#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 {
class AliasAnalysis;
class TargetData;
class MemoryDependenceAnalysis;
+ class PredIteratorCache;
/// MemDepResult - A memory dependence query can return one of three different
/// answers, described below.
/// a instruction definition dependency.
bool isDef() const { return Value.getInt() == Def; }
- /// isNonLocal - Return true if this MemDepResult represents an query that
+ /// isNonLocal - Return true if this MemDepResult represents a 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; }
/// 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
typedef std::pair<BasicBlock*, MemDepResult> NonLocalDepEntry;
typedef std::vector<NonLocalDepEntry> NonLocalDepInfo;
private:
+ /// ValueIsLoadPair - This is a pair<Value*, bool> where the bool is true if
+ /// the dependence is a read only dependence, false if read/write.
+ typedef PointerIntPair<Value*, 1, bool> 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<BasicBlock*, 1, bool> 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 <bb->result> mappings.
+ typedef DenseMap<ValueIsLoadPair, std::pair<BBSkipFirstBlockPair,
+ NonLocalDepInfo> > CachedNonLocalPointerInfo;
+ CachedNonLocalPointerInfo NonLocalPointerDeps;
+
+ // A map from instructions to their non-local pointer dependencies.
+ typedef DenseMap<Instruction*,
+ SmallPtrSet<ValueIsLoadPair, 4> > 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
/// Current AA implementation, just a cache.
AliasAnalysis *AA;
TargetData *TD;
+ OwningPtr<PredIteratorCache> 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.
///
/// this on non-memory instructions.
MemDepResult getDependency(Instruction *QueryInst);
- /// 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.
///
/// 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<NonLocalDepEntry> &Result);
/// removeInstruction - Remove an instruction from the dependence analysis,
/// updating the dependence of instructions that previously depended on it.
void removeInstruction(Instruction *InstToRemove);
- private:
+ /// 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);
- /// getDependencyFrom - Return the instruction on which the memory location
- /// '*Pointer' depends. This starts scanning from the instruction before
- /// the position indicated by ScanIt.
+ private:
MemDepResult getPointerDependencyFrom(Value *Pointer, uint64_t MemSize,
bool isLoad,
BasicBlock::iterator ScanIt,
BasicBlock *BB);
- MemDepResult getCallSiteDependencyFrom(CallSite C,
+ MemDepResult getCallSiteDependencyFrom(CallSite C, bool isReadOnlyCall,
BasicBlock::iterator ScanIt,
BasicBlock *BB);
+ bool getNonLocalPointerDepFromBB(Value *Pointer, uint64_t Size,
+ bool isLoad, BasicBlock *BB,
+ SmallVectorImpl<NonLocalDepEntry> &Result,
+ DenseMap<BasicBlock*, Value*> &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.