private bool ParseSimpleExpression(TokenReader reader, out Expression result)
{
Token start = reader.Peek();
result = null;
Expression outer = null;
if (!this.ParseTermExpression(reader, out outer))
{
return false;
}
Token tok = reader.Peek();
while (tok.Is(Keyword.Plus) || tok.Is(Keyword.Minus) || tok.Is(Keyword.Or))
{
reader.Read();
Expression term = null;
if (!this.ParseTermExpression(reader, out term))
{
return false;
}
outer = new SimpleExpression(start, outer, ((KeywordToken)tok).Value, term);
tok = reader.Peek();
}
result = outer;
return true;
}
private bool TryEmitSimpleExpression(
SimpleExpression expression,
CompilerContext context,
Scope scope,
MethodImpl method,
out TypeDefinition valueType)
{
TypeDefinition rightSideType = null;
if (!this.TryEmitExpression(expression.Right, context, scope, method, out rightSideType))
{
valueType = null;
return false;
}
this.PushResult(method, rightSideType);
TypeDefinition leftSideType = null;
if (!this.TryEmitExpression(expression.Left, context, scope, method, out leftSideType))
{
valueType = null;
return false;
}
if (leftSideType.IsFloatingPoint)
{
if (rightSideType.IsFloatingPoint)
{
if (rightSideType.Size == 8)
{
method.Statements.Add(new AsmStatement { Instruction = "fld qword ptr [esp]" });
}
else
{
method.Statements.Add(new AsmStatement { Instruction = "fld dword ptr [esp]" });
}
method.Statements.Add(new AsmStatement { Instruction = "add esp," + rightSideType.Size });
}
else if (rightSideType.Size <= 4)
{
method.Statements.Add(new AsmStatement { Instruction = "fild [esp]" });
method.Statements.Add(new AsmStatement { Instruction = "add esp," + rightSideType.Size });
}
switch (expression.Operator)
{
case Keyword.Plus:
{
method.Statements.Add(new AsmStatement { Instruction = "faddp" });
} break;
case Keyword.Minus:
{
method.Statements.Add(new AsmStatement { Instruction = "fsubp" });
} break;
}
}
else if (leftSideType.Size <= 4)
{
if (rightSideType.Size <= 4 && !rightSideType.IsFloatingPoint)
{
method.Statements.Add(new AsmStatement { Instruction = "pop ecx" });
switch (expression.Operator)
{
case Keyword.Plus:
{
method.Statements.Add(new AsmStatement { Instruction = "add eax,ecx" });
} break;
case Keyword.Minus:
{
method.Statements.Add(new AsmStatement { Instruction = "sub eax,ecx" });
} break;
case Keyword.Or:
{
method.Statements.Add(new AsmStatement { Instruction = "or eax,ecx" });
} break;
}
}
}
valueType = leftSideType;
return true;
}