X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FAnalysis%2FAliasAnalysis.h;h=7f037fb5e813d8c967c596e899e55b6376dec38e;hb=cf0db29df20d9c665da7e82bb261bdd7cf7f1b2b;hp=8d7f3a1c40f1521e2e420d440fc8e1046647fef5;hpb=16f7993e0df4bd0727f8535bd47a2776bec10545;p=oota-llvm.git diff --git a/include/llvm/Analysis/AliasAnalysis.h b/include/llvm/Analysis/AliasAnalysis.h index 8d7f3a1c40f..7f037fb5e81 100644 --- a/include/llvm/Analysis/AliasAnalysis.h +++ b/include/llvm/Analysis/AliasAnalysis.h @@ -16,11 +16,12 @@ // which automatically provides functionality for the entire suite of client // APIs. // -// This API identifies memory regions with the Location class. The pointer +// This API identifies memory regions with the MemoryLocation class. The pointer // component specifies the base memory address of the region. The Size specifies -// the maximum size (in address units) of the memory region, or UnknownSize if -// the size is not known. The TBAA tag identifies the "type" of the memory -// reference; see the TypeBasedAliasAnalysis class for details. +// the maximum size (in address units) of the memory region, or +// MemoryLocation::UnknownSize if the size is not known. The TBAA tag +// identifies the "type" of the memory reference; see the +// TypeBasedAliasAnalysis class for details. // // Some non-obvious details include: // - Pointers that point to two completely different objects in memory never @@ -34,25 +35,31 @@ // //===----------------------------------------------------------------------===// -#ifndef LLVM_ANALYSIS_ALIAS_ANALYSIS_H -#define LLVM_ANALYSIS_ALIAS_ANALYSIS_H +#ifndef LLVM_ANALYSIS_ALIASANALYSIS_H +#define LLVM_ANALYSIS_ALIASANALYSIS_H -#include "llvm/Support/CallSite.h" -#include +#include "llvm/ADT/DenseMap.h" +#include "llvm/IR/CallSite.h" +#include "llvm/IR/Metadata.h" +#include "llvm/Analysis/MemoryLocation.h" namespace llvm { class LoadInst; class StoreInst; class VAArgInst; -class TargetData; +class DataLayout; +class TargetLibraryInfo; class Pass; class AnalysisUsage; class MemTransferInst; +class MemIntrinsic; +class DominatorTree; class AliasAnalysis { protected: - const TargetData *TD; + const DataLayout *DL; + const TargetLibraryInfo *TLI; private: AliasAnalysis *AA; // Previous Alias Analysis to chain to. @@ -63,7 +70,7 @@ protected: /// typically called by the run* methods of these subclasses. This may be /// called multiple times. /// - void InitializeAliasAnalysis(Pass *P); + void InitializeAliasAnalysis(Pass *P, const DataLayout *DL); /// getAnalysisUsage - All alias analysis implementations should invoke this /// directly (using AliasAnalysis::getAnalysisUsage(AU)). @@ -71,74 +78,23 @@ protected: public: static char ID; // Class identification, replacement for typeinfo - AliasAnalysis() : TD(0), AA(0) {} + AliasAnalysis() : DL(nullptr), TLI(nullptr), AA(nullptr) {} virtual ~AliasAnalysis(); // We want to be subclassed - /// UnknownSize - This is a special value which can be used with the - /// size arguments in alias queries to indicate that the caller does not - /// know the sizes of the potential memory references. - static uint64_t const UnknownSize = ~UINT64_C(0); - - /// getTargetData - Return a pointer to the current TargetData object, or - /// null if no TargetData object is available. + /// getTargetLibraryInfo - Return a pointer to the current TargetLibraryInfo + /// object, or null if no TargetLibraryInfo object is available. /// - const TargetData *getTargetData() const { return TD; } + const TargetLibraryInfo *getTargetLibraryInfo() const { return TLI; } - /// getTypeStoreSize - Return the TargetData store size for the given type, + /// getTypeStoreSize - Return the DataLayout store size for the given type, /// if known, or a conservative value otherwise. /// - uint64_t getTypeStoreSize(const Type *Ty); + uint64_t getTypeStoreSize(Type *Ty); //===--------------------------------------------------------------------===// /// Alias Queries... /// - /// Location - A description of a memory location. - struct Location { - /// Ptr - The address of the start of the location. - const Value *Ptr; - /// Size - The maximum size of the location, in address-units, or - /// UnknownSize if the size is not known. Note that an unknown size does - /// not mean the pointer aliases the entire virtual address space, because - /// there are restrictions on stepping out of one object and into another. - /// See http://llvm.org/docs/LangRef.html#pointeraliasing - uint64_t Size; - /// TBAATag - The metadata node which describes the TBAA type of - /// the location, or null if there is no known unique tag. - const MDNode *TBAATag; - - explicit Location(const Value *P = 0, - uint64_t S = UnknownSize, - const MDNode *N = 0) - : Ptr(P), Size(S), TBAATag(N) {} - - Location getWithNewPtr(const Value *NewPtr) const { - Location Copy(*this); - Copy.Ptr = NewPtr; - return Copy; - } - - Location getWithNewSize(uint64_t NewSize) const { - Location Copy(*this); - Copy.Size = NewSize; - return Copy; - } - - Location getWithoutTBAATag() const { - Location Copy(*this); - Copy.TBAATag = 0; - return Copy; - } - }; - - /// getLocation - Fill in Loc with information about the memory reference by - /// the given instruction. - Location getLocation(const LoadInst *LI); - Location getLocation(const StoreInst *SI); - Location getLocation(const VAArgInst *VI); - static Location getLocationForSource(const MemTransferInst *MTI); - static Location getLocationForDest(const MemTransferInst *MTI); - /// Alias analysis result - Either we know for sure that it does not alias, we /// know for sure it must alias, or we don't know anything: The two pointers /// _might_ alias. This enum is designed so you can do things like: @@ -150,49 +106,67 @@ public: /// enum AliasResult { NoAlias = 0, ///< No dependencies. - MayAlias = 1, ///< Anything goes. - MustAlias = 2 ///< Pointers are equal. + MayAlias, ///< Anything goes. + PartialAlias, ///< Pointers differ, but pointees overlap. + MustAlias ///< Pointers are equal. }; /// alias - The main low level interface to the alias analysis implementation. /// Returns an AliasResult indicating whether the two pointers are aliased to /// each other. This is the interface that must be implemented by specific /// alias analysis implementations. - virtual AliasResult alias(const Location &LocA, const Location &LocB); + virtual AliasResult alias(const MemoryLocation &LocA, + const MemoryLocation &LocB); /// alias - A convenience wrapper. AliasResult alias(const Value *V1, uint64_t V1Size, const Value *V2, uint64_t V2Size) { - return alias(Location(V1, V1Size), Location(V2, V2Size)); + return alias(MemoryLocation(V1, V1Size), MemoryLocation(V2, V2Size)); } /// alias - A convenience wrapper. AliasResult alias(const Value *V1, const Value *V2) { - return alias(V1, UnknownSize, V2, UnknownSize); + return alias(V1, MemoryLocation::UnknownSize, V2, + MemoryLocation::UnknownSize); } /// isNoAlias - A trivial helper function to check to see if the specified /// pointers are no-alias. - bool isNoAlias(const Location &LocA, const Location &LocB) { + bool isNoAlias(const MemoryLocation &LocA, const MemoryLocation &LocB) { return alias(LocA, LocB) == NoAlias; } /// isNoAlias - A convenience wrapper. bool isNoAlias(const Value *V1, uint64_t V1Size, const Value *V2, uint64_t V2Size) { - return isNoAlias(Location(V1, V1Size), Location(V2, V2Size)); + return isNoAlias(MemoryLocation(V1, V1Size), MemoryLocation(V2, V2Size)); + } + + /// isNoAlias - A convenience wrapper. + bool isNoAlias(const Value *V1, const Value *V2) { + return isNoAlias(MemoryLocation(V1), MemoryLocation(V2)); + } + + /// isMustAlias - A convenience wrapper. + bool isMustAlias(const MemoryLocation &LocA, const MemoryLocation &LocB) { + return alias(LocA, LocB) == MustAlias; } + /// isMustAlias - A convenience wrapper. + bool isMustAlias(const Value *V1, const Value *V2) { + return alias(V1, 1, V2, 1) == MustAlias; + } + /// pointsToConstantMemory - If the specified memory location is /// known to be constant, return true. If OrLocal is true and the /// specified memory location is known to be "local" (derived from /// an alloca), return true. Otherwise return false. - virtual bool pointsToConstantMemory(const Location &Loc, + virtual bool pointsToConstantMemory(const MemoryLocation &Loc, bool OrLocal = false); /// pointsToConstantMemory - A convenient wrapper. bool pointsToConstantMemory(const Value *P, bool OrLocal = false) { - return pointsToConstantMemory(Location(P), OrLocal); + return pointsToConstantMemory(MemoryLocation(P), OrLocal); } //===--------------------------------------------------------------------===// @@ -248,6 +222,13 @@ public: UnknownModRefBehavior = Anywhere | ModRef }; + /// Get the ModRef info associated with a pointer argument of a callsite. The + /// result's bits are set to indicate the allowed aliasing ModRef kinds. Note + /// that these bits do not necessarily account for the overall behavior of + /// the function, but rather only provide additional per-argument + /// information. + virtual ModRefResult getArgModRefInfo(ImmutableCallSite CS, unsigned ArgIdx); + /// getModRefBehavior - Return the behavior when calling the given call site. virtual ModRefBehavior getModRefBehavior(ImmutableCallSite CS); @@ -314,22 +295,44 @@ public: } /// doesAccessArgPointees - Return true if functions with the specified - /// behavior are known to potentially read or write from objects pointed + /// behavior are known to potentially read or write from objects pointed /// to be their pointer-typed arguments (with arbitrary offsets). /// static bool doesAccessArgPointees(ModRefBehavior MRB) { return (MRB & ModRef) && (MRB & ArgumentPointees); } + /// getModRefInfo - Return information about whether or not an + /// instruction may read or write memory (without regard to a + /// specific location) + ModRefResult getModRefInfo(const Instruction *I) { + if (auto CS = ImmutableCallSite(I)) { + auto MRB = getModRefBehavior(CS); + if (MRB & ModRef) + return ModRef; + else if (MRB & Ref) + return Ref; + else if (MRB & Mod) + return Mod; + return NoModRef; + } + + return getModRefInfo(I, MemoryLocation()); + } + /// getModRefInfo - Return information about whether or not an instruction may /// read or write the specified memory location. An instruction /// that doesn't read or write memory may be trivially LICM'd for example. - ModRefResult getModRefInfo(const Instruction *I, - const Location &Loc) { + ModRefResult getModRefInfo(const Instruction *I, const MemoryLocation &Loc) { switch (I->getOpcode()) { case Instruction::VAArg: return getModRefInfo((const VAArgInst*)I, Loc); case Instruction::Load: return getModRefInfo((const LoadInst*)I, Loc); case Instruction::Store: return getModRefInfo((const StoreInst*)I, Loc); + case Instruction::Fence: return getModRefInfo((const FenceInst*)I, Loc); + case Instruction::AtomicCmpXchg: + return getModRefInfo((const AtomicCmpXchgInst*)I, Loc); + case Instruction::AtomicRMW: + return getModRefInfo((const AtomicRMWInst*)I, Loc); case Instruction::Call: return getModRefInfo((const CallInst*)I, Loc); case Instruction::Invoke: return getModRefInfo((const InvokeInst*)I,Loc); default: return NoModRef; @@ -339,70 +342,108 @@ public: /// getModRefInfo - A convenience wrapper. ModRefResult getModRefInfo(const Instruction *I, const Value *P, uint64_t Size) { - return getModRefInfo(I, Location(P, Size)); + return getModRefInfo(I, MemoryLocation(P, Size)); } - /// getModRefInfo (for call sites) - Return whether information about whether + /// getModRefInfo (for call sites) - Return information about whether /// a particular call site modifies or reads the specified memory location. virtual ModRefResult getModRefInfo(ImmutableCallSite CS, - const Location &Loc); + const MemoryLocation &Loc); /// getModRefInfo (for call sites) - A convenience wrapper. ModRefResult getModRefInfo(ImmutableCallSite CS, const Value *P, uint64_t Size) { - return getModRefInfo(CS, Location(P, Size)); + return getModRefInfo(CS, MemoryLocation(P, Size)); } - /// getModRefInfo (for calls) - Return whether information about whether + /// getModRefInfo (for calls) - Return information about whether /// a particular call modifies or reads the specified memory location. - ModRefResult getModRefInfo(const CallInst *C, const Location &Loc) { + ModRefResult getModRefInfo(const CallInst *C, const MemoryLocation &Loc) { return getModRefInfo(ImmutableCallSite(C), Loc); } /// getModRefInfo (for calls) - A convenience wrapper. ModRefResult getModRefInfo(const CallInst *C, const Value *P, uint64_t Size) { - return getModRefInfo(C, Location(P, Size)); + return getModRefInfo(C, MemoryLocation(P, Size)); } - /// getModRefInfo (for invokes) - Return whether information about whether + /// getModRefInfo (for invokes) - Return information about whether /// a particular invoke modifies or reads the specified memory location. - ModRefResult getModRefInfo(const InvokeInst *I, - const Location &Loc) { + ModRefResult getModRefInfo(const InvokeInst *I, const MemoryLocation &Loc) { return getModRefInfo(ImmutableCallSite(I), Loc); } /// getModRefInfo (for invokes) - A convenience wrapper. ModRefResult getModRefInfo(const InvokeInst *I, const Value *P, uint64_t Size) { - return getModRefInfo(I, Location(P, Size)); + return getModRefInfo(I, MemoryLocation(P, Size)); } - /// getModRefInfo (for loads) - Return whether information about whether + /// getModRefInfo (for loads) - Return information about whether /// a particular load modifies or reads the specified memory location. - ModRefResult getModRefInfo(const LoadInst *L, const Location &Loc); + ModRefResult getModRefInfo(const LoadInst *L, const MemoryLocation &Loc); /// getModRefInfo (for loads) - A convenience wrapper. ModRefResult getModRefInfo(const LoadInst *L, const Value *P, uint64_t Size) { - return getModRefInfo(L, Location(P, Size)); + return getModRefInfo(L, MemoryLocation(P, Size)); } - /// getModRefInfo (for stores) - Return whether information about whether + /// getModRefInfo (for stores) - Return information about whether /// a particular store modifies or reads the specified memory location. - ModRefResult getModRefInfo(const StoreInst *S, const Location &Loc); + ModRefResult getModRefInfo(const StoreInst *S, const MemoryLocation &Loc); /// getModRefInfo (for stores) - A convenience wrapper. - ModRefResult getModRefInfo(const StoreInst *S, const Value *P, uint64_t Size) { - return getModRefInfo(S, Location(P, Size)); + ModRefResult getModRefInfo(const StoreInst *S, const Value *P, uint64_t Size){ + return getModRefInfo(S, MemoryLocation(P, Size)); } - /// getModRefInfo (for va_args) - Return whether information about whether + /// getModRefInfo (for fences) - Return information about whether + /// a particular store modifies or reads the specified memory location. + ModRefResult getModRefInfo(const FenceInst *S, const MemoryLocation &Loc) { + // Conservatively correct. (We could possibly be a bit smarter if + // Loc is a alloca that doesn't escape.) + return ModRef; + } + + /// getModRefInfo (for fences) - A convenience wrapper. + ModRefResult getModRefInfo(const FenceInst *S, const Value *P, uint64_t Size){ + return getModRefInfo(S, MemoryLocation(P, Size)); + } + + /// getModRefInfo (for cmpxchges) - Return information about whether + /// a particular cmpxchg modifies or reads the specified memory location. + ModRefResult getModRefInfo(const AtomicCmpXchgInst *CX, + const MemoryLocation &Loc); + + /// getModRefInfo (for cmpxchges) - A convenience wrapper. + ModRefResult getModRefInfo(const AtomicCmpXchgInst *CX, + const Value *P, unsigned Size) { + return getModRefInfo(CX, MemoryLocation(P, Size)); + } + + /// getModRefInfo (for atomicrmws) - Return information about whether + /// a particular atomicrmw modifies or reads the specified memory location. + ModRefResult getModRefInfo(const AtomicRMWInst *RMW, + const MemoryLocation &Loc); + + /// getModRefInfo (for atomicrmws) - A convenience wrapper. + ModRefResult getModRefInfo(const AtomicRMWInst *RMW, + const Value *P, unsigned Size) { + return getModRefInfo(RMW, MemoryLocation(P, Size)); + } + + /// getModRefInfo (for va_args) - Return information about whether /// a particular va_arg modifies or reads the specified memory location. - ModRefResult getModRefInfo(const VAArgInst* I, const Location &Loc); + ModRefResult getModRefInfo(const VAArgInst *I, const MemoryLocation &Loc); /// getModRefInfo (for va_args) - A convenience wrapper. - ModRefResult getModRefInfo(const VAArgInst* I, const Value* P, uint64_t Size) { - return getModRefInfo(I, Location(P, Size)); + ModRefResult getModRefInfo(const VAArgInst* I, const Value* P, uint64_t Size){ + return getModRefInfo(I, MemoryLocation(P, Size)); } + /// getModRefInfo - Return information about whether a call and an instruction + /// may refer to the same memory locations. + ModRefResult getModRefInfo(Instruction *I, + ImmutableCallSite Call); /// getModRefInfo - Return information about whether two call sites may refer /// to the same set of memory locations. See @@ -411,30 +452,45 @@ public: virtual ModRefResult getModRefInfo(ImmutableCallSite CS1, ImmutableCallSite CS2); + /// callCapturesBefore - Return information about whether a particular call + /// site modifies or reads the specified memory location. + ModRefResult callCapturesBefore(const Instruction *I, + const MemoryLocation &MemLoc, + DominatorTree *DT); + + /// callCapturesBefore - A convenience wrapper. + ModRefResult callCapturesBefore(const Instruction *I, const Value *P, + uint64_t Size, DominatorTree *DT) { + return callCapturesBefore(I, MemoryLocation(P, Size), DT); + } + //===--------------------------------------------------------------------===// /// Higher level methods for querying mod/ref information. /// /// canBasicBlockModify - Return true if it is possible for execution of the - /// specified basic block to modify the value pointed to by Ptr. - bool canBasicBlockModify(const BasicBlock &BB, const Location &Loc); + /// specified basic block to modify the location Loc. + bool canBasicBlockModify(const BasicBlock &BB, const MemoryLocation &Loc); /// canBasicBlockModify - A convenience wrapper. bool canBasicBlockModify(const BasicBlock &BB, const Value *P, uint64_t Size){ - return canBasicBlockModify(BB, Location(P, Size)); + return canBasicBlockModify(BB, MemoryLocation(P, Size)); } - /// canInstructionRangeModify - Return true if it is possible for the - /// execution of the specified instructions to modify the value pointed to by - /// Ptr. The instructions to consider are all of the instructions in the - /// range of [I1,I2] INCLUSIVE. I1 and I2 must be in the same basic block. - bool canInstructionRangeModify(const Instruction &I1, const Instruction &I2, - const Location &Loc); - - /// canInstructionRangeModify - A convenience wrapper. - bool canInstructionRangeModify(const Instruction &I1, const Instruction &I2, - const Value *Ptr, uint64_t Size) { - return canInstructionRangeModify(I1, I2, Location(Ptr, Size)); + /// canInstructionRangeModRef - Return true if it is possible for the + /// execution of the specified instructions to mod\ref (according to the + /// mode) the location Loc. The instructions to consider are all + /// of the instructions in the range of [I1,I2] INCLUSIVE. + /// I1 and I2 must be in the same basic block. + bool canInstructionRangeModRef(const Instruction &I1, const Instruction &I2, + const MemoryLocation &Loc, + const ModRefResult Mode); + + /// canInstructionRangeModRef - A convenience wrapper. + bool canInstructionRangeModRef(const Instruction &I1, + const Instruction &I2, const Value *Ptr, + uint64_t Size, const ModRefResult Mode) { + return canInstructionRangeModRef(I1, I2, MemoryLocation(Ptr, Size), Mode); } //===--------------------------------------------------------------------===// @@ -458,6 +514,17 @@ public: /// virtual void copyValue(Value *From, Value *To); + /// addEscapingUse - This method should be used whenever an escaping use is + /// added to a pointer value. Analysis implementations may either return + /// conservative responses for that value in the future, or may recompute + /// some or all internal state to continue providing precise responses. + /// + /// Escaping uses are considered by anything _except_ the following: + /// - GEPs or bitcasts of the pointer + /// - Loads through the pointer + /// - Stores through (but not of) the pointer + virtual void addEscapingUse(Use &U); + /// replaceWithNewValue - This method is the obvious combination of the two /// above, and it provided as a helper to simplify client code. /// @@ -471,15 +538,26 @@ public: /// function. bool isNoAliasCall(const Value *V); +/// isNoAliasArgument - Return true if this is an argument with the noalias +/// attribute. +bool isNoAliasArgument(const Value *V); + /// isIdentifiedObject - Return true if this pointer refers to a distinct and /// identifiable object. This returns true for: /// Global Variables and Functions (but not Global Aliases) -/// Allocas and Mallocs +/// Allocas /// ByVal and NoAlias Arguments -/// NoAlias returns +/// NoAlias returns (e.g. calls to malloc) /// bool isIdentifiedObject(const Value *V); -} // End llvm namespace +/// isIdentifiedFunctionLocal - Return true if V is umabigously identified +/// at the function-level. Different IdentifiedFunctionLocals can't alias. +/// Further, an IdentifiedFunctionLocal can not alias with any function +/// arguments other than itself, which is not necessarily true for +/// IdentifiedObjects. +bool isIdentifiedFunctionLocal(const Value *V); + +} // namespace llvm #endif