Comment by api
3 hours ago
ARM is usually bi-endian, and almost always run in little endian mode. All Apple ARM is LE. Not sure about Android but I’d guess it’s the same. I don’t think I’ve ever seen BE ARM in the wild.
Big endian is as far as I know extinct for larger mainstream CPUs. Power still exists but is on life support. MIPS and Sparc are dead. M68k is dead.
X86 has always been LE. RISC-V is LE.
It’s not an arbitrary choice. Little endian is superior because you can cast between integer types without pointer arithmetic and because manually implemented math ops are faster on account of being linear in memory. It’s counter intuitive but everything is faster and simpler.
Network data and most serialization formats are big endian by convention, a legacy from the early net growing on chips like Sparc and M68k. If it were redone now everything would be LE everywhere.
> Little endian is superior because you can cast between integer types without pointer arithmetic
I’ve heard this one several times and it never really made sense. Is the argument that y you can do:
Or vice versa and it kind of works under some circumstances?
Yes. In little-endian, the difference between short and long at a specific address is how many bytes you read from that address. In big-endian, to cast a long to a short, you have to jump forward 6 bytes to get to the 2 least-significant bytes.