[fpc-devel] Generated code of constant parameters of double type

[Florian Klaempfl]

Luiz Americo Pereira Camara schrieb:
> Florian Klaempfl escreveu:
>> Luiz Americo Pereira Camara schrieb:
>>> My point was that this could be a missing optimization opportunity: 
>>> pass by reference a 8 bytes parameter when the pointer size is 4. 
>>
>> Don't forget that this makes an extra memory access.
> 
> I will do my question in a simpler way:
> 
> Using constant parameters (add const keyword in front of an argument) is 
> beneficial for record types with size > pointer size and for string 
> types but not for integer and pointer types.

No, this is not necessarily true. The extra indirect can be also slower.

> 
> Currently is not beneficial for double types and there's no way to 
> improve that. So when developing an interface that uses double types 
> does not matter using const or not. Now and in the future. Right?

It might matter for the optimizer in other situations.