What are the advantages of the general types (int / uint) over specific types (int64 / uint64) in Go lang?

Question

I understand that int and uint are 64bit signed / unsigned integers - just like int64 / uint64. And I also understand that int is not simply an alias for int64 (like byte -> uint8 is), so int64 would need to be converted to int and visa versa when applicable. However what are the benefits of using one over the other? Is there any run time performance penalty for using the general types?

Sorry if this is a common question - I had Googled for the answer (and searched on here too) as I'd have thought others might have cropped up before but didn't find anyone answer the question in terms of how they affect performance (if at all), memory usage (I'm guessing not if they're both 64bit integers?) nor how the compiler treats them.

edit: I'm aware that int / unit are 32bit on 32bit architectures. For the sake of brevity and comparing like for like, I was assuming this is a 64bit Golang environment.

Answer 1

int and uint are only 64-bit on 64-bit architectures. On 32-bit architectures they are 32 bits.

The general answer is that, unless you need a certain precision, sticking with datatypes that are the same size as a word on the current architecture (e.g. 32 bits on a 32-bit architecture) is typically slightly more efficient.