BitSlice fixes
#52335
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BitSlice fixes
#52335
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It has a single callsite, and duplicates some code from that callsite. The code is more concise and clearer this way.
Currently `Word` is `usize`, and there are various places in the code that assume this. This patch mostly just changes `usize` occurrences to `Word`. Most of the changes were found as compile errors when I changed `Word` to a type other than `usize`, but there was one non-obvious case in librustc_mir/dataflow/mod.rs that caused bounds check failures before I fixed it.
In multiple ways: - Two calls to `bits_to_string()` passed in byte lengths rather than bit lengths, which meant only 1/8th of the `BitSlice` was printed. - `bit_str`'s purpose is entirely mysterious. I removed it and changed its callers to print the indices in the obvious way. - `bits_to_string`'s inner loop was totally wrong, such that it printed entirely bogus results. - `bits_to_string` now also adds a '|' between words, which makes the output easier to read, e.g.: `[ff-ff-ff-ff-ff-ff-ff-ff|ff-ff-ff-ff-ff-ff-ff-07]`.
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Jul 17, 2018
`BitSlice` fixes `propagate_bits_into_entry_set_for` and `BitSlice::bitwise` are hot for some benchmarks under NLL. I tried and failed to speed them up. (Increasing the size of `bit_slice::Word` from `usize` to `u128` caused a slowdown, even though decreasing the size of `bitvec::Word` from `u128` to `u64` also caused a slowdown. Weird.) Anyway, along the way I fixed up several problems in and around the `BitSlice` code. r? @nikomatsakis
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☀️ Test successful - status-appveyor, status-travis |
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propagate_bits_into_entry_set_forandBitSlice::bitwiseare hot for some benchmarks under NLL. I tried and failed to speed them up. (Increasing the size ofbit_slice::Wordfromusizetou128caused a slowdown, even though decreasing the size ofbitvec::Wordfromu128tou64also caused a slowdown. Weird.)Anyway, along the way I fixed up several problems in and around the
BitSlicecode.r? @nikomatsakis