reaching a
/// SCEV that does not have a single pointer operand. This returns a
/// SCEVUnknown pointer for well-formed pointer-type expressions, but corner
/// cases do exist.
const SCEV *getPointerBase(const SCEV *V);
/// getSCEVAtScope - Return a SCEV expression for the specified value
/// at the specified scope in the program. The L value specifies a loop
/// nest to evaluate the expression at, where null is the top-level or a
/// specified loop is immediately inside of the loop.
/// Return a SCEV expression for the specified value at the specified scope
/// in the program. The L value specifies a loop nest to evaluate the
/// expression at, where null is the top-level or a specified loop is
/// immediately inside of the loop.
///
/// This method can be used to compute the exit value for a variable defined
/// in a loop by querying what the value will hold in the parent loop.
@ -786,19 +755,17 @@ namespace llvm {
/// original value V is returned.
const SCEV *getSCEVAtScope(const SCEV *S, const Loop *L);
/// getSCEVAtScope - This is a convenience function which does
/// getSCEVAtScope(getSCEV(V), L).
/// This is a convenience function which does getSCEVAtScope(getSCEV(V), L).
const SCEV *getSCEVAtScope(Value *V, const Loop *L);
/// isLoopEntryGuardedByCond - Test whether entry to the loop is protected
/// by a conditional between LHS and RHS. This is used to help avoid max
/// expressions in loop trip counts, and to eliminate casts.
/// Test whether entry to the loop is protected by a conditional between LHS
/// and RHS. This is used to help avoid max expressions in loop trip
/// counts, and to eliminate casts.
bool isLoopEntryGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
const SCEV *LHS, const SCEV *RHS);
/// isLoopBackedgeGuardedByCond - Test whether the backedge of the loop is
/// protected by a conditional between LHS and RHS. This is used to
/// to eliminate casts.
/// Test whether the backedge of the loop is protected by a conditional
/// between LHS and RHS. This is used to to eliminate casts.
bool isLoopBackedgeGuardedByCond(const Loop *L, ICmpInst::Predicate Pred,
const SCEV *LHS, const SCEV *RHS);
@ -809,13 +776,13 @@ namespace llvm {
/// the single exiting block passed to it. See that routine for details.
unsigned getSmallConstantTripCount(Loop *L);
/// getSmallConstantTripCount - Returns the maximum trip count of this loop
/// as a normal unsigned value. Returns 0 if the trip count is unknown or
/// not constant. This "trip count" assumes that control exits via
/// ExitingBlock. More precisely, it is the number of times that control may
/// reach ExitingBlock before taking the branch. For loops with multiple
/// exits, it may not be the number times that the loop header executes if
/// the loop exits prematurely via another branch.
/// Returns the maximum trip count of this loop as a normal unsigned
/// value. Returns 0 if the trip count is unknown or not constant. This
/// "trip count" assumes that control exits via ExitingBlock. More
/// precisely, it is the number of times that control may reach ExitingBlock
/// before taking the branch. For loops with multiple exits, it may not be
/// the number times that the loop header executes if the loop exits
/// prematurely via another branch.
unsigned getSmallConstantTripCount(Loop *L, BasicBlock *ExitingBlock);
/// \brief Returns the largest constant divisor of the trip count of the
@ -826,25 +793,25 @@ namespace llvm {
/// the single exiting block passed to it. See that routine for details.
unsigned getSmallConstantTripMultiple(Loop *L);
/// getSmallConstantTripMultiple - Returns the largest constant divisor of
/// the trip count of this loop as a normal unsigned value, if
/// possible. This means that the actual trip count is always a multiple of
/// the returned value (don't forget the trip count could very well be zero
/// as well!). As explained in the comments for getSmallConstantTripCount,
/// this assumes that control exits the loop via ExitingBlock.
/// Returns the largest constant divisor of the trip count of this loop as a
/// normal unsigned value, if possible. This means that the actual trip
/// count is always a multiple of the returned value (don't forget the trip
/// count could very well be zero as well!). As explained in the comments
/// for getSmallConstantTripCount, this assumes that control exits the loop
/// via ExitingBlock.
unsigned getSmallConstantTripMultiple(Loop *L, BasicBlock *ExitingBlock);
// getExitCount - Get the expression for the number of loop iterations for
// which this loop is guaranteed not to exit via ExitingBlock. Otherwise
// return SCEVCouldNotCompute.
/// Get the expression for the number of loop iterations for which this loop
/// is guaranteed not to exit via ExitingBlock. Otherwise return
/// SCEVCouldNotCompute.
const SCEV *getExitCount(Loop *L, BasicBlock *ExitingBlock);
/// getBackedgeTakenCount - If the specified loop has a predictable
/// backedge-taken count, return it, otherwise return a SCEVCouldNotCompute
/// object. The backedge-taken count is the number of times the loop header
/// will be branched to from within the loop. This is one less than the
/// trip count of the loop, since it doesn't count the first iteration,
/// when the header is branched to from outside the loop.
/// If the specified loop has a predictable backedge-taken count, return it,
/// otherwise return a SCEVCouldNotCompute object. The backedge-taken count
/// is the number of times the loop header will be branched to from within
/// the loop. This is one less than the trip count of the loop, since it
/// doesn't count the first iteration, when the header is branched to from
/// outside the loop.
///
/// Note that it is not valid to call this method on a loop without a
/// loop-invariant backedge-taken count (see
@ -852,24 +819,23 @@ namespace llvm {
///
const SCEV *getBackedgeTakenCount(const Loop *L);
/// getMaxBackedgeTakenCount - Similar to getBackedgeTakenCount, except
/// return the least SCEV value that is known never to be less than the
/// actual backedge taken count.
/// Similar to getBackedgeTakenCount, except return the least SCEV value
/// that is known never to be less than the actual backedge taken count.
const SCEV *getMaxBackedgeTakenCount(const Loop *L);
/// hasLoopInvariantBackedgeTakenCount - Return true if the specified loop
/// has an analyzable loop-invariant backedge-taken count.
/// Return true if the specified loop has an analyzable loop-invariant
/// backedge-taken count.
bool hasLoopInvariantBackedgeTakenCount(const Loop *L);
/// forgetLoop - This method should be called by the client when it has
/// changed a loop in a way that may effect ScalarEvolution's ability to
/// compute a trip count, or if the loop is deleted. This call is
/// potentially expensive for large loop bodies.
/// This method should be called by the client when it has changed a loop in
/// a way that may effect ScalarEvolution's ability to compute a trip count,
/// or if the loop is deleted. This call is potentially expensive for large
/// loop bodies.
void forgetLoop(const Loop *L);
/// forgetValue - This method should be called by the client when it has
/// changed a value in a way that may effect its value, or which may
/// disconnect it from a def-use chain linking it to a loop.
/// This method should be called by the client when it has changed a value
/// in a way that may effect its value, or which may disconnect it from a
/// def-use chain linking it to a loop.
void forgetValue(Value *V);
/// \brief Called when the client has changed the disposition of values in
@ -879,50 +845,46 @@ namespace llvm {
/// recompute is simpler.
void forgetLoopDispositions(const Loop *L) { LoopDispositions.clear(); }
/// GetMinTrailingZeros - Determine the minimum number of zero bits that S
/// is guaranteed to end in (at every loop iteration). It is, at the same
/// time, the minimum number of times S is divisible by 2. For example,
/// given {4,+,8} it returns 2. If S is guaranteed to be 0, it returns the
/// bitwidth of S.
/// Determine the minimum number of zero bits that S is guaranteed to end in
/// (at every loop iteration). It is, at the same time, the minimum number
/// of times S is divisible by 2. For example, given {4,+,8} it returns 2.
/// If S is guaranteed to be 0, it returns the bitwidth of S.
uint32_t GetMinTrailingZeros(const SCEV *S);
/// getUnsignedRange - Determine the unsigned range for a particular SCEV.
/// Determine the unsigned range for a particular SCEV.
///
ConstantRange getUnsignedRange(const SCEV *S) {
return getRange(S, HINT_RANGE_UNSIGNED);
}
/// getSignedRange - Determine the signed range for a particular SCEV.
/// Determine the signed range for a particular SCEV.
///
ConstantRange getSignedRange(const SCEV *S) {
return getRange(S, HINT_RANGE_SIGNED);
}
/// isKnownNegative - Test if the given expression is known to be negative.
/// Test if the given expression is known to be negative.
///
bool isKnownNegative(const SCEV *S);
/// isKnownPositive - Test if the given expression is known to be positive.
/// Test if the given expression is known to be positive.
///
bool isKnownPositive(const SCEV *S);
/// isKnownNonNegative - Test if the given expression is known to be
/// non-negative.
/// Test if the given expression is known to be non-negative.
///
bool isKnownNonNegative(const SCEV *S);
/// isKnownNonPositive - Test if the given expression is known to be
/// non-positive.
/// Test if the given expression is known to be non-positive.
///
bool isKnownNonPositive(const SCEV *S);
/// isKnownNonZero - Test if the given expression is known to be
/// non-zero.
/// Test if the given expression is known to be non-zero.
///
bool isKnownNonZero(const SCEV *S);
/// isKnownPredicate - Test if the given expression is known to satisfy
/// the condition described by Pred, LHS, and RHS.
/// Test if the given expression is known to satisfy the condition described
/// by Pred, LHS, and RHS.
///
bool isKnownPredicate(ICmpInst::Predicate Pred,
const SCEV *LHS, const SCEV *RHS);
@ -937,44 +899,43 @@ namespace llvm {
const SCEV *&InvariantLHS,
const SCEV *&InvariantRHS);
/// SimplifyICmpOperands - Simplify LHS and RHS in a comparison with
/// predicate Pred. Return true iff any changes were made. If the
/// operands are provably equal or unequal, LHS and RHS are set to
/// the same value and Pred is set to either ICMP_EQ or ICMP_NE.
/// Simplify LHS and RHS in a comparison with predicate Pred. Return true
/// iff any changes were made. If the operands are provably equal or
/// unequal, LHS and RHS are set to the same value and Pred is set to either
/// ICMP_EQ or ICMP_NE.
///
bool SimplifyICmpOperands(ICmpInst::Predicate &Pred,
const SCEV *&LHS,
const SCEV *&RHS,
unsigned Depth = 0);
/// getLoopDisposition - Return the "disposition" of the given SCEV with
/// respect to the given loop.
/// Return the "disposition" of the given SCEV with respect to the given
/// loop.
LoopDisposition getLoopDisposition(const SCEV *S, const Loop *L);
/// isLoopInvariant - Return true if the value of the given SCEV is
/// unchanging in the specified loop.
/// Return true if the value of the given SCEV is unchanging in the
/// specified loop.
bool isLoopInvariant(const SCEV *S, const Loop *L);
/// hasComputableLoopEvolution - Return true if the given SCEV changes value
/// in a known way in the specified loop. This property being true implies
/// that the value is variant in the loop AND that we can emit an expression
/// to compute the value of the expression at any particular loop iteration.
/// Return true if the given SCEV changes value in a known way in the
/// specified loop. This property being true implies that the value is
/// variant in the loop AND that we can emit an expression to compute the
/// value of the expression at any particular loop iteration.
bool hasComputableLoopEvolution(const SCEV *S, const Loop *L);
/// getLoopDisposition - Return the "disposition" of the given SCEV with
/// respect to the given block.
/// Return the "disposition" of the given SCEV with respect to the given
/// block.
BlockDisposition getBlockDisposition(const SCEV *S, const BasicBlock *BB);
/// dominates - Return true if elements that makes up the given SCEV
/// dominate the specified basic block.
/// Return true if elements that makes up the given SCEV dominate the
/// specified basic block.
bool dominates(const SCEV *S, const BasicBlock *BB);
/// properlyDominates - Return true if elements that makes up the given SCEV
/// properly dominate the specified basic block.
/// Return true if elements that makes up the given SCEV properly dominate
/// the specified basic block.
bool properlyDominates(const SCEV *S, const BasicBlock *BB);
/// hasOperand - Test whether the given SCEV has Op as a direct or
/// indirect operand.
/// Test whether the given SCEV has Op as a direct or indirect operand.
bool hasOperand(const SCEV *S, const SCEV *Op) const;
/// Return the size of an element read or written by Inst.
@ -1091,9 +1052,9 @@ namespace llvm {
FoldingSet<SCEV> UniqueSCEVs;
BumpPtrAllocator SCEVAllocator;
/// FirstUnknown - The head of a linked list of all SCEVUnknown
/// values that have been allocated. This is used by releaseMemory
/// to locate them all and call their destructors.
/// The head of a linked list of all SCEVUnknown values that have been
/// allocated. This is used by releaseMemory to locate them all and call
/// their destructors.
SCEVUnknown *FirstUnknown;
};