`BitSet` related perf improvements
This commit makes two changes:
1. Changes `MaybeLiveLocals` to use `ChunkedBitSet`
2. Overrides the `fold` method for the iterator for `ChunkedBitSet`
I have local benchmarks verifying that each of these changes individually yield significant perf improvements to #96451 . I'm hoping this will be true outside of that context too. If that is not the case, I'll try to gate things on where they help as needed
r? `@nnethercote` who I believe was working on closely related things, cc `@tmiasko` because of the destprop pr
Move `finish` out of the `Encoder` trait.
This simplifies things, but requires making `CacheEncoder` non-generic.
(This was previously merged as commit 4 in #94732 and then was reverted
in #97905 because it caused a perf regression.)
r? `@ghost`
This is an experimental patch to try to reduce the codegen complexity of
TokenStream's FromIterator and Extend implementations for downstream
crates, by moving the core logic into a helper type. This might help
improve build performance of crates which depend on proc_macro as
iterators are used less, and the compiler may take less time to do
things like attempt specializations or other iterator optimizations.
The change intentionally sacrifices some optimization opportunities,
such as using the specializations for collecting iterators derived from
Vec::into_iter() into Vec.
This is one of the simpler potential approaches to reducing the amount
of code generated in crates depending on proc_macro, so it seems worth
trying before other more-involved changes.
This significantly reduces the cost of common interactions with TokenStream
when running with the CrossThread execution strategy, by reducing the number of
RPC calls required.
Rollup of 5 pull requests
Successful merges:
- #97377 (Do not suggest adding semicolon/changing delimiters for macros in item position that originates in macros)
- #97675 (Make `std::mem::needs_drop` accept `?Sized`)
- #98118 (Test NLL fix of bad lifetime inference for reference captured in closure.)
- #98166 (Add rustdoc-json regression test for #98009)
- #98169 (Keyword docs: Link to wikipedia article for dynamic dispatch)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Make `std::mem::needs_drop` accept `?Sized`
This change attempts to make `needs_drop` work with types like `[u8]` and `str`.
This enables code in types like `Arc<T>` that was not possible before, such as https://github.com/rust-lang/rust/pull/97676.
Compile `unicode-normalization` faster
Various optimizations and cleanups aimed at improving compilation of `unicode-normalization`, which is notable for having several very large `match`es with many char ranges.
Best reviewed one commit at a time.
r? `@oli-obk`
Big const allocations hash a large amount of data for interning:
the whole bytes buffer, and the 1/8th sized initmask, with FxHash.
This hash function is made for shorter keys.
This only hashes the length, and head and tail of these buffers, to
limit possible collisions while avoiding most of the hashing work.
Previously we only show at most 6 lines of suggestions and, if the
suggestions are more than 6 lines apart, we've just showed ... at the
end. This is probably fine, but quite confusing in my opinion.
This commit is an attempt to show ... in places where there is nothing
to suggest instead, for example:
Before:
```text
help: consider enclosing expression in a block
|
3 ~ 'l: { match () { () => break 'l,
4 |
5 |
6 |
7 |
8 |
...
```
After:
```text
help: consider enclosing expression in a block
|
3 ~ 'l: { match () { () => break 'l,
4 |
...
31|
32~ } };
|
```
Support lint expectations for `--force-warn` lints (RFC 2383)
Rustc has a `--force-warn` flag, which overrides lint level attributes and forces the diagnostics to always be warn. This means, that for lint expectations, the diagnostic can't be suppressed as usual. This also means that the expectation would not be fulfilled, even if a lint had been triggered in the expected scope.
This PR now also tracks the expectation ID in the `ForceWarn` level. I've also made some minor adjustments, to possibly catch more bugs and make the whole implementation more robust.
This will probably conflict with https://github.com/rust-lang/rust/pull/97718. That PR should ideally be reviewed and merged first. The conflict itself will be trivial to fix.
---
r? `@wesleywiser`
cc: `@flip1995` since you've helped with the initial review and also discussed this topic with me. 🙃
Follow-up of: https://github.com/rust-lang/rust/pull/87835
Issue: https://github.com/rust-lang/rust/issues/85549
Yeah, and that's it.
This simplifies things, but requires making `CacheEncoder` non-generic.
(This was previously merged as commit 4 in #94732 and then was reverted
in #97905 because it caused a perf regression.)
This commit removes the `a == b` early return, which isn't useful in
practice, and replaces it with one that helps matches with many ranges,
including char ranges.
The code is clearer and simpler without it. Note that the `a == b` early
return at the top of the function means the `a == b` test at the end of
the function could never succeed.
It's never executed when running the entire test suite. I think it's
because of the early return at the top of the function if `a.ty() != ty`
succeeds.
This is a performance win for `unicode-normalization`.
The commit also removes the closure, which isn't necessary. And
reformulates the comparison into a form I find easier to read.
