X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FAnalysis%2FLibCallSemantics.h;h=14ecb55f340b5a0b5d64db2534b7d69ede87e9d4;hb=2f675d1a1df1e785ba3a50f91346646ed221ec9b;hp=f5a9e96cbdd0d5830b48e7efef3c5d6f82a90769;hpb=94c22716d60ff5edf6a98a3c67e0faa001be1142;p=oota-llvm.git diff --git a/include/llvm/Analysis/LibCallSemantics.h b/include/llvm/Analysis/LibCallSemantics.h index f5a9e96cbdd..14ecb55f340 100644 --- a/include/llvm/Analysis/LibCallSemantics.h +++ b/include/llvm/Analysis/LibCallSemantics.h @@ -18,149 +18,66 @@ #include "llvm/Analysis/AliasAnalysis.h" namespace llvm { +class InvokeInst; - /// LibCallLocationInfo - This struct describes a set of memory locations that - /// are accessed by libcalls. Identification of a location is doing with a - /// simple callback function. - /// - /// For example, the LibCallInfo may be set up to model the behavior of - /// standard libm functions. The location that they may be interested in is - /// an abstract location that represents errno for the current target. In - /// this case, a location for errno is anything such that the predicate - /// returns true. On Mac OS/X, this predicate would return true if the - /// pointer is the result of a call to "__error()". - /// - /// Locations can also be defined in a constant-sensitive way. For example, - /// it is possible to define a location that returns true iff it is passed - /// into the call as a specific argument. This is useful for modeling things - /// like "printf", which can store to memory, but only through pointers passed - /// with a '%n' constraint. - /// - struct LibCallLocationInfo { - // TODO: Flags: isContextSensitive etc. - - /// isLocation - Return a LocResult if the specified pointer refers to this - /// location for the specified call site. This returns "Yes" if we can tell - /// that the pointer *does definitely* refer to the location, "No" if we can - /// tell that the location *definitely does not* refer to the location, and - /// returns "Unknown" if we cannot tell for certain. - enum LocResult { - Yes, No, Unknown - }; - LocResult (*isLocation)(ImmutableCallSite CS, - const AliasAnalysis::Location &Loc); + enum class EHPersonality { + Unknown, + GNU_Ada, + GNU_C, + GNU_CXX, + GNU_ObjC, + MSVC_X86SEH, + MSVC_Win64SEH, + MSVC_CXX, + CoreCLR }; - - /// LibCallFunctionInfo - Each record in the array of FunctionInfo structs - /// records the behavior of one libcall that is known by the optimizer. This - /// captures things like the side effects of the call. Side effects are - /// modeled both universally (in the readnone/readonly) sense, but also - /// potentially against a set of abstract locations defined by the optimizer. - /// This allows an optimizer to define that some libcall (e.g. sqrt) is - /// side-effect free except that it might modify errno (thus, the call is - /// *not* universally readonly). Or it might say that the side effects - /// are unknown other than to say that errno is not modified. - /// - struct LibCallFunctionInfo { - /// Name - This is the name of the libcall this describes. - const char *Name; - - /// TODO: Constant folding function: Constant* vector -> Constant*. - - /// UniversalBehavior - This captures the absolute mod/ref behavior without - /// any specific context knowledge. For example, if the function is known - /// to be readonly, this would be set to 'ref'. If known to be readnone, - /// this is set to NoModRef. - AliasAnalysis::ModRefResult UniversalBehavior; - - /// LocationMRInfo - This pair captures info about whether a specific - /// location is modified or referenced by a libcall. - struct LocationMRInfo { - /// LocationID - ID # of the accessed location or ~0U for array end. - unsigned LocationID; - /// MRInfo - Mod/Ref info for this location. - AliasAnalysis::ModRefResult MRInfo; - }; - - /// DetailsType - Indicate the sense of the LocationDetails array. This - /// controls how the LocationDetails array is interpreted. - enum { - /// DoesOnly - If DetailsType is set to DoesOnly, then we know that the - /// *only* mod/ref behavior of this function is captured by the - /// LocationDetails array. If we are trying to say that 'sqrt' can only - /// modify errno, we'd have the {errnoloc,mod} in the LocationDetails - /// array and have DetailsType set to DoesOnly. - DoesOnly, - - /// DoesNot - If DetailsType is set to DoesNot, then the sense of the - /// LocationDetails array is completely inverted. This means that we *do - /// not* know everything about the side effects of this libcall, but we do - /// know things that the libcall cannot do. This is useful for complex - /// functions like 'ctime' which have crazy mod/ref behavior, but are - /// known to never read or write errno. In this case, we'd have - /// {errnoloc,modref} in the LocationDetails array and DetailsType would - /// be set to DoesNot, indicating that ctime does not read or write the - /// errno location. - DoesNot - } DetailsType; - - /// LocationDetails - This is a pointer to an array of LocationMRInfo - /// structs which indicates the behavior of the libcall w.r.t. specific - /// locations. For example, if this libcall is known to only modify - /// 'errno', it would have a LocationDetails array with the errno ID and - /// 'mod' in it. See the DetailsType field for how this is interpreted. - /// - /// In the "DoesOnly" case, this information is 'may' information for: there - /// is no guarantee that the specified side effect actually does happen, - /// just that it could. In the "DoesNot" case, this is 'must not' info. - /// - /// If this pointer is null, no details are known. - /// - const LocationMRInfo *LocationDetails; - }; - - - /// LibCallInfo - Abstract interface to query about library call information. - /// Instances of this class return known information about some set of - /// libcalls. - /// - class LibCallInfo { - // Implementation details of this object, private. - mutable void *Impl; - mutable const LibCallLocationInfo *Locations; - mutable unsigned NumLocations; - public: - LibCallInfo() : Impl(0), Locations(0), NumLocations(0) {} - virtual ~LibCallInfo(); - - //===------------------------------------------------------------------===// - // Accessor Methods: Efficient access to contained data. - //===------------------------------------------------------------------===// - - /// getLocationInfo - Return information about the specified LocationID. - const LibCallLocationInfo &getLocationInfo(unsigned LocID) const; - - - /// getFunctionInfo - Return the LibCallFunctionInfo object corresponding to - /// the specified function if we have it. If not, return null. - const LibCallFunctionInfo *getFunctionInfo(const Function *F) const; - - - //===------------------------------------------------------------------===// - // Implementation Methods: Subclasses should implement these. - //===------------------------------------------------------------------===// - - /// getLocationInfo - Return descriptors for the locations referenced by - /// this set of libcalls. - virtual unsigned getLocationInfo(const LibCallLocationInfo *&Array) const { - return 0; + + /// \brief See if the given exception handling personality function is one + /// that we understand. If so, return a description of it; otherwise return + /// Unknown. + EHPersonality classifyEHPersonality(const Value *Pers); + + /// \brief Returns true if this personality function catches asynchronous + /// exceptions. + inline bool isAsynchronousEHPersonality(EHPersonality Pers) { + // The two SEH personality functions can catch asynch exceptions. We assume + // unknown personalities don't catch asynch exceptions. + switch (Pers) { + case EHPersonality::MSVC_X86SEH: + case EHPersonality::MSVC_Win64SEH: + return true; + default: return false; } - - /// getFunctionInfoArray - Return an array of descriptors that describe the - /// set of libcalls represented by this LibCallInfo object. This array is - /// terminated by an entry with a NULL name. - virtual const LibCallFunctionInfo *getFunctionInfoArray() const = 0; - }; + llvm_unreachable("invalid enum"); + } + + /// \brief Returns true if this is a personality function that invokes + /// handler funclets (which must return to it). + inline bool isFuncletEHPersonality(EHPersonality Pers) { + switch (Pers) { + case EHPersonality::MSVC_CXX: + case EHPersonality::MSVC_X86SEH: + case EHPersonality::MSVC_Win64SEH: + case EHPersonality::CoreCLR: + return true; + default: return false; + } + llvm_unreachable("invalid enum"); + } + + /// \brief Return true if this personality may be safely removed if there + /// are no invoke instructions remaining in the current function. + inline bool isNoOpWithoutInvoke(EHPersonality Pers) { + switch (Pers) { + case EHPersonality::Unknown: + return false; + // All known personalities currently have this behavior + default: return true; + } + llvm_unreachable("invalid enum"); + } + + bool canSimplifyInvokeNoUnwind(const Function *F); } // end namespace llvm