dan/oxc
1
0
Fork 0
mirror of https://github.com/danbulant/oxc synced 2026-05-19 04:08:41 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

perf(ast): reduce size of Comment (#6921)

Browse source 
Reduce `Comment` from 20 bytes to 16. Because `Comment` has `#[ast]` attr, it's `#[repr(C)]` which means the fields don't get re-ordered by the compiler, so it contains excess padding. Moving `attached_to: u32` field removes the padding.

I am in favour of using `oxc_ast_tools` to re-order fields the same way the compiler does, which will solve this problem for all AST types. But may as well fix this one in meantime. Unlike most AST types, field order doesn't matter for `Comment` - it is not visited, so the field order has no semantic meaning.
This commit is contained in:
overlookmotel 2024-10-26 12:40:08 +00:00
parent eba417aa24
commit 6ca01b9c35
5 changed files with 23 additions and 23 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
crates/oxc_ast/src/ast/comment.rs
View file

@ -46,18 +46,18 @@ pub struct Comment {
/// The span of the comment text (without leading/trailing delimiters).
pub span: Span,
/// Line or block comment
pub kind: CommentKind,
/// Leading or trailing comment
pub position: CommentPosition,
/// Start of token this leading comment is attached to.
/// `/* Leading */ token`
/// ^ This start
/// NOTE: Trailing comment attachment is not computed yet.
pub attached_to: u32,
/// Line or block comment
pub kind: CommentKind,
/// Leading or trailing comment
pub position: CommentPosition,
/// Whether this comment has a preceding newline.
/// Used to avoid becoming a trailing comment in codegen.
pub preceded_by_newline: bool,
@ -73,9 +73,9 @@ impl Comment {
let span = Span::new(start, end);
Self {
span,
attached_to: 0,
kind,
position: CommentPosition::Trailing,
attached_to: 0,
preceded_by_newline: false,
followed_by_newline: false,
}

24
crates/oxc_ast/src/generated/assert_layouts.rs
View file

@ -1380,14 +1380,14 @@ const _: () = {
assert!(size_of::<CommentPosition>() == 1usize);
assert!(align_of::<CommentPosition>() == 1usize);
assert!(size_of::<Comment>() == 20usize);
assert!(size_of::<Comment>() == 16usize);
assert!(align_of::<Comment>() == 4usize);
assert!(offset_of!(Comment, span) == 0usize);
assert!(offset_of!(Comment, kind) == 8usize);
assert!(offset_of!(Comment, position) == 9usize);
assert!(offset_of!(Comment, attached_to) == 12usize);
assert!(offset_of!(Comment, preceded_by_newline) == 16usize);
assert!(offset_of!(Comment, followed_by_newline) == 17usize);
assert!(offset_of!(Comment, attached_to) == 8usize);
assert!(offset_of!(Comment, kind) == 12usize);
assert!(offset_of!(Comment, position) == 13usize);
assert!(offset_of!(Comment, preceded_by_newline) == 14usize);
assert!(offset_of!(Comment, followed_by_newline) == 15usize);
assert!(size_of::<NumberBase>() == 1usize);
assert!(align_of::<NumberBase>() == 1usize);
@ -2939,14 +2939,14 @@ const _: () = {
assert!(size_of::<CommentPosition>() == 1usize);
assert!(align_of::<CommentPosition>() == 1usize);
assert!(size_of::<Comment>() == 20usize);
assert!(size_of::<Comment>() == 16usize);
assert!(align_of::<Comment>() == 4usize);
assert!(offset_of!(Comment, span) == 0usize);
assert!(offset_of!(Comment, kind) == 8usize);
assert!(offset_of!(Comment, position) == 9usize);
assert!(offset_of!(Comment, attached_to) == 12usize);
assert!(offset_of!(Comment, preceded_by_newline) == 16usize);
assert!(offset_of!(Comment, followed_by_newline) == 17usize);
assert!(offset_of!(Comment, attached_to) == 8usize);
assert!(offset_of!(Comment, kind) == 12usize);
assert!(offset_of!(Comment, position) == 13usize);
assert!(offset_of!(Comment, preceded_by_newline) == 14usize);
assert!(offset_of!(Comment, followed_by_newline) == 15usize);
assert!(size_of::<NumberBase>() == 1usize);
assert!(align_of::<NumberBase>() == 1usize);

2
crates/oxc_ast/src/generated/derive_clone_in.rs
View file

@ -4256,9 +4256,9 @@ impl<'alloc> CloneIn<'alloc> for Comment {
fn clone_in(&self, allocator: &'alloc Allocator) -> Self::Cloned {
Comment {
span: CloneIn::clone_in(&self.span, allocator),
attached_to: CloneIn::clone_in(&self.attached_to, allocator),
kind: CloneIn::clone_in(&self.kind, allocator),
position: CloneIn::clone_in(&self.position, allocator),
attached_to: CloneIn::clone_in(&self.attached_to, allocator),
preceded_by_newline: CloneIn::clone_in(&self.preceded_by_newline, allocator),
followed_by_newline: CloneIn::clone_in(&self.followed_by_newline, allocator),
}

4
crates/oxc_ast/src/generated/derive_content_eq.rs
View file

@ -4226,9 +4226,9 @@ impl ContentEq for CommentPosition {
impl ContentEq for Comment {
fn content_eq(&self, other: &Self) -> bool {
ContentEq::content_eq(&self.kind, &other.kind)
ContentEq::content_eq(&self.attached_to, &other.attached_to)
&& ContentEq::content_eq(&self.kind, &other.kind)
&& ContentEq::content_eq(&self.position, &other.position)
&& ContentEq::content_eq(&self.attached_to, &other.attached_to)
&& ContentEq::content_eq(&self.preceded_by_newline, &other.preceded_by_newline)
&& ContentEq::content_eq(&self.followed_by_newline, &other.followed_by_newline)
}

2
crates/oxc_ast/src/generated/derive_content_hash.rs
View file

@ -2388,9 +2388,9 @@ impl ContentHash for CommentPosition {
impl ContentHash for Comment {
fn content_hash<H: Hasher>(&self, state: &mut H) {
ContentHash::content_hash(&self.attached_to, state);
ContentHash::content_hash(&self.kind, state);
ContentHash::content_hash(&self.position, state);
ContentHash::content_hash(&self.attached_to, state);
ContentHash::content_hash(&self.preceded_by_newline, state);
ContentHash::content_hash(&self.followed_by_newline, state);
}