EqualBBWrapper Struct Reference

Checking whether two BBs are equal depends on the contents of the BasicBlock and the incoming values of their successor PHINodes. More...

Public Types
using	BB2ValueMap = SmallDenseMap<BasicBlock *, Value *, 8>
using	Phi2IVsMap = DenseMap<PHINode *, BB2ValueMap>

Static Public Member Functions
static bool	canBeMerged (const BasicBlock *BB)

Public Attributes
BasicBlock *	BB
Phi2IVsMap *	PhiPredIVs

Detailed Description

Checking whether two BBs are equal depends on the contents of the BasicBlock and the incoming values of their successor PHINodes.

PHINode::getIncomingValueForBlock is O(|Preds|), so we'd like to avoid calling this function on each BasicBlock every time isEqual is called, especially since the same BasicBlock may be passed as an argument multiple times. To do this, we can precompute a map of PHINode -> Pred BasicBlock -> IncomingValue and add it in the Wrapper so isEqual can do O(1) checking of the incoming values.

Definition at line 7999 of file SimplifyCFG.cpp.

Member Typedef Documentation

BB2ValueMap

using EqualBBWrapper::BB2ValueMap = SmallDenseMap<BasicBlock *, Value *, 8>

Definition at line 8003 of file SimplifyCFG.cpp.

Phi2IVsMap

using EqualBBWrapper::Phi2IVsMap = DenseMap<PHINode *, BB2ValueMap>

Definition at line 8004 of file SimplifyCFG.cpp.

Member Function Documentation

canBeMerged()

bool EqualBBWrapper::canBeMerged ( const BasicBlock * BB )

inlinestatic

Definition at line 8010 of file SimplifyCFG.cpp.

References assert(), BB, llvm::dyn_cast(), llvm::BranchInst::isUnconditional(), and llvm::pred_empty().

Member Data Documentation

BB

BasicBlock* EqualBBWrapper::BB

Definition at line 8000 of file SimplifyCFG.cpp.

Referenced by canBeMerged(), and llvm::DenseMapInfo< const EqualBBWrapper * >::getHashValue().

PhiPredIVs

Phi2IVsMap* EqualBBWrapper::PhiPredIVs

Definition at line 8005 of file SimplifyCFG.cpp.

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

• lib/Transforms/Utils/SimplifyCFG.cpp