LLVM: llvm::AAQueryInfo Class Reference (original) (raw)

This class stores info we want to provide to or retain within an alias query. More...

#include "[llvm/Analysis/AliasAnalysis.h](AliasAnalysis%5F8h%5Fsource.html)"

Public Attributes
AAResults & AAR
AliasCacheT AliasCache
CaptureAnalysis * CA
unsigned Depth = 0
Query depth used to distinguish recursive queries.
int NumAssumptionUses = 0
How many active NoAlias assumption uses there are.
SmallVector< AAQueryInfo::LocPair, 4 > AssumptionBasedResults
Location pairs for which an assumption based result is currently stored.
bool MayBeCrossIteration = false
Tracks whether the accesses may be on different cycle iterations.
bool UseDominatorTree = true
Whether alias analysis is allowed to use the dominator tree, for use by passes that lazily update the DT while performing AA queries.

This class stores info we want to provide to or retain within an alias query.

By default, the root query is stateless and starts with a freshly constructed info object. Specific alias analyses can use this query info to store per-query state that is important for recursive or nested queries to avoid recomputing. To enable preserving this state across multiple queries where safe (due to the IR not changing), use a BatchAAResults wrapper. The information stored in an AAQueryInfo is currently limitted to the caches used by BasicAA, but can further be extended to fit other AA needs.

Definition at line 242 of file AliasAnalysis.h.

◆ AliasCacheT

◆ LocPair

◆ AAR

◆ AliasCache

AliasCacheT llvm::AAQueryInfo::AliasCache

◆ AssumptionBasedResults

Location pairs for which an assumption based result is currently stored.

Used to remove all potentially incorrect results from the cache if an assumption is disproven.

Definition at line 283 of file AliasAnalysis.h.

◆ CA

◆ Depth

◆ MayBeCrossIteration

bool llvm::AAQueryInfo::MayBeCrossIteration = false

Tracks whether the accesses may be on different cycle iterations.

When interpret "Value" pointer equality as value equality we need to make sure that the "Value" is not part of a cycle. Otherwise, two uses could come from different "iterations" of a cycle and see different values for the same "Value" pointer.

The following example shows the problem: p = phi(alloca1, addr2) l = load ptr addr1 = gep, alloca2, 0, l addr2 = gep alloca2, 0, (l + 1) alias(p, addr1) -> MayAlias ! store l, ...

Definition at line 299 of file AliasAnalysis.h.

◆ NumAssumptionUses

int llvm::AAQueryInfo::NumAssumptionUses = 0

How many active NoAlias assumption uses there are.

Definition at line 278 of file AliasAnalysis.h.

◆ UseDominatorTree

bool llvm::AAQueryInfo::UseDominatorTree = true

Whether alias analysis is allowed to use the dominator tree, for use by passes that lazily update the DT while performing AA queries.

Definition at line 303 of file AliasAnalysis.h.

The documentation for this class was generated from the following file: