From 213364a400ec987f2d75cfc82dc014ed9c76274b Mon Sep 17 00:00:00 2001 From: Boshen <1430279+Boshen@users.noreply.github.com> Date: Fri, 27 Dec 2024 02:44:47 +0000 Subject: [PATCH] feat(minifier): minimize `if (x) if (y) z` -> `if (x && y) z` (#8136) --- crates/oxc_ast/src/ast_impl/js.rs | 16 ++++ .../peephole_minimize_conditions.rs | 87 +++++++++---------- tasks/minsize/minsize.snap | 22 ++--- 3 files changed, 68 insertions(+), 57 deletions(-) diff --git a/crates/oxc_ast/src/ast_impl/js.rs b/crates/oxc_ast/src/ast_impl/js.rs index 37df05cc79dfe..db76870660d4a 100644 --- a/crates/oxc_ast/src/ast_impl/js.rs +++ b/crates/oxc_ast/src/ast_impl/js.rs @@ -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> { diff --git a/crates/oxc_minifier/src/ast_passes/peephole_minimize_conditions.rs b/crates/oxc_minifier/src/ast_passes/peephole_minimize_conditions.rs index a4d504c418b7b..95568cd304af2 100644 --- a/crates/oxc_minifier/src/ast_passes/peephole_minimize_conditions.rs +++ b/crates/oxc_minifier/src/ast_passes/peephole_minimize_conditions.rs @@ -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; @@ -89,7 +90,9 @@ impl<'a> PeepholeMinimizeConditions { ctx: &mut TraverseCtx<'a>, ) -> Option> { 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); @@ -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 { @@ -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 { @@ -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> { @@ -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()"); diff --git a/tasks/minsize/minsize.snap b/tasks/minsize/minsize.snap index b944c7e70f5c0..1df8712007678 100644 --- a/tasks/minsize/minsize.snap +++ b/tasks/minsize/minsize.snap @@ -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