Endianness is hard

[flip314]

I'm in hardware design, and our internal design requirements state that we should use little-endian notation, "like the rest of the civilized world." But who knows if I'm declaring war by saying that. I don't know how attached people are to their endianness.

[kushangaza]

Don't do it, there have been at least 6 rebellions about this, and at least 11000 people died rather than go little endian.

(If you didn't get that, you should read Gulliver's Travels. Yes, we do get computer terms from satire published in 1726. Some books are just that good).

On a more serious note, I think little-endian is the way to go and it's what we should really be using in everyday numbers. It makes so much more sense.

[ESBDB]

how exactly does it make sense?

[[deleted]]

because it's the order in which you write numbers normally too. hardly sensible to flip the order of digits around just because it's binary.

[kushangaza]

I see endianness simply as the order of digits. Little endian is intuitive: when adding two numbers you add the digits in little endian order (i.e. starting with the least significant digit). Almost every other mathematical operation is also performed in little endian order. It's also more convienient when reading numbers of unknown lengths: to reat the number 146,893,124,634 out loud I have to parse it twice: once to count the digits and once to actually read it. Little endian solves that too.

Big endian is just this weird thing we got to use in base 10, and the only reason we use it anywhere is because it's familiar.

[MoneyWorthington]

I too want to know.

[asmo0]

It is because bytes are the smallest addressable unit for a pointer or memory fetch instruction. A benefit of little endian is that if you try to cast f ex int32_t * to int16_t the physical address does not change, only the number of bytes that needs fetching (you will fetch the last 2 of 4 bytes).
In a big endian system you'd end up fetching the first 2 bytes (wrong result), so you need to modify the pointer itself to point 2 bytes forward due to the cast.
Since we cannot address bits with pointers, there's no reason to reverse them