terminal/oss/libpopcnt/LICENSE

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Update til::bitmap to use dynamic_bitset<> + libpopcnt (#5092) This commit replaces `std::vector<bool>` with `dynamic_bitset<>` by @pinam45 (https://github.com/pinam45/dynamic_bitset) and with `libpopcnt` for high-performance bit counting by @kimwalisch (https://github.com/kimwalisch/libpopcnt). * [x] In support of performance, incremental rendering, and Terminal "not speed enough" as well as my sanity relative to `std::vector<bool>` * [x] Tests updated and passed. * [x] `LICENSE`, `NOTICE`, and provenance files updated. * [x] I'm a core contributor. I discussed it with @DHowett-MSFT and cleared the licensing checks before pulling this in. ## Details `std::vector<bool>` provided by the Microsoft VC Runtime is incapable of a great many things. Many of the methods you come to expect off of `std::vector<T>` that are dutifully presented through the `bool` variant will spontaneously fail at some future date because it decides you allocated, resized, or manipulated the `vector<bool>` specialization in an unsupported manner. Half of the methods will straight up not work for filling/resizing in bulk. And you will tear your hair out as it will somehow magically forget the assignment of half the bits you gave it part way through an iteration then assert out and die. As such, to preserve my sanity, I searched for an alternative. I came across the self-contained header-only library `dynamic_bitset` by @pinam45 which appears to do as much of `boost::dynamic_bitset` as I wanted, but without including 400kg of boost libraries. It also has a nifty optional dependency on `libpopcnt` by @kimwalisch that will use processor-specific extensions for rapidly counting bits. @DHowett-MSFT and I briefly discussed how nice `popcnt` would have been on `std::vector<bool>` last week... and now we can have it. (To be fair, I don't believe I'm using it yet... but we'll be able to easily dial in `til::bitmap` soon and not worry about a performance hit if we do have to walk bits and count them thanks to `libpopcnt`.) This PR specifically focuses on swapping the dependencies out and ingesting the new libraries. We'll further tune `til::bitmap` in future pulls as necessary. ## Validation * [x] Ran the automated tests for bitmap. * [x] Ran the terminal manually and it looks fine still.
2020-03-25 03:41:10 +01:00
BSD 2-Clause License
Copyright (c) 2016 - 2019, Kim Walisch
Copyright (c) 2016 - 2019, Wojciech Muła
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