6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-09-24 23:28:41 +00:00
Code Issues Projects Releases Wiki Activity

This is a substantial rewrite of the AliasSetTracker class which now uses

Browse Source 
a union-find based algorithm, is significantly faster, and is more general.
It will also scale to handle call instructions correctly, which is a nice
added bonus.

This includes a new pass -print-alias-sets which can be used to show how
alias sets are formed for a particular analysis.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5619 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner
2003-02-24 20:37:56 +00:00
parent 93a7e08d1f
commit 9971ac4a36
2 changed files with 416 additions and 153 deletions
Download Patch File Download Diff File Expand all files Collapse all files

238
include/llvm/Analysis/AliasSetTracker.h
View File

@@ -10,80 +10,194 @@
#ifndef LLVM_ANALYSIS_ALIASSETTRACKER_H
#define LLVM_ANALYSIS_ALIASSETTRACKER_H
#include <vector>
#include "llvm/Support/CallSite.h"
#include "Support/iterator"
#include "Support/hash_map"
#include "Support/ilist"
class AliasAnalysis;
class LoadInst;
class StoreInst;
class CallInst;
class InvokeInst;
class Value;
class AliasSetTracker;
class AliasSet;
class AliasSet {
friend class AliasSetTracker;
std::vector<LoadInst*> Loads;
std::vector<StoreInst*> Stores;
std::vector<CallInst*> Calls;
std::vector<InvokeInst*> Invokes;
public:
struct PointerRec;
typedef std::pair<Value* const, PointerRec> HashNodePair;
class PointerRec {
HashNodePair *NextInList;
AliasSet *AS;
public:
PointerRec() : NextInList(0), AS(0) {}
HashNodePair *getNext() const { return NextInList; }
bool hasAliasSet() const { return AS != 0; }
AliasSet *getAliasSet(AliasSetTracker &AST) {
assert(AS && "No AliasSet yet!");
if (AS->Forward) {
AliasSet *OldAS = AS;
AS = OldAS->getForwardedTarget(AST);
if (--OldAS->RefCount == 0)
OldAS->removeFromTracker(AST);
AS->RefCount++;
}
return AS;
}
void setAliasSet(AliasSet *as) {
assert(AS == 0 && "Already have an alias set!");
AS = as;
}
void setTail(HashNodePair *T) {
assert(NextInList == 0 && "Already have tail!");
NextInList = T;
}
};
HashNodePair *PtrListHead, *PtrListTail; // Singly linked list of nodes
AliasSet *Forward; // Forwarding pointer
AliasSet *Next, *Prev; // Doubly linked list of AliasSets
std::vector<CallSite> CallSites; // All calls & invokes in this node
// RefCount - Number of nodes pointing to this AliasSet plus the number of
// AliasSets forwarding to it.
unsigned RefCount : 29;
/// AccessType - Keep track of whether this alias set merely refers to the
/// locations of memory, whether it modifies the memory, or whether it does
/// both. The lattice goes from "None" (alias set not present) to either Refs
/// or Mods, then to ModRef as neccesary.
/// both. The lattice goes from "NoModRef" to either Refs or Mods, then to
/// ModRef as neccesary.
///
enum AccessType {
Refs, Mods, ModRef
NoModRef = 0, Refs = 1, // Ref = bit 1
Mods = 2, ModRef = 3 // Mod = bit 2
};
unsigned AccessTy : 2;
/// AliasType - Keep track the relationships between the pointers in the set.
/// Lattice goes from MustAlias to MayAlias.
///
enum AliasType {
MustAlias, MayAlias
MustAlias = 0, MayAlias = 1
};
private:
enum AccessType AccessTy;
enum AliasType AliasTy;
unsigned AliasTy : 1;
/// Define an iterator for alias sets... this is just a forward iterator.
class iterator : public forward_iterator<Value*, ptrdiff_t> {
HashNodePair *CurNode;
public:
iterator(HashNodePair *CN = 0) : CurNode(CN) {}
bool operator==(const iterator& x) const {
return CurNode == x.CurNode;
}
bool operator!=(const iterator& x) const { return !operator==(x); }
const iterator &operator=(const iterator &I) {
CurNode = I.CurNode;
return *this;
}
value_type operator*() const {
assert(CurNode && "Dereferencing AliasSet.end()!");
return CurNode->first;
}
value_type operator->() const { return operator*(); }
iterator& operator++() { // Preincrement
assert(CurNode && "Advancing past AliasSet.end()!");
CurNode = CurNode->second.getNext();
return *this;
}
iterator operator++(int) { // Postincrement
iterator tmp = *this; ++*this; return tmp;
}
};
friend class ilist_traits<AliasSet>;
AliasSet *getPrev() const { return Prev; }
AliasSet *getNext() const { return Next; }
void setPrev(AliasSet *P) { Prev = P; }
void setNext(AliasSet *N) { Next = N; }
public:
/// Accessors...
enum AccessType getAccessType() const { return AccessTy; }
enum AliasType getAliasType() const { return AliasTy; }
// TODO: in the future, add a fixed size (4? 2?) cache of pointers that we
// know are in the alias set, to cut down time answering "pointeraliasesset"
// queries.
/// pointerAliasesSet - Return true if the specified pointer "may" (or must)
/// alias one of the members in the set.
///
bool pointerAliasesSet(const Value *Ptr, AliasAnalysis &AA) const;
bool isRef() const { return AccessTy & Refs; }
bool isMod() const { return AccessTy & Mods; }
bool isMustAlias() const { return AliasTy == MustAlias; }
bool isMayAlias() const { return AliasTy == MayAlias; }
/// mergeSetIn - Merge the specified alias set into this alias set...
///
void mergeSetIn(const AliasSet &AS);
void mergeSetIn(AliasSet &AS);
const std::vector<LoadInst*> &getLoads() const { return Loads; }
const std::vector<StoreInst*> &getStores() const { return Stores; }
const std::vector<CallInst*> &getCalls() const { return Calls; }
const std::vector<InvokeInst*> &getInvokes() const { return Invokes; }
// Alias Set iteration - Allow access to all of the pointer which are part of
// this alias set...
iterator begin() const { return iterator(PtrListHead); }
iterator end() const { return iterator(); }
void print(std::ostream &OS) const;
void dump() const;
private:
AliasSet() : AliasTy(MustAlias) {} // Can only be created by AliasSetTracker
void updateAccessType();
Value *getSomePointer() const;
// Can only be created by AliasSetTracker
AliasSet() : PtrListHead(0), PtrListTail(0), Forward(0), RefCount(0),
AccessTy(NoModRef), AliasTy(MustAlias) {
}
Value *getSomePointer() const {
return PtrListHead ? PtrListHead->first : 0;
}
/// getForwardedTarget - Return the real alias set this represents. If this
/// has been merged with another set and is forwarding, return the ultimate
/// destination set. This also implements the union-find collapsing as well.
AliasSet *getForwardedTarget(AliasSetTracker &AST) {
if (!Forward) return this;
AliasSet *Dest = Forward->getForwardedTarget(AST);
if (Dest != Forward) {
Dest->RefCount++;
if (--Forward->RefCount == 0)
Forward->removeFromTracker(AST);
Forward = Dest;
}
return Dest;
}
void removeFromTracker(AliasSetTracker &AST);
void addPointer(AliasSetTracker &AST, HashNodePair &Entry);
void addCallSite(CallSite CS);
/// aliasesPointer - Return true if the specified pointer "may" (or must)
/// alias one of the members in the set.
///
bool aliasesPointer(const Value *Ptr, AliasAnalysis &AA) const;
bool aliasesCallSite(CallSite CS, AliasAnalysis &AA) const;
};
inline std::ostream& operator<<(std::ostream &OS, const AliasSet &AS) {
AS.print(OS);
return OS;
}
class AliasSetTracker {
AliasAnalysis &AA;
std::vector<AliasSet> AliasSets;
ilist<AliasSet> AliasSets;
// Map from pointers to their node
hash_map<Value*, AliasSet::PointerRec> PointerMap;
public:
/// AliasSetTracker ctor - Create an empty collection of AliasSets, and use
/// the specified alias analysis object to disambiguate load and store
/// addresses.
AliasSetTracker(AliasAnalysis &aa) : AA(aa) {}
/// add methods - These methods are used to add different types of
/// instructions to the alias sets. Adding a new instruction can result in
/// one of three actions happening:
@@ -95,15 +209,57 @@ public:
///
void add(LoadInst *LI);
void add(StoreInst *SI);
void add(CallInst *CI);
void add(InvokeInst *II);
void add(CallSite CS); // Call/Invoke instructions
void add(CallInst *CI) { add(CallSite(CI)); }
void add(InvokeInst *II) { add(CallSite(II)); }
void add(Instruction *I); // Dispatch to one of the other add methods...
/// getAliasSets - Return the alias sets that are active.
const std::vector<AliasSet> &getAliasSets() const { return AliasSets; }
const ilist<AliasSet> &getAliasSets() const { return AliasSets; }
/// getAliasSetForPointer - Return the alias set that the specified pointer
/// lives in...
AliasSet &getAliasSetForPointer(Value *P);
/// getAliasAnalysis - Return the underlying alias analysis object used by
/// this tracker.
AliasAnalysis &getAliasAnalysis() const { return AA; }
typedef ilist<AliasSet>::iterator iterator;
typedef ilist<AliasSet>::const_iterator const_iterator;
const_iterator begin() const { return AliasSets.begin(); }
const_iterator end() const { return AliasSets.end(); }
iterator begin() { return AliasSets.begin(); }
iterator end() { return AliasSets.end(); }
void print(std::ostream &OS) const;
void dump() const;
private:
friend class AliasSet;
void removeAliasSet(AliasSet *AS);
AliasSet::HashNodePair &getEntryFor(Value *V) {
// Standard operator[], except that it returns the whole pair, not just
// ->second.
return *PointerMap.insert(AliasSet::HashNodePair(V,
AliasSet::PointerRec())).first;
}
void addPointer(Value *P, AliasSet::AccessType E) {
AliasSet &AS = getAliasSetForPointer(P);
AS.AccessTy |= E;
}
AliasSet *findAliasSetForPointer(const Value *Ptr);
void mergeAllSets();
AliasSet *findAliasSetForCallSite(CallSite CS);
};
inline std::ostream& operator<<(std::ostream &OS, const AliasSetTracker &AST) {
AST.print(OS);
return OS;
}
#endif