Is int faster than byte/short?

[Mariusz Gliwiński]

Hello,
I'm trying to learn high-performance real-time programming.

One of my wonderings are:
Should i use int/uint for all standard arithmetic operations or 
int/short/byte (depends on actual case)?
I believe this question has following subquestions:
* Arithmetic computations performance
* Memory access time

My actual compiler is DMD, but I'm interested in GDC as well.

Lastly, one more question would be:
Could someone recommend any books/resources for this kind of 
informations and tips that could be applied to D? I'd like to defer my 
own experiments with generated assembly and profiling, but i suppose 
people already published general rules that i could apply for my 
programming.

Thanks,
Mariusz Gliwiński