[PATCH] D74943: [GISel][KnownBits]{NFC} Add a cache mechanism to speed compile time

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


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Comment at: llvm/include/llvm/CodeGen/GlobalISel/GISelKnownBits.h:37
+  /// Cache maintained during a computeKnownBits request.
+  DenseMap<const MachineInstr *, KnownBits> ComputeKnownBitsCache;
 
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This assumes an instruction with a single def


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Comment at: llvm/lib/CodeGen/GlobalISel/GISelKnownBits.cpp:119
   unsigned BitWidth = DstTy.getSizeInBits();
+  auto CacheEntry = ComputeKnownBitsCache.find(&MI);
+  if (CacheEntry != ComputeKnownBitsCache.end()) {
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This should at least skip for instructions with multiple defs if not handle them


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D74943/new/

https://reviews.llvm.org/D74943