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Merged
graphite-app merged 1 commit into from
Jan 5, 2025
Merged

feat(minifier): improve constant evaluation #8252

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105 changes: 37 additions & 68 deletions crates/oxc_ecmascript/src/constant_evaluation/mod.rs
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Original file line number Diff line number Diff line change
@@ -1,3 +1,4 @@
use core::f64;
use std::{borrow::Cow, cmp::Ordering};

use num_bigint::BigInt;
Expand Down Expand Up @@ -149,6 +150,9 @@ pub trait ConstantEvaluation<'a> {
UnaryOperator::Void => Some(f64::NAN),
_ => None,
},
Expression::SequenceExpression(s) => {
s.expressions.last().and_then(|e| self.eval_to_number(e))
}
expr => {
use crate::ToNumber;
expr.to_number()
Expand Down Expand Up @@ -247,39 +251,20 @@ pub trait ConstantEvaluation<'a> {
};
Some(ConstantValue::Number(val))
}
#[expect(clippy::cast_sign_loss, clippy::cast_possible_truncation)]
#[expect(clippy::cast_sign_loss)]
BinaryOperator::ShiftLeft
| BinaryOperator::ShiftRight
| BinaryOperator::ShiftRightZeroFill => {
let left_num = self.get_side_free_number_value(left);
let right_num = self.get_side_free_number_value(right);
if let (Some(left_val), Some(right_val)) = (left_num, right_num) {
if left_val.fract() != 0.0 || right_val.fract() != 0.0 {
return None;
}
// only the lower 5 bits are used when shifting, so don't do anything
// if the shift amount is outside [0,32)
if !(0.0..32.0).contains(&right_val) {
return None;
}
let right_val_int = right_val as u32;
let bits = left_val.to_int_32();

let result_val: f64 = match operator {
BinaryOperator::ShiftLeft => f64::from(bits.wrapping_shl(right_val_int)),
BinaryOperator::ShiftRight => f64::from(bits.wrapping_shr(right_val_int)),
BinaryOperator::ShiftRightZeroFill => {
// JavaScript always treats the result of >>> as unsigned.
// We must force Rust to do the same here.
let bits = bits as u32;
let res = bits.wrapping_shr(right_val_int);
f64::from(res)
}
_ => unreachable!(),
};
return Some(ConstantValue::Number(result_val));
}
None
let left = self.get_side_free_number_value(left)?;
let right = self.get_side_free_number_value(right)?;
let left = left.to_int_32();
let right = (right.to_int_32() as u32) & 31;
Some(ConstantValue::Number(match operator {
BinaryOperator::ShiftLeft => f64::from(left << right),
BinaryOperator::ShiftRight => f64::from(left >> right),
BinaryOperator::ShiftRightZeroFill => f64::from((left as u32) >> right),
_ => unreachable!(),
}))
}
BinaryOperator::LessThan => {
self.is_less_than(left, right, true).map(|value| match value {
Expand Down Expand Up @@ -401,52 +386,36 @@ pub trait ConstantEvaluation<'a> {
};
Some(ConstantValue::String(Cow::Borrowed(s)))
}
UnaryOperator::Void => {
if (!expr.argument.is_number() || !expr.argument.is_number_0())
&& !expr.may_have_side_effects()
{
return Some(ConstantValue::Undefined);
}
None
}
UnaryOperator::Void => (expr.argument.is_literal() || !expr.may_have_side_effects())
.then_some(ConstantValue::Undefined),
UnaryOperator::LogicalNot => {
self.get_boolean_value(&expr.argument).map(|b| !b).map(ConstantValue::Boolean)
}
UnaryOperator::UnaryPlus => {
self.eval_to_number(&expr.argument).map(ConstantValue::Number)
}
UnaryOperator::UnaryNegation => {
let ty = ValueType::from(&expr.argument);
match ty {
ValueType::BigInt => {
self.eval_to_big_int(&expr.argument).map(|v| -v).map(ConstantValue::BigInt)
}
ValueType::Number => self
.eval_to_number(&expr.argument)
.map(|v| if v.is_nan() { v } else { -v })
.map(ConstantValue::Number),
_ => None,
UnaryOperator::UnaryNegation => match ValueType::from(&expr.argument) {
ValueType::BigInt => {
self.eval_to_big_int(&expr.argument).map(|v| -v).map(ConstantValue::BigInt)
}
}
UnaryOperator::BitwiseNot => {
let ty = ValueType::from(&expr.argument);
match ty {
ValueType::BigInt => {
self.eval_to_big_int(&expr.argument).map(|v| !v).map(ConstantValue::BigInt)
}
#[expect(clippy::cast_lossless)]
ValueType::Number => self
.eval_to_number(&expr.argument)
.map(|v| !v.to_int_32())
.map(|v| v as f64)
.map(ConstantValue::Number),
ValueType::Undefined | ValueType::Null => Some(ConstantValue::Number(-1.0)),
ValueType::Boolean => self
.get_side_free_boolean_value(&expr.argument)
.map(|v| ConstantValue::Number(if v { -2.0 } else { -1.0 })),
_ => None,
ValueType::Number => self
.eval_to_number(&expr.argument)
.map(|v| if v.is_nan() { v } else { -v })
.map(ConstantValue::Number),
ValueType::Undefined => Some(ConstantValue::Number(f64::NAN)),
ValueType::Null => Some(ConstantValue::Number(-0.0)),
_ => None,
},
UnaryOperator::BitwiseNot => match ValueType::from(&expr.argument) {
ValueType::BigInt => {
self.eval_to_big_int(&expr.argument).map(|v| !v).map(ConstantValue::BigInt)
}
}
#[expect(clippy::cast_lossless)]
_ => self
.eval_to_number(&expr.argument)
.map(|v| (!v.to_int_32()) as f64)
.map(ConstantValue::Number),
},
UnaryOperator::Delete => None,
}
}
Expand Down
24 changes: 22 additions & 2 deletions crates/oxc_ecmascript/src/constant_evaluation/value_type.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -93,6 +93,7 @@ impl<'a> From<&Expression<'a>> for ValueType {
Expression::SequenceExpression(e) => {
e.expressions.last().map_or(ValueType::Undetermined, Self::from)
}
Expression::AssignmentExpression(e) => Self::from(&e.right),
_ => Self::Undetermined,
}
}
Expand All @@ -115,8 +116,27 @@ impl<'a> From<&BinaryExpression<'a>> for ValueType {
}
Self::Undetermined
}
BinaryOperator::Instanceof => Self::Boolean,
_ => Self::Undetermined,
BinaryOperator::Subtraction
| BinaryOperator::Multiplication
| BinaryOperator::Division
| BinaryOperator::Remainder
| BinaryOperator::ShiftLeft
| BinaryOperator::BitwiseOR
| BinaryOperator::ShiftRight
| BinaryOperator::BitwiseXOR
| BinaryOperator::BitwiseAnd
| BinaryOperator::Exponential
| BinaryOperator::ShiftRightZeroFill => Self::Number,
BinaryOperator::Instanceof
| BinaryOperator::In
| BinaryOperator::Equality
| BinaryOperator::Inequality
| BinaryOperator::StrictEquality
| BinaryOperator::StrictInequality
| BinaryOperator::LessThan
| BinaryOperator::LessEqualThan
| BinaryOperator::GreaterThan
| BinaryOperator::GreaterEqualThan => Self::Boolean,
}
}
}
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