perf(span): align `Span` same as `usize` #8298

overlookmotel · 2025-01-06T14:04:40Z

Span consists of 2 x u32 (8 bytes total). Align Span on 8 bytes on 64-bit platforms. This means that, on 64-bit platforms, Span can be treated as equivalent to a u64 and stored in a single register (instead of requiring 2).

A side-effect is that all AST structs also become aligned on 8. This will be a useful property later on as we can remove alignment calculations from Allocator::alloc (since everything now has same alignment).

BooleanLiteral (and BoundaryAssertion, CharacterClassEscape and IndexedReference from oxc_regular_expression crate) increase from 12 bytes to 16 bytes due to the higher alignment. But this makes no practical difference as they'd almost always end up with padding around them in arena anyway, as they'll be surrounded by 8-aligned types.

overlookmotel · 2025-01-06T14:04:57Z

perf(span): compare Spans as single u64s #8300 : 2 dependent PRs (#8574 , #8576 )
perf(span): hash Span as a single u64 #8299
refactor(span): all methods take owned Span #8297
perf(span): align Span same as usize #8298 👈 (View in Graphite)
ci(benchmark): make lexer benchmark more realistic #8573
main

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

0-merge - adds this PR to the back of the merge queue
hotfix - for urgent hot fixes, skip the queue and merge this PR next

You must have a Graphite account in order to use the merge queue. Sign up using this link.

_{An organization admin has enabled the Graphite Merge Queue in this repository.} _{Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.}

This stack of pull requests is managed by Graphite. Learn more about stacking.

codspeed-hq · 2025-01-06T14:11:46Z

CodSpeed Performance Report

Merging #8298 will improve performances by 16.85%

_{Comparing 01-03-perf_span_align_span_same_as_usize_ (3fff7d2) with main (76ea52b)}

Summary

⚡ 1 improvements
✅ 31 untouched benchmarks

Benchmarks breakdown

	Benchmark	`main`	`01-03-perf_span_align_span_same_as_usize_`	Change
⚡	`lexer[RadixUIAdoptionSection.jsx]`	23.8 µs	20.4 µs	+16.85%

overlookmotel · 2025-01-17T22:26:04Z

Weird. When I initially submitted this PR 2 weeks ago, it showed a 5% perf boost on isolated declarations benchmark, now it doesn't.

Still, +2% on codegen benchmark for a very small change ain't bad. The benchmarks showing negative result are noise due to allocations and hashmaps.

graphite-app · 2025-01-18T01:34:21Z

Merge activity

Jan 17, 8:34 PM EST: A user added this pull request to the Graphite merge queue.
Jan 17, 9:01 PM EST: A user merged this pull request with the Graphite merge queue.

`Span` consists of 2 x `u32` (8 bytes total). Align `Span` on 8 bytes on 64-bit platforms. This means that, on 64-bit platforms, `Span` can be treated as equivalent to a `u64` and stored in a single register (instead of requiring 2). A side-effect is that all AST structs also become aligned on 8. This will be a useful property later on as we can remove alignment calculations from `Allocator::alloc` (since everything now has same alignment). `BooleanLiteral` (and `BoundaryAssertion`, `CharacterClassEscape` and `IndexedReference` from `oxc_regular_expression` crate) increase from 12 bytes to 16 bytes due to the higher alignment. But this makes no practical difference as they'd almost always end up with padding around them in arena anyway, as they'll be surrounded by 8-aligned types.

#8298 made `Span` aligned on 8 on 64-bit platforms. Utilize this property to hash `Span` as a single `u64` instead of 2 x `u32`s. This reduces hashing a `Span` with `FxHash` to 3 instructions (down from 7), and 1 register (down from 3). https://godbolt.org/z/4q36xrWG8

#8298 made `Span` aligned on 8 on 64-bit platforms. Utilize this property to compare `Span`s as a single `u64` instead of 2 x `u32`s. This removes some really weird assembly which compiler otherwise produces, using expensive SIMD operations for a simple comparison: https://godbolt.org/z/sEf9MGvsr Note: This only affects comparing `&Span`s. Makes no difference when comparing owned `Span`s.

## [0.47.0] - 2025-01-18 - fae4cd2 allocator: [**BREAKING**] Remove `Vec::into_string` (#8571) (overlookmotel) - 95bc0d7 allocator: [**BREAKING**] `Allocator` do not deref to `bumpalo::Bump` (#8569) (overlookmotel) - 19d3677 ast: [**BREAKING**] Always return `Array<ImportDeclarationSpecifier>` for `ImportDeclaration.specifiers` (#8560) (sapphi-red) - 4ce6329 semantic: [**BREAKING**] Ensure program outlives semantic (#8455) (Valentinas Janeiko) - 7066d1c ast, span, syntax, regular_expression: [**BREAKING**] Remove `ContentHash` (#8512) (overlookmotel) ### Features - bf4e5e1 allocator: Add `HashMap` (#8553) (overlookmotel) - a6d71f8 ast: Add `AstKind::ty` method (#8521) (overlookmotel) - 4d4e805 minifier: Collapse if stmt with empty consequent (#8577) (camc314) - 991a22f minifier: Fold `Array::concat` into literal (#8442) (sapphi-red) - 3dc2d8b minifier: Fold string concat chaining (#8441) (sapphi-red) - a4ae450 minifier: Fold array concat chaining (#8440) (sapphi-red) - 7cc81ef minifier: Fold invalid typeof comparisons (#8550) (camc314) - 927f43f minifier: Improve `.charCodeAt(arg)` when arg is valid (#8534) (Boshen) - 06f14d5 minifier: Remove empty class static block `class Foo { static {} }` (#8525) (Boshen) - 1860411 minifier: Remove last redundant return statement (#8523) (Boshen) - c479a58 napi/parser: Expose dynamic import expressions (#8540) (Boshen) - 2f0314e npm/oxc-minify: Npm package and publish script (#8579) (Boshen) - f413bb5 transformer/optional-chaining: Change parent scope for expression when it wrapped with an arrow function (#8511) (Dunqing) ### Bug Fixes - e87c001 allocator: Statically prevent memory leaks in allocator (#8570) (overlookmotel) - 855c839 codegen: Shorthand assignment target identifier consider mangled names (#8536) (Boshen) - 65c596d minifer: Keep idents if not in scope when minimizing array exprs (#8551) (camc314) - f57aac2 minifier: Incorrect folding of expr in bool ctx (#8542) (camc314) - 946ad76 minifier: `(-Infinity).toString()` -> `'-Infinity'` (#8535) (Boshen) - b1d0186 minifier: Do not fold `!!void b` (#8533) (Boshen) - 53adde5 minifier: `x['-2147483648']` -> `x[-2147483648]` (#8528) (Boshen) - 405b73d minifier: Do not change `delete undefined` to `delete void 0` (#8527) (Boshen) - 92e44cb minifier: Do not remove `undefined` in `var x = undefined` (#8526) (Boshen) - 209e313 minifier: `class C { ['-1']() {} }` cannot be minifized (#8516) (Boshen) - 6585463 minifier: Always keep the last value of sequence expression (#8490) (Boshen) - b552f5c transformer: `wrap_in_arrow_function_iife` take span of input `Expression` (#8547) (overlookmotel) - 9963533 transformer/arrow-functions: Visit arguments to `super()` call (#8494) (overlookmotel) - 06ccb51 transformer/async-to-generator: Move parameters to the inner generator function when they could throw errors (#8500) (Dunqing) - 356f0c1 transformer/class-properties: Handle nested `super()` calls (#8506) (overlookmotel) - a048337 transformer/class-static-blocks: Static block converted to IIFE use span of original block (#8549) (overlookmotel) ### Performance - 76ea52b allocator: Inline `Box` methods (#8572) (overlookmotel) - 93df57f allocator: `#[inline(always)]` methods of `Vec` which just delegate to `allocator_api2` (#8567) (overlookmotel) - 5a28d68 allocator: `#[inline(always)]` methods of `HashMap` which just delegate to `hashbrown` (#8565) (overlookmotel) - d17021c mangler: Optimize `base54` function (#8557) (overlookmotel) - 6b52d7a mangler: Use a single allocation space for temporary vecs (#8495) (Boshen) - 30a869e semantic: Use `oxc_allocator::HashMap` in `ScopeTree` (#8554) (overlookmotel) - 63eb298 span: Compare `Span`s as single `u64`s (#8300) (overlookmotel) - a43560c span: Hash `Span` as a single `u64` (#8299) (overlookmotel) - 3fff7d2 span: Align `Span` same as `usize` (#8298) (overlookmotel) - 53ef263 transformer/arrow-functions: Bail out of visiting early when inserting `_this = this` after `super()` (#8482) (overlookmotel) ### Documentation - fa1a6d5 allocator: Update docs for `Vec` (#8555) (overlookmotel) ### Refactor - ac05134 allocator: `String` type (#8568) (overlookmotel) - 68fab81 allocator: Rename inner `Vec` type (#8566) (overlookmotel) - fcbca32 ast: Rename `#[estree(with)]` to `#[estree(via)]` (#8564) (overlookmotel) - 007e8c0 ast, regular_expression: Shorten `ContentEq` implementations (#8519) (overlookmotel) - b4c87e2 linter: Move DiagnosticsReporters to oxlint (#8454) (Alexander S.) - 8f57929 minifier: Merge `try_compress_type_of_equal_string` into `try_minimize_binary` (#8561) (sapphi-red) - 2857ae1 parser: Refactor visitor in regexp example (#8524) (overlookmotel) - b5ed58e span: All methods take owned `Span` (#8297) (overlookmotel) - 712633f transformer: `wrap_statements_in_arrow_function_iife` utility function (#8548) (overlookmotel) - 5206c6a transformer: Rename `wrap_in_arrow_function_iife` (#8546) (overlookmotel) - 61077ca transformer: `wrap_arrow_function_iife` receive an owned `Expression` (#8545) (overlookmotel) - 6820d24 transformer: Move `wrap_arrow_function_iife` to root utils module (#8529) (Dunqing) - 52bd0b1 transformer: Move common utils functions to the root module (#8513) (Dunqing) - c30654a transformer/arrow-function: Wrapping arrow function iife by using `wrap_arrow_function_iife` (#8530) (Dunqing) - 2bc5175 transformer/arrow-functions: Rename method (#8481) (overlookmotel) - 72f425f transformer/class-properties: Fix lint warning in release mode (#8539) (overlookmotel) - 7e61b23 transformer/typescript: Shorten code (#8504) (overlookmotel) - 04bc259 traverse: Remove unnecessary `#[allow]` (#8518) (overlookmotel) - a368726 traverse: Harden soundness of `Traverse` and document safety invariants better (#8507) (overlookmotel) ### Testing - e0f5d6c minifier: Update esbuild test (Boshen) - 629c417 minifier: Port esbuild minification tests (#8497) (Boshen) Co-authored-by: Boshen <[email protected]>

github-actions bot added A-ast Area - AST A-ast-tools Area - AST tools labels Jan 6, 2025

github-actions bot added the C-performance Category - Solution not expected to change functional behavior, only performance label Jan 6, 2025

overlookmotel marked this pull request as ready for review January 6, 2025 14:16

overlookmotel marked this pull request as draft January 6, 2025 14:17

This was referenced Jan 6, 2025

perf(span): hash Span as a single u64 #8299

Merged

perf(span): compare Spans as single u64s #8300

Merged

overlookmotel force-pushed the 01-03-perf_span_align_span_same_as_usize_ branch from 2135503 to 1b5a978 Compare January 6, 2025 16:13

This was referenced Jan 6, 2025

refactor(span): all methods take owned Span #8297

Merged

perf(parser): reduce Token size to 8 bytes from 16 #8153

Draft

overlookmotel force-pushed the 01-03-perf_span_align_span_same_as_usize_ branch from 1b5a978 to ec9d7e5 Compare January 17, 2025 21:41

overlookmotel changed the base branch from main to 01-17-ci_benchmark_make_lexer_benchmark_more_realistic January 17, 2025 21:41

overlookmotel mentioned this pull request Jan 17, 2025

ci(benchmark): make lexer benchmark more realistic #8573

Merged

overlookmotel marked this pull request as ready for review January 17, 2025 22:24

This was referenced Jan 17, 2025

perf(lexer): align Token on 8 #8574

Closed

perf(lexer): set discrimant for default variant of Kind to 0 #8575

Closed

perf(lexer): finish_next only clear kind and flags #8576

Draft

graphite-app bot added the 0-merge Merge with Graphite Merge Queue label Jan 18, 2025

Boshen force-pushed the 01-17-ci_benchmark_make_lexer_benchmark_more_realistic branch from c206be3 to bfd0b0d Compare January 18, 2025 01:47

Boshen force-pushed the 01-03-perf_span_align_span_same_as_usize_ branch from ec9d7e5 to 3fff7d2 Compare January 18, 2025 01:47

Base automatically changed from 01-17-ci_benchmark_make_lexer_benchmark_more_realistic to main January 18, 2025 01:54

graphite-app bot merged commit 3fff7d2 into main Jan 18, 2025
26 checks passed

graphite-app bot deleted the 01-03-perf_span_align_span_same_as_usize_ branch January 18, 2025 02:01

oxc-bot mentioned this pull request Jan 18, 2025

release(crates): v0.47.0 #8580

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

perf(span): align `Span` same as `usize` #8298

perf(span): align `Span` same as `usize` #8298

overlookmotel commented Jan 6, 2025 •

edited

Loading

overlookmotel commented Jan 6, 2025 •

edited

Loading

codspeed-hq bot commented Jan 6, 2025 •

edited

Loading

overlookmotel commented Jan 17, 2025

graphite-app bot commented Jan 18, 2025 •

edited

Loading

perf(span): align Span same as usize #8298

perf(span): align Span same as usize #8298

Conversation

overlookmotel commented Jan 6, 2025 • edited Loading

overlookmotel commented Jan 6, 2025 • edited Loading

How to use the Graphite Merge Queue

codspeed-hq bot commented Jan 6, 2025 • edited Loading

CodSpeed Performance Report

Merging #8298 will improve performances by 16.85%

Summary

Benchmarks breakdown

overlookmotel commented Jan 17, 2025

graphite-app bot commented Jan 18, 2025 • edited Loading

Merge activity

perf(span): align `Span` same as `usize` #8298

perf(span): align `Span` same as `usize` #8298

overlookmotel commented Jan 6, 2025 •

edited

Loading

overlookmotel commented Jan 6, 2025 •

edited

Loading

codspeed-hq bot commented Jan 6, 2025 •

edited

Loading

graphite-app bot commented Jan 18, 2025 •

edited

Loading