LLVM API Documentation
#include <AliasAnalysis.h>
Collaboration diagram for llvm::AliasAnalysis:
Definition at line 45 of file AliasAnalysis.h.
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.
Definition at line 82 of file AliasAnalysis.h.
ModRefResult - Represent the result of a mod/ref query. Mod and Ref are bits which may be or'd together.
Definition at line 113 of file AliasAnalysis.h.
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.
DoesNotAccessMemory | |
AccessesArguments | |
AccessesArgumentsAndGlobals | |
OnlyReadsMemory | |
UnknownModRefBehavior |
Definition at line 120 of file AliasAnalysis.h.
llvm::AliasAnalysis::AliasAnalysis | ( | ) | [inline] |
Definition at line 63 of file AliasAnalysis.h.
AliasAnalysis::~AliasAnalysis | ( | ) | [virtual] |
Definition at line 141 of file AliasAnalysis.cpp.
void AliasAnalysis::InitializeAliasAnalysis | ( | Pass * | P | ) | [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.
Definition at line 146 of file AliasAnalysis.cpp.
References AA, llvm::Pass::getAnalysis(), and TD.
void AliasAnalysis::getAnalysisUsage | ( | AnalysisUsage & | AU | ) | const [protected, virtual] |
const TargetData& llvm::AliasAnalysis::getTargetData | ( | ) | const [inline] |
getTargetData - Every alias analysis implementation depends on the size of data items in the current Target. This provides a uniform way to handle it.
Definition at line 70 of file AliasAnalysis.h.
References TD.
Referenced by llvm::AliasSetTracker::add(), and llvm::AliasSetTracker::remove().
AliasAnalysis::AliasResult AliasAnalysis::alias | ( | const Value * | V1, | |
unsigned | V1Size, | |||
const Value * | V2, | |||
unsigned | V2Size | |||
) | [virtual] |
alias - The main low level interface to the alias analysis implementation. Returns a Result indicating whether the two pointers are aliased to each other. This is the interface that must be implemented by specific alias analysis implementations.
Definition at line 46 of file AliasAnalysis.cpp.
Referenced by alias(), getModRefInfo(), and llvm::AliasSet::mergeSetIn().
getMustAliases - If there are any pointers known that must alias this pointer, return them now. This allows alias-set based alias analyses to perform a form a value numbering (which is exposed by load-vn). If an alias analysis supports this, it should ADD any must aliased pointers to the specified vector.
Definition at line 52 of file AliasAnalysis.cpp.
References AA, and getMustAliases().
Referenced by getMustAliases().
bool AliasAnalysis::pointsToConstantMemory | ( | const Value * | P | ) | [virtual] |
pointsToConstantMemory - If the specified pointer is known to point into constant global memory, return true. This allows disambiguation of store instructions from constant pointers.
Definition at line 57 of file AliasAnalysis.cpp.
References AA, and pointsToConstantMemory().
Referenced by getModRefInfo(), and pointsToConstantMemory().
AliasAnalysis::ModRefBehavior AliasAnalysis::getModRefBehavior | ( | Function * | F, | |
CallSite | CS, | |||
std::vector< PointerAccessInfo > * | Info = 0 | |||
) | [virtual] |
getModRefBehavior - Return the behavior of the specified function if called from the specified call site. The call site may be null in which case the most generic behavior of this function should be returned.
Definition at line 63 of file AliasAnalysis.cpp.
References AA, F, and getModRefBehavior().
Referenced by doesNotAccessMemory(), getModRefBehavior(), getModRefInfo(), and onlyReadsMemory().
bool llvm::AliasAnalysis::doesNotAccessMemory | ( | Function * | F | ) | [inline] |
doesNotAccessMemory - If the specified function is known to never read or write memory, return true. If the function only reads from known-constant memory, it is also legal to return true. Functions that unwind the stack are not legal for this predicate.
Many optimizations (such as CSE and LICM) can be performed on calls to it, without worrying about aliasing properties, and many functions have this property (e.g. 'sin' and 'cos').
This property corresponds to the GCC 'const' attribute.
Definition at line 204 of file AliasAnalysis.h.
References DoesNotAccessMemory, F, and getModRefBehavior().
Referenced by llvm::AliasSetTracker::add(), llvm::AliasSetTracker::deleteValue(), and llvm::AliasSetTracker::remove().
bool llvm::AliasAnalysis::onlyReadsMemory | ( | Function * | F | ) | [inline] |
onlyReadsMemory - If the specified function is known to only read from non-volatile memory (or not access memory at all), return true. Functions that unwind the stack are not 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.
FIXME: If the analysis returns more precise info, we can reduce it to this.
Definition at line 217 of file AliasAnalysis.h.
References DoesNotAccessMemory, F, getModRefBehavior(), and OnlyReadsMemory.
AliasAnalysis::ModRefResult AliasAnalysis::getModRefInfo | ( | CallSite | CS, | |
Value * | P, | |||
unsigned | Size | |||
) | [virtual] |
getModRefInfo (for call sites) - Return whether information about whether a particular call site modifies or reads the memory specified by the pointer.
Definition at line 116 of file AliasAnalysis.cpp.
References AA, DoesNotAccessMemory, F, llvm::CallSite::getCalledFunction(), getModRefBehavior(), getModRefInfo(), Mod, ModRef, NoModRef, OnlyReadsMemory, pointsToConstantMemory(), and Ref.
Referenced by canInstructionRangeModify(), and getModRefInfo().
AliasAnalysis::ModRefResult AliasAnalysis::getModRefInfo | ( | CallSite | CS1, | |
CallSite | CS2 | |||
) | [virtual] |
getModRefInfo - Return information about whether two call sites may refer to the same set of memory locations. This function returns NoModRef if the two calls refer to disjoint memory locations, Ref if CS1 reads memory written by CS2, Mod if CS1 writes to memory read or written by CS2, or ModRef if CS1 might read or write memory accessed by CS2.
Definition at line 85 of file AliasAnalysis.cpp.
References AA, and getModRefInfo().
bool AliasAnalysis::hasNoModRefInfoForCalls | ( | ) | const [virtual] |
hasNoModRefInfoForCalls - Return true if the analysis has no mod/ref information for pairs of function calls (other than "pure" and "const" functions). This can be used by clients to avoid many pointless queries. Remember that if you override this and chain to another analysis, you must make sure that it doesn't have mod/ref info either.
Definition at line 69 of file AliasAnalysis.cpp.
References AA, and hasNoModRefInfoForCalls().
Referenced by hasNoModRefInfoForCalls().
AliasAnalysis::ModRefResult AliasAnalysis::getModRefInfo | ( | LoadInst * | L, | |
Value * | P, | |||
unsigned | Size | |||
) |
Convenience functions...
Definition at line 97 of file AliasAnalysis.cpp.
References alias(), llvm::UnaryInstruction::getOperand(), llvm::Value::getType(), llvm::TargetData::getTypeSize(), NoModRef, Ref, and TD.
AliasAnalysis::ModRefResult AliasAnalysis::getModRefInfo | ( | StoreInst * | S, | |
Value * | P, | |||
unsigned | Size | |||
) |
Definition at line 103 of file AliasAnalysis.cpp.
References alias(), llvm::StoreInst::getOperand(), llvm::Value::getType(), llvm::TargetData::getTypeSize(), Mod, NoModRef, pointsToConstantMemory(), and TD.
ModRefResult llvm::AliasAnalysis::getModRefInfo | ( | CallInst * | C, | |
Value * | P, | |||
unsigned | Size | |||
) | [inline] |
ModRefResult llvm::AliasAnalysis::getModRefInfo | ( | InvokeInst * | I, | |
Value * | P, | |||
unsigned | Size | |||
) | [inline] |
ModRefResult llvm::AliasAnalysis::getModRefInfo | ( | VAArgInst * | I, | |
Value * | P, | |||
unsigned | Size | |||
) | [inline] |
ModRefResult llvm::AliasAnalysis::getModRefInfo | ( | Instruction * | I, | |
Value * | P, | |||
unsigned | Size | |||
) | [inline] |
Definition at line 263 of file AliasAnalysis.h.
References llvm::Instruction::Call, getModRefInfo(), llvm::Instruction::getOpcode(), llvm::Instruction::Load, NoModRef, llvm::SPII::Store, and llvm::Instruction::VAArg.
bool AliasAnalysis::canBasicBlockModify | ( | const BasicBlock & | BB, | |
const Value * | P, | |||
unsigned | Size | |||
) |
canBasicBlockModify - Return true if it is possible for execution of the specified basic block to modify the value pointed to by Ptr.
Definition at line 162 of file AliasAnalysis.cpp.
References llvm::BasicBlock::back(), BB, canInstructionRangeModify(), and llvm::BasicBlock::front().
Referenced by isPathTransparentTo().
bool AliasAnalysis::canInstructionRangeModify | ( | const Instruction & | I1, | |
const Instruction & | I2, | |||
const Value * | Ptr, | |||
unsigned | 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.
Definition at line 172 of file AliasAnalysis.cpp.
References E, getModRefInfo(), llvm::Instruction::getParent(), and Mod.
Referenced by canBasicBlockModify().
void AliasAnalysis::deleteValue | ( | Value * | V | ) | [virtual] |
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.
Definition at line 74 of file AliasAnalysis.cpp.
References AA, deleteValue(), and V.
Referenced by llvm::AliasSetTracker::deleteValue(), deleteValue(), FindPHIToPartitionLoops(), and replaceWithNewValue().
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.
Definition at line 79 of file AliasAnalysis.cpp.
References AA, and copyValue().
Referenced by llvm::AliasSetTracker::copyValue(), copyValue(), and replaceWithNewValue().
replaceWithNewValue - This method is the obvious combination of the two above, and it provided as a helper to simplify client code.
Definition at line 315 of file AliasAnalysis.h.
References copyValue(), and deleteValue().
const TargetData* llvm::AliasAnalysis::TD [protected] |
Definition at line 47 of file AliasAnalysis.h.
Referenced by getModRefInfo(), getTargetData(), and InitializeAliasAnalysis().
AliasAnalysis* llvm::AliasAnalysis::AA [protected] |
Definition at line 48 of file AliasAnalysis.h.
Referenced by alias(), copyValue(), deleteValue(), getModRefBehavior(), getModRefInfo(), getMustAliases(), hasNoModRefInfoForCalls(), InitializeAliasAnalysis(), and pointsToConstantMemory().