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feat(minifier): minify one child if statement expression (#7230)
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@7086cmd
7086cmd authored Nov 26, 2024
1 parent c133693 commit ac0d25c
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Showing 4 changed files with 95 additions and 26 deletions.
1 change: 1 addition & 0 deletions crates/oxc_minifier/src/ast_passes/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -80,6 +80,7 @@ impl<'a> Traverse<'a> for EarlyPass {

fn exit_statement(&mut self, stmt: &mut Statement<'a>, ctx: &mut TraverseCtx<'a>) {
self.x1_peephole_remove_dead_code.exit_statement(stmt, ctx);
self.x2_peephole_minimize_conditions.exit_statement(stmt, ctx);
}

fn exit_program(&mut self, program: &mut Program<'a>, ctx: &mut TraverseCtx<'a>) {
Expand Down
92 changes: 80 additions & 12 deletions crates/oxc_minifier/src/ast_passes/peephole_minimize_conditions.rs
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Original file line number Diff line number Diff line change
@@ -1,4 +1,6 @@
use oxc_ast::ast::*;
use oxc_ecmascript::ToBoolean;
use oxc_span::SPAN;
use oxc_traverse::{Traverse, TraverseCtx};

use crate::CompressorPass;
Expand Down Expand Up @@ -35,6 +37,16 @@ impl<'a> Traverse<'a> for PeepholeMinimizeConditions {
self.changed = true;
};
}

fn exit_statement(&mut self, node: &mut Statement<'a>, ctx: &mut TraverseCtx<'a>) {
if let Statement::IfStatement(if_stmt) = node {
self.try_fold_if_block_one(if_stmt, ctx);
if let Some(new_stmt) = Self::try_fold_if_one_child(if_stmt, ctx) {
*node = new_stmt;
self.changed = true;
}
}
}
}

impl<'a> PeepholeMinimizeConditions {
Expand All @@ -56,6 +68,63 @@ impl<'a> PeepholeMinimizeConditions {
}
None
}

/// Duplicate logic to DCE part.
fn try_fold_if_block_one(&mut self, if_stmt: &mut IfStatement<'a>, ctx: &mut TraverseCtx<'a>) {
if let Statement::BlockStatement(block) = &mut if_stmt.consequent {
if block.body.len() == 1 {
self.changed = true;
if_stmt.consequent = ctx.ast.move_statement(block.body.first_mut().unwrap());
}
}
if let Some(Statement::BlockStatement(block)) = &mut if_stmt.alternate {
if block.body.len() == 1 {
self.changed = true;
if_stmt.alternate = Some(ctx.ast.move_statement(block.body.first_mut().unwrap()));
}
}
}

fn try_fold_if_one_child(
if_stmt: &mut IfStatement<'a>,
ctx: &mut TraverseCtx<'a>,
) -> Option<Statement<'a>> {
if let Statement::ExpressionStatement(expr) = &mut if_stmt.consequent {
// The rest of things for known boolean are tasks for dce instead of here.
(if_stmt.alternate.is_none() && if_stmt.test.to_boolean().is_none()).then(|| {
// Make if (x) y; => x && y;
let (operator, mut test) = match &mut if_stmt.test {
Expression::UnaryExpression(unary) if unary.operator.is_not() => {
let arg = ctx.ast.move_expression(&mut unary.argument);
(LogicalOperator::Or, arg)
}
_ => (LogicalOperator::And, ctx.ast.move_expression(&mut if_stmt.test)),
};
match &mut test {
Expression::BinaryExpression(bin) if bin.operator.is_equality() => {
if !bin.left.is_literal() && bin.right.is_literal() {
test = ctx.ast.expression_binary(
SPAN,
ctx.ast.move_expression(&mut bin.right),
bin.operator,
ctx.ast.move_expression(&mut bin.left),
);
}
}
_ => {}
}
let new_expr = ctx.ast.expression_logical(
SPAN,
test,
operator,
ctx.ast.move_expression(&mut expr.expression),
);
ctx.ast.statement_expression(SPAN, new_expr)
})
} else {
None
}
}
}

/// <https://github.com/google/closure-compiler/blob/v20240609/test/com/google/javascript/jscomp/PeepholeMinimizeConditionsTest.java>
Expand Down Expand Up @@ -85,7 +154,6 @@ mod test {

/** Check that removing blocks with 1 child works */
#[test]
#[ignore]
fn test_fold_one_child_blocks() {
// late = false;
fold("function f(){if(x)a();x=3}", "function f(){x&&a();x=3}");
Expand All @@ -100,7 +168,7 @@ mod test {

// Try it out with functions
fold("function f(){if(x){foo()}}", "function f(){x&&foo()}");
fold("function f(){if(x){foo()}else{bar()}}", "function f(){x?foo():bar()}");
// fold("function f(){if(x){foo()}else{bar()}}", "function f(){x?foo():bar()}");

// Try it out with properties and methods
fold("function f(){if(x){a.b=1}}", "function f(){x&&(a.b=1)}");
Expand All @@ -117,22 +185,22 @@ mod test {
fold_same("function f(){switch(x){case 1:break}}");

// Do while loops stay in a block if that's where they started
fold_same("function f(){if(e1){do foo();while(e2)}else foo2()}");
// fold_same("function f(){if(e1){do foo();while(e2)}else foo2()}");
// Test an obscure case with do and while
fold("if(x){do{foo()}while(y)}else bar()", "if(x){do foo();while(y)}else bar()");
// 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();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()");
// fold("if(e1){while(e2){if(e3){foo()}}}else{bar()}", "if(e1)while(e2)e3&&foo();else bar()");

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

fold("if(a||b){if(c||d){var x;}}", "if(a||b)if(c||d)var x");
fold("if(x){ if(y){var x;}else{var z;} }", "if(x)if(y)var x;else var z");
Expand Down
4 changes: 2 additions & 2 deletions crates/oxc_minifier/tests/ast_passes/dead_code_elimination.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -49,11 +49,11 @@ fn dce_if_statement() {
test("if (!false) { foo }", "foo");
test("if (!true) { foo } else { bar }", "bar");

test("if (!false && xxx) { foo }", "if (xxx) foo");
test("if (!false && xxx) { foo }", "xxx && foo");
test("if (!true && yyy) { foo } else { bar }", "bar");

test("if (true || xxx) { foo }", "foo");
test("if (false || xxx) { foo }", "if (xxx) foo");
test("if (false || xxx) { foo }", "xxx && foo");

test("if ('production' == 'production') { foo } else { bar }", "foo");
test("if ('development' == 'production') { foo } else { bar }", "bar");
Expand Down
24 changes: 12 additions & 12 deletions tasks/minsize/minsize.snap
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@@ -1,26 +1,26 @@
Original | Minified | esbuild | Gzip | esbuild

72.14 kB | 24.12 kB | 23.70 kB | 8.62 kB | 8.54 kB | react.development.js
72.14 kB | 24.06 kB | 23.70 kB | 8.68 kB | 8.54 kB | react.development.js

173.90 kB | 61.67 kB | 59.82 kB | 19.54 kB | 19.33 kB | moment.js
173.90 kB | 61.54 kB | 59.82 kB | 19.64 kB | 19.33 kB | moment.js

287.63 kB | 92.70 kB | 90.07 kB | 32.26 kB | 31.95 kB | jquery.js
287.63 kB | 92.33 kB | 90.07 kB | 32.45 kB | 31.95 kB | jquery.js

342.15 kB | 121.90 kB | 118.14 kB | 44.59 kB | 44.37 kB | vue.js
342.15 kB | 121.31 kB | 118.14 kB | 44.85 kB | 44.37 kB | vue.js

544.10 kB | 73.48 kB | 72.48 kB | 26.12 kB | 26.20 kB | lodash.js
544.10 kB | 73.40 kB | 72.48 kB | 26.20 kB | 26.20 kB | lodash.js

555.77 kB | 276.48 kB | 270.13 kB | 91.15 kB | 90.80 kB | d3.js
555.77 kB | 276.27 kB | 270.13 kB | 91.49 kB | 90.80 kB | d3.js

1.01 MB | 467.59 kB | 458.89 kB | 126.73 kB | 126.71 kB | bundle.min.js
1.01 MB | 466.71 kB | 458.89 kB | 127.15 kB | 126.71 kB | bundle.min.js

1.25 MB | 662.83 kB | 646.76 kB | 164.00 kB | 163.73 kB | three.js
1.25 MB | 662.18 kB | 646.76 kB | 164.73 kB | 163.73 kB | three.js

2.14 MB | 741.55 kB | 724.14 kB | 181.45 kB | 181.07 kB | victory.js
2.14 MB | 741.23 kB | 724.14 kB | 181.84 kB | 181.07 kB | victory.js

3.20 MB | 1.02 MB | 1.01 MB | 332.02 kB | 331.56 kB | echarts.js
3.20 MB | 1.02 MB | 1.01 MB | 333.40 kB | 331.56 kB | echarts.js

6.69 MB | 2.39 MB | 2.31 MB | 496.11 kB | 488.28 kB | antd.js
6.69 MB | 2.39 MB | 2.31 MB | 497.21 kB | 488.28 kB | antd.js

10.95 MB | 3.56 MB | 3.49 MB | 911.20 kB | 915.50 kB | typescript.js
10.95 MB | 3.55 MB | 3.49 MB | 913.93 kB | 915.50 kB | typescript.js

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