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Merged
lahma merged 1 commit into from
Mar 22, 2026
Merged

Optimize interpreter hot paths for arithmetic, comparisons, and control flow #2345

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126 changes: 120 additions & 6 deletions Jint/Runtime/Interpreter/Expressions/JintBinaryExpression.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -281,6 +281,16 @@ protected override object EvaluateInternal(EvaluationContext context)
var equal = left == right;
return equal ? JsBoolean.True : JsBoolean.False;
}

public override bool GetBooleanValue(EvaluationContext context)
{
if (!TryEvaluateOperands(context, out var left, out var right))
{
return false;
}

return left == right;
}
}

private sealed class StrictlyNotEqualBinaryExpression : JintBinaryExpression
Expand All @@ -298,6 +308,16 @@ protected override object EvaluateInternal(EvaluationContext context)

return left == right ? JsBoolean.False : JsBoolean.True;
}

public override bool GetBooleanValue(EvaluationContext context)
{
if (!TryEvaluateOperands(context, out var left, out var right))
{
return false;
}

return left != right;
}
}

private sealed class LessBinaryExpression : JintBinaryExpression
Expand All @@ -323,6 +343,23 @@ protected override object EvaluateInternal(EvaluationContext context)

return value._type == InternalTypes.Undefined ? JsBoolean.False : value;
}

public override bool GetBooleanValue(EvaluationContext context)
{
if (!TryEvaluateOperands(context, out var left, out var right))
{
return false;
}

if (context.OperatorOverloadingAllowed
&& TryOperatorOverloading(context, left, right, "op_LessThan", out var opResult))
{
return TypeConverter.ToBoolean(JsValue.FromObject(context.Engine, opResult));
}

var value = Compare(left, right);
return value._type != InternalTypes.Undefined && ((JsBoolean) value)._value;
}
}

private sealed class GreaterBinaryExpression : JintBinaryExpression
Expand All @@ -348,6 +385,23 @@ protected override object EvaluateInternal(EvaluationContext context)

return value._type == InternalTypes.Undefined ? JsBoolean.False : value;
}

public override bool GetBooleanValue(EvaluationContext context)
{
if (!TryEvaluateOperands(context, out var left, out var right))
{
return false;
}

if (context.OperatorOverloadingAllowed
&& TryOperatorOverloading(context, left, right, "op_GreaterThan", out var opResult))
{
return TypeConverter.ToBoolean(JsValue.FromObject(context.Engine, opResult));
}

var value = Compare(right, left, false);
return value._type != InternalTypes.Undefined && ((JsBoolean) value)._value;
}
}

private sealed class PlusBinaryExpression : JintBinaryExpression
Expand All @@ -374,6 +428,11 @@ protected override object EvaluateInternal(EvaluationContext context)
return JsNumber.Create((long) left.AsInteger() + right.AsInteger());
}

if (left._type == InternalTypes.Number && right._type == InternalTypes.Number)
{
return JsNumber.Create(((JsNumber) left)._value + ((JsNumber) right)._value);
}

var lprim = TypeConverter.ToPrimitive(left);
var rprim = TypeConverter.ToPrimitive(right);
JsValue result;
Expand Down Expand Up @@ -498,15 +557,21 @@ protected override object EvaluateInternal(EvaluationContext context)
return JsValue.FromObject(context.Engine, opResult);
}

JsValue number;
left = TypeConverter.ToNumeric(left);
right = TypeConverter.ToNumeric(right);

if (AreIntegerOperands(left, right))
{
number = JsNumber.Create((long) left.AsInteger() - right.AsInteger());
return JsNumber.Create((long) left.AsInteger() - right.AsInteger());
}
else if (AreNonBigIntOperands(left, right))

if (left._type == InternalTypes.Number && right._type == InternalTypes.Number)
{
return JsNumber.Create(((JsNumber) left)._value - ((JsNumber) right)._value);
}

left = TypeConverter.ToNumeric(left);
right = TypeConverter.ToNumeric(right);

JsValue number;
if (AreNonBigIntOperands(left, right))
{
number = JsNumber.Create(left.AsNumber() - right.AsNumber());
}
Expand Down Expand Up @@ -543,6 +608,10 @@ protected override object EvaluateInternal(EvaluationContext context)
{
result = JsNumber.Create((long) left.AsInteger() * right.AsInteger());
}
else if (left._type == InternalTypes.Number && right._type == InternalTypes.Number)
{
result = JsNumber.Create(((JsNumber) left)._value * ((JsNumber) right)._value);
}
else
{
var leftNumeric = TypeConverter.ToNumeric(left);
Expand Down Expand Up @@ -582,6 +651,11 @@ protected override object EvaluateInternal(EvaluationContext context)
return JsValue.FromObject(context.Engine, opResult);
}

if (left._type == InternalTypes.Number && right._type == InternalTypes.Number)
{
return JsNumber.Create(((JsNumber) left)._value / ((JsNumber) right)._value);
}

left = TypeConverter.ToNumeric(left);
right = TypeConverter.ToNumeric(right);
return Divide(context, left, right);
Expand Down Expand Up @@ -617,6 +691,26 @@ protected override object EvaluateInternal(EvaluationContext context)

return equality == !_invert ? JsBoolean.True : JsBoolean.False;
}

public override bool GetBooleanValue(EvaluationContext context)
{
if (!TryEvaluateOperands(context, out var left, out var right))
{
return false;
}

if (context.OperatorOverloadingAllowed
&& TryOperatorOverloading(context, left, right, _invert ? "op_Inequality" : "op_Equality", out var opResult))
{
return TypeConverter.ToBoolean(JsValue.FromObject(context.Engine, opResult));
}

var equality = left.Type == right.Type
? left.Equals(right)
: left.IsLooselyEqual(right);

return _invert ? !equality : equality;
}
}

private sealed class CompareBinaryExpression : JintBinaryExpression
Expand Down Expand Up @@ -647,6 +741,26 @@ protected override object EvaluateInternal(EvaluationContext context)
var value = Compare(left, right, _leftFirst);
return value.IsUndefined() || ((JsBoolean) value)._value ? JsBoolean.False : JsBoolean.True;
}

public override bool GetBooleanValue(EvaluationContext context)
{
if (!TryEvaluateOperands(context, out var leftValue, out var rightValue))
{
return false;
}

if (context.OperatorOverloadingAllowed
&& TryOperatorOverloading(context, leftValue, rightValue, _leftFirst ? "op_GreaterThanOrEqual" : "op_LessThanOrEqual", out var opResult))
{
return TypeConverter.ToBoolean(JsValue.FromObject(context.Engine, opResult));
}

var left = _leftFirst ? leftValue : rightValue;
var right = _leftFirst ? rightValue : leftValue;

var value = Compare(left, right, _leftFirst);
return !value.IsUndefined() && !((JsBoolean) value)._value;
}
}

private sealed class InstanceOfBinaryExpression : JintBinaryExpression
Expand Down
113 changes: 63 additions & 50 deletions Jint/Runtime/Interpreter/Expressions/JintExpression.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -54,6 +54,15 @@ internal object EvaluateWithoutNodeTracking(EvaluationContext context)

protected abstract object EvaluateInternal(EvaluationContext context);

/// <summary>
/// Resolves this expression as a boolean value.
/// Comparison expressions override this to avoid creating a JsBoolean wrapper.
/// </summary>
public virtual bool GetBooleanValue(EvaluationContext context)
{
return TypeConverter.ToBoolean(GetValue(context));
}

/// <summary>
/// If we'd get Esprima source, we would just refer to it, but this makes error messages easier to decipher.
/// </summary>
Expand Down Expand Up @@ -147,8 +156,6 @@ protected internal static JintExpression Build(Expression expression)
protected static JsValue Remainder(EvaluationContext context, JsValue left, JsValue right)
{
var result = JsValue.Undefined;
left = TypeConverter.ToNumeric(left);
right = TypeConverter.ToNumeric(right);
if (AreIntegerOperands(left, right))
{
var leftInteger = left.AsInteger();
Expand All @@ -171,50 +178,56 @@ protected static JsValue Remainder(EvaluationContext context, JsValue left, JsVa
}
}
}
else if (JintBinaryExpression.AreNonBigIntOperands(left, right))
else
{
var n = left.AsNumber();
var d = right.AsNumber();
left = TypeConverter.ToNumeric(left);
right = TypeConverter.ToNumeric(right);

if (double.IsNaN(n) || double.IsNaN(d) || double.IsInfinity(n))
{
result = JsNumber.DoubleNaN;
}
else if (double.IsInfinity(d))
{
result = n;
}
else if (NumberInstance.IsPositiveZero(d) || NumberInstance.IsNegativeZero(d))
{
result = JsNumber.DoubleNaN;
}
else if (NumberInstance.IsPositiveZero(n) || NumberInstance.IsNegativeZero(n))
if (JintBinaryExpression.AreNonBigIntOperands(left, right))
{
result = n;
var n = left.AsNumber();
var d = right.AsNumber();

if (double.IsNaN(n) || double.IsNaN(d) || double.IsInfinity(n))
{
result = JsNumber.DoubleNaN;
}
else if (double.IsInfinity(d))
{
result = n;
}
else if (NumberInstance.IsPositiveZero(d) || NumberInstance.IsNegativeZero(d))
{
result = JsNumber.DoubleNaN;
}
else if (NumberInstance.IsPositiveZero(n) || NumberInstance.IsNegativeZero(n))
{
result = n;
}
else
{
result = JsNumber.Create(n % d);
}
}
else
{
result = JsNumber.Create(n % d);
}
}
else
{
JintBinaryExpression.AssertValidBigIntArithmeticOperands(left, right);
JintBinaryExpression.AssertValidBigIntArithmeticOperands(left, right);

var n = TypeConverter.ToBigInt(left);
var d = TypeConverter.ToBigInt(right);
var bn = TypeConverter.ToBigInt(left);
var bd = TypeConverter.ToBigInt(right);

if (d == 0)
{
Throw.RangeError(context.Engine.Realm, "Division by zero");
}
else if (n == 0)
{
result = JsBigInt.Zero;
}
else
{
result = JsBigInt.Create(n % d);
if (bd == 0)
{
Throw.RangeError(context.Engine.Realm, "Division by zero");
}
else if (bn == 0)
{
result = JsBigInt.Zero;
}
else
{
result = JsBigInt.Create(bn % bd);
}
}
}

Expand Down Expand Up @@ -332,29 +345,29 @@ protected static JsValue Compare(JsValue x, JsValue y, bool leftFirst = true) =>

private static JsValue CompareNumber(JsValue x, JsValue y, bool leftFirst)
{
if (x.IsInteger() && y.IsInteger())
{
return x.AsInteger() < y.AsInteger() ? JsBoolean.True : JsBoolean.False;
}

double nx, ny;
if (leftFirst)
{
nx = x.AsNumber();
ny = y.AsNumber();
nx = ((JsNumber) x)._value;
ny = ((JsNumber) y)._value;
}
else
{
ny = y.AsNumber();
nx = x.AsNumber();
ny = ((JsNumber) y)._value;
nx = ((JsNumber) x)._value;
}

if (x.IsInteger() && y.IsInteger())
if (double.IsNaN(nx) || double.IsNaN(ny))
{
return (int) nx < (int) ny ? JsBoolean.True : JsBoolean.False;
}

if (!double.IsInfinity(nx) && !double.IsInfinity(ny) && !double.IsNaN(nx) && !double.IsNaN(ny))
{
return nx < ny ? JsBoolean.True : JsBoolean.False;
return JsValue.Undefined;
}

return CompareComplex(x, y, leftFirst);
return nx < ny ? JsBoolean.True : JsBoolean.False;
}

private static JsValue CompareComplex(JsValue x, JsValue y, bool leftFirst)
Expand Down
14 changes: 6 additions & 8 deletions Jint/Runtime/Interpreter/Statements/JintForStatement.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -261,16 +261,14 @@ private Completion ForBodyEvaluation(EvaluationContext context)
{
debugHandler?.OnStep(_test._expression);

var testValue = _test.GetValue(context);

// Check for async suspension in test expression
if (context.IsSuspended())
if (!_test.GetBooleanValue(context))
{
return new Completion(CompletionType.Return, JsValue.Undefined, ((JintStatement) this)._statement);
}
// Check for async suspension in test expression
if (context.IsSuspended())
{
return new Completion(CompletionType.Return, JsValue.Undefined, ((JintStatement) this)._statement);
}

if (!TypeConverter.ToBoolean(testValue))
{
return new Completion(CompletionType.Normal, v, ((JintStatement) this)._statement);
}
}
Expand Down
2 changes: 1 addition & 1 deletion Jint/Runtime/Interpreter/Statements/JintIfStatement.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,7 @@ protected override void Initialize(EvaluationContext context)
protected override Completion ExecuteInternal(EvaluationContext context)
{
Completion result;
if (TypeConverter.ToBoolean(_test.GetValue(context)))
if (_test.GetBooleanValue(context))
{
// B.3.2/B.3.3: IfStatement function declarations need runtime AnnexB handling
if (_consequentIsFunctionDecl && !StrictModeScope.IsStrictModeCode)
Expand Down
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