mirror of
https://github.com/rust-lang/rust.git
synced 2025-10-04 11:17:04 +00:00

A `ChunkedBitSet` has to be at least 2048 bits for it to outperform a `BitSet`, because that's the chunk size. The largest `SparseBitMatrix` encountered when compiling the compiler and the entire rustc-perf benchmark suite is less than 600 bits. This change is a tiny perf win, but the motivation is more about avoiding uses of `ChunkedBitSet` outside of `MixedBitSet`. The test change is necessary to avoid hitting the `<BitSet<T> as BitRelations<ChunkedBitSet<T>>>::subtract` method that has `unimplemented!` in its body and isn't otherwise used.