X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FAnalysis%2FMemoryDependenceAnalysis.h;h=d7d795e08a16eaa9469b5b0228a9b10b57008d5c;hb=b1d7a5d1146c30a54002b7ab49daf024e3174b95;hp=5e0612177e2ba600620cf44210721be79feb1514;hpb=0f41ad3bc9a295332a8e6d025b42cebc9b9e8125;p=oota-llvm.git diff --git a/include/llvm/Analysis/MemoryDependenceAnalysis.h b/include/llvm/Analysis/MemoryDependenceAnalysis.h index 5e0612177e2..d7d795e08a1 100644 --- a/include/llvm/Analysis/MemoryDependenceAnalysis.h +++ b/include/llvm/Analysis/MemoryDependenceAnalysis.h @@ -18,6 +18,7 @@ #include "llvm/Pass.h" #include "llvm/ADT/DenseMap.h" #include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/OwningPtr.h" #include "llvm/ADT/PointerIntPair.h" namespace llvm { @@ -28,6 +29,7 @@ namespace llvm { class AliasAnalysis; class TargetData; class MemoryDependenceAnalysis; + class PredIteratorCache; /// MemDepResult - A memory dependence query can return one of three different /// answers, described below. @@ -36,20 +38,36 @@ namespace llvm { /// Invalid - Clients of MemDep never see this. Invalid = 0, - /// Normal - This is a normal instruction dependence. The pointer member - /// of the MemDepResult pair holds the instruction. - Normal, + /// Clobber - This is a dependence on the specified instruction which + /// clobbers the desired value. The pointer member of the MemDepResult + /// pair holds the instruction that clobbers the memory. For example, + /// this occurs when we see a may-aliased store to the memory location we + /// care about. + Clobber, + /// Def - This is a dependence on the specified instruction which + /// defines/produces the desired memory location. The pointer member of + /// the MemDepResult pair holds the instruction that defines the memory. + /// Cases of interest: + /// 1. This could be a load or store for dependence queries on + /// load/store. The value loaded or stored is the produced value. + /// Note that the pointer operand may be different than that of the + /// queried pointer due to must aliases and phi translation. Note + /// that the def may not be the same type as the query, the pointers + /// may just be must aliases. + /// 2. For loads and stores, this could be an allocation instruction. In + /// this case, the load is loading an undef value or a store is the + /// first store to (that part of) the allocation. + /// 3. Dependence queries on calls return Def only when they are + /// readonly calls with identical callees and no intervening + /// clobbers. No validation is done that the operands to the calls + /// are the same. + Def, + /// NonLocal - This marker indicates that the query has no dependency in /// the specified block. To find out more, the client should query other /// predecessor blocks. - NonLocal, - - /// None - This dependence type indicates that the query does not depend - /// on any instructions, either because it is not a memory instruction or - /// because it scanned to the definition of the memory (alloca/malloc) - /// being accessed. - None + NonLocal }; typedef PointerIntPair PairTy; PairTy Value; @@ -59,37 +77,37 @@ namespace llvm { /// get methods: These are static ctor methods for creating various /// MemDepResult kinds. - static MemDepResult get(Instruction *Inst) { - return MemDepResult(PairTy(Inst, Normal)); + static MemDepResult getDef(Instruction *Inst) { + return MemDepResult(PairTy(Inst, Def)); + } + static MemDepResult getClobber(Instruction *Inst) { + return MemDepResult(PairTy(Inst, Clobber)); } static MemDepResult getNonLocal() { return MemDepResult(PairTy(0, NonLocal)); } - static MemDepResult getNone() { - return MemDepResult(PairTy(0, None)); - } - /// isNormal - Return true if this MemDepResult represents a query that is - /// a normal instruction dependency. - bool isNormal() const { return Value.getInt() == Normal; } + /// isClobber - Return true if this MemDepResult represents a query that is + /// a instruction clobber dependency. + bool isClobber() const { return Value.getInt() == Clobber; } + + /// isDef - Return true if this MemDepResult represents a query that is + /// a instruction definition dependency. + bool isDef() const { return Value.getInt() == Def; } /// isNonLocal - Return true if this MemDepResult represents an query that /// is transparent to the start of the block, but where a non-local hasn't /// been done. bool isNonLocal() const { return Value.getInt() == NonLocal; } - /// isNone - Return true if this MemDepResult represents a query that - /// doesn't depend on any instruction. - bool isNone() const { return Value.getInt() == None; } - /// getInst() - If this is a normal dependency, return the instruction that /// is depended on. Otherwise, return null. Instruction *getInst() const { return Value.getPointer(); } - bool operator==(const MemDepResult &M) const { return M.Value == Value; } - bool operator!=(const MemDepResult &M) const { return M.Value != Value; } - bool operator<(const MemDepResult &M) const { return M.Value < Value; } - bool operator>(const MemDepResult &M) const { return M.Value > Value; } + bool operator==(const MemDepResult &M) const { return Value == M.Value; } + bool operator!=(const MemDepResult &M) const { return Value != M.Value; } + bool operator<(const MemDepResult &M) const { return Value < M.Value; } + bool operator>(const MemDepResult &M) const { return Value > M.Value; } private: friend class MemoryDependenceAnalysis; /// Dirty - Entries with this marker occur in a LocalDeps map or @@ -135,6 +153,28 @@ namespace llvm { typedef std::pair NonLocalDepEntry; typedef std::vector NonLocalDepInfo; private: + /// ValueIsLoadPair - This is a pair where the bool is true if + /// the dependence is a read only dependence, false if read/write. + typedef PointerIntPair ValueIsLoadPair; + + /// BBSkipFirstBlockPair - This pair is used when caching information for a + /// block. If the pointer is null, the cache value is not a full query that + /// starts at the specified block. If non-null, the bool indicates whether + /// or not the contents of the block was skipped. + typedef PointerIntPair BBSkipFirstBlockPair; + + /// CachedNonLocalPointerInfo - This map stores the cached results of doing + /// a pointer lookup at the bottom of a block. The key of this map is the + /// pointer+isload bit, the value is a list of result> mappings. + typedef DenseMap > CachedNonLocalPointerInfo; + CachedNonLocalPointerInfo NonLocalPointerDeps; + + // A map from instructions to their non-local pointer dependencies. + typedef DenseMap > ReverseNonLocalPtrDepTy; + ReverseNonLocalPtrDepTy ReverseNonLocalPtrDeps; + /// PerInstNLInfo - This is the instruction we keep for each cached access /// that we have for an instruction. The pointer is an owning pointer and @@ -158,43 +198,30 @@ namespace llvm { /// Current AA implementation, just a cache. AliasAnalysis *AA; TargetData *TD; + OwningPtr PredCache; public: - MemoryDependenceAnalysis() : FunctionPass(&ID) {} + MemoryDependenceAnalysis(); + ~MemoryDependenceAnalysis(); static char ID; /// Pass Implementation stuff. This doesn't do any analysis eagerly. bool runOnFunction(Function &); /// Clean up memory in between runs - void releaseMemory() { - LocalDeps.clear(); - NonLocalDeps.clear(); - NonLocalDeps.clear(); - ReverseLocalDeps.clear(); - ReverseNonLocalDeps.clear(); - } - + void releaseMemory(); + /// getAnalysisUsage - Does not modify anything. It uses Value Numbering /// and Alias Analysis. /// virtual void getAnalysisUsage(AnalysisUsage &AU) const; /// getDependency - Return the instruction on which a memory operation - /// depends. See the class comment for more details. + /// depends. See the class comment for more details. It is illegal to call + /// this on non-memory instructions. MemDepResult getDependency(Instruction *QueryInst); - /// getDependencyFrom - Return the instruction on which the memory operation - /// 'QueryInst' depends. This starts scanning from the instruction before - /// the position indicated by ScanIt. - /// - /// Note that this method does no caching at all. You should use - /// getDependency where possible. - MemDepResult getDependencyFrom(Instruction *QueryInst, - BasicBlock::iterator ScanIt, BasicBlock *BB); - - - /// getNonLocalDependency - Perform a full dependency query for the - /// specified instruction, returning the set of blocks that the value is + /// getNonLocalCallDependency - Perform a full dependency query for the + /// specified call, returning the set of blocks that the value is /// potentially live across. The returned set of results will include a /// "NonLocal" result for all blocks where the value is live across. /// @@ -205,19 +232,54 @@ namespace llvm { /// invalidated on the next non-local query or when an instruction is /// removed. Clients must copy this data if they want it around longer than /// that. - const NonLocalDepInfo &getNonLocalDependency(Instruction *QueryInst); + const NonLocalDepInfo &getNonLocalCallDependency(CallSite QueryCS); + + + /// getNonLocalPointerDependency - Perform a full dependency query for an + /// access to the specified (non-volatile) memory location, returning the + /// set of instructions that either define or clobber the value. + /// + /// This method assumes the pointer has a "NonLocal" dependency within BB. + void getNonLocalPointerDependency(Value *Pointer, bool isLoad, + BasicBlock *BB, + SmallVectorImpl &Result); /// removeInstruction - Remove an instruction from the dependence analysis, /// updating the dependence of instructions that previously depended on it. void removeInstruction(Instruction *InstToRemove); + /// invalidateCachedPointerInfo - This method is used to invalidate cached + /// information about the specified pointer, because it may be too + /// conservative in memdep. This is an optional call that can be used when + /// the client detects an equivalence between the pointer and some other + /// value and replaces the other value with ptr. This can make Ptr available + /// in more places that cached info does not necessarily keep. + void invalidateCachedPointerInfo(Value *Ptr); + private: + MemDepResult getPointerDependencyFrom(Value *Pointer, uint64_t MemSize, + bool isLoad, + BasicBlock::iterator ScanIt, + BasicBlock *BB); + MemDepResult getCallSiteDependencyFrom(CallSite C, bool isReadOnlyCall, + BasicBlock::iterator ScanIt, + BasicBlock *BB); + bool getNonLocalPointerDepFromBB(Value *Pointer, uint64_t Size, + bool isLoad, BasicBlock *BB, + SmallVectorImpl &Result, + DenseMap &Visited, + bool SkipFirstBlock = false); + MemDepResult GetNonLocalInfoForBlock(Value *Pointer, uint64_t PointeeSize, + bool isLoad, BasicBlock *BB, + NonLocalDepInfo *Cache, + unsigned NumSortedEntries); + + void RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair P); + /// verifyRemoved - Verify that the specified instruction does not occur /// in our internal data structures. void verifyRemoved(Instruction *Inst) const; - MemDepResult getCallSiteDependency(CallSite C, BasicBlock::iterator ScanIt, - BasicBlock *BB); }; } // End llvm namespace