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

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

Definition at line 55 of file MemorySSAUpdater.h.

◆ applyInsertUpdates()

◆ applyUpdates()

Apply CFG updates, analogous with the DT edge updates.

By default, the DT is assumed to be already up to date. If UpdateDTFirst is true, first update the DT with the same updates.

Definition at line 784 of file MemorySSAUpdater.cpp.

References applyInsertUpdates(), llvm::DominatorTreeBase< NodeT, IsPostDom >::applyUpdates(), llvm::DominatorTreeBase< NodeT, IsPostDom >::Delete, DenseMapInfo< LocallyHashedType >::Empty, llvm::SmallVectorTemplateCommon< T, typename >::empty(), llvm::DominatorTreeBase< NodeT, IsPostDom >::Insert, llvm::SmallVectorTemplateBase< T, bool >::push_back(), and removeEdge().

Referenced by injectPendingInvariantConditions(), llvm::splitBlockBefore(), and unswitchTrivialSwitch().

◆ changeToUnreachable()

◆ createMemoryAccessAfter()

◆ createMemoryAccessBefore()

◆ createMemoryAccessInBB()

Create a MemoryAccess in MemorySSA at a specified point in a block.

When used by itself, this method will only insert the new MemoryAccess into the access list, but not make any other changes, such as inserting MemoryPHI nodes, or updating users to point to the new MemoryAccess. You must specify a correct Definition in this case.

Usually, this API is instead combined with insertUse() or insertDef(), which will perform all the necessary MSSA updates. If these APIs are used, then nullptr can be used as Definition, as the correct defining access will be automatically determined.

Note: If a MemoryAccess already exists for I, this function will make it inaccessible and it must have removeMemoryAccess called on it.

Definition at line 1410 of file MemorySSAUpdater.cpp.

References I.

Referenced by buildPartialInvariantUnswitchConditionalBranch(), cloneInstructionInExitBlock(), llvm::promoteLoopAccessesToScalars(), and sinkInstruction().

◆ getMemorySSA()

Get handle on MemorySSA.

Definition at line 243 of file MemorySSAUpdater.h.

Referenced by buildPartialInvariantUnswitchConditionalBranch(), llvm::canSinkOrHoistInst(), cloneInstructionInExitBlock(), collectUnswitchCandidates(), llvm::hoistRegion(), injectPendingInvariantConditions(), isOnlyMemoryAccess(), llvm::Loop::makeLoopInvariant(), llvm::MergeBlockIntoPredecessor(), mergeBlocksIntoPredecessors(), moveInstructionBefore(), llvm::promoteLoopAccessesToScalars(), simplifyLoopInst(), simplifyOneLoop(), sinkInstruction(), llvm::sinkRegion(), llvm::splitBlockBefore(), turnGuardIntoBranch(), turnSelectIntoBranch(), unswitchAllTrivialConditions(), unswitchNontrivialInvariants(), unswitchTrivialBranch(), and unswitchTrivialSwitch().

◆ insertDef()

Insert a definition into the MemorySSA IR.

RenameUses will rename any use below the new def block (and any inserted phis). RenameUses should be set to true if the definition may cause new aliases for loads below it. This is not the case for hoisting or sinking or other forms of code movement. It is the case for straight code insertion. For example: store a if (foo) { } load a

Moving the store into the if block, and calling insertDef, does not require RenameUses. However, changing it to: store a if (foo) { store b } load a Where a mayalias b, does require RenameUses be set to true.

Definition at line 307 of file MemorySSAUpdater.cpp.

References assert(), llvm::IDFCalculatorBase< NodeTy, IsPostDom >::calculate(), llvm::cast_or_null(), llvm::dyn_cast(), llvm::dyn_cast_or_null(), llvm::MemoryAccess::getBlock(), llvm::MemoryUseOrDef::getDefiningAccess(), llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::SmallSet< T, N, C >::insert(), llvm::is_contained(), llvm::isa(), llvm::predecessors(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::Value::replaceUsesWithIf(), llvm::MemoryUseOrDef::setDefiningAccess(), llvm::IDFCalculatorBase< NodeTy, IsPostDom >::setDefiningBlocks(), and llvm::SmallSet< T, N, C >::size().

Referenced by cloneInstructionInExitBlock(), and sinkInstruction().

◆ insertUse()

◆ moveAfter()

◆ moveAllAfterMergeBlocks()

From block was merged into To.

There is a CFG edge from To to From.To still branches to From, but all instructions were moved and From is now an empty block; From is about to be deleted. Move all accesses from From to To starting at instruction Start. To may have multiple successors, From has a single predecessor. From may have successors with MPhi nodes, replace their incoming block with To. |---—| |---—|

\/ | | |---—| | | <- Start | From | | | |---—| |---—|

Definition at line 1239 of file MemorySSAUpdater.cpp.

References assert(), llvm::BasicBlock::getUniquePredecessor(), and llvm::successors().

Referenced by llvm::MergeBlockIntoPredecessor().

◆ moveAllAfterSpliceBlocks()

From block was spliced into From and To.

There is a CFG edge from From to To. Move all accesses from From to To starting at instruction Start. To is newly created BB, so empty of MemorySSA::MemoryAccesses. Edges are already updated, so successors of To with MPhi nodes need to update incoming block. |---—| |---—|

| | => \/ | | |---—| <- Start | | | To | |---—| |---—|

Definition at line 1228 of file MemorySSAUpdater.cpp.

References assert(), and llvm::successors().

Referenced by SplitBlockImpl(), turnGuardIntoBranch(), and turnSelectIntoBranch().

◆ moveBefore()

◆ moveToPlace()

◆ removeBlocks()

Remove all MemoryAcceses in a set of BasicBlocks about to be deleted.

Assumption we make here: all uses of deleted defs and phi must either occur in blocks about to be deleted (thus will be deleted as well), or they occur in phis that will simply lose an incoming value. Deleted blocks still have successor info, but their predecessor edges and Phi nodes may already be updated. Instructions in DeadBlocks should be deleted after this call.

Definition at line 1353 of file MemorySSAUpdater.cpp.

References assert(), llvm::SetVector< T, Vector, Set, N >::count(), llvm::User::dropAllReferences(), llvm::BasicBlock::getTerminator(), llvm::make_early_inc_range(), and llvm::successors().

Referenced by deleteDeadBlocksFromLoop(), deleteDeadClonedBlocks(), llvm::removeUnreachableBlocks(), and simplifyOneLoop().

◆ removeDuplicatePhiEdgesBetween()

◆ removeEdge()

◆ removeMemoryAccess() [1/2]

◆ removeMemoryAccess() [2/2]

Remove a MemoryAccess from MemorySSA, including updating all definitions and uses.

This should be called when a memory instruction that has a MemoryAccess associated with it is erased from the program. For example, if a store or load is simply erased (not replaced), removeMemoryAccess should be called on the MemoryAccess for that store/load.

Definition at line 1286 of file MemorySSAUpdater.cpp.

References assert(), llvm::SetVector< T, Vector, Set, N >::begin(), llvm::cast(), llvm::cast_or_null(), llvm::SetVector< T, Vector, Set, N >::clear(), llvm::dyn_cast(), llvm::SetVector< T, Vector, Set, N >::empty(), llvm::SetVector< T, Vector, Set, N >::end(), llvm::Value::hasValueHandle(), llvm::SetVector< T, Vector, Set, N >::insert(), llvm::isa(), onlySingleValue(), llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateCommon< T, typename >::size(), llvm::Value::use_begin(), llvm::Value::use_empty(), and llvm::ValueHandleBase::ValueIsRAUWd().

Referenced by changeToUnreachable(), eliminateGuard(), eraseInstruction(), llvm::RecursivelyDeleteTriviallyDeadInstructions(), removeMemoryAccess(), and updateForClonedLoop().

◆ updateExitBlocksForClonedLoop() [1/2]

◆ updateExitBlocksForClonedLoop() [2/2]

◆ updateForClonedBlockIntoPred()

◆ updateForClonedLoop()

Update MemorySSA after a loop was cloned, given the blocks in RPO order, the exit blocks and a 1:1 mapping of all blocks and instructions cloned.

This involves duplicating all defs and uses in the cloned blocks Updating phi nodes in exit block successors is done separately.

Definition at line 660 of file MemorySSAUpdater.cpp.

References assert(), llvm::cast(), llvm::cast_or_null(), llvm::concat(), llvm::SetVector< T, Vector, Set, N >::contains(), llvm::SmallPtrSetImpl< PtrType >::count(), llvm::from_range, getNewDefiningAccessForClone(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::lookup(), llvm::ValueMap< KeyT, ValueT, Config >::lookup(), onlySingleValue(), llvm::predecessors(), ProcessBlock(), and removeMemoryAccess().

Referenced by unswitchNontrivialInvariants().

◆ updatePhisWhenInsertingUniqueBackedgeBlock()

◆ wireOldPredecessorsToNewImmediatePredecessor()

A new empty BasicBlock (New) now branches directly to Old.

Some of Old's predecessors (Preds) are now branching to New instead of Old. If New is the only predecessor, move Old's Phi, if present, to New. Otherwise, add a new Phi in New with appropriate incoming values, and update the incoming values in Old's Phi node too, if present.

Definition at line 1249 of file MemorySSAUpdater.cpp.

References llvm::MemoryPhi::addIncoming(), assert(), B(), llvm::MemorySSA::Beginning, llvm::SmallPtrSetImpl< PtrType >::count(), llvm::ArrayRef< T >::empty(), llvm::SmallPtrSetImpl< PtrType >::erase(), llvm::from_range, llvm::BasicBlock::hasNPredecessors(), llvm::pred_size(), llvm::ArrayRef< T >::size(), and llvm::SmallPtrSetImplBase::size().

Referenced by UpdateAnalysisInformation().

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

• include/llvm/Analysis/MemorySSAUpdater.h
• lib/Analysis/MemorySSAUpdater.cpp