Duncan P. N. Exon Smith 203cbe7f6f AsmPrinter: Document why DIEValueList uses a linked-list, NFC ... There are two main reasons why a linked-list makes sense for `DIEValueList`. 1. We want `DIE` to be on a `BumpPtrAllocator` to improve teardown efficiency. Making `DIEValueList` array-based would make that much more complicated. 2. The singly-linked list is fairly memory efficient. The histogram [1] shows that most DIEs have relatively few values, so we often pay less than the 2/3-pointer static overhead of a vector. Furthermore, we don't know ahead of time exactly how many values a `DIE` needs, so a vector-like scheme will on average over-allocate by ~50%. As it happens, that's the same memory overhead as the linked list node. [1]: http://lists.cs.uiuc.edu/pipermail/llvmdev/2015-May/085910.html The comment I added to the code is a little more succinct, but I think it's enough to give the idea. llvm-svn: 240868		2015-06-27 01:19:17 +00:00
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llvm	AsmPrinter: Document why DIEValueList uses a linked-list, NFC	2015-06-27 01:19:17 +00:00
llvm-c	Update LLVM bindings after r239940. Apparently these aren't included in	2015-06-18 11:51:16 +00:00