[llvm-branch-commits] [llvm] [GVN] More restructuring of `GVN.h` to reduce its size (NFC) (PR #211541)

[Momchil Velikov via llvm-branch-commits]

================
@@ -123,197 +123,25 @@ struct GVNOptions {
 ///
 /// FIXME: We should have a good summary of the GVN algorithm implemented by
 /// this particular pass here.
+class GVNPassImpl;
 class GVNPass : public OptionalPassInfoMixin<GVNPass> {
-public:
-  struct AvailableValue;
-  struct AvailableValueInBlock;
-  struct ReachingMemVal;
-  struct DependencyBlockInfo;
-
-  friend class GVNValueTable;
-  friend class GVNLegacyPass;
-
-private:
-  GVNOptions Options;
-  MemoryDependenceResults *MD = nullptr;
-  DominatorTree *DT = nullptr;
-  const TargetLibraryInfo *TLI = nullptr;
-  AssumptionCache *AC = nullptr;
-  SetVector<BasicBlock *> DeadBlocks;
-  OptimizationRemarkEmitter *ORE = nullptr;
-  ImplicitControlFlowTracking *ICF = nullptr;
-  LoopInfo *LI = nullptr;
-  AAResults *AA = nullptr;
-  MemorySSAUpdater *MSSAU = nullptr;
-  GVNValueTable VN;
-  GVNLeaderMap LeaderTable;
-
-  // Map the block to reversed postorder traversal number. It is used to
-  // find back edge easily.
-  DenseMap<AssertingVH<BasicBlock>, uint32_t> BlockRPONumber;
-
-  // This is set 'true' initially and also when new blocks have been added to
-  // the function being analyzed. This boolean is used to control the updating
-  // of BlockRPONumber prior to accessing the contents of BlockRPONumber.
-  bool InvalidBlockRPONumbers = true;
-
-  // List of critical edges to be split between iterations.
-  SmallVector<std::pair<Instruction *, unsigned>, 4> ToSplit;
+  std::unique_ptr<GVNPassImpl> Impl;
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momchil-velikov wrote:

It can. But then it will destroy it. So this here is trading a little indirection for  construction/destruction of `GVNPassImpl` members like `VN`, `LeaderTable`, etc.

https://github.com/llvm/llvm-project/pull/211541