Reid Kleckner c175e28bde [PDB] Hash types up front when merging types instead of using StringMap ... Summary: First, StringMap uses llvm::HashString, which is only good for short identifiers and really bad for large blobs of binary data like type records. Moving to `DenseMap<StringRef, TypeIndex>` with some tricks for memory allocation fixes that. Unfortunately, that didn't buy very much performance. Profiling showed that we spend a long time during DenseMap growth rehashing existing entries. Also, in general, DenseMap is faster when the keys are small. This change takes that to the logical conclusion by introducing a small wrapper value type around a pointer to key data. The key data contains a precomputed hash, the original record data (pointer and size), and the type index, which is the "value" of our original map. This reduces the time to produce llvm-as.exe and llvm-as.pdb from ~15s on my machine to 3.5s, which is about a 4x improvement. Reviewers: zturner, inglorion, ruiu Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D33428 llvm-svn: 303665		2017-05-23 18:23:59 +00:00
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llvm	[PDB] Hash types up front when merging types instead of using StringMap	2017-05-23 18:23:59 +00:00
llvm-c	Introduce LLVMDIBuilderRef	2017-04-20 14:22:47 +00:00