[PATCH] D43073: [CodeGen] Optimize AccelTable

[Pavel Labath via Phabricator via llvm-commits]

labath added inline comments.


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Comment at: llvm/trunk/include/llvm/CodeGen/AccelTable.h:239
 
-  std::vector<HashData *> Data;
-
-  using StringEntries = StringMap<DataArray, BumpPtrAllocator &>;
+  using StringEntries = StringMap<HashData, BumpPtrAllocator &>;
   StringEntries Entries;
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I see one more (and possibly bigger) improvement that we can make here:
This string map will store a copy of the string from the HashData structure (along with it's hash, which it will need to recompute). However, HashData already contains a hash *and* the string, which has even been uniqued by the dwarf string pool.

So, we could store the HashData in a DenseMap (with a custom DenseMapInfo) and save both space (no string copies) and time (efficient equality comparison).

The only additional requirement here would be that all the `DwarfStringPoolEntryRef`s come from a single string pool. As far as I can tell, this is already the case (and I can't imagine why one would do it differently), but I don't see a way to enforce that in code.

WDYT?


Repository:
  rL LLVM

https://reviews.llvm.org/D43073