208 lines
6.9 KiB
C++
208 lines
6.9 KiB
C++
//===- llvm/Analysis/IVUsers.h - Induction Variable Users -------*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements bookkeeping for "interesting" users of expressions
|
|
// computed from induction variables.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_ANALYSIS_IVUSERS_H
|
|
#define LLVM_ANALYSIS_IVUSERS_H
|
|
|
|
#include "llvm/Analysis/LoopPass.h"
|
|
#include "llvm/Support/ValueHandle.h"
|
|
|
|
namespace llvm {
|
|
|
|
class DominatorTree;
|
|
class Instruction;
|
|
class Value;
|
|
class IVUsers;
|
|
class ScalarEvolution;
|
|
class SCEV;
|
|
|
|
/// IVStrideUse - Keep track of one use of a strided induction variable.
|
|
/// The Expr member keeps track of the expression, User is the actual user
|
|
/// instruction of the operand, and 'OperandValToReplace' is the operand of
|
|
/// the User that is the use.
|
|
class IVStrideUse : public CallbackVH, public ilist_node<IVStrideUse> {
|
|
public:
|
|
IVStrideUse(IVUsers *P, const SCEV *S, const SCEV *Off,
|
|
Instruction* U, Value *O)
|
|
: CallbackVH(U), Parent(P), Stride(S), Offset(Off),
|
|
OperandValToReplace(O), IsUseOfPostIncrementedValue(false) {
|
|
}
|
|
|
|
/// getUser - Return the user instruction for this use.
|
|
Instruction *getUser() const {
|
|
return cast<Instruction>(getValPtr());
|
|
}
|
|
|
|
/// setUser - Assign a new user instruction for this use.
|
|
void setUser(Instruction *NewUser) {
|
|
setValPtr(NewUser);
|
|
}
|
|
|
|
/// getParent - Return a pointer to the IVUsers that owns
|
|
/// this IVStrideUse.
|
|
IVUsers *getParent() const { return Parent; }
|
|
|
|
/// getStride - Return the expression for the stride for the use.
|
|
const SCEV *getStride() const { return Stride; }
|
|
|
|
/// setStride - Assign a new stride to this use.
|
|
void setStride(const SCEV *Val) {
|
|
Stride = Val;
|
|
}
|
|
|
|
/// getOffset - Return the offset to add to a theoeretical induction
|
|
/// variable that starts at zero and counts up by the stride to compute
|
|
/// the value for the use. This always has the same type as the stride.
|
|
const SCEV *getOffset() const { return Offset; }
|
|
|
|
/// setOffset - Assign a new offset to this use.
|
|
void setOffset(const SCEV *Val) {
|
|
Offset = Val;
|
|
}
|
|
|
|
/// getOperandValToReplace - Return the Value of the operand in the user
|
|
/// instruction that this IVStrideUse is representing.
|
|
Value *getOperandValToReplace() const {
|
|
return OperandValToReplace;
|
|
}
|
|
|
|
/// setOperandValToReplace - Assign a new Value as the operand value
|
|
/// to replace.
|
|
void setOperandValToReplace(Value *Op) {
|
|
OperandValToReplace = Op;
|
|
}
|
|
|
|
/// isUseOfPostIncrementedValue - True if this should use the
|
|
/// post-incremented version of this IV, not the preincremented version.
|
|
/// This can only be set in special cases, such as the terminating setcc
|
|
/// instruction for a loop or uses dominated by the loop.
|
|
bool isUseOfPostIncrementedValue() const {
|
|
return IsUseOfPostIncrementedValue;
|
|
}
|
|
|
|
/// setIsUseOfPostIncrmentedValue - set the flag that indicates whether
|
|
/// this is a post-increment use.
|
|
void setIsUseOfPostIncrementedValue(bool Val) {
|
|
IsUseOfPostIncrementedValue = Val;
|
|
}
|
|
|
|
private:
|
|
/// Parent - a pointer to the IVUsers that owns this IVStrideUse.
|
|
IVUsers *Parent;
|
|
|
|
/// Stride - The stride for this use.
|
|
const SCEV *Stride;
|
|
|
|
/// Offset - The offset to add to the base induction expression.
|
|
const SCEV *Offset;
|
|
|
|
/// OperandValToReplace - The Value of the operand in the user instruction
|
|
/// that this IVStrideUse is representing.
|
|
WeakVH OperandValToReplace;
|
|
|
|
/// IsUseOfPostIncrementedValue - True if this should use the
|
|
/// post-incremented version of this IV, not the preincremented version.
|
|
bool IsUseOfPostIncrementedValue;
|
|
|
|
/// Deleted - Implementation of CallbackVH virtual function to
|
|
/// recieve notification when the User is deleted.
|
|
virtual void deleted();
|
|
};
|
|
|
|
template<> struct ilist_traits<IVStrideUse>
|
|
: public ilist_default_traits<IVStrideUse> {
|
|
// createSentinel is used to get hold of a node that marks the end of
|
|
// the list...
|
|
// The sentinel is relative to this instance, so we use a non-static
|
|
// method.
|
|
IVStrideUse *createSentinel() const {
|
|
// since i(p)lists always publicly derive from the corresponding
|
|
// traits, placing a data member in this class will augment i(p)list.
|
|
// But since the NodeTy is expected to publicly derive from
|
|
// ilist_node<NodeTy>, there is a legal viable downcast from it
|
|
// to NodeTy. We use this trick to superpose i(p)list with a "ghostly"
|
|
// NodeTy, which becomes the sentinel. Dereferencing the sentinel is
|
|
// forbidden (save the ilist_node<NodeTy>) so no one will ever notice
|
|
// the superposition.
|
|
return static_cast<IVStrideUse*>(&Sentinel);
|
|
}
|
|
static void destroySentinel(IVStrideUse*) {}
|
|
|
|
IVStrideUse *provideInitialHead() const { return createSentinel(); }
|
|
IVStrideUse *ensureHead(IVStrideUse*) const { return createSentinel(); }
|
|
static void noteHead(IVStrideUse*, IVStrideUse*) {}
|
|
|
|
private:
|
|
mutable ilist_node<IVStrideUse> Sentinel;
|
|
};
|
|
|
|
class IVUsers : public LoopPass {
|
|
friend class IVStrideUse;
|
|
Loop *L;
|
|
LoopInfo *LI;
|
|
DominatorTree *DT;
|
|
ScalarEvolution *SE;
|
|
SmallPtrSet<Instruction*,16> Processed;
|
|
|
|
/// IVUses - A list of all tracked IV uses of induction variable expressions
|
|
/// we are interested in.
|
|
ilist<IVStrideUse> IVUses;
|
|
|
|
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
|
|
|
|
virtual bool runOnLoop(Loop *L, LPPassManager &LPM);
|
|
|
|
virtual void releaseMemory();
|
|
|
|
public:
|
|
static char ID; // Pass ID, replacement for typeid
|
|
IVUsers();
|
|
|
|
/// AddUsersIfInteresting - Inspect the specified Instruction. If it is a
|
|
/// reducible SCEV, recursively add its users to the IVUsesByStride set and
|
|
/// return true. Otherwise, return false.
|
|
bool AddUsersIfInteresting(Instruction *I);
|
|
|
|
IVStrideUse &AddUser(const SCEV *Stride, const SCEV *Offset,
|
|
Instruction *User, Value *Operand);
|
|
|
|
/// getReplacementExpr - Return a SCEV expression which computes the
|
|
/// value of the OperandValToReplace of the given IVStrideUse.
|
|
const SCEV *getReplacementExpr(const IVStrideUse &U) const;
|
|
|
|
/// getCanonicalExpr - Return a SCEV expression which computes the
|
|
/// value of the SCEV of the given IVStrideUse, ignoring the
|
|
/// isUseOfPostIncrementedValue flag.
|
|
const SCEV *getCanonicalExpr(const IVStrideUse &U) const;
|
|
|
|
typedef ilist<IVStrideUse>::iterator iterator;
|
|
typedef ilist<IVStrideUse>::const_iterator const_iterator;
|
|
iterator begin() { return IVUses.begin(); }
|
|
iterator end() { return IVUses.end(); }
|
|
const_iterator begin() const { return IVUses.begin(); }
|
|
const_iterator end() const { return IVUses.end(); }
|
|
bool empty() const { return IVUses.empty(); }
|
|
|
|
void print(raw_ostream &OS, const Module* = 0) const;
|
|
|
|
/// dump - This method is used for debugging.
|
|
void dump() const;
|
|
};
|
|
|
|
Pass *createIVUsersPass();
|
|
|
|
}
|
|
|
|
#endif
|