// 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
#define LLVM_ANALYSIS_ALIASANALYSIS_H
#include "llvm/ADT/DenseMap.h"
-#include "llvm/Support/CallSite.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/Analysis/MemoryLocation.h"
namespace llvm {
-
+class BasicAAResult;
class LoadInst;
class StoreInst;
class VAArgInst;
class MemTransferInst;
class MemIntrinsic;
class DominatorTree;
+class OrderedBasicBlock;
-class AliasAnalysis {
-protected:
- const DataLayout *TD;
- const TargetLibraryInfo *TLI;
-
-private:
- AliasAnalysis *AA; // Previous Alias Analysis to chain to.
-
-protected:
- /// InitializeAliasAnalysis - Subclasses must call this method to initialize
- /// the AliasAnalysis interface before any other methods are called. This is
- /// typically called by the run* methods of these subclasses. This may be
- /// called multiple times.
+/// The possible results of an alias query.
+///
+/// These results are always computed between two MemoryLocation objects as
+/// a query to some alias analysis.
+///
+/// Note that these are unscoped enumerations because we would like to support
+/// implicitly testing a result for the existence of any possible aliasing with
+/// a conversion to bool, but an "enum class" doesn't support this. The
+/// canonical names from the literature are suffixed and unique anyways, and so
+/// they serve as global constants in LLVM for these results.
+///
+/// See docs/AliasAnalysis.html for more information on the specific meanings
+/// of these values.
+enum AliasResult {
+ /// The two locations do not alias at all.
///
- void InitializeAliasAnalysis(Pass *P);
-
- /// getAnalysisUsage - All alias analysis implementations should invoke this
- /// directly (using AliasAnalysis::getAnalysisUsage(AU)).
- virtual void getAnalysisUsage(AnalysisUsage &AU) const;
+ /// This value is arranged to convert to false, while all other values
+ /// convert to true. This allows a boolean context to convert the result to
+ /// a binary flag indicating whether there is the possibility of aliasing.
+ NoAlias = 0,
+ /// The two locations may or may not alias. This is the least precise result.
+ MayAlias,
+ /// The two locations alias, but only due to a partial overlap.
+ PartialAlias,
+ /// The two locations precisely alias each other.
+ MustAlias,
+};
-public:
- static char ID; // Class identification, replacement for typeinfo
- AliasAnalysis() : TD(0), TLI(0), AA(0) {}
- virtual ~AliasAnalysis(); // We want to be subclassed
+/// Flags indicating whether a memory access modifies or references memory.
+///
+/// This is no access at all, a modification, a reference, or both
+/// a modification and a reference. These are specifically structured such that
+/// they form a two bit matrix and bit-tests for 'mod' or 'ref' work with any
+/// of the possible values.
+enum ModRefInfo {
+ /// The access neither references nor modifies the value stored in memory.
+ MRI_NoModRef = 0,
+ /// The access references the value stored in memory.
+ MRI_Ref = 1,
+ /// The access modifies the value stored in memory.
+ MRI_Mod = 2,
+ /// The access both references and modifies the value stored in memory.
+ MRI_ModRef = MRI_Ref | MRI_Mod
+};
- /// 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);
+/// The locations at which a function might access memory.
+///
+/// These are primarily used in conjunction with the \c AccessKind bits to
+/// describe both the nature of access and the locations of access for a
+/// function call.
+enum FunctionModRefLocation {
+ /// Base case is no access to memory.
+ FMRL_Nowhere = 0,
+ /// Access to memory via argument pointers.
+ FMRL_ArgumentPointees = 4,
+ /// Access to any memory.
+ FMRL_Anywhere = 8 | FMRL_ArgumentPointees
+};
- /// getDataLayout - Return a pointer to the current DataLayout object, or
- /// null if no DataLayout object is available.
+/// Summary of how a function affects memory in the program.
+///
+/// Loads from constant globals are not considered memory accesses for this
+/// interface. Also, functions may freely modify stack space local to their
+/// invocation without having to report it through these interfaces.
+enum FunctionModRefBehavior {
+ /// This function does not perform any non-local loads or stores to memory.
///
- const DataLayout *getDataLayout() const { return TD; }
+ /// This property corresponds to the GCC 'const' attribute.
+ /// This property corresponds to the LLVM IR 'readnone' attribute.
+ /// This property corresponds to the IntrNoMem LLVM intrinsic flag.
+ FMRB_DoesNotAccessMemory = FMRL_Nowhere | MRI_NoModRef,
- /// getTargetLibraryInfo - Return a pointer to the current TargetLibraryInfo
- /// object, or null if no TargetLibraryInfo object is available.
+ /// The only memory references in this function (if it has any) are
+ /// non-volatile loads from objects pointed to by its pointer-typed
+ /// arguments, with arbitrary offsets.
///
- const TargetLibraryInfo *getTargetLibraryInfo() const { return TLI; }
+ /// This property corresponds to the IntrReadArgMem LLVM intrinsic flag.
+ FMRB_OnlyReadsArgumentPointees = FMRL_ArgumentPointees | MRI_Ref,
- /// getTypeStoreSize - Return the DataLayout store size for the given type,
- /// if known, or a conservative value otherwise.
+ /// The only memory references in this function (if it has any) are
+ /// non-volatile loads and stores from objects pointed to by its
+ /// pointer-typed arguments, with arbitrary offsets.
///
- uint64_t getTypeStoreSize(Type *Ty);
+ /// This property corresponds to the IntrReadWriteArgMem LLVM intrinsic flag.
+ FMRB_OnlyAccessesArgumentPointees = FMRL_ArgumentPointees | MRI_ModRef,
- //===--------------------------------------------------------------------===//
- /// Alias Queries...
+ /// This function does not perform any non-local stores or volatile loads,
+ /// but may read from any memory location.
///
+ /// This property corresponds to the GCC 'pure' attribute.
+ /// This property corresponds to the LLVM IR 'readonly' attribute.
+ /// This property corresponds to the IntrReadMem LLVM intrinsic flag.
+ FMRB_OnlyReadsMemory = FMRL_Anywhere | MRI_Ref,
- /// 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;
- }
+ /// This indicates that the function could not be classified into one of the
+ /// behaviors above.
+ FMRB_UnknownModRefBehavior = FMRL_Anywhere | MRI_ModRef
+};
- Location getWithoutTBAATag() const {
- Location Copy(*this);
- Copy.TBAATag = 0;
- return Copy;
- }
- };
+class AAResults {
+public:
+ // Make these results default constructable and movable. We have to spell
+ // these out because MSVC won't synthesize them.
+ AAResults() {}
+ AAResults(AAResults &&Arg);
+ AAResults &operator=(AAResults &&Arg);
+ ~AAResults();
+
+ /// Register a specific AA result.
+ template <typename AAResultT> void addAAResult(AAResultT &AAResult) {
+ // FIXME: We should use a much lighter weight system than the usual
+ // polymorphic pattern because we don't own AAResult. It should
+ // ideally involve two pointers and no separate allocation.
+ AAs.emplace_back(new Model<AAResultT>(AAResult, *this));
+ }
- /// 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);
- Location getLocation(const AtomicCmpXchgInst *CXI);
- Location getLocation(const AtomicRMWInst *RMWI);
- static Location getLocationForSource(const MemTransferInst *MTI);
- static Location getLocationForDest(const MemIntrinsic *MI);
-
- /// 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:
- /// if (AA.alias(P1, P2)) { ... }
- /// to check to see if two pointers might alias.
- ///
- /// See docs/AliasAnalysis.html for more information on the specific meanings
- /// of these values.
- ///
- enum AliasResult {
- NoAlias = 0, ///< No dependencies.
- MayAlias, ///< Anything goes.
- PartialAlias, ///< Pointers differ, but pointees overlap.
- MustAlias ///< Pointers are equal.
- };
+ //===--------------------------------------------------------------------===//
+ /// \name Alias Queries
+ /// @{
- /// alias - The main low level interface to the alias analysis implementation.
+ /// 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
+ /// each other. This is the interface that must be implemented by specific
/// alias analysis implementations.
- virtual AliasResult alias(const Location &LocA, const Location &LocB);
+ 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));
+ /// A convenience wrapper around the primary \c alias interface.
+ AliasResult alias(const Value *V1, uint64_t V1Size, const Value *V2,
+ uint64_t V2Size) {
+ return alias(MemoryLocation(V1, V1Size), MemoryLocation(V2, V2Size));
}
- /// alias - A convenience wrapper.
+ /// A convenience wrapper around the primary \c alias interface.
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) {
+ /// A trivial helper function to check to see if the specified pointers are
+ /// no-alias.
+ 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));
+ /// A convenience wrapper around the \c isNoAlias helper interface.
+ bool isNoAlias(const Value *V1, uint64_t V1Size, const Value *V2,
+ uint64_t V2Size) {
+ return isNoAlias(MemoryLocation(V1, V1Size), MemoryLocation(V2, V2Size));
}
-
- /// isNoAlias - A convenience wrapper.
+
+ /// A convenience wrapper around the \c isNoAlias helper interface.
bool isNoAlias(const Value *V1, const Value *V2) {
- return isNoAlias(Location(V1), Location(V2));
+ return isNoAlias(MemoryLocation(V1), MemoryLocation(V2));
}
-
- /// isMustAlias - A convenience wrapper.
- bool isMustAlias(const Location &LocA, const Location &LocB) {
+
+ /// A trivial helper function to check to see if the specified pointers are
+ /// must-alias.
+ bool isMustAlias(const MemoryLocation &LocA, const MemoryLocation &LocB) {
return alias(LocA, LocB) == MustAlias;
}
- /// isMustAlias - A convenience wrapper.
+ /// A convenience wrapper around the \c isMustAlias helper interface.
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,
- bool OrLocal = false);
- /// pointsToConstantMemory - A convenient wrapper.
+ /// Checks whether the given location points to constant memory, or if
+ /// \p OrLocal is true whether it points to a local alloca.
+ bool pointsToConstantMemory(const MemoryLocation &Loc, bool OrLocal = false);
+
+ /// A convenience wrapper around the primary \c pointsToConstantMemory
+ /// interface.
bool pointsToConstantMemory(const Value *P, bool OrLocal = false) {
- return pointsToConstantMemory(Location(P), OrLocal);
+ return pointsToConstantMemory(MemoryLocation(P), OrLocal);
}
+ /// @}
//===--------------------------------------------------------------------===//
- /// Simple mod/ref information...
- ///
+ /// \name Simple mod/ref information
+ /// @{
- /// ModRefResult - Represent the result of a mod/ref query. Mod and Ref are
- /// bits which may be or'd together.
- ///
- enum ModRefResult { NoModRef = 0, Ref = 1, Mod = 2, ModRef = 3 };
-
- /// These values define additional bits used to define the
- /// ModRefBehavior values.
- enum { Nowhere = 0, ArgumentPointees = 4, Anywhere = 8 | ArgumentPointees };
-
- /// ModRefBehavior - Summary of how a function affects memory in the program.
- /// Loads from constant globals are not considered memory accesses for this
- /// interface. Also, functions may freely modify stack space local to their
- /// invocation without having to report it through these interfaces.
- enum ModRefBehavior {
- /// DoesNotAccessMemory - This function does not perform any non-local loads
- /// or stores to memory.
- ///
- /// This property corresponds to the GCC 'const' attribute.
- /// This property corresponds to the LLVM IR 'readnone' attribute.
- /// This property corresponds to the IntrNoMem LLVM intrinsic flag.
- DoesNotAccessMemory = Nowhere | NoModRef,
-
- /// OnlyReadsArgumentPointees - The only memory references in this function
- /// (if it has any) are non-volatile loads from objects pointed to by its
- /// pointer-typed arguments, with arbitrary offsets.
- ///
- /// This property corresponds to the IntrReadArgMem LLVM intrinsic flag.
- OnlyReadsArgumentPointees = ArgumentPointees | Ref,
-
- /// OnlyAccessesArgumentPointees - The only memory references in this
- /// function (if it has any) are non-volatile loads and stores from objects
- /// pointed to by its pointer-typed arguments, with arbitrary offsets.
- ///
- /// This property corresponds to the IntrReadWriteArgMem LLVM intrinsic flag.
- OnlyAccessesArgumentPointees = ArgumentPointees | ModRef,
-
- /// OnlyReadsMemory - This function does not perform any non-local stores or
- /// volatile loads, but may read from any memory location.
- ///
- /// This property corresponds to the GCC 'pure' attribute.
- /// This property corresponds to the LLVM IR 'readonly' attribute.
- /// This property corresponds to the IntrReadMem LLVM intrinsic flag.
- OnlyReadsMemory = Anywhere | Ref,
-
- /// UnknownModRefBehavior - This indicates that the function could not be
- /// classified into one of the behaviors above.
- 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.
+ ModRefInfo getArgModRefInfo(ImmutableCallSite CS, unsigned ArgIdx);
- /// getModRefBehavior - Return the behavior when calling the given call site.
- virtual ModRefBehavior getModRefBehavior(ImmutableCallSite CS);
+ /// Return the behavior of the given call site.
+ FunctionModRefBehavior getModRefBehavior(ImmutableCallSite CS);
- /// getModRefBehavior - Return the behavior when calling the given function.
- /// For use when the call site is not known.
- virtual ModRefBehavior getModRefBehavior(const Function *F);
+ /// Return the behavior when calling the given function.
+ FunctionModRefBehavior getModRefBehavior(const Function *F);
- /// doesNotAccessMemory - If the specified call is known to never read or
- /// write memory, return true. If the call only reads from known-constant
- /// memory, it is also legal to return true. Calls that unwind the stack
- /// are legal for this predicate.
+ /// Checks if the specified call is known to never read or write memory.
+ ///
+ /// Note that if the call only reads from known-constant memory, it is also
+ /// legal to return true. Also, calls that unwind the stack are legal for
+ /// this predicate.
///
/// Many optimizations (such as CSE and LICM) can be performed on such calls
/// without worrying about aliasing properties, and many calls have this
/// property (e.g. calls to 'sin' and 'cos').
///
/// This property corresponds to the GCC 'const' attribute.
- ///
bool doesNotAccessMemory(ImmutableCallSite CS) {
- return getModRefBehavior(CS) == DoesNotAccessMemory;
+ return getModRefBehavior(CS) == FMRB_DoesNotAccessMemory;
}
- /// doesNotAccessMemory - If the specified function is known to never read or
- /// write memory, return true. For use when the call site is not known.
+ /// Checks if the specified function is known to never read or write memory.
+ ///
+ /// Note that if the function only reads from known-constant memory, it is
+ /// also legal to return true. Also, function that unwind the stack are legal
+ /// for this predicate.
///
+ /// Many optimizations (such as CSE and LICM) can be performed on such calls
+ /// to such functions without worrying about aliasing properties, and many
+ /// functions have this property (e.g. 'sin' and 'cos').
+ ///
+ /// This property corresponds to the GCC 'const' attribute.
bool doesNotAccessMemory(const Function *F) {
- return getModRefBehavior(F) == DoesNotAccessMemory;
+ return getModRefBehavior(F) == FMRB_DoesNotAccessMemory;
}
- /// onlyReadsMemory - If the specified call is known to only read from
- /// non-volatile memory (or not access memory at all), return true. Calls
- /// that unwind the stack are legal for this predicate.
+ /// Checks if the specified call is known to only read from non-volatile
+ /// memory (or not access memory at all).
+ ///
+ /// Calls that unwind the stack are legal for this predicate.
///
/// This property allows many common optimizations to be performed in the
/// absence of interfering store instructions, such as CSE of strlen calls.
///
/// This property corresponds to the GCC 'pure' attribute.
- ///
bool onlyReadsMemory(ImmutableCallSite CS) {
return onlyReadsMemory(getModRefBehavior(CS));
}
- /// onlyReadsMemory - If the specified function is known to only read from
- /// non-volatile memory (or not access memory at all), return true. For use
- /// when the call site is not known.
+ /// Checks if the specified function is known to only read from non-volatile
+ /// memory (or not access memory at all).
///
- bool onlyReadsMemory(const Function *F) {
- return onlyReadsMemory(getModRefBehavior(F));
- }
-
- /// onlyReadsMemory - Return true if functions with the specified behavior are
- /// known to only read from non-volatile memory (or not access memory at all).
+ /// Functions that unwind the stack are legal for this predicate.
///
- static bool onlyReadsMemory(ModRefBehavior MRB) {
- return !(MRB & Mod);
- }
-
- /// onlyAccessesArgPointees - Return true if functions with the specified
- /// behavior are known to read and write at most from objects pointed to by
- /// their pointer-typed arguments (with arbitrary offsets).
+ /// This property allows many common optimizations to be performed in the
+ /// absence of interfering store instructions, such as CSE of strlen calls.
///
- static bool onlyAccessesArgPointees(ModRefBehavior MRB) {
- return !(MRB & Anywhere & ~ArgumentPointees);
+ /// This property corresponds to the GCC 'pure' attribute.
+ bool onlyReadsMemory(const Function *F) {
+ return onlyReadsMemory(getModRefBehavior(F));
}
- /// doesAccessArgPointees - Return true if functions with the specified
- /// 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);
+ /// Checks if functions with the specified behavior are known to only read
+ /// from non-volatile memory (or not access memory at all).
+ static bool onlyReadsMemory(FunctionModRefBehavior MRB) {
+ return !(MRB & MRI_Mod);
}
- /// 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) {
- 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;
- }
+ /// Checks if functions with the specified behavior are known to read and
+ /// write at most from objects pointed to by their pointer-typed arguments
+ /// (with arbitrary offsets).
+ static bool onlyAccessesArgPointees(FunctionModRefBehavior MRB) {
+ return !(MRB & FMRL_Anywhere & ~FMRL_ArgumentPointees);
}
- /// getModRefInfo - A convenience wrapper.
- ModRefResult getModRefInfo(const Instruction *I,
- const Value *P, uint64_t Size) {
- return getModRefInfo(I, Location(P, Size));
+ /// Checks if functions with the specified behavior are known to potentially
+ /// read or write from objects pointed to be their pointer-typed arguments
+ /// (with arbitrary offsets).
+ static bool doesAccessArgPointees(FunctionModRefBehavior MRB) {
+ return (MRB & MRI_ModRef) && (MRB & FMRL_ArgumentPointees);
}
/// 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);
+ ModRefInfo getModRefInfo(ImmutableCallSite CS, 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));
+ ModRefInfo getModRefInfo(ImmutableCallSite CS, const Value *P,
+ uint64_t Size) {
+ return getModRefInfo(CS, MemoryLocation(P, Size));
}
/// 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) {
+ ModRefInfo 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));
+ ModRefInfo getModRefInfo(const CallInst *C, const Value *P, uint64_t Size) {
+ return getModRefInfo(C, MemoryLocation(P, Size));
}
/// 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) {
+ ModRefInfo 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));
+ ModRefInfo getModRefInfo(const InvokeInst *I, const Value *P, uint64_t Size) {
+ return getModRefInfo(I, MemoryLocation(P, Size));
}
/// 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);
+ ModRefInfo 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));
+ ModRefInfo getModRefInfo(const LoadInst *L, const Value *P, uint64_t Size) {
+ return getModRefInfo(L, MemoryLocation(P, Size));
}
/// 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);
+ ModRefInfo 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));
+ ModRefInfo getModRefInfo(const StoreInst *S, const Value *P, uint64_t Size) {
+ return getModRefInfo(S, MemoryLocation(P, Size));
}
/// getModRefInfo (for fences) - Return information about whether
/// a particular store modifies or reads the specified memory location.
- ModRefResult getModRefInfo(const FenceInst *S, const Location &Loc) {
+ ModRefInfo 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;
+ return MRI_ModRef;
}
/// getModRefInfo (for fences) - A convenience wrapper.
- ModRefResult getModRefInfo(const FenceInst *S, const Value *P, uint64_t Size){
- return getModRefInfo(S, Location(P, Size));
+ ModRefInfo 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 Location &Loc);
+ ModRefInfo 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, Location(P, Size));
+ ModRefInfo 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 Location &Loc);
+ ModRefInfo 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, Location(P, Size));
+ ModRefInfo 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);
+ ModRefInfo 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));
+ ModRefInfo getModRefInfo(const VAArgInst *I, const Value *P, uint64_t Size) {
+ return getModRefInfo(I, MemoryLocation(P, Size));
}
- /// getModRefInfo - Return information about whether two call sites may refer
- /// to the same set of memory locations. See
- /// http://llvm.org/docs/AliasAnalysis.html#ModRefInfo
- /// for details.
- virtual ModRefResult getModRefInfo(ImmutableCallSite CS1,
- ImmutableCallSite CS2);
+ /// Check whether or not an instruction may read or write memory (without
+ /// regard to a specific location).
+ ///
+ /// For function calls, this delegates to the alias-analysis specific
+ /// call-site mod-ref behavior queries. Otherwise it delegates to the generic
+ /// mod ref information query without a location.
+ ModRefInfo getModRefInfo(const Instruction *I) {
+ if (auto CS = ImmutableCallSite(I)) {
+ auto MRB = getModRefBehavior(CS);
+ if (MRB & MRI_ModRef)
+ return MRI_ModRef;
+ else if (MRB & MRI_Ref)
+ return MRI_Ref;
+ else if (MRB & MRI_Mod)
+ return MRI_Mod;
+ return MRI_NoModRef;
+ }
- /// callCapturesBefore - Return information about whether a particular call
- /// site modifies or reads the specified memory location.
- ModRefResult callCapturesBefore(const Instruction *I,
- const AliasAnalysis::Location &MemLoc,
- DominatorTree *DT);
+ return getModRefInfo(I, MemoryLocation());
+ }
- /// callCapturesBefore - A convenience wrapper.
- ModRefResult callCapturesBefore(const Instruction *I, const Value *P,
- uint64_t Size, DominatorTree *DT) {
- return callCapturesBefore(I, Location(P, Size), DT);
+ /// Check 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.
+ ///
+ /// This primarily delegates to specific helpers above.
+ ModRefInfo 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 MRI_NoModRef;
+ }
+ }
+
+ /// A convenience wrapper for constructing the memory location.
+ ModRefInfo getModRefInfo(const Instruction *I, const Value *P,
+ uint64_t Size) {
+ return getModRefInfo(I, MemoryLocation(P, Size));
}
+ /// Return information about whether a call and an instruction may refer to
+ /// the same memory locations.
+ ModRefInfo getModRefInfo(Instruction *I, ImmutableCallSite Call);
+
+ /// Return information about whether two call sites may refer to the same set
+ /// of memory locations. See the AA documentation for details:
+ /// http://llvm.org/docs/AliasAnalysis.html#ModRefInfo
+ ModRefInfo getModRefInfo(ImmutableCallSite CS1, ImmutableCallSite CS2);
+
+ /// \brief Return information about whether a particular call site modifies
+ /// or reads the specified memory location \p MemLoc before instruction \p I
+ /// in a BasicBlock. A ordered basic block \p OBB can be used to speed up
+ /// instruction ordering queries inside the BasicBlock containing \p I.
+ ModRefInfo callCapturesBefore(const Instruction *I,
+ const MemoryLocation &MemLoc, DominatorTree *DT,
+ OrderedBasicBlock *OBB = nullptr);
+
+ /// \brief A convenience wrapper to synthesize a memory location.
+ ModRefInfo callCapturesBefore(const Instruction *I, const Value *P,
+ uint64_t Size, DominatorTree *DT,
+ OrderedBasicBlock *OBB = nullptr) {
+ return callCapturesBefore(I, MemoryLocation(P, Size), DT, OBB);
+ }
+
+ /// @}
//===--------------------------------------------------------------------===//
- /// Higher level methods for querying mod/ref information.
+ /// \name Higher level methods for querying mod/ref information.
+ /// @{
+
+ /// Check if it is possible for execution of the specified basic block to
+ /// modify the location Loc.
+ bool canBasicBlockModify(const BasicBlock &BB, const MemoryLocation &Loc);
+
+ /// A convenience wrapper synthesizing a memory location.
+ bool canBasicBlockModify(const BasicBlock &BB, const Value *P,
+ uint64_t Size) {
+ return canBasicBlockModify(BB, MemoryLocation(P, Size));
+ }
+
+ /// Check 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 ModRefInfo Mode);
+
+ /// A convenience wrapper synthesizing a memory location.
+ bool canInstructionRangeModRef(const Instruction &I1, const Instruction &I2,
+ const Value *Ptr, uint64_t Size,
+ const ModRefInfo Mode) {
+ return canInstructionRangeModRef(I1, I2, MemoryLocation(Ptr, Size), Mode);
+ }
+
+private:
+ class Concept;
+ template <typename T> class Model;
+
+ template <typename T> friend class AAResultBase;
+
+ std::vector<std::unique_ptr<Concept>> AAs;
+};
+
+/// Temporary typedef for legacy code that uses a generic \c AliasAnalysis
+/// pointer or reference.
+typedef AAResults AliasAnalysis;
+
+/// A private abstract base class describing the concept of an individual alias
+/// analysis implementation.
+///
+/// This interface is implemented by any \c Model instantiation. It is also the
+/// interface which a type used to instantiate the model must provide.
+///
+/// All of these methods model methods by the same name in the \c
+/// AAResults class. Only differences and specifics to how the
+/// implementations are called are documented here.
+class AAResults::Concept {
+public:
+ virtual ~Concept() = 0;
+
+ /// An update API used internally by the AAResults to provide
+ /// a handle back to the top level aggregation.
+ virtual void setAAResults(AAResults *NewAAR) = 0;
- /// 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);
+ //===--------------------------------------------------------------------===//
+ /// \name Alias Queries
+ /// @{
+
+ /// 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 MemoryLocation &LocA,
+ const MemoryLocation &LocB) = 0;
+
+ /// Checks whether the given location points to constant memory, or if
+ /// \p OrLocal is true whether it points to a local alloca.
+ virtual bool pointsToConstantMemory(const MemoryLocation &Loc,
+ bool OrLocal) = 0;
+
+ /// @}
+ //===--------------------------------------------------------------------===//
+ /// \name Simple mod/ref information
+ /// @{
+
+ /// 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 ModRefInfo getArgModRefInfo(ImmutableCallSite CS,
+ unsigned ArgIdx) = 0;
+
+ /// Return the behavior of the given call site.
+ virtual FunctionModRefBehavior getModRefBehavior(ImmutableCallSite CS) = 0;
+
+ /// Return the behavior when calling the given function.
+ virtual FunctionModRefBehavior getModRefBehavior(const Function *F) = 0;
+
+ /// getModRefInfo (for call sites) - Return information about whether
+ /// a particular call site modifies or reads the specified memory location.
+ virtual ModRefInfo getModRefInfo(ImmutableCallSite CS,
+ const MemoryLocation &Loc) = 0;
+
+ /// Return information about whether two call sites may refer to the same set
+ /// of memory locations. See the AA documentation for details:
+ /// http://llvm.org/docs/AliasAnalysis.html#ModRefInfo
+ virtual ModRefInfo getModRefInfo(ImmutableCallSite CS1,
+ ImmutableCallSite CS2) = 0;
+
+ /// @}
+};
- /// canBasicBlockModify - A convenience wrapper.
- bool canBasicBlockModify(const BasicBlock &BB, const Value *P, uint64_t Size){
- return canBasicBlockModify(BB, Location(P, Size));
+/// A private class template which derives from \c Concept and wraps some other
+/// type.
+///
+/// This models the concept by directly forwarding each interface point to the
+/// wrapped type which must implement a compatible interface. This provides
+/// a type erased binding.
+template <typename AAResultT> class AAResults::Model final : public Concept {
+ AAResultT &Result;
+
+public:
+ explicit Model(AAResultT &Result, AAResults &AAR) : Result(Result) {
+ Result.setAAResults(&AAR);
}
+ ~Model() override {}
- /// 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);
+ void setAAResults(AAResults *NewAAR) override { Result.setAAResults(NewAAR); }
- /// 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));
+ AliasResult alias(const MemoryLocation &LocA,
+ const MemoryLocation &LocB) override {
+ return Result.alias(LocA, LocB);
}
- //===--------------------------------------------------------------------===//
- /// Methods that clients should call when they transform the program to allow
- /// alias analyses to update their internal data structures. Note that these
- /// methods may be called on any instruction, regardless of whether or not
- /// they have pointer-analysis implications.
- ///
+ bool pointsToConstantMemory(const MemoryLocation &Loc,
+ bool OrLocal) override {
+ return Result.pointsToConstantMemory(Loc, OrLocal);
+ }
- /// deleteValue - This method should be called whenever an LLVM Value is
- /// deleted from the program, for example when an instruction is found to be
- /// redundant and is eliminated.
- ///
- virtual void deleteValue(Value *V);
+ ModRefInfo getArgModRefInfo(ImmutableCallSite CS, unsigned ArgIdx) override {
+ return Result.getArgModRefInfo(CS, ArgIdx);
+ }
- /// copyValue - This method should be used whenever a preexisting value in the
- /// program is copied or cloned, introducing a new value. Note that analysis
- /// implementations should tolerate clients that use this method to introduce
- /// the same value multiple times: if the analysis already knows about a
- /// value, it should ignore the request.
- ///
- virtual void copyValue(Value *From, Value *To);
+ FunctionModRefBehavior getModRefBehavior(ImmutableCallSite CS) override {
+ return Result.getModRefBehavior(CS);
+ }
- /// 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.
- ///
- void replaceWithNewValue(Value *Old, Value *New) {
- copyValue(Old, New);
- deleteValue(Old);
+ FunctionModRefBehavior getModRefBehavior(const Function *F) override {
+ return Result.getModRefBehavior(F);
+ }
+
+ ModRefInfo getModRefInfo(ImmutableCallSite CS,
+ const MemoryLocation &Loc) override {
+ return Result.getModRefInfo(CS, Loc);
+ }
+
+ ModRefInfo getModRefInfo(ImmutableCallSite CS1,
+ ImmutableCallSite CS2) override {
+ return Result.getModRefInfo(CS1, CS2);
}
};
-// Specialize DenseMapInfo for Location.
-template<>
-struct DenseMapInfo<AliasAnalysis::Location> {
- static inline AliasAnalysis::Location getEmptyKey() {
- return
- AliasAnalysis::Location(DenseMapInfo<const Value *>::getEmptyKey(),
- 0, 0);
- }
- static inline AliasAnalysis::Location getTombstoneKey() {
- return
- AliasAnalysis::Location(DenseMapInfo<const Value *>::getTombstoneKey(),
- 0, 0);
- }
- static unsigned getHashValue(const AliasAnalysis::Location &Val) {
- return DenseMapInfo<const Value *>::getHashValue(Val.Ptr) ^
- DenseMapInfo<uint64_t>::getHashValue(Val.Size) ^
- DenseMapInfo<const MDNode *>::getHashValue(Val.TBAATag);
- }
- static bool isEqual(const AliasAnalysis::Location &LHS,
- const AliasAnalysis::Location &RHS) {
- return LHS.Ptr == RHS.Ptr &&
- LHS.Size == RHS.Size &&
- LHS.TBAATag == RHS.TBAATag;
+/// A CRTP-driven "mixin" base class to help implement the function alias
+/// analysis results concept.
+///
+/// Because of the nature of many alias analysis implementations, they often
+/// only implement a subset of the interface. This base class will attempt to
+/// implement the remaining portions of the interface in terms of simpler forms
+/// of the interface where possible, and otherwise provide conservatively
+/// correct fallback implementations.
+///
+/// Implementors of an alias analysis should derive from this CRTP, and then
+/// override specific methods that they wish to customize. There is no need to
+/// use virtual anywhere, the CRTP base class does static dispatch to the
+/// derived type passed into it.
+template <typename DerivedT> class AAResultBase {
+ // Expose some parts of the interface only to the AAResults::Model
+ // for wrapping. Specifically, this allows the model to call our
+ // setAAResults method without exposing it as a fully public API.
+ friend class AAResults::Model<DerivedT>;
+
+ /// A pointer to the AAResults object that this AAResult is
+ /// aggregated within. May be null if not aggregated.
+ AAResults *AAR;
+
+ /// Helper to dispatch calls back through the derived type.
+ DerivedT &derived() { return static_cast<DerivedT &>(*this); }
+
+ /// A setter for the AAResults pointer, which is used to satisfy the
+ /// AAResults::Model contract.
+ void setAAResults(AAResults *NewAAR) { AAR = NewAAR; }
+
+protected:
+ /// This proxy class models a common pattern where we delegate to either the
+ /// top-level \c AAResults aggregation if one is registered, or to the
+ /// current result if none are registered.
+ class AAResultsProxy {
+ AAResults *AAR;
+ DerivedT &CurrentResult;
+
+ public:
+ AAResultsProxy(AAResults *AAR, DerivedT &CurrentResult)
+ : AAR(AAR), CurrentResult(CurrentResult) {}
+
+ AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB) {
+ return AAR ? AAR->alias(LocA, LocB) : CurrentResult.alias(LocA, LocB);
+ }
+
+ bool pointsToConstantMemory(const MemoryLocation &Loc, bool OrLocal) {
+ return AAR ? AAR->pointsToConstantMemory(Loc, OrLocal)
+ : CurrentResult.pointsToConstantMemory(Loc, OrLocal);
+ }
+
+ ModRefInfo getArgModRefInfo(ImmutableCallSite CS, unsigned ArgIdx) {
+ return AAR ? AAR->getArgModRefInfo(CS, ArgIdx) : CurrentResult.getArgModRefInfo(CS, ArgIdx);
+ }
+
+ FunctionModRefBehavior getModRefBehavior(ImmutableCallSite CS) {
+ return AAR ? AAR->getModRefBehavior(CS) : CurrentResult.getModRefBehavior(CS);
+ }
+
+ FunctionModRefBehavior getModRefBehavior(const Function *F) {
+ return AAR ? AAR->getModRefBehavior(F) : CurrentResult.getModRefBehavior(F);
+ }
+
+ ModRefInfo getModRefInfo(ImmutableCallSite CS, const MemoryLocation &Loc) {
+ return AAR ? AAR->getModRefInfo(CS, Loc)
+ : CurrentResult.getModRefInfo(CS, Loc);
+ }
+
+ ModRefInfo getModRefInfo(ImmutableCallSite CS1, ImmutableCallSite CS2) {
+ return AAR ? AAR->getModRefInfo(CS1, CS2) : CurrentResult.getModRefInfo(CS1, CS2);
+ }
+ };
+
+ const TargetLibraryInfo &TLI;
+
+ explicit AAResultBase(const TargetLibraryInfo &TLI) : TLI(TLI) {}
+
+ // Provide all the copy and move constructors so that derived types aren't
+ // constrained.
+ AAResultBase(const AAResultBase &Arg) : TLI(Arg.TLI) {}
+ AAResultBase(AAResultBase &&Arg) : TLI(Arg.TLI) {}
+
+ /// Get a proxy for the best AA result set to query at this time.
+ ///
+ /// When this result is part of a larger aggregation, this will proxy to that
+ /// aggregation. When this result is used in isolation, it will just delegate
+ /// back to the derived class's implementation.
+ AAResultsProxy getBestAAResults() { return AAResultsProxy(AAR, derived()); }
+
+public:
+ AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB) {
+ return MayAlias;
+ }
+
+ bool pointsToConstantMemory(const MemoryLocation &Loc, bool OrLocal) {
+ return false;
+ }
+
+ ModRefInfo getArgModRefInfo(ImmutableCallSite CS, unsigned ArgIdx) {
+ return MRI_ModRef;
}
+
+ FunctionModRefBehavior getModRefBehavior(ImmutableCallSite CS) {
+ if (const Function *F = CS.getCalledFunction())
+ return getBestAAResults().getModRefBehavior(F);
+
+ return FMRB_UnknownModRefBehavior;
+ }
+
+ FunctionModRefBehavior getModRefBehavior(const Function *F) {
+ return FMRB_UnknownModRefBehavior;
+ }
+
+ ModRefInfo getModRefInfo(ImmutableCallSite CS, const MemoryLocation &Loc);
+
+ ModRefInfo getModRefInfo(ImmutableCallSite CS1, ImmutableCallSite CS2);
};
+/// Synthesize \c ModRefInfo for a call site and memory location by examining
+/// the general behavior of the call site and any specific information for its
+/// arguments.
+///
+/// This essentially, delegates across the alias analysis interface to collect
+/// information which may be enough to (conservatively) fulfill the query.
+template <typename DerivedT>
+ModRefInfo AAResultBase<DerivedT>::getModRefInfo(ImmutableCallSite CS,
+ const MemoryLocation &Loc) {
+ auto MRB = getBestAAResults().getModRefBehavior(CS);
+ if (MRB == FMRB_DoesNotAccessMemory)
+ return MRI_NoModRef;
+
+ ModRefInfo Mask = MRI_ModRef;
+ if (AAResults::onlyReadsMemory(MRB))
+ Mask = MRI_Ref;
+
+ if (AAResults::onlyAccessesArgPointees(MRB)) {
+ bool DoesAlias = false;
+ ModRefInfo AllArgsMask = MRI_NoModRef;
+ if (AAResults::doesAccessArgPointees(MRB)) {
+ for (ImmutableCallSite::arg_iterator AI = CS.arg_begin(),
+ AE = CS.arg_end();
+ AI != AE; ++AI) {
+ const Value *Arg = *AI;
+ if (!Arg->getType()->isPointerTy())
+ continue;
+ unsigned ArgIdx = std::distance(CS.arg_begin(), AI);
+ MemoryLocation ArgLoc = MemoryLocation::getForArgument(CS, ArgIdx, TLI);
+ AliasResult ArgAlias = getBestAAResults().alias(ArgLoc, Loc);
+ if (ArgAlias != NoAlias) {
+ ModRefInfo ArgMask = getBestAAResults().getArgModRefInfo(CS, ArgIdx);
+ DoesAlias = true;
+ AllArgsMask = ModRefInfo(AllArgsMask | ArgMask);
+ }
+ }
+ }
+ if (!DoesAlias)
+ return MRI_NoModRef;
+ Mask = ModRefInfo(Mask & AllArgsMask);
+ }
+
+ // If Loc is a constant memory location, the call definitely could not
+ // modify the memory location.
+ if ((Mask & MRI_Mod) &&
+ getBestAAResults().pointsToConstantMemory(Loc, /*OrLocal*/ false))
+ Mask = ModRefInfo(Mask & ~MRI_Mod);
+
+ return Mask;
+}
+
+/// Synthesize \c ModRefInfo for two call sites by examining the general
+/// behavior of the call site and any specific information for its arguments.
+///
+/// This essentially, delegates across the alias analysis interface to collect
+/// information which may be enough to (conservatively) fulfill the query.
+template <typename DerivedT>
+ModRefInfo AAResultBase<DerivedT>::getModRefInfo(ImmutableCallSite CS1,
+ ImmutableCallSite CS2) {
+ // If CS1 or CS2 are readnone, they don't interact.
+ auto CS1B = getBestAAResults().getModRefBehavior(CS1);
+ if (CS1B == FMRB_DoesNotAccessMemory)
+ return MRI_NoModRef;
+
+ auto CS2B = getBestAAResults().getModRefBehavior(CS2);
+ if (CS2B == FMRB_DoesNotAccessMemory)
+ return MRI_NoModRef;
+
+ // If they both only read from memory, there is no dependence.
+ if (AAResults::onlyReadsMemory(CS1B) && AAResults::onlyReadsMemory(CS2B))
+ return MRI_NoModRef;
+
+ ModRefInfo Mask = MRI_ModRef;
+
+ // If CS1 only reads memory, the only dependence on CS2 can be
+ // from CS1 reading memory written by CS2.
+ if (AAResults::onlyReadsMemory(CS1B))
+ Mask = ModRefInfo(Mask & MRI_Ref);
+
+ // If CS2 only access memory through arguments, accumulate the mod/ref
+ // information from CS1's references to the memory referenced by
+ // CS2's arguments.
+ if (AAResults::onlyAccessesArgPointees(CS2B)) {
+ ModRefInfo R = MRI_NoModRef;
+ if (AAResults::doesAccessArgPointees(CS2B)) {
+ for (ImmutableCallSite::arg_iterator I = CS2.arg_begin(),
+ E = CS2.arg_end();
+ I != E; ++I) {
+ const Value *Arg = *I;
+ if (!Arg->getType()->isPointerTy())
+ continue;
+ unsigned CS2ArgIdx = std::distance(CS2.arg_begin(), I);
+ auto CS2ArgLoc = MemoryLocation::getForArgument(CS2, CS2ArgIdx, TLI);
+
+ // ArgMask indicates what CS2 might do to CS2ArgLoc, and the dependence
+ // of CS1 on that location is the inverse.
+ ModRefInfo ArgMask =
+ getBestAAResults().getArgModRefInfo(CS2, CS2ArgIdx);
+ if (ArgMask == MRI_Mod)
+ ArgMask = MRI_ModRef;
+ else if (ArgMask == MRI_Ref)
+ ArgMask = MRI_Mod;
+
+ ArgMask = ModRefInfo(ArgMask &
+ getBestAAResults().getModRefInfo(CS1, CS2ArgLoc));
+
+ R = ModRefInfo((R | ArgMask) & Mask);
+ if (R == Mask)
+ break;
+ }
+ }
+ return R;
+ }
+
+ // If CS1 only accesses memory through arguments, check if CS2 references
+ // any of the memory referenced by CS1's arguments. If not, return NoModRef.
+ if (AAResults::onlyAccessesArgPointees(CS1B)) {
+ ModRefInfo R = MRI_NoModRef;
+ if (AAResults::doesAccessArgPointees(CS1B)) {
+ for (ImmutableCallSite::arg_iterator I = CS1.arg_begin(),
+ E = CS1.arg_end();
+ I != E; ++I) {
+ const Value *Arg = *I;
+ if (!Arg->getType()->isPointerTy())
+ continue;
+ unsigned CS1ArgIdx = std::distance(CS1.arg_begin(), I);
+ auto CS1ArgLoc = MemoryLocation::getForArgument(CS1, CS1ArgIdx, TLI);
+
+ // ArgMask indicates what CS1 might do to CS1ArgLoc; if CS1 might Mod
+ // CS1ArgLoc, then we care about either a Mod or a Ref by CS2. If CS1
+ // might Ref, then we care only about a Mod by CS2.
+ ModRefInfo ArgMask = getBestAAResults().getArgModRefInfo(CS1, CS1ArgIdx);
+ ModRefInfo ArgR = getBestAAResults().getModRefInfo(CS2, CS1ArgLoc);
+ if (((ArgMask & MRI_Mod) != MRI_NoModRef &&
+ (ArgR & MRI_ModRef) != MRI_NoModRef) ||
+ ((ArgMask & MRI_Ref) != MRI_NoModRef &&
+ (ArgR & MRI_Mod) != MRI_NoModRef))
+ R = ModRefInfo((R | ArgMask) & Mask);
+
+ if (R == Mask)
+ break;
+ }
+ }
+ return R;
+ }
+
+ return Mask;
+}
+
/// isNoAliasCall - Return true if this pointer is returned by a noalias
/// 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)
///
bool isIdentifiedObject(const Value *V);
-/// isKnownNonNull - Return true if this pointer couldn't possibly be null by
-/// its definition. This returns true for allocas, non-extern-weak globals and
-/// byval arguments.
-bool isKnownNonNull(const Value *V);
+/// 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);
+
+/// A manager for alias analyses.
+///
+/// This class can have analyses registered with it and when run, it will run
+/// all of them and aggregate their results into single AA results interface
+/// that dispatches across all of the alias analysis results available.
+///
+/// Note that the order in which analyses are registered is very significant.
+/// That is the order in which the results will be aggregated and queried.
+///
+/// This manager effectively wraps the AnalysisManager for registering alias
+/// analyses. When you register your alias analysis with this manager, it will
+/// ensure the analysis itself is registered with its AnalysisManager.
+class AAManager {
+public:
+ typedef AAResults Result;
+
+ // This type hase value semantics. We have to spell these out because MSVC
+ // won't synthesize them.
+ AAManager() {}
+ AAManager(AAManager &&Arg)
+ : FunctionResultGetters(std::move(Arg.FunctionResultGetters)) {}
+ AAManager(const AAManager &Arg)
+ : FunctionResultGetters(Arg.FunctionResultGetters) {}
+ AAManager &operator=(AAManager &&RHS) {
+ FunctionResultGetters = std::move(RHS.FunctionResultGetters);
+ return *this;
+ }
+ AAManager &operator=(const AAManager &RHS) {
+ FunctionResultGetters = RHS.FunctionResultGetters;
+ return *this;
+ }
+
+ /// Register a specific AA result.
+ template <typename AnalysisT> void registerFunctionAnalysis() {
+ FunctionResultGetters.push_back(&getFunctionAAResultImpl<AnalysisT>);
+ }
+
+ Result run(Function &F, AnalysisManager<Function> &AM) {
+ Result R;
+ for (auto &Getter : FunctionResultGetters)
+ (*Getter)(F, AM, R);
+ return R;
+ }
+
+private:
+ SmallVector<void (*)(Function &F, AnalysisManager<Function> &AM,
+ AAResults &AAResults),
+ 4> FunctionResultGetters;
+
+ template <typename AnalysisT>
+ static void getFunctionAAResultImpl(Function &F,
+ AnalysisManager<Function> &AM,
+ AAResults &AAResults) {
+ AAResults.addAAResult(AM.template getResult<AnalysisT>(F));
+ }
+};
+
+/// A wrapper pass to provide the legacy pass manager access to a suitably
+/// prepared AAResults object.
+class AAResultsWrapperPass : public FunctionPass {
+ std::unique_ptr<AAResults> AAR;
+
+public:
+ static char ID;
+
+ AAResultsWrapperPass();
+
+ AAResults &getAAResults() { return *AAR; }
+ const AAResults &getAAResults() const { return *AAR; }
+
+ bool runOnFunction(Function &F) override;
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override;
+};
+
+FunctionPass *createAAResultsWrapperPass();
+
+/// A wrapper pass around a callback which can be used to populate the
+/// AAResults in the AAResultsWrapperPass from an external AA.
+///
+/// The callback provided here will be used each time we prepare an AAResults
+/// object, and will receive a reference to the function wrapper pass, the
+/// function, and the AAResults object to populate. This should be used when
+/// setting up a custom pass pipeline to inject a hook into the AA results.
+ImmutablePass *createExternalAAWrapperPass(
+ std::function<void(Pass &, Function &, AAResults &)> Callback);
+
+/// A helper for the legacy pass manager to create a \c AAResults
+/// object populated to the best of our ability for a particular function when
+/// inside of a \c ModulePass or a \c CallGraphSCCPass.
+AAResults createLegacyPMAAResults(Pass &P, Function &F, BasicAAResult &BAR);
} // End llvm namespace
projects / oota-llvm.git / blobdiff