Skip to content

Commit

Permalink
feat(minifier): minimize if (x) if (y) z -> if (x && y) z (#8136)
Browse files Browse the repository at this point in the history
  • Loading branch information
@Boshen
Boshen committed Dec 27, 2024
1 parent ad61e70 commit 213364a
Show file tree
Hide file tree
Showing 3 changed files with 68 additions and 57 deletions.
16 changes: 16 additions & 0 deletions crates/oxc_ast/src/ast_impl/js.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -767,6 +767,22 @@ impl Statement<'_> {
| Statement::WhileStatement(_)
)
}

/// Returns the single statement from block statement, or self
pub fn get_one_child(&self) -> Option<&Self> {
if let Statement::BlockStatement(block_stmt) = self {
return (block_stmt.body.len() == 1).then(|| &block_stmt.body[0]);
}
Some(self)
}

/// Returns the single statement from block statement, or self
pub fn get_one_child_mut(&mut self) -> Option<&mut Self> {
if let Statement::BlockStatement(block_stmt) = self {
return (block_stmt.body.len() == 1).then_some(&mut block_stmt.body[0]);
}
Some(self)
}
}

impl<'a> FromIn<'a, Expression<'a>> for Statement<'a> {
Expand Down
87 changes: 41 additions & 46 deletions crates/oxc_minifier/src/ast_passes/peephole_minimize_conditions.rs
View file
Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
use oxc_allocator::Vec;
use oxc_ast::ast::*;
use oxc_span::GetSpan;
use oxc_traverse::{traverse_mut_with_ctx, ReusableTraverseCtx, Traverse, TraverseCtx};

use crate::CompressorPass;
Expand Down Expand Up @@ -89,7 +90,9 @@ impl<'a> PeepholeMinimizeConditions {
ctx: &mut TraverseCtx<'a>,
) -> Option<Statement<'a>> {
let Statement::IfStatement(if_stmt) = stmt else { unreachable!() };
match &if_stmt.alternate {
let then_branch = &if_stmt.consequent;
let else_branch = &if_stmt.alternate;
match else_branch {
None => {
if Self::is_foldable_express_block(&if_stmt.consequent) {
let right = Self::get_block_expression(&mut if_stmt.consequent, ctx);
Expand All @@ -116,11 +119,31 @@ impl<'a> PeepholeMinimizeConditions {
);
return Some(ctx.ast.statement_expression(if_stmt.span, logical_expr));
}
} else {
// `if (x) if (y) z` -> `if (x && y) z`
if let Some(Statement::IfStatement(then_if_stmt)) = then_branch.get_one_child()
{
if then_if_stmt.alternate.is_none() {
let and_left = ctx.ast.move_expression(&mut if_stmt.test);
let Statement::IfStatement(mut then_if_stmt) =
ctx.ast.move_statement(&mut if_stmt.consequent)
else {
unreachable!()
};
let and_right = ctx.ast.move_expression(&mut then_if_stmt.test);
then_if_stmt.test = ctx.ast.expression_logical(
and_left.span(),
and_left,
LogicalOperator::And,
and_right,
);
return Some(Statement::IfStatement(then_if_stmt));
}
}
}
}
Some(else_branch) => {
let then_branch_is_expression_block =
Self::is_foldable_express_block(&if_stmt.consequent);
let then_branch_is_expression_block = Self::is_foldable_express_block(then_branch);
let else_branch_is_expression_block = Self::is_foldable_express_block(else_branch);
// `if(foo) bar else baz` -> `foo ? bar : baz`
if then_branch_is_expression_block && else_branch_is_expression_block {
Expand Down Expand Up @@ -184,37 +207,18 @@ impl<'a> PeepholeMinimizeConditions {
}

fn is_foldable_express_block(stmt: &Statement<'a>) -> bool {
match stmt {
Statement::BlockStatement(block_stmt) if block_stmt.body.len() == 1 => {
matches!(&block_stmt.body[0], Statement::ExpressionStatement(_))
}
Statement::ExpressionStatement(_) => true,
_ => false,
}
matches!(stmt.get_one_child(), Some(Statement::ExpressionStatement(_)))
}

fn get_block_expression(stmt: &mut Statement<'a>, ctx: &mut TraverseCtx<'a>) -> Expression<'a> {
match stmt {
Statement::BlockStatement(block_stmt) if block_stmt.body.len() == 1 => {
if let Statement::ExpressionStatement(s) = &mut block_stmt.body[0] {
ctx.ast.move_expression(&mut s.expression)
} else {
unreachable!()
}
}
Statement::ExpressionStatement(s) => ctx.ast.move_expression(&mut s.expression),
_ => unreachable!(),
}
let Some(Statement::ExpressionStatement(s)) = stmt.get_one_child_mut() else {
unreachable!()
};
ctx.ast.move_expression(&mut s.expression)
}

fn is_return_block(stmt: &Statement<'a>) -> bool {
match stmt {
Statement::BlockStatement(block_stmt) if block_stmt.body.len() == 1 => {
matches!(block_stmt.body[0], Statement::ReturnStatement(_))
}
Statement::ReturnStatement(_) => true,
_ => false,
}
matches!(stmt.get_one_child(), Some(Statement::ReturnStatement(_)))
}

fn is_return_expression(stmt: &Statement<'a>) -> bool {
Expand All @@ -235,17 +239,8 @@ impl<'a> PeepholeMinimizeConditions {
stmt: &mut Statement<'a>,
ctx: &mut TraverseCtx<'a>,
) -> Expression<'a> {
match stmt {
Statement::BlockStatement(block_stmt) if block_stmt.body.len() == 1 => {
if let Statement::ReturnStatement(_) = &mut block_stmt.body[0] {
Self::take_return_argument(stmt, ctx)
} else {
unreachable!()
}
}
Statement::ReturnStatement(_) => Self::take_return_argument(stmt, ctx),
_ => unreachable!(),
}
let Some(stmt) = stmt.get_one_child_mut() else { unreachable!() };
Self::take_return_argument(stmt, ctx)
}

fn take_return_argument(stmt: &mut Statement<'a>, ctx: &mut TraverseCtx<'a>) -> Expression<'a> {
Expand Down Expand Up @@ -323,13 +318,13 @@ mod test {
// fold("if(x){do{foo()}while(y)}else bar()", "if(x){do foo();while(y)}else bar()");

// Play with nested IFs
// fold("function f(){if(x){if(y)foo()}}", "function f(){x && (y && foo())}");
// fold("function f(){if(x){if(y)foo();else bar()}}", "function f(){x&&(y?foo():bar())}");
// fold("function f(){if(x){if(y)foo()}else bar()}", "function f(){x?y&&foo():bar()}");
// fold(
// "function f(){if(x){if(y)foo();else bar()}else{baz()}}",
// "function f(){x?y?foo():bar():baz()}",
// );
fold("function f(){if(x){if(y)foo()}}", "function f(){x && (y && foo())}");
fold("function f(){if(x){if(y)foo();else bar()}}", "function f(){x&&(y?foo():bar())}");
fold("function f(){if(x){if(y)foo()}else bar()}", "function f(){x?y&&foo():bar()}");
fold(
"function f(){if(x){if(y)foo();else bar()}else{baz()}}",
"function f(){x?y?foo():bar():baz()}",
);

// fold("if(e1){while(e2){if(e3){foo()}}}else{bar()}", "if(e1)while(e2)e3&&foo();else bar()");

Expand Down
22 changes: 11 additions & 11 deletions tasks/minsize/minsize.snap
View file
Original file line number Diff line number Diff line change
@@ -1,27 +1,27 @@
| Oxc | ESBuild | Oxc | ESBuild |
Original | minified | minified | gzip | gzip | Fixture
-------------------------------------------------------------------------------------
72.14 kB | 23.77 kB | 23.70 kB | 8.62 kB | 8.54 kB | react.development.js
72.14 kB | 23.74 kB | 23.70 kB | 8.62 kB | 8.54 kB | react.development.js

173.90 kB | 60.22 kB | 59.82 kB | 19.49 kB | 19.33 kB | moment.js

287.63 kB | 90.77 kB | 90.07 kB | 32.23 kB | 31.95 kB | jquery.js
287.63 kB | 90.76 kB | 90.07 kB | 32.22 kB | 31.95 kB | jquery.js

342.15 kB | 119.00 kB | 118.14 kB | 44.65 kB | 44.37 kB | vue.js
342.15 kB | 119.00 kB | 118.14 kB | 44.66 kB | 44.37 kB | vue.js

544.10 kB | 72.54 kB | 72.48 kB | 26.23 kB | 26.20 kB | lodash.js
544.10 kB | 72.53 kB | 72.48 kB | 26.23 kB | 26.20 kB | lodash.js

555.77 kB | 274.27 kB | 270.13 kB | 91.27 kB | 90.80 kB | d3.js
555.77 kB | 274.26 kB | 270.13 kB | 91.26 kB | 90.80 kB | d3.js

1.01 MB | 461.18 kB | 458.89 kB | 126.93 kB | 126.71 kB | bundle.min.js
1.01 MB | 461.13 kB | 458.89 kB | 126.91 kB | 126.71 kB | bundle.min.js

1.25 MB | 657.26 kB | 646.76 kB | 164.24 kB | 163.73 kB | three.js
1.25 MB | 657.23 kB | 646.76 kB | 164.23 kB | 163.73 kB | three.js

2.14 MB | 735.73 kB | 724.14 kB | 181.11 kB | 181.07 kB | victory.js
2.14 MB | 735.70 kB | 724.14 kB | 181.11 kB | 181.07 kB | victory.js

3.20 MB | 1.01 MB | 1.01 MB | 332.37 kB | 331.56 kB | echarts.js
3.20 MB | 1.01 MB | 1.01 MB | 332.35 kB | 331.56 kB | echarts.js

6.69 MB | 2.38 MB | 2.31 MB | 495.35 kB | 488.28 kB | antd.js
6.69 MB | 2.38 MB | 2.31 MB | 495.34 kB | 488.28 kB | antd.js

10.95 MB | 3.52 MB | 3.49 MB | 911.00 kB | 915.50 kB | typescript.js
10.95 MB | 3.51 MB | 3.49 MB | 910.94 kB | 915.50 kB | typescript.js

0 comments on commit 213364a

Please sign in to comment.