traits: preallocate 2 Vecs of known initial size by ljedrz · Pull Request #69022 · rust-lang/rust

ljedrz · 2020-02-10T14:26:51Z

The 2 preallocations are pretty obvious; both vectors will be as big as or larger than the collections they are created from.

In WfPredicates::normalize the change from a functional style improves readability and should be perf-friendly, too.

rust-highfive · 2020-02-10T14:26:54Z

r? @petrochenkov

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petrochenkov · 2020-02-10T20:09:30Z

@bors r+ rollup

bors · 2020-02-11T06:28:27Z

📌 Commit b8893df has been approved by petrochenkov

…enkov traits: preallocate 2 Vecs of known initial size The 2 preallocations are pretty obvious; both vectors will be as big as or larger than the collections they are created from. In `WfPredicates::normalize` the change from a functional style improves readability and should be perf-friendly, too.

@ghost

Rollup of 8 pull requests Successful merges: - #66498 (Remove unused feature gates) - #68816 (Tweak borrow error on `FnMut` when `Fn` is expected) - #68824 (Enable Control Flow Guard in rustbuild) - #69022 (traits: preallocate 2 Vecs of known initial size) - #69031 (Use `dyn Trait` more in tests) - #69044 (Don't run coherence twice for future-compat lints) - #69047 (Don't rustfmt check the vendor directory.) - #69055 (Clean up E0307 explanation) Failed merges: r? @ghost

jonas-schievink · 2020-02-12T13:11:45Z

This got rolled up with #69044, but I think it has made a really big improvement, nice job! https://perf.rust-lang.org/compare.html?start=b6690a8c35e9afa3e0f65140cc69d4ba1b9e78c4&end=3f32e3001e3a64c1baa509d3d1734dff53f14d81&stat=instructions:u

(I expect #69044 to only improve packed-simd)

ljedrz · 2020-02-12T15:09:14Z

Aww yiss, thanks for letting me know 😄

Pkgsrc changes: * Bump rust bootstrap version to 1.42.0, except for Darwin/i686 where the bootstrap is not (yet?) available. Upstream changes: Version 1.43.0 (2020-04-23) ========================== Language -------- - [Fixed using binary operations with `&{number}` (e.g. `&1.0`) not having the type inferred correctly.][68129] - [Attributes such as `#[cfg()]` can now be used on `if` expressions.][69201] **Syntax only changes** - [Allow `type Foo: Ord` syntactically.][69361] - [Fuse associated and extern items up to defaultness.][69194] - [Syntactically allow `self` in all `fn` contexts.][68764] - [Merge `fn` syntax + cleanup item parsing.][68728] - [`item` macro fragments can be interpolated into `trait`s, `impl`s, and `extern` blocks.][69366] For example, you may now write: ```rust macro_rules! mac_trait { ($i:item) => { trait T { $i } } } mac_trait! { fn foo() {} } ``` These are still rejected *semantically*, so you will likely receive an error but these changes can be seen and parsed by macros and conditional compilation. Compiler -------- - [You can now pass multiple lint flags to rustc to override the previous flags.][67885] For example; `rustc -D unused -A unused-variables` denies everything in the `unused` lint group except `unused-variables` which is explicitly allowed. However, passing `rustc -A unused-variables -D unused` denies everything in the `unused` lint group **including** `unused-variables` since the allow flag is specified before the deny flag (and therefore overridden). - [rustc will now prefer your system MinGW libraries over its bundled libraries if they are available on `windows-gnu`.][67429] - [rustc now buffers errors/warnings printed in JSON.][69227] Libraries --------- - [`Arc<[T; N]>`, `Box<[T; N]>`, and `Rc<[T; N]>`, now implement `TryFrom<Arc<[T]>>`,`TryFrom<Box<[T]>>`, and `TryFrom<Rc<[T]>>` respectively.][69538] **Note** These conversions are only available when `N` is `0..=32`. - [You can now use associated constants on floats and integers directly, rather than having to import the module.][68952] e.g. You can now write `u32::MAX` or `f32::NAN` with no imports. - [`u8::is_ascii` is now `const`.][68984] - [`String` now implements `AsMut<str>`.][68742] - [Added the `primitive` module to `std` and `core`.][67637] This module reexports Rust's primitive types. This is mainly useful in macros where you want avoid these types being shadowed. - [Relaxed some of the trait bounds on `HashMap` and `HashSet`.][67642] - [`string::FromUtf8Error` now implements `Clone + Eq`.][68738] Stabilized APIs --------------- - [`Once::is_completed`] - [`f32::LOG10_2`] - [`f32::LOG2_10`] - [`f64::LOG10_2`] - [`f64::LOG2_10`] - [`iter::once_with`] Cargo ----- - [You can now set config `[profile]`s in your `.cargo/config`, or through your environment.][cargo/7823] - [Cargo will now set `CARGO_BIN_EXE_<name>` pointing to a binary's executable path when running integration tests or benchmarks.][cargo/7697] `<name>` is the name of your binary as-is e.g. If you wanted the executable path for a binary named `my-program`you would use `env!("CARGO_BIN_EXE_my-program")`. Misc ---- - [Certain checks in the `const_err` lint were deemed unrelated to const evaluation][69185], and have been moved to the `unconditional_panic` and `arithmetic_overflow` lints. Compatibility Notes ------------------- - [Having trailing syntax in the `assert!` macro is now a hard error.][69548] This has been a warning since 1.36.0. - [Fixed `Self` not having the correctly inferred type.][69340] This incorrectly led to some instances being accepted, and now correctly emits a hard error. [69340]: rust-lang/rust#69340 Internal Only ------------- These changes provide no direct user facing benefits, but represent significant improvements to the internals and overall performance of `rustc` and related tools. - [All components are now built with `opt-level=3` instead of `2`.][67878] - [Improved how rustc generates drop code.][67332] - [Improved performance from `#[inline]`-ing certain hot functions.][69256] - [traits: preallocate 2 Vecs of known initial size][69022] - [Avoid exponential behaviour when relating types][68772] - [Skip `Drop` terminators for enum variants without drop glue][68943] - [Improve performance of coherence checks][68966] - [Deduplicate types in the generator witness][68672] - [Invert control in struct_lint_level.][68725] [67332]: rust-lang/rust#67332 [67429]: rust-lang/rust#67429 [67637]: rust-lang/rust#67637 [67642]: rust-lang/rust#67642 [67878]: rust-lang/rust#67878 [67885]: rust-lang/rust#67885 [68129]: rust-lang/rust#68129 [68672]: rust-lang/rust#68672 [68725]: rust-lang/rust#68725 [68728]: rust-lang/rust#68728 [68738]: rust-lang/rust#68738 [68742]: rust-lang/rust#68742 [68764]: rust-lang/rust#68764 [68772]: rust-lang/rust#68772 [68943]: rust-lang/rust#68943 [68952]: rust-lang/rust#68952 [68966]: rust-lang/rust#68966 [68984]: rust-lang/rust#68984 [69022]: rust-lang/rust#69022 [69185]: rust-lang/rust#69185 [69194]: rust-lang/rust#69194 [69201]: rust-lang/rust#69201 [69227]: rust-lang/rust#69227 [69548]: rust-lang/rust#69548 [69256]: rust-lang/rust#69256 [69361]: rust-lang/rust#69361 [69366]: rust-lang/rust#69366 [69538]: rust-lang/rust#69538 [cargo/7823]: rust-lang/cargo#7823 [cargo/7697]: rust-lang/cargo#7697 [`Once::is_completed`]: https://doc.rust-lang.org/std/sync/struct.Once.html#method.is_completed [`f32::LOG10_2`]: https://doc.rust-lang.org/std/f32/consts/constant.LOG10_2.html [`f32::LOG2_10`]: https://doc.rust-lang.org/std/f32/consts/constant.LOG2_10.html [`f64::LOG10_2`]: https://doc.rust-lang.org/std/f64/consts/constant.LOG10_2.html [`f64::LOG2_10`]: https://doc.rust-lang.org/std/f64/consts/constant.LOG2_10.html [`iter::once_with`]: https://doc.rust-lang.org/std/iter/fn.once_with.html

preallocate 2 Vecs in traits; tweak WfPredicates::normalize
b8893df

rust-highfive assigned petrochenkov Feb 10, 2020

rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Feb 10, 2020

petrochenkov added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Feb 10, 2020

jonas-schievink mentioned this pull request Feb 11, 2020
Rollup of 11 pull requests #69056
Closed

Dylan-DPC-zz mentioned this pull request Feb 11, 2020
Rollup of 8 pull requests #69062
Merged

bors merged commit b8893df into rust-lang:masterFeb 11, 2020

ljedrz deleted the traits_tweak_vecs branch February 11, 2020 22:29

jonas-schievink added relnotes Marks issues that should be documented in the release notes of the next release. relnotes-perf Performance improvements that should be mentioned in the release notes. labels Mar 13, 2020

jonas-schievink modified the milestones: 1.44, 1.43 Mar 13, 2020

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traits: preallocate 2 Vecs of known initial size - #69022

traits: preallocate 2 Vecs of known initial size#69022
bors merged 1 commit into
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ljedrz:traits_tweak_vecs

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