Thanks for your answers. I never expected the size to be a problem, but given both your answers, it won't be a problem to me. I was more worried about the order of bytes. I'll explain it as the idiot I am:
in my java world I'll pack an 4-byte int of 4 bytes(A,B,C,D) like this:
ABCD
As long as I'm in my java world, it will always have this order.
But then I put it into one of those LWJGL high-tech buffers and send it out to System/GPU memory. My fear is that some system might now read the int like this:
DCBA
(from my java perspective)
This, my shader data might get the wrong values.
I don't really think this problem might occur, but I just want to double check. Also, endianness might be the same on all x86 platforms?
PS. YEs, I just checked, it's little endian on all x86 platforms, as well as most others, don't mind me.
But still, it would be in theory interesting to know the answer, might be some mobile platforms where things could get weird.